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GitHub Repository: PojavLauncherTeam/openjdk-multiarch-jdk8u
Path: blob/aarch64-shenandoah-jdk8u272-b10/hotspot/src/share/vm/prims/jvmti.xml
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<?xml version="1.0" encoding="ISO-8859-1"?>
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<?xml-stylesheet type="text/xsl" href="jvmti.xsl"?>
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<!--
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Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
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DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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This code is free software; you can redistribute it and/or modify it
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published by the Free Software Foundation.
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This code is distributed in the hope that it will be useful, but WITHOUT
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<!DOCTYPE specification [
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<!ELEMENT specification (title, intro*, functionsection, errorsection,
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eventsection, datasection, issuessection, changehistory)>
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<!ATTLIST specification label CDATA #REQUIRED
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majorversion CDATA #REQUIRED
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minorversion CDATA #REQUIRED
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microversion CDATA #REQUIRED>
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<!ELEMENT title (#PCDATA|jvmti|tm)*>
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<!ATTLIST title subtitle CDATA #REQUIRED>
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<!ELEMENT intro ANY>
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<!ATTLIST intro id CDATA #IMPLIED
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label CDATA "">
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<!ELEMENT functionsection (intro*, category*)>
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<!ATTLIST functionsection label CDATA #REQUIRED>
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<!ELEMENT category ((intro|typedef|uniontypedef|capabilitiestypedef)*,
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(function|callback|elide)*)>
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<!ATTLIST category id CDATA #REQUIRED
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label CDATA #REQUIRED>
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<!ELEMENT function (synopsis, typedef*, description?, origin,
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(capabilities|eventcapabilities),
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parameters, errors)>
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<!ATTLIST function id CDATA #REQUIRED
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num CDATA #REQUIRED
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phase (onload|onloadOnly|start|live|any) #IMPLIED
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callbacksafe (safe|unsafe) #IMPLIED
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impl CDATA #IMPLIED
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hide CDATA #IMPLIED
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jkernel (yes|no) #IMPLIED
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since CDATA "1.0">
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<!ELEMENT callback ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
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jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void),
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synopsis, description?, parameters)>
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<!ATTLIST callback id CDATA #REQUIRED
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since CDATA "1.0">
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<!ELEMENT synopsis (#PCDATA|jvmti)*>
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<!ELEMENT typedef (description?, field*)>
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<!ATTLIST typedef id CDATA #REQUIRED
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label CDATA #REQUIRED
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since CDATA "1.0">
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<!ELEMENT uniontypedef (description?, field*)>
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<!ATTLIST uniontypedef id CDATA #REQUIRED
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label CDATA #REQUIRED
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since CDATA "1.0">
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<!ELEMENT field ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
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jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|allocfieldbuf|inptr|inbuf|outbuf|vmbuf|ptrtype|struct),
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description)>
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<!ATTLIST field id CDATA #REQUIRED>
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<!ELEMENT capabilitiestypedef (description?, capabilityfield*)>
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<!ATTLIST capabilitiestypedef id CDATA #REQUIRED
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label CDATA #REQUIRED>
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<!ELEMENT capabilityfield (description)>
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<!ATTLIST capabilityfield id CDATA #REQUIRED
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disp1 CDATA ""
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disp2 CDATA ""
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since CDATA "1.0">
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<!ELEMENT description ANY>
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<!ELEMENT capabilities (required*, capability*)>
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<!ELEMENT eventcapabilities EMPTY>
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<!ELEMENT required ANY>
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<!ATTLIST required id CDATA #REQUIRED>
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<!ELEMENT capability ANY>
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<!ATTLIST capability id CDATA #REQUIRED>
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<!ELEMENT parameters (param*)>
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<!ELEMENT param ((jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|jthreadGroup|jobject|
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jvalue|enum|jint|jlong|jfloat|jdouble|jlocation|jboolean|char|uchar|size_t|void|varargs|struct|ptrtype|
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outptr|allocbuf|allocallocbuf|inptr|inbuf|outbuf|vmbuf|agentbuf),
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description)>
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<!ATTLIST param id CDATA #REQUIRED>
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<!ELEMENT jmethodID EMPTY>
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<!ATTLIST jmethodID class CDATA #IMPLIED
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native CDATA #IMPLIED>
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<!ELEMENT jfieldID EMPTY>
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<!ATTLIST jfieldID class CDATA #IMPLIED>
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<!ELEMENT jclass EMPTY>
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<!ATTLIST jclass method CDATA #IMPLIED
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field CDATA #IMPLIED>
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<!ELEMENT jframeID EMPTY>
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<!ATTLIST jframeID thread CDATA #IMPLIED>
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<!ELEMENT jrawMonitorID EMPTY>
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<!ELEMENT jthread EMPTY>
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<!ATTLIST jthread started CDATA #IMPLIED
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null CDATA #IMPLIED
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frame CDATA #IMPLIED
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impl CDATA #IMPLIED>
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<!ELEMENT varargs EMPTY>
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<!ELEMENT jthreadGroup EMPTY>
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<!ELEMENT jobject EMPTY>
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<!ELEMENT jvalue EMPTY>
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<!ELEMENT jchar EMPTY>
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<!ELEMENT jint EMPTY>
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<!ATTLIST jint min CDATA #IMPLIED>
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<!ELEMENT jlong EMPTY>
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<!ELEMENT jfloat EMPTY>
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<!ELEMENT jdouble EMPTY>
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<!ELEMENT jlocation EMPTY>
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<!ELEMENT jboolean EMPTY>
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<!ELEMENT char EMPTY>
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<!ELEMENT uchar EMPTY>
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<!ELEMENT size_t EMPTY>
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<!ELEMENT void EMPTY>
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<!ELEMENT enum (#PCDATA)*>
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<!ELEMENT struct (#PCDATA)*>
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<!ELEMENT nullok ANY>
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<!ELEMENT ptrtype ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue), nullok?)>
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<!ELEMENT outptr ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void), nullok?)>
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<!ELEMENT allocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void), nullok?)>
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<!ATTLIST allocbuf incount CDATA #IMPLIED
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outcount CDATA #IMPLIED>
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<!ELEMENT allocallocbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void), nullok?)>
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<!ATTLIST allocallocbuf incount CDATA #IMPLIED
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outcount CDATA #IMPLIED>
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<!ELEMENT inptr (struct, nullok?)>
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<!ELEMENT inbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void), nullok?)>
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<!ATTLIST inbuf incount CDATA #IMPLIED>
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<!ELEMENT outbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void|outbuf), nullok?)>
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<!ATTLIST outbuf incount CDATA #IMPLIED
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outcount CDATA #IMPLIED>
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<!ELEMENT vmbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jchar|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void), nullok?)>
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<!ATTLIST vmbuf incount CDATA #IMPLIED
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outcount CDATA #IMPLIED>
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<!ELEMENT agentbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void), nullok?)>
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<!ATTLIST agentbuf incount CDATA #IMPLIED
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outcount CDATA #IMPLIED>
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<!ELEMENT allocfieldbuf ((struct|jmethodID|jfieldID|jframeID|jrawMonitorID|jclass|jthread|
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jthreadGroup|jobject|jvalue|enum|jint|jlong|jfloat|jdouble|
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jlocation|jboolean|char|uchar|size_t|void))>
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<!ATTLIST allocfieldbuf outcount CDATA #IMPLIED>
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<!ELEMENT errors (error*)>
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<!ELEMENT error ANY>
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<!ATTLIST error id CDATA #REQUIRED>
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<!ELEMENT errorsection (intro*, errorcategory*)>
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<!ATTLIST errorsection label CDATA #REQUIRED>
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<!ELEMENT errorcategory (intro*, errorid*)>
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<!ATTLIST errorcategory id CDATA #REQUIRED
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label CDATA #REQUIRED>
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<!ELEMENT errorid ANY>
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<!ATTLIST errorid id CDATA #REQUIRED
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num CDATA #REQUIRED>
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<!ELEMENT datasection (intro*, basetypes*)>
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<!ELEMENT basetypes (intro*, basetype*)>
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<!ATTLIST basetypes id CDATA #REQUIRED
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label CDATA #REQUIRED>
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<!ELEMENT basetype (definition?,description)>
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<!ATTLIST basetype id CDATA #REQUIRED>
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<!ELEMENT definition (#PCDATA|jvmti)*>
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<!ELEMENT eventsection (intro*, (event|elide)*)>
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<!ATTLIST eventsection label CDATA #REQUIRED>
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<!ELEMENT event (description, origin, typedef*, capabilities, parameters)>
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<!ATTLIST event id CDATA #REQUIRED
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label CDATA #REQUIRED
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const CDATA #REQUIRED
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num CDATA #REQUIRED
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phase (onload|start|live|any) #IMPLIED
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filtered (thread|global) #IMPLIED
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since CDATA "1.0">
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<!ELEMENT issuessection (intro*)>
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<!ATTLIST issuessection label CDATA #REQUIRED>
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<!ELEMENT changehistory (intro*, change*)>
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<!ATTLIST changehistory update CDATA #REQUIRED
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id CDATA #REQUIRED>
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<!ELEMENT change ANY>
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<!ATTLIST change date CDATA #REQUIRED
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version CDATA #IMPLIED>
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<!ELEMENT functionlink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST functionlink id CDATA #REQUIRED>
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<!ELEMENT datalink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST datalink id CDATA #REQUIRED>
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<!ELEMENT typelink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST typelink id CDATA #REQUIRED>
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<!ELEMENT fieldlink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST fieldlink id CDATA #REQUIRED
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struct CDATA #REQUIRED>
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<!ELEMENT paramlink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST paramlink id CDATA #REQUIRED>
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<!ELEMENT eventlink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST eventlink id CDATA #REQUIRED>
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<!ELEMENT errorlink (#PCDATA|jvmti|code|i|b|tm)*>
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<!ATTLIST errorlink id CDATA #REQUIRED>
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<!ELEMENT externallink (#PCDATA|jvmti|code|i|b|tm)*>
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<!ATTLIST externallink id CDATA #REQUIRED>
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<!ELEMENT vmspec EMPTY>
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<!ATTLIST vmspec chapter CDATA #IMPLIED>
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<!ELEMENT internallink (#PCDATA|jvmti|code|i|b)*>
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<!ATTLIST internallink id CDATA #REQUIRED>
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<!ELEMENT functionphaselist EMPTY>
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<!ATTLIST functionphaselist phase (onload|onloadOnly|start|live|any) #REQUIRED>
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<!ELEMENT eventphaselist EMPTY>
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<!ATTLIST eventphaselist phase (onload|start|live|any) #REQUIRED>
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<!ELEMENT issue ANY>
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<!ELEMENT rationale ANY>
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<!ELEMENT todo ANY>
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<!ELEMENT origin (#PCDATA)*>
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<!ELEMENT elide (intro|function|callback|event)*>
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<!ATTLIST elide why CDATA #IMPLIED>
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<!ELEMENT constants (constant*)>
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<!ATTLIST constants id CDATA #REQUIRED
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label CDATA #REQUIRED
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kind (enum|bits|const) #REQUIRED
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since CDATA "1.0">
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<!ELEMENT constant ANY>
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<!ATTLIST constant id CDATA #REQUIRED
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num CDATA #REQUIRED>
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<!ELEMENT tm (#PCDATA)>
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<!ELEMENT i (#PCDATA|jvmti|tm)*>
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<!ELEMENT b (#PCDATA|jvmti|code)*>
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<!ELEMENT code (#PCDATA|space)*>
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<!ELEMENT pre ANY>
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<!ELEMENT space EMPTY>
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<!ELEMENT jvmti EMPTY>
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<!ELEMENT example (#PCDATA|i)*>
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<!ELEMENT br EMPTY>
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<!ELEMENT p EMPTY>
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<!ELEMENT dl (dt|dd)+>
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<!ELEMENT dd ANY>
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<!ELEMENT dt (#PCDATA|jvmti|code|i|b)*>
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<!ELEMENT table (tr)+>
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<!ELEMENT tr (td|th)*>
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<!ELEMENT td ANY>
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<!ATTLIST td align (left|right|center) "center">
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<!ELEMENT th ANY>
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<!ATTLIST th align (left|right|center) "center">
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<!ELEMENT ul (li)+>
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<!ATTLIST ul type (disc|circle|square) "disc">
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<!ELEMENT li ANY>
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]>
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<specification label="JVM(TM) Tool Interface"
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majorversion="1"
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minorversion="2"
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microversion="3">
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<title subtitle="Version">
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<tm>JVM</tm> Tool Interface
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</title>
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<intro id="whatIs" label="What is the JVM Tool Interface?">
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The <tm>JVM</tm> Tool Interface (<jvmti/>)
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is a programming interface used by development and monitoring tools.
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It provides both a way to inspect the state and
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to control the execution of applications running in the
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<tm>Java</tm> virtual machine (VM).
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<p/>
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<jvmti/> is intended to provide a VM interface for the full breadth of tools
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that need access to VM state, including but not limited to: profiling,
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debugging, monitoring, thread analysis, and coverage analysis tools.
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<p/>
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<jvmti/> may not be available in all implementations of the <tm>Java</tm> virtual
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machine.
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<p/>
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<jvmti/> is a two-way interface.
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A client of <jvmti/>, hereafter called an <i>agent</i>,
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can be notified of
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interesting occurrences through <internallink id="EventSection">events</internallink>.
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<jvmti/>
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can query and control the application through many
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<internallink id="FunctionSection">functions</internallink>,
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either in response to events or
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independent of them.
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<p/>
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Agents run in the same process with and communicate directly with
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the virtual machine executing
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the application being examined. This communication is
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through a native interface (<jvmti/>). The native in-process interface allows
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maximal control with minimal intrusion on the part of a tool.
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Typically, agents are relatively compact. They can be controlled
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by a separate process which implements the bulk of a tool's
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function without interfering with the target application's normal execution.
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</intro>
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<intro id="architecture" label="Architecture">
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Tools can be written directly to <jvmti/> or indirectly
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through higher level interfaces.
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The Java Platform Debugger Architecture includes <jvmti/>, but also
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contains higher-level, out-of-process debugger interfaces. The higher-level
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interfaces are more appropriate than <jvmti/> for many tools.
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For more information on the Java Platform Debugger Architecture,
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see the
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<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jpda/architecture.html">Java
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Platform Debugger Architecture website</externallink>.
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</intro>
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<intro id="writingAgents" label="Writing Agents">
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Agents can be written in any native language that supports C
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language calling conventions and C or C++
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definitions.
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<p/>
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The function, event, data type, and constant definitions needed for
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using <jvmti/> are defined in the include file <code>jvmti.h</code>.
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To use these definitions add the <tm>J2SE</tm> include directory
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to your include path and add
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<example>
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#include &lt;jvmti.h&gt;
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</example>
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to your source code.
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</intro>
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<intro id="deployingAgents" label="Deploying Agents">
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An agent is deployed in a platform specific manner but is typically the
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platform equivalent of a dynamic library. On the <tm>Windows</tm> operating
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system, for example, an agent library is a "Dynamic Linked Library" (DLL).
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On the <tm>Solaris</tm> Operating Environment, an agent library is a shared
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object (<code>.so</code> file).
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<p/>
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An agent may be started at VM startup by specifying the agent library
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name using a <internallink id="starting">command line option</internallink>.
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Some implementations may support a mechanism to <internallink id="onattach">
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start agents</internallink> in the live <functionlink id="GetPhase">phase</functionlink>.
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The details of how this is initiated are implementation specific.
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</intro>
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<intro id="entry point" label="Statically Linked Agents (since version 1.2.3)">
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A native JVMTI Agent may be <i>statically linked</i> with the VM.
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The manner in which the library and VM image are combined is
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implementation-dependent.
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An agent L whose image has been combined with the VM is defined as
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<i>statically linked</i> if and only if the agent exports a function
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called Agent_OnLoad_L.
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<p/>
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If a <i>statically linked</i> agent L exports a function called
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Agent_OnLoad_L and a function called Agent_OnLoad, the Agent_OnLoad
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function will be ignored.
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If an agent L is <i>statically linked</i>, an Agent_OnLoad_L
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function will be invoked with the same arguments and expected return
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value as specified for the Agent_OnLoad function.
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An agent L that is <i>statically linked</i> will prohibit an agent of
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the same name from being loaded dynamically.
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<p/>
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The VM will invoke the Agent_OnUnload_L function of the agent, if such
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a function is exported, at the same point during VM execution as it would
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have called the dynamic entry point Agent_OnUnLoad. A statically loaded
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agent cannot be unloaded. The Agent_OnUnload_L function will still be
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called to do any other agent shutdown related tasks.
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If a <i>statically linked</i> agent L exports a function called
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Agent_OnUnLoad_L and a function called Agent_OnUnLoad, the Agent_OnUnLoad
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function will be ignored.
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<p/>
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If an agent L is <i>statically linked</i>, an Agent_OnAttach_L function
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will be invoked with the same arguments and expected return value as
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specified for the Agent_OnAttach function.
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If a <i>statically linked</i> agent L exports a function called
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Agent_OnAttach_L and a function called Agent_OnAttach, the Agent_OnAttach
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function will be ignored.
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</intro>
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<intro id="starting" label="Agent Command Line Options">
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The term "command-line option" is used below to
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mean options supplied in the <code>JavaVMInitArgs</code> argument
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to the <code>JNI_CreateJavaVM</code> function of the JNI
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Invocation API.
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<p/>
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One of the two following
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command-line options is used on VM startup to
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properly load and run agents.
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These arguments identify the library containing
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the agent as well as an options
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string to be passed in at startup.
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<dl>
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<dt><code>-agentlib:</code><i>&lt;agent-lib-name&gt;</i><code>=</code><i>&lt;options&gt;</i></dt>
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<dd>
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The name following <code>-agentlib:</code> is the name of the
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library to load. Lookup of the library, both its full name and location,
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proceeds in a platform-specific manner.
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Typically, the <i>&lt;agent-lib-name&gt;</i> is expanded to an
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operating system specific file name.
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The <i>&lt;options&gt;</i> will be passed to the agent on start-up.
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For example, if the option
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<code>-agentlib:foo=opt1,opt2</code> is specified, the VM will attempt to
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load the shared library <code>foo.dll</code> from the system <code>PATH</code>
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under <tm>Windows</tm> or <code>libfoo.so</code> from the
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<code>LD_LIBRARY_PATH</code> under the <tm>Solaris</tm> operating
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environment.
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If the agent library is statically linked into the executable
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then no actual loading takes place.
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<p/>
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</dd>
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<dt><code>-agentpath:</code><i>&lt;path-to-agent&gt;</i><code>=</code><i>&lt;options&gt;</i></dt>
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<dd>
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The path following <code>-agentpath:</code> is the absolute path from which
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to load the library.
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No library name expansion will occur.
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The <i>&lt;options&gt;</i> will be passed to the agent on start-up.
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For example, if the option
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<code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code> is specified, the VM will attempt to
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load the shared library <code>c:\myLibs\foo.dll</code>. If the agent
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library is statically linked into the executable
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then no actual loading takes place.
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<p/>
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</dd>
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</dl>
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For a dynamic shared library agent, the start-up routine
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<internallink id="onload"><code>Agent_OnLoad</code></internallink>
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in the library will be invoked. If the agent library is statically linked
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into the executable then the system will attempt to invoke the
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<code>Agent_OnLoad_&lt;agent-lib-name&gt;</code> entry point where
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&lt;agent-lib-name&gt; is the basename of the
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agent. In the above example <code>-agentpath:c:\myLibs\foo.dll=opt1,opt2</code>,
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the system will attempt to find and call the <code>Agent_OnLoad_foo</code> start-up routine.
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<p/>
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Libraries loaded with <code>-agentlib:</code> or <code>-agentpath:</code>
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will be searched for JNI native method implementations to facilitate the
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use of Java programming language code in tools, as is needed for
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<internallink id="bci">bytecode instrumentation</internallink>.
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<p/>
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The agent libraries will be searched after all other libraries have been
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searched (agents wishing to override or intercept the native method
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implementations of non-agent methods can use the
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<eventlink id="NativeMethodBind">NativeMethodBind event</eventlink>).
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<p/>
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These switches do the above and nothing more - they do not change the
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state of the VM or <jvmti/>. No command line options are needed
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to enable <jvmti/>
544
or aspects of <jvmti/>, this is handled programmatically
545
by the use of
546
<internallink id="capability">capabilities</internallink>.
547
</intro>
548
549
<intro id="startup" label="Agent Start-Up">
550
The VM starts each agent by invoking a start-up function.
551
If the agent is started in the <code>OnLoad</code>
552
<functionlink id="GetPhase">phase</functionlink> the function
553
<internallink id="onload"><code>Agent_OnLoad</code></internallink>
554
or <internallink id="onload"><code>Agent_OnLoad_L</code></internallink>
555
for statically linked agents will be invoked.
556
If the agent is started in the live
557
<functionlink id="GetPhase">phase</functionlink> the function
558
<internallink id="onattach"><code>Agent_OnAttach</code></internallink>
559
or <internallink id="onattach"><code>Agent_OnAttach_L</code></internallink>
560
for statically linked agents will be invoked.
561
Exactly one call to a start-up function is made per agent.
562
</intro>
563
564
<intro id="onload" label="Agent Start-Up (OnLoad phase)">
565
If an agent is started during the <code>OnLoad</code> phase then its
566
agent library must export a start-up function with the following prototype:
567
<example>
568
JNIEXPORT jint JNICALL
569
Agent_OnLoad(JavaVM *vm, char *options, void *reserved)</example>
570
Or for a statically linked agent named 'L':
571
<example>
572
JNIEXPORT jint JNICALL
573
Agent_OnLoad_L(JavaVM *vm, char *options, void *reserved)</example>
574
575
The VM will start the agent by calling this function.
576
It will be called early enough in VM initialization that:
577
<ul>
578
<li><functionlink id="SetSystemProperty">system properties</functionlink>
579
may be set before they have been used in the start-up of the VM</li>
580
<li>the full set of
581
<internallink id="capability">capabilities</internallink>
582
is still available (note that capabilities that configure the VM
583
may only be available at this time--see the
584
<internallink id="capability">Capability function section</internallink>)</li>
585
<li>no bytecodes have executed</li>
586
<li>no classes have been loaded</li>
587
<li>no objects have been created</li>
588
</ul>
589
<p/>
590
The VM will call the <code>Agent_OnLoad</code> or
591
<code>Agent_OnLoad_&lt;agent-lib-name&gt;</code> function with
592
<i>&lt;options&gt;</i> as the second argument -
593
that is, using the command-line option examples,
594
<code>"opt1,opt2"</code> will be passed to the <code>char *options</code>
595
argument of <code>Agent_OnLoad</code>.
596
The <code>options</code> argument is encoded as a
597
<internallink id="mUTF">modified UTF-8</internallink> string.
598
If <i>=&lt;options&gt;</i> is not specified,
599
a zero length string is passed to <code>options</code>.
600
The lifespan of the <code>options</code> string is the
601
<code>Agent_OnLoad</code> or <code>Agent_OnLoad_&lt;agent-lib-name&gt;</code>
602
call. If needed beyond this time the string or parts of the string must
603
be copied.
604
The period between when <code>Agent_OnLoad</code> is called and when it
605
returns is called the <i>OnLoad phase</i>.
606
Since the VM is not initialized during the OnLoad
607
<functionlink id="GetPhase">phase</functionlink>,
608
the set of allowed operations
609
inside <code>Agent_OnLoad</code> is restricted (see the function descriptions for the
610
functionality available at this time).
611
The agent can safely process the options and set
612
event callbacks with <functionlink id="SetEventCallbacks"></functionlink>. Once
613
the VM initialization event is received
614
(that is, the <eventlink id="VMInit">VMInit</eventlink>
615
callback is invoked), the agent
616
can complete its initialization.
617
<rationale>
618
Early startup is required so that agents can set the desired capabilities,
619
many of which must be set before the VM is initialized.
620
In JVMDI, the -Xdebug command-line option provided
621
very coarse-grain control of capabilities.
622
JVMPI implementations use various tricks to provide a single "JVMPI on" switch.
623
No reasonable command-line
624
option could provide the fine-grain of control required to balance needed capabilities vs
625
performance impact.
626
Early startup is also needed so that agents can control the execution
627
environment - modifying the file system and system properties to install
628
their functionality.
629
</rationale>
630
<p/>
631
The return value from <code>Agent_OnLoad</code> or
632
<code>Agent_OnLoad_&lt;agent-lib-name&gt;</code> is used to indicate an error.
633
Any value other than zero indicates an error and causes termination of the VM.
634
</intro>
635
636
<intro id="onattach" label="Agent Start-Up (Live phase)">
637
A VM may support a mechanism that allows agents to be started in the VM during the live
638
<functionlink id="GetPhase">phase</functionlink>. The details of how this is supported,
639
are implementation specific. For example, a tool may use some platform specific mechanism,
640
or implementation specific API, to attach to the running VM, and request it start a given
641
agent.
642
<p/>
643
If an agent is started during the live phase then its agent library
644
must export a start-up function
645
with the following prototype:
646
<example>
647
JNIEXPORT jint JNICALL
648
Agent_OnAttach(JavaVM* vm, char *options, void *reserved)</example>
649
Or for a statically linked agent named 'L':
650
<example>
651
JNIEXPORT jint JNICALL
652
Agent_OnAttach_L(JavaVM* vm, char *options, void *reserved)</example>
653
654
<p/>
655
The VM will start the agent by calling this function.
656
It will be called in the context of a thread
657
that is attached to the VM. The first argument <i>&lt;vm&gt;</i> is the Java VM.
658
The <i>&lt;options&gt;</i> argument is the startup options provided to the agent.
659
<i>&lt;options&gt;</i> is encoded as a <internallink id="mUTF">modified UTF-8
660
</internallink> string.
661
If startup options were not provided, a zero length string is passed to
662
<code>options</code>. The lifespan of the <code>options</code> string is the
663
<code>Agent_OnAttach</code> or <code>Agent_OnAttach_&lt;agent-lib-name&gt;</code> call.
664
If needed beyond this time the string or parts of the string must be copied.
665
<p/>
666
Note that some <internallink id="capability">capabilities</internallink>
667
may not be available in the live phase.
668
<p/>
669
The <code>Agent_OnAttach</code> or <code>Agent_OnAttach_&lt;agent-lib-name
670
&gt;</code> function initializes the agent and returns a value
671
to the VM to indicate if an error occurred. Any value other than zero indicates an error.
672
An error does not cause the VM to terminate. Instead the VM ignores the error, or takes
673
some implementation specific action -- for example it might print an error to standard error,
674
or record the error in a system log.
675
</intro>
676
677
<intro id="onunload" label="Agent Shutdown">
678
The library may optionally export a
679
shutdown function with the following prototype:
680
<example>
681
JNIEXPORT void JNICALL
682
Agent_OnUnload(JavaVM *vm)</example>
683
Or for a statically linked agent named 'L':
684
<example>
685
JNIEXPORT void JNICALL
686
Agent_OnUnload_L(JavaVM *vm)</example>
687
688
This function will be called by the VM when the library is about to be unloaded.
689
The library will be unloaded (unless it is statically linked into the
690
executable) and this function will be called if some platform specific
691
mechanism causes the unload (an unload mechanism is not specified in this document)
692
or the library is (in effect) unloaded by the termination of the VM whether through
693
normal termination or VM failure, including start-up failure.
694
Uncontrolled shutdown is, of couse, an exception to this rule.
695
Note the distinction between this function and the
696
<eventlink id="VMDeath">VM Death event</eventlink>: for the VM Death event
697
to be sent, the VM must have run at least to the point of initialization and a valid
698
<jvmti/> environment must exist which has set a callback for VMDeath
699
and enabled the event.
700
None of these are required for <code>Agent_OnUnload</code> or
701
<code>Agent_OnUnload_&lt;agent-lib-name&gt;</code> and this function
702
is also called if the library is unloaded for other reasons.
703
In the case that a VM Death event is sent, it will be sent before this
704
function is called (assuming this function is called due to VM termination).
705
This function can be used to clean-up resources allocated by the agent.
706
</intro>
707
708
<intro id="tooloptions" label="JAVA_TOOL_OPTIONS">
709
Since the command-line cannot always be accessed or modified, for example in embedded VMs
710
or simply VMs launched deep within scripts, a <code>JAVA_TOOL_OPTIONS</code> variable is
711
provided so that agents may be launched in these cases.
712
<p/>
713
Platforms which support environment variables or other named strings, may support the
714
<code>JAVA_TOOL_OPTIONS</code> variable. This variable will be broken into options at white-space
715
boundaries. White-space characters include space, tab, carriage-return, new-line,
716
vertical-tab, and form-feed. Sequences of white-space characters are considered
717
equivalent to a single white-space character. No white-space is included in the options
718
unless quoted. Quoting is as follows:
719
<ul>
720
<li>All characters enclosed between a pair of single quote marks (''), except a single
721
quote, are quoted.</li>
722
<li>Double quote characters have no special meaning inside a pair of single quote marks.</li>
723
<li>All characters enclosed between a pair of double quote marks (""), except a double
724
quote, are quoted.</li>
725
<li>Single quote characters have no special meaning inside a pair of double quote marks.</li>
726
<li>A quoted part can start or end anywhere in the variable.</li>
727
<li>White-space characters have no special meaning when quoted -- they are included in
728
the option like any other character and do not mark white-space boundaries.</li>
729
<li>The pair of quote marks is not included in the option.</li>
730
</ul>
731
<code>JNI_CreateJavaVM</code> (in the JNI Invocation API) will prepend these options to the options supplied
732
in its <code>JavaVMInitArgs</code> argument. Platforms may disable this feature in cases where security is
733
a concern; for example, the Reference Implementation disables this feature on Unix systems when
734
the effective user or group ID differs from the real ID.
735
This feature is intended to support the initialization of tools -- specifically including the
736
launching of native or Java programming language agents. Multiple tools may wish to use this
737
feature, so the variable should not be overwritten, instead, options should be appended to
738
the variable. Note that since the variable is processed at the time of the JNI Invocation
739
API create VM call, options processed by a launcher (e.g., VM selection options) will not be handled.
740
</intro>
741
742
<intro id="environments" label="Environments">
743
The <jvmti/> specification supports the use of multiple simultaneous
744
<jvmti/> agents.
745
Each agent has its own <jvmti/> environment.
746
That is, the <jvmti/> state is
747
separate for each agent - changes to one environment do not affect the
748
others. The state of a <jvmti/>
749
environment includes:
750
<ul>
751
<li><functionlink id="SetEventCallbacks">the event callbacks</functionlink></li>
752
<li><functionlink id="SetEventNotificationMode">the set of events which are enabled</functionlink></li>
753
<li><internallink id="capability">the capabilities</internallink></li>
754
<li><internallink id="memory">the memory allocation/deallocation hooks</internallink></li>
755
</ul>
756
Although their <jvmti/> state
757
is separate, agents inspect and modify the shared state
758
of the VM, they also share the native environment in which they execute.
759
As such, an agent can perturb the results of other agents or cause them
760
to fail. It is the responsibility of the agent writer to specify the level
761
of compatibility with other agents. <jvmti/> implementations are not capable
762
of preventing destructive interactions between agents. Techniques to reduce
763
the likelihood of these occurrences are beyond the scope of this document.
764
<p/>
765
An agent creates a <jvmti/> environment
766
by passing a <jvmti/> version
767
as the interface ID to the JNI Invocation API function
768
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/invocation.html#GetEnv"><code>GetEnv</code></externallink>.
769
See <internallink id="jvmtiEnvAccess">Accessing <jvmti/> Functions</internallink>
770
for more details on the creation and use of
771
<jvmti/> environments.
772
Typically, <jvmti/> environments are created by calling <code>GetEnv</code> from
773
<internallink id="onload"><code>Agent_OnLoad</code></internallink>.
774
</intro>
775
776
<intro id="bci" label="Bytecode Instrumentation">
777
This interface does not include some events that one might expect in an interface with
778
profiling support. Some examples include object allocation events and full speed
779
method enter and exit events. The interface instead provides support for
780
<i>bytecode instrumentation</i>, the ability to alter the Java virtual machine
781
bytecode instructions which comprise the target program. Typically, these alterations
782
are to add "events" to the code of a method - for example, to add, at the beginning of a method,
783
a call to <code>MyProfiler.methodEntered()</code>.
784
Since the changes are purely additive, they do not modify application
785
state or behavior.
786
Because the inserted agent code is standard bytecodes, the VM can run at full speed,
787
optimizing not only the target program but also the instrumentation. If the
788
instrumentation does not involve switching from bytecode execution, no expensive
789
state transitions are needed. The result is high performance events.
790
This approach also provides complete control to the agent: instrumentation can be
791
restricted to "interesting" portions of the code (e.g., the end user's code) and
792
can be conditional. Instrumentation can run entirely in Java programming language
793
code or can call into the native agent. Instrumentation can simply maintain
794
counters or can statistically sample events.
795
<p/>
796
Instrumentation can be inserted in one of three ways:
797
<ul>
798
<li>
799
Static Instrumentation: The class file is instrumented before it
800
is loaded into the VM - for example, by creating a duplicate directory of
801
<code>*.class</code> files which have been modified to add the instrumentation.
802
This method is extremely awkward and, in general, an agent cannot know
803
the origin of the class files which will be loaded.
804
</li>
805
<li>
806
Load-Time Instrumentation: When a class file is loaded by the VM, the raw
807
bytes of the class file are sent for instrumentation to the agent.
808
The <eventlink id="ClassFileLoadHook"/>
809
event, triggered by the class load,
810
provides this functionality. This mechanism provides efficient
811
and complete access to one-time instrumentation.
812
</li>
813
<li>
814
Dynamic Instrumentation: A class which is already loaded (and possibly
815
even running) is modified. This optional feature is provided by the
816
<eventlink id="ClassFileLoadHook"/> event, triggered by calling the
817
<functionlink id="RetransformClasses"/> function.
818
Classes can be modified multiple times and can be returned to their
819
original state.
820
The mechanism allows instrumentation which changes during the
821
course of execution.
822
</li>
823
</ul>
824
<p/>
825
The class modification functionality provided in this interface
826
is intended to provide a mechanism for instrumentation
827
(the <eventlink id="ClassFileLoadHook"/> event
828
and the <functionlink id="RetransformClasses"/> function)
829
and, during development, for fix-and-continue debugging
830
(the <functionlink id="RedefineClasses"/> function).
831
<p/>
832
Care must be taken to avoid perturbing dependencies, especially when
833
instrumenting core classes. For example, an approach to getting notification
834
of every object allocation is to instrument the constructor on
835
<code>Object</code>. Assuming that the constructor is initially
836
empty, the constructor could be changed to:
837
<example>
838
public Object() {
839
MyProfiler.allocationTracker(this);
840
}
841
</example>
842
However, if this change was made using the
843
<eventlink id="ClassFileLoadHook"/>
844
event then this might impact a typical VM as follows:
845
the first created object will call the constructor causing a class load of
846
<code>MyProfiler</code>; which will then cause
847
object creation, and since <code>MyProfiler</code> isn't loaded yet,
848
infinite recursion; resulting in a stack overflow. A refinement of this
849
would be to delay invoking the tracking method until a safe time. For
850
example, <code>trackAllocations</code> could be set in the
851
handler for the <code>VMInit</code> event.
852
<example>
853
static boolean trackAllocations = false;
854
855
public Object() {
856
if (trackAllocations) {
857
MyProfiler.allocationTracker(this);
858
}
859
}
860
</example>
861
<p/>
862
The <functionlink id="SetNativeMethodPrefix"/> allows native methods
863
to be instrumented by the use of wrapper methods.
864
</intro>
865
866
<intro id="mUTF" label="Modified UTF-8 String Encoding">
867
<jvmti/> uses modified UTF-8 to encode character strings.
868
This is the same encoding used by JNI.
869
Modified UTF-8 differs
870
from standard UTF-8 in the representation of supplementary characters
871
and of the null character. See the
872
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/types.html#wp16542">
873
Modified UTF-8 Strings</externallink>
874
section of the JNI specification for details.
875
</intro>
876
877
<intro id="context" label="Specification Context">
878
Since this interface provides access to the state of applications running in the
879
Java virtual machine;
880
terminology refers to the Java platform and not the native
881
platform (unless stated otherwise). For example:
882
<ul>
883
<li>"thread" means Java programming language thread.</li>
884
<li>"stack frame" means Java virtual machine stack frame.</li>
885
<li>"class" means Java programming language class.</li>
886
<li>"heap" means Java virtual machine heap.</li>
887
<li>"monitor" means Java programming language object monitor.</li>
888
</ul>
889
<p/>
890
Sun, Sun Microsystems, the Sun logo, Java, and JVM
891
are trademarks or registered trademarks of Oracle
892
and/or its affiliates, in the U.S. and other countries.
893
</intro>
894
895
896
<functionsection label="Functions">
897
<intro id="jvmtiEnvAccess" label="Accessing Functions">
898
Native code accesses <jvmti/> features
899
by calling <jvmti/> functions.
900
Access to <jvmti/> functions is by use of an interface pointer
901
in the same manner as
902
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/design.html">Java
903
Native Interface (JNI) functions</externallink> are accessed.
904
The <jvmti/> interface pointer is called the
905
<i>environment pointer</i>.
906
<p/>
907
An environment pointer is a pointer to an environment and has
908
the type <code>jvmtiEnv*</code>.
909
An environment has information about its <jvmti/> connection.
910
The first value in the environment is a pointer to the function table.
911
The function table is an array of pointers to <jvmti/> functions.
912
Every function pointer is at a predefined offset inside the
913
array.
914
<p/>
915
When used from the C language:
916
double indirection is used to access the functions;
917
the environment pointer provides context and is the first
918
parameter of each function call; for example:
919
<example>
920
jvmtiEnv *jvmti;
921
...
922
jvmtiError err = (*jvmti)->GetLoadedClasses(jvmti, &amp;class_count, &amp;classes);
923
</example>
924
<p/>
925
When used from the C++ language:
926
functions are accessed as member functions of <code>jvmtiEnv</code>;
927
the environment pointer is not passed to the function call; for example:
928
<example>
929
jvmtiEnv *jvmti;
930
...
931
jvmtiError err = jvmti->GetLoadedClasses(&amp;class_count, &amp;classes);
932
</example>
933
Unless otherwise stated, all examples and declarations in this
934
specification use the C language.
935
<p/>
936
A <jvmti/> environment can be obtained through the JNI Invocation API
937
<code>GetEnv</code> function:
938
<example>
939
jvmtiEnv *jvmti;
940
...
941
(*jvm)->GetEnv(jvm, &amp;jvmti, JVMTI_VERSION_1_0);
942
</example>
943
Each call to <code>GetEnv</code>
944
creates a new <jvmti/> connection and thus
945
a new <jvmti/> environment.
946
The <code>version</code> argument of <code>GetEnv</code> must be
947
a <jvmti/> version.
948
The returned environment may have a different version than the
949
requested version but the returned environment must be compatible.
950
<code>GetEnv</code> will return <code>JNI_EVERSION</code> if a
951
compatible version is not available, if <jvmti/> is not supported or
952
<jvmti/> is not supported in the current VM configuration.
953
Other interfaces may be added for creating <jvmti/> environments
954
in specific contexts.
955
Each environment has its own state (for example,
956
<functionlink id="SetEventNotificationMode">desired events</functionlink>,
957
<functionlink id="SetEventCallbacks">event handling functions</functionlink>, and
958
<functionlink id="AddCapabilities">capabilities</functionlink>).
959
An environment is released with
960
<functionlink id="DisposeEnvironment"></functionlink>.
961
Thus, unlike JNI which has one environment per thread, <jvmti/> environments work
962
across threads and are created dynamically.
963
</intro>
964
965
<intro id="functionReturn" label="Function Return Values">
966
<jvmti/> functions always return an
967
<internallink id="ErrorSection">error code</internallink> via the
968
<datalink id="jvmtiError"/> function return value.
969
Some functions can return additional
970
values through pointers provided by the calling function.
971
In some cases, <jvmti/> functions allocate memory that your program must
972
explicitly deallocate. This is indicated in the individual <jvmti/>
973
function descriptions. Empty lists, arrays, sequences, etc are
974
returned as <code>NULL</code>.
975
<p/>
976
In the event that the <jvmti/> function encounters
977
an error (any return value other than <code>JVMTI_ERROR_NONE</code>) the values
978
of memory referenced by argument pointers is undefined, but no memory
979
will have been allocated and no global references will have been allocated.
980
If the error occurs because of invalid input, no action will have occurred.
981
</intro>
982
983
<intro id="refs" label="Managing JNI Object References">
984
<jvmti/> functions identify objects with JNI references
985
(<datalink id="jobject"/> and <datalink id="jclass"/>)
986
and their derivatives
987
(<datalink id="jthread"/> and <datalink id="jthreadGroup"/>).
988
References passed to
989
<jvmti/> functions can be either global or local, but they must be
990
strong references. All references returned by <jvmti/> functions are
991
local references--these local references are created
992
during the <jvmti/> call.
993
Local references are a resource that must be managed (see the
994
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/functions.html#wp18654">JNI Documentation</externallink>).
995
When threads return from native code all local references
996
are freed. Note that some threads, including typical
997
agent threads, will never return from native code.
998
A thread is ensured the ability to create sixteen local
999
references without the need for any explicit management.
1000
For threads executing a limited number of <jvmti/> calls before
1001
returning from native code
1002
(for example, threads processing events),
1003
it may be determined that no explicit management
1004
is needed.
1005
However, long running agent threads will need explicit
1006
local reference management--usually with the JNI functions
1007
<code>PushLocalFrame</code> and <code>PopLocalFrame</code>.
1008
Conversely, to preserve references beyond the
1009
return from native code, they must be converted to global references.
1010
These rules do not apply to <datalink id="jmethodID"/> and <datalink id="jfieldID"/>
1011
as they are not <datalink id="jobject"/>s.
1012
</intro>
1013
1014
<intro id="prereqState" label="Prerequisite State for Calling Functions">
1015
Unless the function explicitly states that the agent must bring
1016
a thread or the VM to a particular state (for example, suspended),
1017
the <jvmti/> implementation is responsible for bringing the VM to a
1018
safe and consistent state for performing the function.
1019
</intro>
1020
1021
<intro id="functionsExceptions" label="Exceptions and Functions">
1022
<jvmti/> functions never throw exceptions; error conditions are
1023
communicated via the
1024
<internallink id="functionReturn">function return value</internallink>.
1025
Any existing exception state is preserved across a call to a
1026
<jvmti/> function.
1027
See the
1028
<externallink
1029
id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/design.html#wp770"
1030
>Java Exceptions</externallink>
1031
section of the JNI specification for information on handling exceptions.
1032
</intro>
1033
1034
<category id="memory" label="Memory Management">
1035
<intro>
1036
These functions provide for the allocation and deallocation of
1037
memory used by <jvmti/> functionality and can be used to provide
1038
working memory for agents.
1039
Memory managed by <jvmti/> is not compatible with other memory
1040
allocation libraries and mechanisms.
1041
</intro>
1042
1043
<function id="Allocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="46">
1044
<synopsis>Allocate</synopsis>
1045
<description>
1046
Allocate an area of memory through the <jvmti/> allocator.
1047
The allocated
1048
memory should be freed with <functionlink id="Deallocate"></functionlink>.
1049
</description>
1050
<origin>jvmdi</origin>
1051
<capabilities>
1052
</capabilities>
1053
<parameters>
1054
<param id="size">
1055
<jlong/>
1056
<description>
1057
The number of bytes to allocate.
1058
<rationale>
1059
<code>jlong</code> is used for compatibility with JVMDI.
1060
</rationale>
1061
</description>
1062
</param>
1063
<param id="mem_ptr">
1064
<allocbuf incount="size"><uchar/></allocbuf>
1065
<description>
1066
On return, a pointer to the beginning of the allocated memory.
1067
If <code>size</code> is zero, <code>NULL</code> is returned.
1068
</description>
1069
</param>
1070
</parameters>
1071
<errors>
1072
<error id="JVMTI_ERROR_OUT_OF_MEMORY">
1073
Memory request cannot be honored.
1074
</error>
1075
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
1076
<paramlink id="size"></paramlink> is less than zero.
1077
</error>
1078
</errors>
1079
</function>
1080
1081
<function id="Deallocate" jkernel="yes" phase="any" callbacksafe="safe" impl="notrace" num="47">
1082
<synopsis>Deallocate</synopsis>
1083
<description>
1084
Deallocate <code>mem</code> using the <jvmti/> allocator.
1085
This function should
1086
be used to deallocate any memory allocated and returned
1087
by a <jvmti/> function
1088
(including memory allocated with <functionlink id="Allocate"></functionlink>).
1089
All allocated memory must be deallocated
1090
or the memory cannot be reclaimed.
1091
</description>
1092
<origin>jvmdi</origin>
1093
<capabilities>
1094
</capabilities>
1095
<parameters>
1096
<param id="mem">
1097
<outbuf>
1098
<uchar/>
1099
<nullok>the call is ignored</nullok>
1100
</outbuf>
1101
<description>
1102
A pointer to the beginning of the allocated memory.
1103
Please ignore "On return, the elements are set."
1104
<todo>keep it from generating "On return, the elements are set"</todo>
1105
</description>
1106
</param>
1107
</parameters>
1108
<errors>
1109
</errors>
1110
</function>
1111
</category>
1112
1113
<category id="threadCategory" label="Thread">
1114
<intro>
1115
</intro>
1116
1117
<function id="GetThreadState" num="17">
1118
<synopsis>Get Thread State</synopsis>
1119
<description>
1120
Get the state of a thread. The state of the thread is represented by the
1121
answers to the hierarchical set of questions below:
1122
<ul type="circle">
1123
<li><i>Alive?</i>
1124
<ul>
1125
<li>Not alive.
1126
<ul type="circle">
1127
<li><i>Why not alive?</i>
1128
<ul>
1129
<li>New.</li>
1130
<li>Terminated (<datalink
1131
id="JVMTI_THREAD_STATE_TERMINATED"><code>JVMTI_THREAD_STATE_TERMINATED</code></datalink>)</li>
1132
</ul>
1133
</li>
1134
</ul>
1135
</li>
1136
<li>Alive (<datalink
1137
id="JVMTI_THREAD_STATE_ALIVE"><code>JVMTI_THREAD_STATE_ALIVE</code></datalink>)
1138
<ul type="circle">
1139
<li><i>Suspended?</i>
1140
<ul>
1141
<li>Suspended (<datalink
1142
id="JVMTI_THREAD_STATE_SUSPENDED"><code>JVMTI_THREAD_STATE_SUSPENDED</code></datalink>)</li>
1143
<li>Not suspended</li>
1144
</ul>
1145
</li>
1146
<li><i>Interrupted?</i>
1147
<ul>
1148
<li>Interrupted (<datalink
1149
id="JVMTI_THREAD_STATE_INTERRUPTED"><code>JVMTI_THREAD_STATE_INTERRUPTED</code></datalink>)</li>
1150
<li>Not interrupted.</li>
1151
</ul>
1152
</li>
1153
<li><i>In native?</i>
1154
<ul>
1155
<li>In native code (<datalink
1156
id="JVMTI_THREAD_STATE_IN_NATIVE"><code>JVMTI_THREAD_STATE_IN_NATIVE</code></datalink>)</li>
1157
<li>In Java programming language code</li>
1158
</ul>
1159
</li>
1160
<li><i>What alive state?</i>
1161
<ul>
1162
<li>Runnable (<datalink
1163
id="JVMTI_THREAD_STATE_RUNNABLE"><code>JVMTI_THREAD_STATE_RUNNABLE</code></datalink>)</li>
1164
<li>Blocked (<datalink
1165
id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER"><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></datalink>)</li>
1166
<li>Waiting (<datalink
1167
id="JVMTI_THREAD_STATE_WAITING"><code>JVMTI_THREAD_STATE_WAITING</code></datalink>)
1168
<ul type="circle">
1169
<li><i>Timed wait?</i>
1170
<ul>
1171
<li>Indefinite (<datalink
1172
id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY"><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></datalink></li>
1173
<li>Timed (<datalink
1174
id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT"><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></datalink>)</li>
1175
</ul>
1176
</li>
1177
<li><i>Why waiting?</i>
1178
<ul>
1179
<li>Object.wait (<datalink
1180
id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT"><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></datalink>)</li>
1181
<li>LockSupport.park (<datalink
1182
id="JVMTI_THREAD_STATE_PARKED"><code>JVMTI_THREAD_STATE_PARKED</code></datalink>)</li>
1183
<li>Sleeping (<datalink
1184
id="JVMTI_THREAD_STATE_SLEEPING"><code>JVMTI_THREAD_STATE_SLEEPING</code></datalink>)</li>
1185
</ul>
1186
</li>
1187
</ul>
1188
</li>
1189
</ul>
1190
</li>
1191
</ul>
1192
</li>
1193
</ul>
1194
</li>
1195
</ul>
1196
<p/>
1197
The answers are represented by the following bit vector.
1198
<constants id="jvmtiThreadState" label="Thread State Flags" kind="bits">
1199
<constant id="JVMTI_THREAD_STATE_ALIVE" num="0x0001">
1200
Thread is alive. Zero if thread is new (not started) or terminated.
1201
</constant>
1202
<constant id="JVMTI_THREAD_STATE_TERMINATED" num="0x0002">
1203
Thread has completed execution.
1204
</constant>
1205
<constant id="JVMTI_THREAD_STATE_RUNNABLE" num="0x0004">
1206
Thread is runnable.
1207
</constant>
1208
<constant id="JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER" num="0x0400">
1209
Thread is waiting to enter a synchronization block/method or,
1210
after an <code>Object.wait()</code>, waiting to re-enter a
1211
synchronization block/method.
1212
</constant>
1213
<constant id="JVMTI_THREAD_STATE_WAITING" num="0x0080">
1214
Thread is waiting.
1215
</constant>
1216
<constant id="JVMTI_THREAD_STATE_WAITING_INDEFINITELY" num="0x0010">
1217
Thread is waiting without a timeout.
1218
For example, <code>Object.wait()</code>.
1219
</constant>
1220
<constant id="JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT" num="0x0020">
1221
Thread is waiting with a maximum time to wait specified.
1222
For example, <code>Object.wait(long)</code>.
1223
</constant>
1224
<constant id="JVMTI_THREAD_STATE_SLEEPING" num="0x0040">
1225
Thread is sleeping -- <code>Thread.sleep(long)</code>.
1226
</constant>
1227
<constant id="JVMTI_THREAD_STATE_IN_OBJECT_WAIT" num="0x0100">
1228
Thread is waiting on an object monitor -- <code>Object.wait</code>.
1229
</constant>
1230
<constant id="JVMTI_THREAD_STATE_PARKED" num="0x0200">
1231
Thread is parked, for example: <code>LockSupport.park</code>,
1232
<code>LockSupport.parkUtil</code> and <code>LockSupport.parkNanos</code>.
1233
</constant>
1234
<constant id="JVMTI_THREAD_STATE_SUSPENDED" num="0x100000">
1235
Thread suspended.
1236
<code>java.lang.Thread.suspend()</code>
1237
or a <jvmti/> suspend function
1238
(such as <functionlink id="SuspendThread"></functionlink>)
1239
has been called on the thread. If this bit
1240
is set, the other bits refer to the thread state before suspension.
1241
</constant>
1242
<constant id="JVMTI_THREAD_STATE_INTERRUPTED" num="0x200000">
1243
Thread has been interrupted.
1244
</constant>
1245
<constant id="JVMTI_THREAD_STATE_IN_NATIVE" num="0x400000">
1246
Thread is in native code--that is, a native method is running
1247
which has not called back into the VM or Java programming
1248
language code.
1249
<p/>
1250
This flag is not set when running VM compiled Java programming
1251
language code nor is it set when running VM code or
1252
VM support code. Native VM interface functions, such as JNI and
1253
<jvmti/> functions, may be implemented as VM code.
1254
</constant>
1255
<constant id="JVMTI_THREAD_STATE_VENDOR_1" num="0x10000000">
1256
Defined by VM vendor.
1257
</constant>
1258
<constant id="JVMTI_THREAD_STATE_VENDOR_2" num="0x20000000">
1259
Defined by VM vendor.
1260
</constant>
1261
<constant id="JVMTI_THREAD_STATE_VENDOR_3" num="0x40000000">
1262
Defined by VM vendor.
1263
</constant>
1264
</constants>
1265
The following definitions are used to convert <jvmti/> thread state
1266
to <code>java.lang.Thread.State</code> style states.
1267
<constants id="jvmtiJavaLangThreadState" label="java.lang.Thread.State Conversion Masks" kind="bits">
1268
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_MASK"
1269
num="JVMTI_THREAD_STATE_TERMINATED | JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1270
Mask the state with this before comparison
1271
</constant>
1272
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_NEW"
1273
num="0">
1274
<code>java.lang.Thread.State.NEW</code>
1275
</constant>
1276
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED"
1277
num="JVMTI_THREAD_STATE_TERMINATED">
1278
<code>java.lang.Thread.State.TERMINATED</code>
1279
</constant>
1280
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE"
1281
num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_RUNNABLE">
1282
<code>java.lang.Thread.State.RUNNABLE</code>
1283
</constant>
1284
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED"
1285
num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER">
1286
<code>java.lang.Thread.State.BLOCKED</code>
1287
</constant>
1288
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_WAITING"
1289
num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_INDEFINITELY">
1290
<code>java.lang.Thread.State.WAITING</code>
1291
</constant>
1292
<constant id="JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING"
1293
num="JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_WAITING | JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT">
1294
<code>java.lang.Thread.State.TIMED_WAITING</code>
1295
</constant>
1296
</constants>
1297
<b>Rules</b>
1298
<p/>
1299
There can be no more than one answer to a question, although there can be no
1300
answer (because the answer is unknown, does not apply, or none of the answers is
1301
correct). An answer is set only when the enclosing answers match.
1302
That is, no more than one of
1303
<ul type="circle">
1304
<li><code>JVMTI_THREAD_STATE_RUNNABLE</code></li>
1305
<li><code>JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER</code></li>
1306
<li><code>JVMTI_THREAD_STATE_WAITING</code></li>
1307
</ul>
1308
can be set (a <tm>J2SE</tm> compliant implementation will always set
1309
one of these if <code>JVMTI_THREAD_STATE_ALIVE</code> is set).
1310
And if any of these are set, the enclosing answer
1311
<code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1312
No more than one of
1313
<ul type="circle">
1314
<li><code>JVMTI_THREAD_STATE_WAITING_INDEFINITELY</code></li>
1315
<li><code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code></li>
1316
</ul>
1317
can be set (a <tm>J2SE</tm> compliant implementation will always set
1318
one of these if <code>JVMTI_THREAD_STATE_WAITING</code> is set).
1319
And if either is set, the enclosing answers
1320
<code>JVMTI_THREAD_STATE_ALIVE</code> and
1321
<code>JVMTI_THREAD_STATE_WAITING</code> are set.
1322
No more than one of
1323
<ul type="circle">
1324
<li><code>JVMTI_THREAD_STATE_IN_OBJECT_WAIT</code></li>
1325
<li><code>JVMTI_THREAD_STATE_PARKED</code></li>
1326
<li><code>JVMTI_THREAD_STATE_SLEEPING</code></li>
1327
</ul>
1328
can be set. And if any of these is set, the enclosing answers
1329
<code>JVMTI_THREAD_STATE_ALIVE</code> and
1330
<code>JVMTI_THREAD_STATE_WAITING</code> are set.
1331
Also, if <code>JVMTI_THREAD_STATE_SLEEPING</code> is set,
1332
then <code>JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT</code> is set.
1333
If a state <i>A</i> is implemented using the mechanism of
1334
state <i>B</i> then it is state <i>A</i> which
1335
is returned by this function.
1336
For example, if <code>Thread.sleep(long)</code>
1337
is implemented using <code>Object.wait(long)</code>
1338
then it is still <code>JVMTI_THREAD_STATE_SLEEPING</code>
1339
which is returned.
1340
More than one of
1341
<ul type="circle">
1342
<li><code>JVMTI_THREAD_STATE_SUSPENDED</code></li>
1343
<li><code>JVMTI_THREAD_STATE_INTERRUPTED</code></li>
1344
<li><code>JVMTI_THREAD_STATE_IN_NATIVE</code></li>
1345
</ul>
1346
can be set, but if any is set,
1347
<code>JVMTI_THREAD_STATE_ALIVE</code> is set.
1348
<p/>
1349
And finally,
1350
<code>JVMTI_THREAD_STATE_TERMINATED</code> cannot be set unless
1351
<code>JVMTI_THREAD_STATE_ALIVE</code> is not set.
1352
<p/>
1353
The thread state representation is designed for extension in future versions
1354
of the specification; thread state values should be used accordingly, that is
1355
they should not be used as ordinals.
1356
Most queries can be made by testing a single bit, if use in a switch statement is desired,
1357
the state bits should be masked with the interesting bits.
1358
All bits not defined above are reserved for future use.
1359
A VM, compliant to the current specification, must set reserved bits to zero.
1360
An agent should ignore reserved bits --
1361
they should not be assumed to be zero and thus should not be included in comparisons.
1362
<p/>
1363
<b>Examples</b>
1364
<p/>
1365
Note that the values below exclude reserved and vendor bits.
1366
<p/>
1367
The state of a thread blocked at a <code>synchronized</code>-statement would be:
1368
<example>
1369
JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_BLOCKED_ON_MONITOR_ENTER
1370
</example>
1371
The state of a thread which hasn't started yet would be:
1372
<example>
1373
0
1374
</example>
1375
The state of a thread at a <code>Object.wait(3000)</code> would be:
1376
<example>
1377
JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_WAITING +
1378
JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT +
1379
JVMTI_THREAD_STATE_MONITOR_WAITING
1380
</example>
1381
The state of a thread suspended while runnable would be:
1382
<example>
1383
JVMTI_THREAD_STATE_ALIVE + JVMTI_THREAD_STATE_RUNNABLE + JVMTI_THREAD_STATE_SUSPENDED
1384
</example>
1385
<p/>
1386
<b>Testing the State</b>
1387
<p/>
1388
In most cases, the thread state can be determined by testing the one bit corresponding
1389
to that question. For example, the code to test if a thread is sleeping:
1390
<example>
1391
jint state;
1392
jvmtiError err;
1393
1394
err = (*jvmti)-&gt;GetThreadState(jvmti, thread, &amp;state);
1395
if (err == JVMTI_ERROR_NONE) {
1396
if (state &amp; JVMTI_THREAD_STATE_SLEEPING) { ...
1397
</example>
1398
<p/>
1399
For waiting (that is, in <code>Object.wait</code>, parked, or sleeping) it would be:
1400
<example>
1401
if (state &amp; JVMTI_THREAD_STATE_WAITING) { ...
1402
</example>
1403
For some states, more than one bit will need to be tested as is the case
1404
when testing if a thread has not yet been started:
1405
<example>
1406
if ((state &amp; (JVMTI_THREAD_STATE_ALIVE | JVMTI_THREAD_STATE_TERMINATED)) == 0) { ...
1407
</example>
1408
To distinguish timed from untimed <code>Object.wait</code>:
1409
<example>
1410
if (state &amp; JVMTI_THREAD_STATE_IN_OBJECT_WAIT) {
1411
if (state &amp; JVMTI_THREAD_STATE_WAITING_WITH_TIMEOUT) {
1412
printf("in Object.wait(long timeout)\n");
1413
} else {
1414
printf("in Object.wait()\n");
1415
}
1416
}
1417
</example>
1418
<p/>
1419
<b>Relationship to <code>java.lang.Thread.State</code></b>
1420
<p/>
1421
The thread state represented by <code>java.lang.Thread.State</code>
1422
returned from <code>java.lang.Thread.getState()</code> is a subset of the
1423
information returned from this function.
1424
The corresponding <code>java.lang.Thread.State</code> can be determined
1425
by using the provided conversion masks.
1426
For example, this returns the name of the <code>java.lang.Thread.State</code> thread state:
1427
<example>
1428
err = (*jvmti)-&gt;GetThreadState(jvmti, thread, &amp;state);
1429
abortOnError(err);
1430
switch (state &amp; JVMTI_JAVA_LANG_THREAD_STATE_MASK) {
1431
case JVMTI_JAVA_LANG_THREAD_STATE_NEW:
1432
return "NEW";
1433
case JVMTI_JAVA_LANG_THREAD_STATE_TERMINATED:
1434
return "TERMINATED";
1435
case JVMTI_JAVA_LANG_THREAD_STATE_RUNNABLE:
1436
return "RUNNABLE";
1437
case JVMTI_JAVA_LANG_THREAD_STATE_BLOCKED:
1438
return "BLOCKED";
1439
case JVMTI_JAVA_LANG_THREAD_STATE_WAITING:
1440
return "WAITING";
1441
case JVMTI_JAVA_LANG_THREAD_STATE_TIMED_WAITING:
1442
return "TIMED_WAITING";
1443
}
1444
</example>
1445
</description>
1446
<origin>new</origin>
1447
<capabilities>
1448
</capabilities>
1449
<parameters>
1450
<param id="thread">
1451
<jthread null="current" started="maybe" impl="noconvert"/>
1452
<description>
1453
The thread to query.
1454
</description>
1455
</param>
1456
<param id="thread_state_ptr">
1457
<outptr><jint/></outptr>
1458
<description>
1459
On return, points to state flags,
1460
as defined by the <internallink id="jvmtiThreadState">Thread State Flags</internallink>.
1461
</description>
1462
</param>
1463
</parameters>
1464
<errors>
1465
</errors>
1466
</function>
1467
1468
<function id="GetCurrentThread" phase="start" num="18" since="1.1">
1469
<synopsis>Get Current Thread</synopsis>
1470
<description>
1471
Get the current thread.
1472
The current thread is the Java programming language thread which has called the function.
1473
<p/>
1474
Note that most <jvmti/> functions that take a thread
1475
as an argument will accept <code>NULL</code> to mean
1476
the current thread.
1477
</description>
1478
<origin>new</origin>
1479
<capabilities>
1480
</capabilities>
1481
<parameters>
1482
<param id="thread_ptr">
1483
<outptr><jthread/></outptr>
1484
<description>
1485
On return, points to the current thread.
1486
</description>
1487
</param>
1488
</parameters>
1489
<errors>
1490
</errors>
1491
</function>
1492
1493
<function id="GetAllThreads" num="4">
1494
<synopsis>Get All Threads</synopsis>
1495
<description>
1496
Get all live threads.
1497
The threads are Java programming language threads;
1498
that is, threads that are attached to the VM.
1499
A thread is live if <code>java.lang.Thread.isAlive()</code>
1500
would return <code>true</code>, that is, the thread has
1501
been started and has not yet died.
1502
The universe of threads is determined by the context of the <jvmti/>
1503
environment, which typically is all threads attached to the VM.
1504
Note that this includes <jvmti/> agent threads
1505
(see <functionlink id="RunAgentThread"/>).
1506
</description>
1507
<origin>jvmdi</origin>
1508
<capabilities>
1509
</capabilities>
1510
<parameters>
1511
<param id="threads_count_ptr">
1512
<outptr><jint/></outptr>
1513
<description>
1514
On return, points to the number of running threads.
1515
</description>
1516
</param>
1517
<param id="threads_ptr">
1518
<allocbuf outcount="threads_count_ptr"><jthread/></allocbuf>
1519
<description>
1520
On return, points to an array of references, one
1521
for each running thread.
1522
</description>
1523
</param>
1524
</parameters>
1525
<errors>
1526
</errors>
1527
</function>
1528
1529
<function id="SuspendThread" num="5">
1530
<synopsis>Suspend Thread</synopsis>
1531
<description>
1532
Suspend the specified thread. If the calling thread is specified,
1533
this function will not return until some other thread calls
1534
<functionlink id="ResumeThread"></functionlink>.
1535
If the thread is currently suspended, this function
1536
does nothing and returns an error.
1537
</description>
1538
<origin>jvmdi</origin>
1539
<capabilities>
1540
<required id="can_suspend"></required>
1541
</capabilities>
1542
<parameters>
1543
<param id="thread">
1544
<jthread null="current"/>
1545
<description>
1546
The thread to suspend.
1547
</description>
1548
</param>
1549
</parameters>
1550
<errors>
1551
<error id="JVMTI_ERROR_THREAD_SUSPENDED">
1552
Thread already suspended.
1553
</error>
1554
</errors>
1555
</function>
1556
1557
<elide>
1558
<function id="SuspendAllThreads" num="101">
1559
<synopsis>Suspend All Threads</synopsis>
1560
<description>
1561
<issue>
1562
There has been no explicit call for this function, and it will
1563
thus be removed if there is no interest.
1564
</issue>
1565
Suspend all live threads except:
1566
<ul>
1567
<li>already suspended threads</li>
1568
<li>those listed in <paramlink id="except_list"></paramlink></li>
1569
<li>certain system (non application) threads, as determined
1570
by the VM implementation</li>
1571
</ul>
1572
The threads are Java programming language threads;
1573
native threads which are not attached to the VM are not
1574
Java programming language threads.
1575
A thread is live if <code>java.lang.Thread.isAlive()</code>
1576
would return <code>true</code>, that is, the thread has
1577
been started and has not yet died.
1578
The universe of threads is determined
1579
by the context of the <jvmti/>
1580
environment, which, typically, is all threads attached to the VM,
1581
except critical VM internal threads and <jvmti/> agent threads
1582
(see <functionlink id="RunAgentThread"/>).
1583
<p/>
1584
If the calling thread is specified,
1585
all other threads are suspended first then the caller thread is suspended -
1586
this function will not return until some other thread calls
1587
<functionlink id="ResumeThread"></functionlink>.
1588
<p/>
1589
The list of actually
1590
suspended threads is returned in
1591
<paramlink id="suspended_list_ptr"></paramlink>.
1592
Suspension is as defined in <functionlink id="SuspendThread"></functionlink>.
1593
<functionlink id="ResumeThreadList"></functionlink>
1594
can be used to resume the suspended threads.
1595
</description>
1596
<origin>new</origin>
1597
<capabilities>
1598
<required id="can_suspend"></required>
1599
</capabilities>
1600
<parameters>
1601
<param id="except_count">
1602
<jint min="0"/>
1603
<description>
1604
The number of threads in the list of threads not to be suspended.
1605
</description>
1606
</param>
1607
<param id="except_list">
1608
<inbuf incount="except_count">
1609
<jthread/>
1610
<nullok>not an error if <code>except_count == 0</code></nullok>
1611
</inbuf>
1612
<description>
1613
The list of threads not to be suspended.
1614
</description>
1615
</param>
1616
<param id="suspended_count_ptr">
1617
<outptr><jint/></outptr>
1618
<description>
1619
On return, points to the number of threads suspended by this call.
1620
</description>
1621
</param>
1622
<param id="suspended_list_ptr">
1623
<allocbuf outcount="suspended_count_ptr"><jthread/></allocbuf>
1624
<description>
1625
On return, points to an array of references, one
1626
for each thread suspended.
1627
</description>
1628
</param>
1629
</parameters>
1630
<errors>
1631
<error id="JVMTI_ERROR_INVALID_THREAD">
1632
A thread in <paramlink id="except_list"></paramlink> was invalid.
1633
</error>
1634
<error id="JVMTI_ERROR_NULL_POINTER">
1635
Both <paramlink id="except_list"></paramlink> was <code>NULL</code>
1636
and <paramlink id="except_count"></paramlink> was non-zero.
1637
</error>
1638
</errors>
1639
</function>
1640
</elide>
1641
1642
<function id="SuspendThreadList" num="92">
1643
<synopsis>Suspend Thread List</synopsis>
1644
<description>
1645
Suspend the <paramlink id="request_count"></paramlink>
1646
threads specified in the
1647
<paramlink id="request_list"></paramlink> array.
1648
Threads may be resumed with
1649
<functionlink id="ResumeThreadList"></functionlink> or
1650
<functionlink id="ResumeThread"></functionlink>.
1651
If the calling thread is specified in the
1652
<paramlink id="request_list"></paramlink> array, this function will
1653
not return until some other thread resumes it.
1654
Errors encountered in the suspension of a thread
1655
are returned in the <paramlink id="results"></paramlink>
1656
array, <b>not</b> in the return value of this function.
1657
Threads that are currently suspended do not change state.
1658
</description>
1659
<origin>jvmdi</origin>
1660
<capabilities>
1661
<required id="can_suspend"></required>
1662
</capabilities>
1663
<parameters>
1664
<param id="request_count">
1665
<jint min="0"/>
1666
<description>
1667
The number of threads to suspend.
1668
</description>
1669
</param>
1670
<param id="request_list">
1671
<inbuf incount="request_count"><jthread/></inbuf>
1672
<description>
1673
The list of threads to suspend.
1674
</description>
1675
</param>
1676
<param id="results">
1677
<outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1678
<description>
1679
An agent supplied array of
1680
<paramlink id="request_count"></paramlink> elements.
1681
On return, filled with the error code for
1682
the suspend of the corresponding thread.
1683
The error code will be
1684
<errorlink id="JVMTI_ERROR_NONE"></errorlink>
1685
if the thread was suspended by this call.
1686
Possible error codes are those specified
1687
for <functionlink id="SuspendThread"></functionlink>.
1688
</description>
1689
</param>
1690
</parameters>
1691
<errors>
1692
</errors>
1693
</function>
1694
1695
<function id="ResumeThread" num="6">
1696
<synopsis>Resume Thread</synopsis>
1697
<description>
1698
Resume a suspended thread.
1699
Any threads currently suspended through
1700
a <jvmti/> suspend function (eg.
1701
<functionlink id="SuspendThread"></functionlink>)
1702
or <code>java.lang.Thread.suspend()</code>
1703
will resume execution;
1704
all other threads are unaffected.
1705
</description>
1706
<origin>jvmdi</origin>
1707
<capabilities>
1708
<required id="can_suspend"></required>
1709
</capabilities>
1710
<parameters>
1711
<param id="thread">
1712
<jthread/>
1713
<description>
1714
The thread to resume.
1715
</description>
1716
</param>
1717
</parameters>
1718
<errors>
1719
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
1720
Thread was not suspended.
1721
</error>
1722
<error id="JVMTI_ERROR_INVALID_TYPESTATE">
1723
The state of the thread has been modified, and is now inconsistent.
1724
</error>
1725
</errors>
1726
</function>
1727
1728
<function id="ResumeThreadList" num="93">
1729
<synopsis>Resume Thread List</synopsis>
1730
<description>
1731
Resume the <paramlink id="request_count"></paramlink>
1732
threads specified in the
1733
<paramlink id="request_list"></paramlink> array.
1734
Any thread suspended through
1735
a <jvmti/> suspend function (eg.
1736
<functionlink id="SuspendThreadList"></functionlink>)
1737
or <code>java.lang.Thread.suspend()</code>
1738
will resume execution.
1739
</description>
1740
<origin>jvmdi</origin>
1741
<capabilities>
1742
<required id="can_suspend"></required>
1743
</capabilities>
1744
<parameters>
1745
<param id="request_count">
1746
<jint min="0"/>
1747
<description>
1748
The number of threads to resume.
1749
</description>
1750
</param>
1751
<param id="request_list">
1752
<inbuf incount="request_count"><jthread/></inbuf>
1753
<description>
1754
The threads to resume.
1755
</description>
1756
</param>
1757
<param id="results">
1758
<outbuf incount="request_count"><enum>jvmtiError</enum></outbuf>
1759
<description>
1760
An agent supplied array of
1761
<paramlink id="request_count"></paramlink> elements.
1762
On return, filled with the error code for
1763
the resume of the corresponding thread.
1764
The error code will be
1765
<errorlink id="JVMTI_ERROR_NONE"></errorlink>
1766
if the thread was suspended by this call.
1767
Possible error codes are those specified
1768
for <functionlink id="ResumeThread"></functionlink>.
1769
</description>
1770
</param>
1771
</parameters>
1772
<errors>
1773
</errors>
1774
</function>
1775
1776
<function id="StopThread" num="7">
1777
<synopsis>Stop Thread</synopsis>
1778
<description>
1779
Send the specified asynchronous exception to the specified thread
1780
(similar to <code>java.lang.Thread.stop</code>).
1781
Normally, this function is used to kill the specified thread with an
1782
instance of the exception <code>ThreadDeath</code>.
1783
</description>
1784
<origin>jvmdi</origin>
1785
<capabilities>
1786
<required id="can_signal_thread"></required>
1787
</capabilities>
1788
<parameters>
1789
<param id="thread">
1790
<jthread/>
1791
<description>
1792
The thread to stop.
1793
</description>
1794
</param>
1795
<param id="exception">
1796
<jobject/>
1797
<description>
1798
The asynchronous exception object.
1799
</description>
1800
</param>
1801
</parameters>
1802
<errors>
1803
</errors>
1804
</function>
1805
1806
<function id="InterruptThread" num="8">
1807
<synopsis>Interrupt Thread</synopsis>
1808
<description>
1809
Interrupt the specified thread
1810
(similar to <code>java.lang.Thread.interrupt</code>).
1811
</description>
1812
<origin>jvmdi</origin>
1813
<capabilities>
1814
<required id="can_signal_thread"></required>
1815
</capabilities>
1816
<parameters>
1817
<param id="thread">
1818
<jthread impl="noconvert"/>
1819
<description>
1820
The thread to interrupt.
1821
</description>
1822
</param>
1823
</parameters>
1824
<errors>
1825
</errors>
1826
</function>
1827
1828
<function id="GetThreadInfo" num="9">
1829
<synopsis>Get Thread Info</synopsis>
1830
<typedef id="jvmtiThreadInfo" label="Thread information structure">
1831
<field id="name">
1832
<allocfieldbuf><char/></allocfieldbuf>
1833
<description>
1834
The thread name, encoded as a
1835
<internallink id="mUTF">modified UTF-8</internallink> string.
1836
</description>
1837
</field>
1838
<field id="priority">
1839
<jint/>
1840
<description>
1841
The thread priority. See the thread priority constants:
1842
<datalink id="jvmtiThreadPriority"></datalink>.
1843
</description>
1844
</field>
1845
<field id="is_daemon">
1846
<jboolean/>
1847
<description>
1848
Is this a daemon thread?
1849
</description>
1850
</field>
1851
<field id="thread_group">
1852
<jthreadGroup/>
1853
<description>
1854
The thread group to which this thread belongs.
1855
<code>NULL</code> if the thread has died.
1856
</description>
1857
</field>
1858
<field id="context_class_loader">
1859
<jobject/>
1860
<description>
1861
The context class loader associated with this thread.
1862
</description>
1863
</field>
1864
</typedef>
1865
<description>
1866
Get thread information. The fields of the <datalink id="jvmtiThreadInfo"/> structure
1867
are filled in with details of the specified thread.
1868
</description>
1869
<origin>jvmdi</origin>
1870
<capabilities>
1871
</capabilities>
1872
<parameters>
1873
<param id="thread">
1874
<jthread null="current" impl="noconvert" started="maybe"/>
1875
<description>
1876
The thread to query.
1877
</description>
1878
</param>
1879
<param id="info_ptr">
1880
<outptr><struct>jvmtiThreadInfo</struct></outptr>
1881
<description>
1882
On return, filled with information describing the specified thread.
1883
<p/>
1884
For JDK 1.1 implementations that don't
1885
recognize context class loaders,
1886
the <code>context_class_loader</code> field will be NULL.
1887
</description>
1888
</param>
1889
</parameters>
1890
<errors>
1891
</errors>
1892
</function>
1893
1894
<function id="GetOwnedMonitorInfo" num="10">
1895
<synopsis>Get Owned Monitor Info</synopsis>
1896
<description>
1897
Get information about the monitors owned by the
1898
specified thread.
1899
</description>
1900
<origin>jvmdiClone</origin>
1901
<capabilities>
1902
<required id="can_get_owned_monitor_info"></required>
1903
</capabilities>
1904
<parameters>
1905
<param id="thread">
1906
<jthread null="current"/>
1907
<description>
1908
The thread to query.
1909
</description>
1910
</param>
1911
<param id="owned_monitor_count_ptr">
1912
<outptr><jint/></outptr>
1913
<description>
1914
The number of monitors returned.
1915
</description>
1916
</param>
1917
<param id="owned_monitors_ptr">
1918
<allocbuf outcount="owned_monitor_count_ptr"><jobject/></allocbuf>
1919
<description>
1920
The array of owned monitors.
1921
</description>
1922
</param>
1923
</parameters>
1924
<errors>
1925
</errors>
1926
</function>
1927
1928
<function id="GetOwnedMonitorStackDepthInfo" num="153" since="1.1">
1929
<synopsis>Get Owned Monitor Stack Depth Info</synopsis>
1930
<typedef id="jvmtiMonitorStackDepthInfo"
1931
label="Monitor stack depth information structure">
1932
<field id="monitor">
1933
<jobject/>
1934
<description>
1935
The owned monitor.
1936
</description>
1937
</field>
1938
<field id="stack_depth">
1939
<jint/>
1940
<description>
1941
The stack depth. Corresponds to the stack depth used in the
1942
<internallink id="stack">Stack Frame functions</internallink>.
1943
That is, zero is the current frame, one is the frame which
1944
called the current frame. And it is negative one if the
1945
implementation cannot determine the stack depth (e.g., for
1946
monitors acquired by JNI <code>MonitorEnter</code>).
1947
</description>
1948
</field>
1949
</typedef>
1950
<description>
1951
Get information about the monitors owned by the
1952
specified thread and the depth of the stack frame which locked them.
1953
</description>
1954
<origin>new</origin>
1955
<capabilities>
1956
<required id="can_get_owned_monitor_stack_depth_info"></required>
1957
</capabilities>
1958
<parameters>
1959
<param id="thread">
1960
<jthread null="current"/>
1961
<description>
1962
The thread to query.
1963
</description>
1964
</param>
1965
<param id="monitor_info_count_ptr">
1966
<outptr><jint/></outptr>
1967
<description>
1968
The number of monitors returned.
1969
</description>
1970
</param>
1971
<param id="monitor_info_ptr">
1972
<allocbuf outcount="monitor_info_count_ptr">
1973
<struct>jvmtiMonitorStackDepthInfo</struct>
1974
</allocbuf>
1975
<description>
1976
The array of owned monitor depth information.
1977
</description>
1978
</param>
1979
</parameters>
1980
<errors>
1981
</errors>
1982
</function>
1983
1984
<function id="GetCurrentContendedMonitor" num="11">
1985
<synopsis>Get Current Contended Monitor</synopsis>
1986
<description>
1987
Get the object, if any, whose monitor the specified thread is waiting to
1988
enter or waiting to regain through <code>java.lang.Object.wait</code>.
1989
</description>
1990
<origin>jvmdi</origin>
1991
<capabilities>
1992
<required id="can_get_current_contended_monitor"></required>
1993
</capabilities>
1994
<parameters>
1995
<param id="thread">
1996
<jthread null="current"/>
1997
<description>
1998
The thread to query.
1999
</description>
2000
</param>
2001
<param id="monitor_ptr">
2002
<outptr><jobject/></outptr>
2003
<description>
2004
On return, filled with the current contended monitor, or
2005
NULL if there is none.
2006
</description>
2007
</param>
2008
</parameters>
2009
<errors>
2010
</errors>
2011
</function>
2012
2013
<callback id="jvmtiStartFunction">
2014
<void/>
2015
<synopsis>Agent Start Function</synopsis>
2016
<description>
2017
Agent supplied callback function.
2018
This function is the entry point for an agent thread
2019
started with
2020
<functionlink id="RunAgentThread"></functionlink>.
2021
</description>
2022
<parameters>
2023
<param id="jvmti_env">
2024
<outptr>
2025
<struct>jvmtiEnv</struct>
2026
</outptr>
2027
<description>
2028
The <jvmti/> environment.
2029
</description>
2030
</param>
2031
<param id="jni_env">
2032
<outptr>
2033
<struct>JNIEnv</struct>
2034
</outptr>
2035
<description>
2036
The JNI environment.
2037
</description>
2038
</param>
2039
<param id="arg">
2040
<outptr>
2041
<void/>
2042
</outptr>
2043
<description>
2044
The <code>arg</code> parameter passed to
2045
<functionlink id="RunAgentThread"></functionlink>.
2046
</description>
2047
</param>
2048
</parameters>
2049
</callback>
2050
2051
<function id="RunAgentThread" num="12">
2052
<synopsis>Run Agent Thread</synopsis>
2053
<description>
2054
Starts the execution of an agent thread. with the specified native function.
2055
The parameter <paramlink id="arg"></paramlink> is forwarded on to the
2056
<functionlink id="jvmtiStartFunction">start function</functionlink>
2057
(specified with <paramlink id="proc"></paramlink>) as its single argument.
2058
This function allows the creation of agent threads
2059
for handling communication with another process or for handling events
2060
without the need to load a special subclass of <code>java.lang.Thread</code> or
2061
implementer of <code>java.lang.Runnable</code>.
2062
Instead, the created thread can run entirely in native code.
2063
However, the created thread does require a newly created instance
2064
of <code>java.lang.Thread</code> (referenced by the argument <code>thread</code>) to
2065
which it will be associated.
2066
The thread object can be created with JNI calls.
2067
<p/>
2068
The following common thread priorities are provided for your convenience:
2069
<constants id="jvmtiThreadPriority" label="Thread Priority Constants" kind="const">
2070
<constant id="JVMTI_THREAD_MIN_PRIORITY" num="1">
2071
Minimum possible thread priority
2072
</constant>
2073
<constant id="JVMTI_THREAD_NORM_PRIORITY" num="5">
2074
Normal thread priority
2075
</constant>
2076
<constant id="JVMTI_THREAD_MAX_PRIORITY" num="10">
2077
Maximum possible thread priority
2078
</constant>
2079
</constants>
2080
<p/>
2081
The new thread is started as a daemon thread with the specified
2082
<paramlink id="priority"></paramlink>.
2083
If enabled, a <eventlink id="ThreadStart"/> event will be sent.
2084
<p/>
2085
Since the thread has been started, the thread will be live when this function
2086
returns, unless the thread has died immediately.
2087
<p/>
2088
The thread group of the thread is ignored -- specifically, the thread is not
2089
added to the thread group and the thread is not seen on queries of the thread
2090
group at either the Java programming language or <jvmti/> levels.
2091
<p/>
2092
The thread is not visible to Java programming language queries but is
2093
included in <jvmti/> queries (for example,
2094
<functionlink id="GetAllThreads"/> and
2095
<functionlink id="GetAllStackTraces"/>).
2096
<p/>
2097
Upon execution of <code>proc</code>, the new thread will be attached to the
2098
VM--see the JNI documentation on
2099
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/invocation.html#wp1060"
2100
>Attaching to the VM</externallink>.
2101
</description>
2102
<origin>jvmdiClone</origin>
2103
<capabilities>
2104
</capabilities>
2105
<parameters>
2106
<param id="thread">
2107
<jthread impl="noconvert" started="no"/>
2108
<description>
2109
The thread to run.
2110
</description>
2111
</param>
2112
<param id="proc">
2113
<ptrtype>
2114
<struct>jvmtiStartFunction</struct>
2115
</ptrtype>
2116
<description>
2117
The start function.
2118
</description>
2119
</param>
2120
<param id="arg">
2121
<inbuf>
2122
<void/>
2123
<nullok><code>NULL</code> is passed to the start function</nullok>
2124
</inbuf>
2125
<description>
2126
The argument to the start function.
2127
</description>
2128
</param>
2129
<param id="priority">
2130
<jint/>
2131
<description>
2132
The priority of the started thread. Any thread
2133
priority allowed by <code>java.lang.Thread.setPriority</code> can be used including
2134
those in <datalink id="jvmtiThreadPriority"></datalink>.
2135
</description>
2136
</param>
2137
</parameters>
2138
<errors>
2139
<error id="JVMTI_ERROR_INVALID_PRIORITY">
2140
<paramlink id="priority"/> is less than
2141
<datalink id="JVMTI_THREAD_MIN_PRIORITY"/>
2142
or greater than
2143
<datalink id="JVMTI_THREAD_MAX_PRIORITY"/>
2144
</error>
2145
</errors>
2146
</function>
2147
2148
<function id="SetThreadLocalStorage" jkernel="yes" impl="notrace" phase="start" num="103">
2149
<synopsis>Set Thread Local Storage</synopsis>
2150
<description>
2151
The VM stores a pointer value associated with each environment-thread
2152
pair. This pointer value is called <i>thread-local storage</i>.
2153
This value is <code>NULL</code> unless set with this function.
2154
Agents can allocate memory in which they store thread specific
2155
information. By setting thread-local storage it can then be
2156
accessed with
2157
<functionlink id="GetThreadLocalStorage"></functionlink>.
2158
<p/>
2159
This function is called by the agent to set the value of the <jvmti/>
2160
thread-local storage. <jvmti/> supplies to the agent a pointer-size
2161
thread-local storage that can be used to record per-thread
2162
information.
2163
</description>
2164
<origin>jvmpi</origin>
2165
<capabilities>
2166
</capabilities>
2167
<parameters>
2168
<param id="thread">
2169
<jthread null="current"/>
2170
<description>
2171
Store to this thread.
2172
</description>
2173
</param>
2174
<param id="data">
2175
<inbuf>
2176
<void/>
2177
<nullok>value is set to <code>NULL</code></nullok>
2178
</inbuf>
2179
<description>
2180
The value to be entered into the thread-local storage.
2181
</description>
2182
</param>
2183
</parameters>
2184
<errors>
2185
</errors>
2186
</function>
2187
2188
<function id="GetThreadLocalStorage" jkernel="yes" impl="innative notrace" phase="start" num="102">
2189
<synopsis>Get Thread Local Storage</synopsis>
2190
<description>
2191
Called by the agent to get the value of the <jvmti/> thread-local
2192
storage.
2193
</description>
2194
<origin>jvmpi</origin>
2195
<capabilities>
2196
</capabilities>
2197
<parameters>
2198
<param id="thread">
2199
<jthread null="current" impl="noconvert"/>
2200
<description>
2201
Retrieve from this thread.
2202
</description>
2203
</param>
2204
<param id="data_ptr">
2205
<agentbuf><void/></agentbuf>
2206
<description>
2207
Pointer through which the value of the thread local
2208
storage is returned.
2209
If thread-local storage has not been set with
2210
<functionlink id="SetThreadLocalStorage"></functionlink> the returned
2211
pointer is <code>NULL</code>.
2212
</description>
2213
</param>
2214
</parameters>
2215
<errors>
2216
</errors>
2217
</function>
2218
2219
</category>
2220
2221
<category id="thread_groups" label="Thread Group">
2222
<intro>
2223
</intro>
2224
2225
<function id="GetTopThreadGroups" num="13">
2226
<synopsis>Get Top Thread Groups</synopsis>
2227
<description>
2228
Return all top-level (parentless) thread groups in the VM.
2229
</description>
2230
<origin>jvmdi</origin>
2231
<capabilities>
2232
</capabilities>
2233
<parameters>
2234
<param id="group_count_ptr">
2235
<outptr><jint/></outptr>
2236
<description>
2237
On return, points to the number of top-level thread groups.
2238
</description>
2239
</param>
2240
<param id="groups_ptr">
2241
<allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2242
<description>
2243
On return, refers to a pointer to the top-level thread group array.
2244
</description>
2245
</param>
2246
</parameters>
2247
<errors>
2248
</errors>
2249
</function>
2250
2251
<function id="GetThreadGroupInfo" num="14">
2252
<synopsis>Get Thread Group Info</synopsis>
2253
<typedef id="jvmtiThreadGroupInfo" label="Thread group information structure">
2254
<field id="parent">
2255
<jthreadGroup/>
2256
<description>
2257
The parent thread group.
2258
</description>
2259
</field>
2260
<field id="name">
2261
<allocfieldbuf><char/></allocfieldbuf>
2262
<description>
2263
The thread group's name, encoded as a
2264
<internallink id="mUTF">modified UTF-8</internallink> string.
2265
</description>
2266
</field>
2267
<field id="max_priority">
2268
<jint/>
2269
<description>
2270
The maximum priority for this thread group.
2271
</description>
2272
</field>
2273
<field id="is_daemon">
2274
<jboolean/>
2275
<description>
2276
Is this a daemon thread group?
2277
</description>
2278
</field>
2279
</typedef>
2280
<description>
2281
Get information about the thread group. The fields of the
2282
<functionlink id="jvmtiThreadGroupInfo"></functionlink> structure
2283
are filled in with details of the specified thread group.
2284
</description>
2285
<origin>jvmdi</origin>
2286
<capabilities>
2287
</capabilities>
2288
<parameters>
2289
<param id="group">
2290
<jthreadGroup/>
2291
<description>
2292
The thread group to query.
2293
</description>
2294
</param>
2295
<param id="info_ptr">
2296
<outptr><struct>jvmtiThreadGroupInfo</struct></outptr>
2297
<description>
2298
On return, filled with information describing the specified
2299
thread group.
2300
</description>
2301
</param>
2302
</parameters>
2303
<errors>
2304
</errors>
2305
</function>
2306
2307
<function id="GetThreadGroupChildren" num="15">
2308
<synopsis>Get Thread Group Children</synopsis>
2309
<description>
2310
Get the live threads and active subgroups in this thread group.
2311
</description>
2312
<origin>jvmdi</origin>
2313
<capabilities>
2314
</capabilities>
2315
<parameters>
2316
<param id="group">
2317
<jthreadGroup/>
2318
<description>
2319
The group to query.
2320
</description>
2321
</param>
2322
<param id="thread_count_ptr">
2323
<outptr><jint/></outptr>
2324
<description>
2325
On return, points to the number of live threads in this thread group.
2326
</description>
2327
</param>
2328
<param id="threads_ptr">
2329
<allocbuf outcount="thread_count_ptr"><jthread/></allocbuf>
2330
<description>
2331
On return, points to an array of the live threads in this thread group.
2332
</description>
2333
</param>
2334
<param id="group_count_ptr">
2335
<outptr><jint/></outptr>
2336
<description>
2337
On return, points to the number of active child thread groups
2338
</description>
2339
</param>
2340
<param id="groups_ptr">
2341
<allocbuf outcount="group_count_ptr"><jthreadGroup/></allocbuf>
2342
<description>
2343
On return, points to an array of the active child thread groups.
2344
</description>
2345
</param>
2346
</parameters>
2347
<errors>
2348
</errors>
2349
</function>
2350
</category>
2351
2352
<category id="stack" label="Stack Frame">
2353
<intro>
2354
These functions provide information about the stack of a thread.
2355
Stack frames are referenced by depth.
2356
The frame at depth zero is the current frame.
2357
<p/>
2358
Stack frames are as described in
2359
<vmspec chapter="3.6"/>,
2360
That is, they correspond to method
2361
invocations (including native methods) but do not correspond to platform native or
2362
VM internal frames.
2363
<p/>
2364
A <jvmti/> implementation may use method invocations to launch a thread and
2365
the corresponding frames may be included in the stack as presented by these functions --
2366
that is, there may be frames shown
2367
deeper than <code>main()</code> and <code>run()</code>.
2368
However this presentation must be consistent across all <jvmti/> functionality which
2369
uses stack frames or stack depth.
2370
</intro>
2371
2372
<typedef id="jvmtiFrameInfo" label="Stack frame information structure">
2373
<description>
2374
Information about a stack frame is returned in this structure.
2375
</description>
2376
<field id="method">
2377
<jmethodID/>
2378
<description>
2379
The method executing in this frame.
2380
</description>
2381
</field>
2382
<field id="location">
2383
<jlocation/>
2384
<description>
2385
The index of the instruction executing in this frame.
2386
<code>-1</code> if the frame is executing a native method.
2387
</description>
2388
</field>
2389
</typedef>
2390
2391
<typedef id="jvmtiStackInfo" label="Stack information structure">
2392
<description>
2393
Information about a set of stack frames is returned in this structure.
2394
</description>
2395
<field id="thread">
2396
<jthread/>
2397
<description>
2398
On return, the thread traced.
2399
</description>
2400
</field>
2401
<field id="state">
2402
<jint/>
2403
<description>
2404
On return, the thread state. See <functionlink id="GetThreadState"></functionlink>.
2405
</description>
2406
</field>
2407
<field id="frame_buffer">
2408
<outbuf incount="max_frame_count">
2409
<struct>jvmtiFrameInfo</struct>
2410
</outbuf>
2411
<description>
2412
On return, this agent allocated buffer is filled
2413
with stack frame information.
2414
</description>
2415
</field>
2416
<field id="frame_count">
2417
<jint/>
2418
<description>
2419
On return, the number of records filled into
2420
<code>frame_buffer</code>.
2421
This will be
2422
min(<code>max_frame_count</code>, <i>stackDepth</i>).
2423
</description>
2424
</field>
2425
</typedef>
2426
2427
<function id="GetStackTrace" num="104">
2428
<synopsis>Get Stack Trace</synopsis>
2429
<description>
2430
Get information about the stack of a thread.
2431
If <paramlink id="max_frame_count"></paramlink> is less than the depth of the stack,
2432
the <paramlink id="max_frame_count"></paramlink> topmost frames are returned,
2433
otherwise the entire stack is returned.
2434
The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2435
<p/>
2436
The following example causes up to five of the topmost frames
2437
to be returned and (if there are any frames) the currently
2438
executing method name to be printed.
2439
<example>
2440
jvmtiFrameInfo frames[5];
2441
jint count;
2442
jvmtiError err;
2443
2444
err = (*jvmti)-&gt;GetStackTrace(jvmti, aThread, 0, 5,
2445
frames, &amp;count);
2446
if (err == JVMTI_ERROR_NONE &amp;&amp; count &gt;= 1) {
2447
char *methodName;
2448
err = (*jvmti)-&gt;GetMethodName(jvmti, frames[0].method,
2449
&amp;methodName, NULL, NULL);
2450
if (err == JVMTI_ERROR_NONE) {
2451
printf("Executing method: %s", methodName);
2452
}
2453
}
2454
</example>
2455
<todo>
2456
check example code.
2457
</todo>
2458
<p/>
2459
The <paramlink id="thread"></paramlink> need not be suspended
2460
to call this function.
2461
<p/>
2462
The <functionlink id="GetLineNumberTable"></functionlink>
2463
function can be used to map locations to line numbers. Note that
2464
this mapping can be done lazily.
2465
</description>
2466
<origin>jvmpi</origin>
2467
<capabilities>
2468
</capabilities>
2469
<parameters>
2470
<param id="thread">
2471
<jthread null="current"/>
2472
<description>
2473
Fetch the stack trace of this thread.
2474
</description>
2475
</param>
2476
<param id="start_depth">
2477
<jint/>
2478
<description>
2479
Begin retrieving frames at this depth.
2480
If non-negative, count from the current frame,
2481
the first frame retrieved is at depth <code>start_depth</code>.
2482
For example, if zero, start from the current frame; if one, start from the
2483
caller of the current frame; if two, start from the caller of the
2484
caller of the current frame; and so on.
2485
If negative, count from below the oldest frame,
2486
the first frame retrieved is at depth <i>stackDepth</i><code> + start_depth</code>,
2487
where <i>stackDepth</i> is the count of frames on the stack.
2488
For example, if negative one, only the oldest frame is retrieved;
2489
if negative two, start from the frame called by the oldest frame.
2490
</description>
2491
</param>
2492
<param id="max_frame_count">
2493
<jint min="0"/>
2494
<description>
2495
The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2496
</description>
2497
</param>
2498
<param id="frame_buffer">
2499
<outbuf incount="max_frame_count" outcount="count_ptr">
2500
<struct>jvmtiFrameInfo</struct>
2501
</outbuf>
2502
<description>
2503
On return, this agent allocated buffer is filled
2504
with stack frame information.
2505
</description>
2506
</param>
2507
<param id="count_ptr">
2508
<outptr><jint/></outptr>
2509
<description>
2510
On return, points to the number of records filled in.
2511
For non-negative <code>start_depth</code>, this will be
2512
min(<code>max_frame_count</code>, <i>stackDepth</i><code> - start_depth</code>).
2513
For negative <code>start_depth</code>, this will be
2514
min(<code>max_frame_count</code>, <code>-start_depth</code>).
2515
</description>
2516
</param>
2517
</parameters>
2518
<errors>
2519
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
2520
<paramlink id="start_depth"/> is positive and greater than or equal to <i>stackDepth</i>.
2521
Or <paramlink id="start_depth"/> is negative and less than <i>-stackDepth</i>.
2522
</error>
2523
</errors>
2524
</function>
2525
2526
2527
<function id="GetAllStackTraces" num="100">
2528
<synopsis>Get All Stack Traces</synopsis>
2529
<description>
2530
Get information about the stacks of all live threads
2531
(including <internallink id="RunAgentThread">agent threads</internallink>).
2532
If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2533
the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2534
otherwise the entire stack is returned.
2535
The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2536
<p/>
2537
All stacks are collected simultaneously, that is, no changes will occur to the
2538
thread state or stacks between the sampling of one thread and the next.
2539
The threads need not be suspended.
2540
2541
<example>
2542
jvmtiStackInfo *stack_info;
2543
jint thread_count;
2544
int ti;
2545
jvmtiError err;
2546
2547
err = (*jvmti)-&gt;GetAllStackTraces(jvmti, MAX_FRAMES, &amp;stack_info, &amp;thread_count);
2548
if (err != JVMTI_ERROR_NONE) {
2549
...
2550
}
2551
for (ti = 0; ti &lt; thread_count; ++ti) {
2552
jvmtiStackInfo *infop = &amp;stack_info[ti];
2553
jthread thread = infop-&gt;thread;
2554
jint state = infop-&gt;state;
2555
jvmtiFrameInfo *frames = infop-&gt;frame_buffer;
2556
int fi;
2557
2558
myThreadAndStatePrinter(thread, state);
2559
for (fi = 0; fi &lt; infop-&gt;frame_count; fi++) {
2560
myFramePrinter(frames[fi].method, frames[fi].location);
2561
}
2562
}
2563
/* this one Deallocate call frees all data allocated by GetAllStackTraces */
2564
err = (*jvmti)-&gt;Deallocate(jvmti, stack_info);
2565
</example>
2566
<todo>
2567
check example code.
2568
</todo>
2569
2570
</description>
2571
<origin>new</origin>
2572
<capabilities>
2573
</capabilities>
2574
<parameters>
2575
<param id="max_frame_count">
2576
<jint min="0"/>
2577
<description>
2578
The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2579
</description>
2580
</param>
2581
<param id="stack_info_ptr">
2582
<allocbuf>
2583
<struct>jvmtiStackInfo</struct>
2584
</allocbuf>
2585
<description>
2586
On return, this buffer is filled
2587
with stack information for each thread.
2588
The number of <datalink id="jvmtiStackInfo"/> records is determined
2589
by <paramlink id="thread_count_ptr"/>.
2590
<p/>
2591
Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2592
buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2593
These buffers must not be separately deallocated.
2594
</description>
2595
</param>
2596
<param id="thread_count_ptr">
2597
<outptr><jint/></outptr>
2598
<description>
2599
The number of threads traced.
2600
</description>
2601
</param>
2602
</parameters>
2603
<errors>
2604
</errors>
2605
</function>
2606
2607
<function id="GetThreadListStackTraces" num="101">
2608
<synopsis>Get Thread List Stack Traces</synopsis>
2609
<description>
2610
Get information about the stacks of the supplied threads.
2611
If <paramlink id="max_frame_count"/> is less than the depth of a stack,
2612
the <paramlink id="max_frame_count"/> topmost frames are returned for that thread,
2613
otherwise the entire stack is returned.
2614
The topmost frames, those most recently invoked, are at the beginning of the returned buffer.
2615
<p/>
2616
All stacks are collected simultaneously, that is, no changes will occur to the
2617
thread state or stacks between the sampling one thread and the next.
2618
The threads need not be suspended.
2619
<p/>
2620
If a thread has not yet started or terminates before the stack information is collected,
2621
a zero length stack (<datalink id="jvmtiStackInfo.frame_count"/> will be zero)
2622
will be returned and the thread <datalink id="jvmtiStackInfo.state"/> can be checked.
2623
<p/>
2624
See the example for the similar function
2625
<functionlink id="GetAllStackTraces"/>.
2626
</description>
2627
<origin>new</origin>
2628
<capabilities>
2629
</capabilities>
2630
<parameters>
2631
<param id="thread_count">
2632
<jint min="0"/>
2633
<description>
2634
The number of threads to trace.
2635
</description>
2636
</param>
2637
<param id="thread_list">
2638
<inbuf incount="thread_count"><jthread/></inbuf>
2639
<description>
2640
The list of threads to trace.
2641
</description>
2642
</param>
2643
<param id="max_frame_count">
2644
<jint min="0"/>
2645
<description>
2646
The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve per thread.
2647
</description>
2648
</param>
2649
<param id="stack_info_ptr">
2650
<allocbuf outcount="thread_count">
2651
<struct>jvmtiStackInfo</struct>
2652
</allocbuf>
2653
<description>
2654
On return, this buffer is filled
2655
with stack information for each thread.
2656
The number of <datalink id="jvmtiStackInfo"/> records is determined
2657
by <paramlink id="thread_count"/>.
2658
<p/>
2659
Note that this buffer is allocated to include the <datalink id="jvmtiFrameInfo"/>
2660
buffers pointed to by <datalink id="jvmtiStackInfo.frame_buffer"/>.
2661
These buffers must not be separately deallocated.
2662
</description>
2663
</param>
2664
</parameters>
2665
<errors>
2666
<error id="JVMTI_ERROR_INVALID_THREAD">
2667
An element in <paramlink id="thread_list"/> is not a thread object.
2668
</error>
2669
</errors>
2670
</function>
2671
2672
<elide>
2673
<function id="AsyncGetStackTrace" num="1000">
2674
<synopsis>Get Stack Trace--Asynchronous</synopsis>
2675
<description>
2676
Get information about the entire stack of a thread (or a sub-section of it).
2677
This is the asynchronous version of <functionlink id="GetStackTrace"></functionlink>
2678
and is reentrant and safe to call
2679
from asynchronous signal handlers.
2680
The stack trace is returned only for the calling thread.
2681
<p/>
2682
The <functionlink id="GetLineNumberTable"></functionlink>
2683
function can be used to map locations to line numbers. Note that
2684
this mapping can be done lazily.
2685
</description>
2686
<origin>jvmpi</origin>
2687
<capabilities>
2688
<required id="can_get_async_stack_trace"></required>
2689
<capability id="can_show_JVM_spec_async_frames">
2690
If <code>false</code>,
2691
<paramlink id="use_java_stack"></paramlink>
2692
must be <code>false</code>.
2693
</capability>
2694
</capabilities>
2695
<parameters>
2696
<param id="use_java_stack">
2697
<jboolean/>
2698
<description>
2699
Return the stack showing <vmspec/>
2700
model of the stack;
2701
otherwise, show the internal representation of the stack with
2702
inlined and optimized methods missing. If the virtual machine
2703
is using the <i>Java Virtual Machine Specification</i> stack model
2704
internally, this flag is ignored.
2705
</description>
2706
</param>
2707
<param id="max_count">
2708
<jint min="0"/>
2709
<description>
2710
The maximum number of <datalink id="jvmtiFrameInfo"/> records to retrieve.
2711
Retrieve this many unless the stack depth is less than <code>max_count</code>.
2712
</description>
2713
</param>
2714
<param id="frame_buffer">
2715
<outbuf incount="max_count" outcount="count_ptr">
2716
<struct>jvmtiFrameInfo</struct>
2717
<nullok>this information is not returned</nullok>
2718
</outbuf>
2719
<description>
2720
The agent passes in a buffer
2721
large enough to hold <code>max_count</code> records of
2722
<datalink id="jvmtiFrameInfo"></datalink>. This buffer must be
2723
pre-allocated by the agent.
2724
</description>
2725
</param>
2726
<param id="count_ptr">
2727
<outptr><jint/></outptr>
2728
<description>
2729
On return, points to the number of records filled in..
2730
</description>
2731
</param>
2732
</parameters>
2733
<errors>
2734
<error id="JVMTI_ERROR_UNATTACHED_THREAD">
2735
The thread being used to call this function is not attached
2736
to the virtual machine. Calls must be made from attached threads.
2737
</error>
2738
</errors>
2739
</function>
2740
</elide>
2741
2742
<function id="GetFrameCount" num="16">
2743
<synopsis>Get Frame Count</synopsis>
2744
<description>
2745
Get the number of frames currently in the specified thread's call stack.
2746
<p/>
2747
If this function is called for a thread actively executing bytecodes (for example,
2748
not the current thread and not suspended), the information returned is transient.
2749
</description>
2750
<origin>jvmdi</origin>
2751
<capabilities>
2752
</capabilities>
2753
<parameters>
2754
<param id="thread">
2755
<jthread null="current"/>
2756
<description>
2757
The thread to query.
2758
</description>
2759
</param>
2760
<param id="count_ptr">
2761
<outptr><jint/></outptr>
2762
<description>
2763
On return, points to the number of frames in the call stack.
2764
</description>
2765
</param>
2766
</parameters>
2767
<errors>
2768
</errors>
2769
</function>
2770
2771
<function id="PopFrame" num="80">
2772
<synopsis>Pop Frame</synopsis>
2773
<description>
2774
Pop the current frame of <code>thread</code>'s stack.
2775
Popping a frame takes you to the previous frame.
2776
When the thread is resumed, the execution
2777
state of the thread is reset to the state
2778
immediately before the called method was invoked.
2779
That is (using <vmspec/> terminology):
2780
<ul>
2781
<li>the current frame is discarded as the previous frame becomes the current one</li>
2782
<li>the operand stack is restored--the argument values are added back
2783
and if the invoke was not <code>invokestatic</code>,
2784
<code>objectref</code> is added back as well</li>
2785
<li>the Java virtual machine PC is restored to the opcode
2786
of the invoke instruction</li>
2787
</ul>
2788
Note however, that any changes to the arguments, which
2789
occurred in the called method, remain;
2790
when execution continues, the first instruction to
2791
execute will be the invoke.
2792
<p/>
2793
Between calling <code>PopFrame</code> and resuming the
2794
thread the state of the stack is undefined.
2795
To pop frames beyond the first,
2796
these three steps must be repeated:
2797
<ul>
2798
<li>suspend the thread via an event (step, breakpoint, ...)</li>
2799
<li>call <code>PopFrame</code></li>
2800
<li>resume the thread</li>
2801
</ul>
2802
<p/>
2803
A lock acquired by calling the called method
2804
(if it is a <code>synchronized</code> method)
2805
and locks acquired by entering <code>synchronized</code>
2806
blocks within the called method are released.
2807
Note: this does not apply to native locks or
2808
<code>java.util.concurrent.locks</code> locks.
2809
<p/>
2810
Finally blocks are not executed.
2811
<p/>
2812
Changes to global state are not addressed and thus remain changed.
2813
<p/>
2814
The specified thread must be suspended (which implies it cannot be the current thread).
2815
<p/>
2816
Both the called method and calling method must be non-native Java programming
2817
language methods.
2818
<p/>
2819
No <jvmti/> events are generated by this function.
2820
</description>
2821
<origin>jvmdi</origin>
2822
<capabilities>
2823
<required id="can_pop_frame"></required>
2824
</capabilities>
2825
<parameters>
2826
<param id="thread">
2827
<jthread/>
2828
<description>
2829
The thread whose current frame is to be popped.
2830
</description>
2831
</param>
2832
</parameters>
2833
<errors>
2834
<error id="JVMTI_ERROR_OPAQUE_FRAME">
2835
Called or calling method is a native method.
2836
The implementation is unable to pop this frame.
2837
</error>
2838
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2839
Thread was not suspended.
2840
</error>
2841
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
2842
There are less than two stack frames on the call stack.
2843
</error>
2844
</errors>
2845
</function>
2846
2847
<function id="GetFrameLocation" num="19">
2848
<synopsis>Get Frame Location</synopsis>
2849
<description>
2850
<p/>
2851
For a Java programming language frame, return the location of the instruction
2852
currently executing.
2853
</description>
2854
<origin>jvmdiClone</origin>
2855
<capabilities>
2856
</capabilities>
2857
<parameters>
2858
<param id="thread">
2859
<jthread null="current" frame="frame"/>
2860
<description>
2861
The thread of the frame to query.
2862
</description>
2863
</param>
2864
<param id="depth">
2865
<jframeID thread="thread"/>
2866
<description>
2867
The depth of the frame to query.
2868
</description>
2869
</param>
2870
<param id="method_ptr">
2871
<outptr><jmethodID/></outptr>
2872
<description>
2873
On return, points to the method for the current location.
2874
</description>
2875
</param>
2876
<param id="location_ptr">
2877
<outptr><jlocation/></outptr>
2878
<description>
2879
On return, points to the index of the currently
2880
executing instruction.
2881
Is set to <code>-1</code> if the frame is executing
2882
a native method.
2883
</description>
2884
</param>
2885
</parameters>
2886
<errors>
2887
</errors>
2888
</function>
2889
2890
<function id="NotifyFramePop" num="20">
2891
<synopsis>Notify Frame Pop</synopsis>
2892
<description>
2893
When the frame that is currently at <paramlink id="depth"></paramlink>
2894
is popped from the stack, generate a
2895
<eventlink id="FramePop"></eventlink> event. See the
2896
<eventlink id="FramePop"></eventlink> event for details.
2897
Only frames corresponding to non-native Java programming language
2898
methods can receive notification.
2899
<p/>
2900
The specified thread must either be the current thread
2901
or the thread must be suspended.
2902
</description>
2903
<origin>jvmdi</origin>
2904
<capabilities>
2905
<required id="can_generate_frame_pop_events"></required>
2906
</capabilities>
2907
<parameters>
2908
<param id="thread">
2909
<jthread null="current" frame="depth"/>
2910
<description>
2911
The thread of the frame for which the frame pop event will be generated.
2912
</description>
2913
</param>
2914
<param id="depth">
2915
<jframeID thread="thread"/>
2916
<description>
2917
The depth of the frame for which the frame pop event will be generated.
2918
</description>
2919
</param>
2920
</parameters>
2921
<errors>
2922
<error id="JVMTI_ERROR_OPAQUE_FRAME">
2923
The frame at <code>depth</code> is executing a
2924
native method.
2925
</error>
2926
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
2927
Thread was not suspended and was not the current thread.
2928
</error>
2929
</errors>
2930
</function>
2931
2932
</category>
2933
2934
<category id="ForceEarlyReturn" label="Force Early Return">
2935
<intro>
2936
These functions allow an agent to force a method
2937
to return at any point during its execution.
2938
The method which will return early is referred to as the <i>called method</i>.
2939
The called method is the current method
2940
(as defined by
2941
<vmspec chapter="3.6"/>)
2942
for the specified thread at
2943
the time the function is called.
2944
<p/>
2945
The specified thread must be suspended or must be the current thread.
2946
The return occurs when execution of Java programming
2947
language code is resumed on this thread.
2948
Between calling one of these functions and resumption
2949
of thread execution, the state of the stack is undefined.
2950
<p/>
2951
No further instructions are executed in the called method.
2952
Specifically, finally blocks are not executed.
2953
Note: this can cause inconsistent states in the application.
2954
<p/>
2955
A lock acquired by calling the called method
2956
(if it is a <code>synchronized</code> method)
2957
and locks acquired by entering <code>synchronized</code>
2958
blocks within the called method are released.
2959
Note: this does not apply to native locks or
2960
<code>java.util.concurrent.locks</code> locks.
2961
<p/>
2962
Events, such as <eventlink id="MethodExit"></eventlink>,
2963
are generated as they would be in a normal return.
2964
<p/>
2965
The called method must be a non-native Java programming
2966
language method.
2967
Forcing return on a thread with only one frame on the
2968
stack causes the thread to exit when resumed.
2969
</intro>
2970
2971
<function id="ForceEarlyReturnObject" num="81" since="1.1">
2972
<synopsis>Force Early Return - Object</synopsis>
2973
<description>
2974
This function can be used to return from a method whose
2975
result type is <code>Object</code>
2976
or a subclass of <code>Object</code>.
2977
</description>
2978
<origin>new</origin>
2979
<capabilities>
2980
<required id="can_force_early_return"></required>
2981
</capabilities>
2982
<parameters>
2983
<param id="thread">
2984
<jthread null="current"/>
2985
<description>
2986
The thread whose current frame is to return early.
2987
</description>
2988
</param>
2989
<param id="value">
2990
<jobject/>
2991
<description>
2992
The return value for the called frame.
2993
An object or <code>NULL</code>.
2994
</description>
2995
</param>
2996
</parameters>
2997
<errors>
2998
<error id="JVMTI_ERROR_OPAQUE_FRAME">
2999
Attempted to return early from a frame
3000
corresponding to a native method.
3001
Or the implementation is unable to provide
3002
this functionality on this frame.
3003
</error>
3004
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3005
The result type of the called method is not
3006
<code>Object</code> or a subclass of <code>Object</code>.
3007
</error>
3008
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3009
The supplied <paramlink id="value"/> is not compatible with the
3010
result type of the called method.
3011
</error>
3012
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3013
Thread was not the current thread and was not suspended.
3014
</error>
3015
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
3016
There are no more frames on the call stack.
3017
</error>
3018
</errors>
3019
</function>
3020
3021
<function id="ForceEarlyReturnInt" num="82" since="1.1">
3022
<synopsis>Force Early Return - Int</synopsis>
3023
<description>
3024
This function can be used to return from a method whose
3025
result type is <code>int</code>, <code>short</code>,
3026
<code>char</code>, <code>byte</code>, or
3027
<code>boolean</code>.
3028
</description>
3029
<origin>new</origin>
3030
<capabilities>
3031
<required id="can_force_early_return"></required>
3032
</capabilities>
3033
<parameters>
3034
<param id="thread">
3035
<jthread null="current"/>
3036
<description>
3037
The thread whose current frame is to return early.
3038
</description>
3039
</param>
3040
<param id="value">
3041
<jint/>
3042
<description>
3043
The return value for the called frame.
3044
</description>
3045
</param>
3046
</parameters>
3047
<errors>
3048
<error id="JVMTI_ERROR_OPAQUE_FRAME">
3049
Attempted to return early from a frame
3050
corresponding to a native method.
3051
Or the implementation is unable to provide
3052
this functionality on this frame.
3053
</error>
3054
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3055
The result type of the called method is not
3056
<code>int</code>, <code>short</code>,
3057
<code>char</code>, <code>byte</code>, or
3058
<code>boolean</code>.
3059
</error>
3060
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3061
Thread was not the current thread and was not suspended.
3062
</error>
3063
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
3064
There are no frames on the call stack.
3065
</error>
3066
</errors>
3067
</function>
3068
3069
<function id="ForceEarlyReturnLong" num="83" since="1.1">
3070
<synopsis>Force Early Return - Long</synopsis>
3071
<description>
3072
This function can be used to return from a method whose
3073
result type is <code>long</code>.
3074
</description>
3075
<origin>new</origin>
3076
<capabilities>
3077
<required id="can_force_early_return"></required>
3078
</capabilities>
3079
<parameters>
3080
<param id="thread">
3081
<jthread null="current"/>
3082
<description>
3083
The thread whose current frame is to return early.
3084
</description>
3085
</param>
3086
<param id="value">
3087
<jlong/>
3088
<description>
3089
The return value for the called frame.
3090
</description>
3091
</param>
3092
</parameters>
3093
<errors>
3094
<error id="JVMTI_ERROR_OPAQUE_FRAME">
3095
Attempted to return early from a frame
3096
corresponding to a native method.
3097
Or the implementation is unable to provide
3098
this functionality on this frame.
3099
</error>
3100
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3101
The result type of the called method is not <code>long</code>.
3102
</error>
3103
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3104
Thread was not the current thread and was not suspended.
3105
</error>
3106
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
3107
There are no frames on the call stack.
3108
</error>
3109
</errors>
3110
</function>
3111
3112
<function id="ForceEarlyReturnFloat" num="84" since="1.1">
3113
<synopsis>Force Early Return - Float</synopsis>
3114
<description>
3115
This function can be used to return from a method whose
3116
result type is <code>float</code>.
3117
</description>
3118
<origin>new</origin>
3119
<capabilities>
3120
<required id="can_force_early_return"></required>
3121
</capabilities>
3122
<parameters>
3123
<param id="thread">
3124
<jthread null="current"/>
3125
<description>
3126
The thread whose current frame is to return early.
3127
</description>
3128
</param>
3129
<param id="value">
3130
<jfloat/>
3131
<description>
3132
The return value for the called frame.
3133
</description>
3134
</param>
3135
</parameters>
3136
<errors>
3137
<error id="JVMTI_ERROR_OPAQUE_FRAME">
3138
Attempted to return early from a frame
3139
corresponding to a native method.
3140
Or the implementation is unable to provide
3141
this functionality on this frame.
3142
</error>
3143
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3144
The result type of the called method is not <code>float</code>.
3145
</error>
3146
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3147
Thread was not the current thread and was not suspended.
3148
</error>
3149
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
3150
There are no frames on the call stack.
3151
</error>
3152
</errors>
3153
</function>
3154
3155
<function id="ForceEarlyReturnDouble" num="85" since="1.1">
3156
<synopsis>Force Early Return - Double</synopsis>
3157
<description>
3158
This function can be used to return from a method whose
3159
result type is <code>double</code>.
3160
</description>
3161
<origin>new</origin>
3162
<capabilities>
3163
<required id="can_force_early_return"></required>
3164
</capabilities>
3165
<parameters>
3166
<param id="thread">
3167
<jthread null="current"/>
3168
<description>
3169
The thread whose current frame is to return early.
3170
</description>
3171
</param>
3172
<param id="value">
3173
<jdouble/>
3174
<description>
3175
The return value for the called frame.
3176
</description>
3177
</param>
3178
</parameters>
3179
<errors>
3180
<error id="JVMTI_ERROR_OPAQUE_FRAME">
3181
Attempted to return early from a frame corresponding to a native method.
3182
Or the implementation is unable to provide this functionality on this frame.
3183
</error>
3184
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3185
The result type of the called method is not <code>double</code>.
3186
</error>
3187
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3188
Thread was not the current thread and was not suspended.
3189
</error>
3190
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
3191
There are no frames on the call stack.
3192
</error>
3193
</errors>
3194
</function>
3195
3196
<function id="ForceEarlyReturnVoid" num="86" since="1.1">
3197
<synopsis>Force Early Return - Void</synopsis>
3198
<description>
3199
This function can be used to return from a method with no result type.
3200
That is, the called method must be declared <code>void</code>.
3201
</description>
3202
<origin>new</origin>
3203
<capabilities>
3204
<required id="can_force_early_return"></required>
3205
</capabilities>
3206
<parameters>
3207
<param id="thread">
3208
<jthread null="current"/>
3209
<description>
3210
The thread whose current frame is to return early.
3211
</description>
3212
</param>
3213
</parameters>
3214
<errors>
3215
<error id="JVMTI_ERROR_OPAQUE_FRAME">
3216
Attempted to return early from a frame
3217
corresponding to a native method.
3218
Or the implementation is unable to provide
3219
this functionality on this frame.
3220
</error>
3221
<error id="JVMTI_ERROR_TYPE_MISMATCH">
3222
The called method has a result type.
3223
</error>
3224
<error id="JVMTI_ERROR_THREAD_NOT_SUSPENDED">
3225
Thread was not the current thread and was not suspended.
3226
</error>
3227
<error id="JVMTI_ERROR_NO_MORE_FRAMES">
3228
There are no frames on the call stack.
3229
</error>
3230
</errors>
3231
</function>
3232
3233
</category>
3234
3235
<category id="Heap" label="Heap">
3236
<intro>
3237
These functions are used to analyze the heap.
3238
Functionality includes the ability to view the objects in the
3239
heap and to tag these objects.
3240
</intro>
3241
3242
<intro id="objectTags" label="Object Tags">
3243
A <i>tag</i> is a value associated with an object.
3244
Tags are explicitly set by the agent using the
3245
<functionlink id="SetTag"></functionlink> function or by
3246
callback functions such as <functionlink id="jvmtiHeapIterationCallback"/>.
3247
<p/>
3248
Tags are local to the environment; that is, the tags of one
3249
environment are not visible in another.
3250
<p/>
3251
Tags are <code>jlong</code> values which can be used
3252
simply to mark an object or to store a pointer to more detailed
3253
information. Objects which have not been tagged have a
3254
tag of zero.
3255
Setting a tag to zero makes the object untagged.
3256
</intro>
3257
3258
<intro id="heapCallbacks" label="Heap Callback Functions">
3259
Heap functions which iterate through the heap and recursively
3260
follow object references use agent supplied callback functions
3261
to deliver the information.
3262
<p/>
3263
These heap callback functions must adhere to the following restrictions --
3264
These callbacks must not use JNI functions.
3265
These callbacks must not use <jvmti/> functions except
3266
<i>callback safe</i> functions which
3267
specifically allow such use (see the raw monitor, memory management,
3268
and environment local storage functions).
3269
<p/>
3270
An implementation may invoke a callback on an internal thread or
3271
the thread which called the iteration function.
3272
Heap callbacks are single threaded -- no more than one callback will
3273
be invoked at a time.
3274
<p/>
3275
The Heap Filter Flags can be used to prevent reporting
3276
based on the tag status of an object or its class.
3277
If no flags are set (the <code>jint</code> is zero), objects
3278
will not be filtered out.
3279
3280
<constants id="jvmtiHeapFilter" label="Heap Filter Flags" kind="bits">
3281
<constant id="JVMTI_HEAP_FILTER_TAGGED" num="0x4">
3282
Filter out tagged objects. Objects which are tagged are not included.
3283
</constant>
3284
<constant id="JVMTI_HEAP_FILTER_UNTAGGED" num="0x8">
3285
Filter out untagged objects. Objects which are not tagged are not included.
3286
</constant>
3287
<constant id="JVMTI_HEAP_FILTER_CLASS_TAGGED" num="0x10">
3288
Filter out objects with tagged classes. Objects whose class is tagged are not included.
3289
</constant>
3290
<constant id="JVMTI_HEAP_FILTER_CLASS_UNTAGGED" num="0x20">
3291
Filter out objects with untagged classes. Objects whose class is not tagged are not included.
3292
</constant>
3293
</constants>
3294
3295
<p/>
3296
The Heap Visit Control Flags are returned by the heap callbacks
3297
and can be used to abort the iteration. For the
3298
<functionlink id="jvmtiHeapReferenceCallback">Heap
3299
Reference Callback</functionlink>, it can also be used
3300
to prune the graph of traversed references
3301
(<code>JVMTI_VISIT_OBJECTS</code> is not set).
3302
3303
<constants id="jvmtiHeapVisitControl"
3304
label="Heap Visit Control Flags"
3305
kind="bits"
3306
since="1.1">
3307
<constant id="JVMTI_VISIT_OBJECTS" num="0x100">
3308
If we are visiting an object and if this callback
3309
was initiated by <functionlink id="FollowReferences"/>,
3310
traverse the references of this object.
3311
Otherwise ignored.
3312
</constant>
3313
<constant id="JVMTI_VISIT_ABORT" num="0x8000">
3314
Abort the iteration. Ignore all other bits.
3315
</constant>
3316
</constants>
3317
3318
<p/>
3319
The Heap Reference Enumeration is provided by the
3320
<functionlink id="jvmtiHeapReferenceCallback">Heap
3321
Reference Callback</functionlink> and
3322
<functionlink id="jvmtiPrimitiveFieldCallback">Primitive Field
3323
Callback</functionlink> to
3324
describe the kind of reference
3325
being reported.
3326
3327
<constants id="jvmtiHeapReferenceKind"
3328
label="Heap Reference Enumeration"
3329
kind="enum"
3330
since="1.1">
3331
<constant id="JVMTI_HEAP_REFERENCE_CLASS" num="1">
3332
Reference from an object to its class.
3333
</constant>
3334
<constant id="JVMTI_HEAP_REFERENCE_FIELD" num="2">
3335
Reference from an object to the value of one of its instance fields.
3336
</constant>
3337
<constant id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT" num="3">
3338
Reference from an array to one of its elements.
3339
</constant>
3340
<constant id="JVMTI_HEAP_REFERENCE_CLASS_LOADER" num="4">
3341
Reference from a class to its class loader.
3342
</constant>
3343
<constant id="JVMTI_HEAP_REFERENCE_SIGNERS" num="5">
3344
Reference from a class to its signers array.
3345
</constant>
3346
<constant id="JVMTI_HEAP_REFERENCE_PROTECTION_DOMAIN" num="6">
3347
Reference from a class to its protection domain.
3348
</constant>
3349
<constant id="JVMTI_HEAP_REFERENCE_INTERFACE" num="7">
3350
Reference from a class to one of its interfaces.
3351
Note: interfaces are defined via a constant pool reference,
3352
so the referenced interfaces may also be reported with a
3353
<code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3354
</constant>
3355
<constant id="JVMTI_HEAP_REFERENCE_STATIC_FIELD" num="8">
3356
Reference from a class to the value of one of its static fields.
3357
</constant>
3358
<constant id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL" num="9">
3359
Reference from a class to a resolved entry in the constant pool.
3360
</constant>
3361
<constant id="JVMTI_HEAP_REFERENCE_SUPERCLASS" num="10">
3362
Reference from a class to its superclass.
3363
A callback is bot sent if the superclass is <code>java.lang.Object</code>.
3364
Note: loaded classes define superclasses via a constant pool
3365
reference, so the referenced superclass may also be reported with
3366
a <code>JVMTI_HEAP_REFERENCE_CONSTANT_POOL</code> reference kind.
3367
</constant>
3368
<constant id="JVMTI_HEAP_REFERENCE_JNI_GLOBAL" num="21">
3369
Heap root reference: JNI global reference.
3370
</constant>
3371
<constant id="JVMTI_HEAP_REFERENCE_SYSTEM_CLASS" num="22">
3372
Heap root reference: System class.
3373
</constant>
3374
<constant id="JVMTI_HEAP_REFERENCE_MONITOR" num="23">
3375
Heap root reference: monitor.
3376
</constant>
3377
<constant id="JVMTI_HEAP_REFERENCE_STACK_LOCAL" num="24">
3378
Heap root reference: local variable on the stack.
3379
</constant>
3380
<constant id="JVMTI_HEAP_REFERENCE_JNI_LOCAL" num="25">
3381
Heap root reference: JNI local reference.
3382
</constant>
3383
<constant id="JVMTI_HEAP_REFERENCE_THREAD" num="26">
3384
Heap root reference: Thread.
3385
</constant>
3386
<constant id="JVMTI_HEAP_REFERENCE_OTHER" num="27">
3387
Heap root reference: other heap root reference.
3388
</constant>
3389
</constants>
3390
3391
<p/>
3392
Definitions for the single character type descriptors of
3393
primitive types.
3394
3395
<constants id="jvmtiPrimitiveType"
3396
label="Primitive Type Enumeration"
3397
kind="enum"
3398
since="1.1">
3399
<constant id="JVMTI_PRIMITIVE_TYPE_BOOLEAN" num="90">
3400
'Z' - Java programming language <code>boolean</code> - JNI <code>jboolean</code>
3401
</constant>
3402
<constant id="JVMTI_PRIMITIVE_TYPE_BYTE" num="66">
3403
'B' - Java programming language <code>byte</code> - JNI <code>jbyte</code>
3404
</constant>
3405
<constant id="JVMTI_PRIMITIVE_TYPE_CHAR" num="67">
3406
'C' - Java programming language <code>char</code> - JNI <code>jchar</code>
3407
</constant>
3408
<constant id="JVMTI_PRIMITIVE_TYPE_SHORT" num="83">
3409
'S' - Java programming language <code>short</code> - JNI <code>jshort</code>
3410
</constant>
3411
<constant id="JVMTI_PRIMITIVE_TYPE_INT" num="73">
3412
'I' - Java programming language <code>int</code> - JNI <code>jint</code>
3413
</constant>
3414
<constant id="JVMTI_PRIMITIVE_TYPE_LONG" num="74">
3415
'J' - Java programming language <code>long</code> - JNI <code>jlong</code>
3416
</constant>
3417
<constant id="JVMTI_PRIMITIVE_TYPE_FLOAT" num="70">
3418
'F' - Java programming language <code>float</code> - JNI <code>jfloat</code>
3419
</constant>
3420
<constant id="JVMTI_PRIMITIVE_TYPE_DOUBLE" num="68">
3421
'D' - Java programming language <code>double</code> - JNI <code>jdouble</code>
3422
</constant>
3423
</constants>
3424
</intro>
3425
3426
<typedef id="jvmtiHeapReferenceInfoField"
3427
label="Reference information structure for Field references"
3428
since="1.1">
3429
<description>
3430
Reference information returned for
3431
<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> and
3432
<datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3433
</description>
3434
<field id="index">
3435
<jint/>
3436
<description>
3437
For <datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>, the
3438
referrer object is not a class or an inteface.
3439
In this case, <code>index</code> is the index of the field
3440
in the class of the referrer object.
3441
This class is referred to below as <i>C</i>.
3442
<p/>
3443
For <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
3444
the referrer object is a class (referred to below as <i>C</i>)
3445
or an interface (referred to below as <i>I</i>).
3446
In this case, <code>index</code> is the index of the field in
3447
that class or interface.
3448
<p/>
3449
If the referrer object is not an interface, then the field
3450
indices are determined as follows:
3451
<ul>
3452
<li>make a list of all the fields in <i>C</i> and its
3453
superclasses, starting with all the fields in
3454
<code>java.lang.Object</code> and ending with all the
3455
fields in <i>C</i>.</li>
3456
<li>Within this list, put
3457
the fields for a given class in the order returned by
3458
<functionlink id="GetClassFields"/>.</li>
3459
<li>Assign the fields in this list indices
3460
<i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3461
is the count of the fields in all the interfaces
3462
implemented by <i>C</i>.
3463
Note that <i>C</i> implements all interfaces
3464
directly implemented by its superclasses; as well
3465
as all superinterfaces of these interfaces.</li>
3466
</ul>
3467
If the referrer object is an interface, then the field
3468
indices are determined as follows:
3469
<ul>
3470
<li>make a list of the fields directly declared in
3471
<i>I</i>.</li>
3472
<li>Within this list, put
3473
the fields in the order returned by
3474
<functionlink id="GetClassFields"/>.</li>
3475
<li>Assign the fields in this list indices
3476
<i>n</i>, <i>n</i>+1, ..., in order, where <i>n</i>
3477
is the count of the fields in all the superinterfaces
3478
of <i>I</i>.</li>
3479
</ul>
3480
All fields are included in this computation, regardless of
3481
field modifier (static, public, private, etc).
3482
<p/>
3483
For example, given the following classes and interfaces:
3484
<example>
3485
interface I0 {
3486
int p = 0;
3487
}
3488
3489
interface I1 extends I0 {
3490
int x = 1;
3491
}
3492
3493
interface I2 extends I0 {
3494
int y = 2;
3495
}
3496
3497
class C1 implements I1 {
3498
public static int a = 3;
3499
private int b = 4;
3500
}
3501
3502
class C2 extends C1 implements I2 {
3503
static int q = 5;
3504
final int r = 6;
3505
}
3506
</example>
3507
Assume that <functionlink id="GetClassFields"/> called on
3508
<code>C1</code> returns the fields of <code>C1</code> in the
3509
order: a, b; and that the fields of <code>C2</code> are
3510
returned in the order: q, r.
3511
An instance of class <code>C1</code> will have the
3512
following field indices:
3513
<dl><dd><table>
3514
<tr>
3515
<td>
3516
a
3517
</td>
3518
<td>
3519
2
3520
</td>
3521
<td align="left">
3522
The count of the fields in the interfaces
3523
implemented by <code>C1</code> is two (<i>n</i>=2):
3524
<code>p</code> of <code>I0</code>
3525
and <code>x</code> of <code>I1</code>.
3526
</td>
3527
</tr>
3528
<tr>
3529
<td>
3530
b
3531
</td>
3532
<td>
3533
3
3534
</td>
3535
<td align="left">
3536
the subsequent index.
3537
</td>
3538
</tr>
3539
</table></dd></dl>
3540
The class <code>C1</code> will have the same field indices.
3541
<p/>
3542
An instance of class <code>C2</code> will have the
3543
following field indices:
3544
<dl><dd><table>
3545
<tr>
3546
<td>
3547
a
3548
</td>
3549
<td>
3550
3
3551
</td>
3552
<td align="left">
3553
The count of the fields in the interfaces
3554
implemented by <code>C2</code> is three (<i>n</i>=3):
3555
<code>p</code> of <code>I0</code>,
3556
<code>x</code> of <code>I1</code> and <code>y</code> of <code>I2</code>
3557
(an interface of <code>C2</code>). Note that the field <code>p</code>
3558
of <code>I0</code> is only included once.
3559
</td>
3560
</tr>
3561
<tr>
3562
<td>
3563
b
3564
</td>
3565
<td>
3566
4
3567
</td>
3568
<td align="left">
3569
the subsequent index to "a".
3570
</td>
3571
</tr>
3572
<tr>
3573
<td>
3574
q
3575
</td>
3576
<td>
3577
5
3578
</td>
3579
<td align="left">
3580
the subsequent index to "b".
3581
</td>
3582
</tr>
3583
<tr>
3584
<td>
3585
r
3586
</td>
3587
<td>
3588
6
3589
</td>
3590
<td align="left">
3591
the subsequent index to "q".
3592
</td>
3593
</tr>
3594
</table></dd></dl>
3595
The class <code>C2</code> will have the same field indices.
3596
Note that a field may have a different index depending on the
3597
object that is viewing it -- for example field "a" above.
3598
Note also: not all field indices may be visible from the
3599
callbacks, but all indices are shown for illustrative purposes.
3600
<p/>
3601
The interface <code>I1</code> will have the
3602
following field indices:
3603
<dl><dd><table>
3604
<tr>
3605
<td>
3606
x
3607
</td>
3608
<td>
3609
1
3610
</td>
3611
<td align="left">
3612
The count of the fields in the superinterfaces
3613
of <code>I1</code> is one (<i>n</i>=1):
3614
<code>p</code> of <code>I0</code>.
3615
</td>
3616
</tr>
3617
</table></dd></dl>
3618
</description>
3619
</field>
3620
</typedef>
3621
3622
<typedef id="jvmtiHeapReferenceInfoArray"
3623
label="Reference information structure for Array references"
3624
since="1.1">
3625
<description>
3626
Reference information returned for
3627
<datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3628
</description>
3629
<field id="index">
3630
<jint/>
3631
<description>
3632
The array index.
3633
</description>
3634
</field>
3635
</typedef>
3636
3637
<typedef id="jvmtiHeapReferenceInfoConstantPool"
3638
label="Reference information structure for Constant Pool references"
3639
since="1.1">
3640
<description>
3641
Reference information returned for
3642
<datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3643
</description>
3644
<field id="index">
3645
<jint/>
3646
<description>
3647
The index into the constant pool of the class. See the description in
3648
<vmspec chapter="4.4"/>.
3649
</description>
3650
</field>
3651
</typedef>
3652
3653
<typedef id="jvmtiHeapReferenceInfoStackLocal"
3654
label="Reference information structure for Local Variable references"
3655
since="1.1">
3656
<description>
3657
Reference information returned for
3658
<datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3659
</description>
3660
<field id="thread_tag">
3661
<jlong/>
3662
<description>
3663
The tag of the thread corresponding to this stack, zero if not tagged.
3664
</description>
3665
</field>
3666
<field id="thread_id">
3667
<jlong/>
3668
<description>
3669
The unique thread ID of the thread corresponding to this stack.
3670
</description>
3671
</field>
3672
<field id="depth">
3673
<jint/>
3674
<description>
3675
The depth of the frame.
3676
</description>
3677
</field>
3678
<field id="method">
3679
<jmethodID/>
3680
<description>
3681
The method executing in this frame.
3682
</description>
3683
</field>
3684
<field id="location">
3685
<jlocation/>
3686
<description>
3687
The currently executing location in this frame.
3688
</description>
3689
</field>
3690
<field id="slot">
3691
<jint/>
3692
<description>
3693
The slot number of the local variable.
3694
</description>
3695
</field>
3696
</typedef>
3697
3698
<typedef id="jvmtiHeapReferenceInfoJniLocal"
3699
label="Reference information structure for JNI local references"
3700
since="1.1">
3701
<description>
3702
Reference information returned for
3703
<datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3704
</description>
3705
<field id="thread_tag">
3706
<jlong/>
3707
<description>
3708
The tag of the thread corresponding to this stack, zero if not tagged.
3709
</description>
3710
</field>
3711
<field id="thread_id">
3712
<jlong/>
3713
<description>
3714
The unique thread ID of the thread corresponding to this stack.
3715
</description>
3716
</field>
3717
<field id="depth">
3718
<jint/>
3719
<description>
3720
The depth of the frame.
3721
</description>
3722
</field>
3723
<field id="method">
3724
<jmethodID/>
3725
<description>
3726
The method executing in this frame.
3727
</description>
3728
</field>
3729
</typedef>
3730
3731
<typedef id="jvmtiHeapReferenceInfoReserved"
3732
label="Reference information structure for Other references"
3733
since="1.1">
3734
<description>
3735
Reference information returned for other references.
3736
</description>
3737
<field id="reserved1">
3738
<jlong/>
3739
<description>
3740
reserved for future use.
3741
</description>
3742
</field>
3743
<field id="reserved2">
3744
<jlong/>
3745
<description>
3746
reserved for future use.
3747
</description>
3748
</field>
3749
<field id="reserved3">
3750
<jlong/>
3751
<description>
3752
reserved for future use.
3753
</description>
3754
</field>
3755
<field id="reserved4">
3756
<jlong/>
3757
<description>
3758
reserved for future use.
3759
</description>
3760
</field>
3761
<field id="reserved5">
3762
<jlong/>
3763
<description>
3764
reserved for future use.
3765
</description>
3766
</field>
3767
<field id="reserved6">
3768
<jlong/>
3769
<description>
3770
reserved for future use.
3771
</description>
3772
</field>
3773
<field id="reserved7">
3774
<jlong/>
3775
<description>
3776
reserved for future use.
3777
</description>
3778
</field>
3779
<field id="reserved8">
3780
<jlong/>
3781
<description>
3782
reserved for future use.
3783
</description>
3784
</field>
3785
</typedef>
3786
3787
<uniontypedef id="jvmtiHeapReferenceInfo"
3788
label="Reference information structure"
3789
since="1.1">
3790
<description>
3791
The information returned about referrers.
3792
Represented as a union of the various kinds of reference information.
3793
</description>
3794
<field id="field">
3795
<struct>jvmtiHeapReferenceInfoField</struct>
3796
<description>
3797
The referrer information for
3798
<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>
3799
and <datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/> references.
3800
</description>
3801
</field>
3802
<field id="array">
3803
<struct>jvmtiHeapReferenceInfoArray</struct>
3804
<description>
3805
The referrer information for
3806
For <datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/> references.
3807
</description>
3808
</field>
3809
<field id="constant_pool">
3810
<struct>jvmtiHeapReferenceInfoConstantPool</struct>
3811
<description>
3812
The referrer information for
3813
For <datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/> references.
3814
</description>
3815
</field>
3816
<field id="stack_local">
3817
<struct>jvmtiHeapReferenceInfoStackLocal</struct>
3818
<description>
3819
The referrer information for
3820
For <datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/> references.
3821
</description>
3822
</field>
3823
<field id="jni_local">
3824
<struct>jvmtiHeapReferenceInfoJniLocal</struct>
3825
<description>
3826
The referrer information for
3827
For <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/> references.
3828
</description>
3829
</field>
3830
<field id="other">
3831
<struct>jvmtiHeapReferenceInfoReserved</struct>
3832
<description>
3833
reserved for future use.
3834
</description>
3835
</field>
3836
</uniontypedef>
3837
3838
<typedef id="jvmtiHeapCallbacks"
3839
label="Heap callback function structure"
3840
since="1.1">
3841
<field id="heap_iteration_callback">
3842
<ptrtype>
3843
<struct>jvmtiHeapIterationCallback</struct>
3844
</ptrtype>
3845
<description>
3846
The callback to be called to describe an
3847
object in the heap. Used by the
3848
<functionlink id="IterateThroughHeap"/> function, ignored by the
3849
<functionlink id="FollowReferences"/> function.
3850
</description>
3851
</field>
3852
<field id="heap_reference_callback">
3853
<ptrtype>
3854
<struct>jvmtiHeapReferenceCallback</struct>
3855
</ptrtype>
3856
<description>
3857
The callback to be called to describe an
3858
object reference. Used by the
3859
<functionlink id="FollowReferences"/> function, ignored by the
3860
<functionlink id="IterateThroughHeap"/> function.
3861
</description>
3862
</field>
3863
<field id="primitive_field_callback">
3864
<ptrtype>
3865
<struct>jvmtiPrimitiveFieldCallback</struct>
3866
</ptrtype>
3867
<description>
3868
The callback to be called to describe a
3869
primitive field.
3870
</description>
3871
</field>
3872
<field id="array_primitive_value_callback">
3873
<ptrtype>
3874
<struct>jvmtiArrayPrimitiveValueCallback</struct>
3875
</ptrtype>
3876
<description>
3877
The callback to be called to describe an
3878
array of primitive values.
3879
</description>
3880
</field>
3881
<field id="string_primitive_value_callback">
3882
<ptrtype>
3883
<struct>jvmtiStringPrimitiveValueCallback</struct>
3884
</ptrtype>
3885
<description>
3886
The callback to be called to describe a String value.
3887
</description>
3888
</field>
3889
<field id="reserved5">
3890
<ptrtype>
3891
<struct>jvmtiReservedCallback</struct>
3892
</ptrtype>
3893
<description>
3894
Reserved for future use..
3895
</description>
3896
</field>
3897
<field id="reserved6">
3898
<ptrtype>
3899
<struct>jvmtiReservedCallback</struct>
3900
</ptrtype>
3901
<description>
3902
Reserved for future use..
3903
</description>
3904
</field>
3905
<field id="reserved7">
3906
<ptrtype>
3907
<struct>jvmtiReservedCallback</struct>
3908
</ptrtype>
3909
<description>
3910
Reserved for future use..
3911
</description>
3912
</field>
3913
<field id="reserved8">
3914
<ptrtype>
3915
<struct>jvmtiReservedCallback</struct>
3916
</ptrtype>
3917
<description>
3918
Reserved for future use..
3919
</description>
3920
</field>
3921
<field id="reserved9">
3922
<ptrtype>
3923
<struct>jvmtiReservedCallback</struct>
3924
</ptrtype>
3925
<description>
3926
Reserved for future use..
3927
</description>
3928
</field>
3929
<field id="reserved10">
3930
<ptrtype>
3931
<struct>jvmtiReservedCallback</struct>
3932
</ptrtype>
3933
<description>
3934
Reserved for future use..
3935
</description>
3936
</field>
3937
<field id="reserved11">
3938
<ptrtype>
3939
<struct>jvmtiReservedCallback</struct>
3940
</ptrtype>
3941
<description>
3942
Reserved for future use..
3943
</description>
3944
</field>
3945
<field id="reserved12">
3946
<ptrtype>
3947
<struct>jvmtiReservedCallback</struct>
3948
</ptrtype>
3949
<description>
3950
Reserved for future use..
3951
</description>
3952
</field>
3953
<field id="reserved13">
3954
<ptrtype>
3955
<struct>jvmtiReservedCallback</struct>
3956
</ptrtype>
3957
<description>
3958
Reserved for future use..
3959
</description>
3960
</field>
3961
<field id="reserved14">
3962
<ptrtype>
3963
<struct>jvmtiReservedCallback</struct>
3964
</ptrtype>
3965
<description>
3966
Reserved for future use..
3967
</description>
3968
</field>
3969
<field id="reserved15">
3970
<ptrtype>
3971
<struct>jvmtiReservedCallback</struct>
3972
</ptrtype>
3973
<description>
3974
Reserved for future use..
3975
</description>
3976
</field>
3977
</typedef>
3978
3979
3980
<intro>
3981
<rationale>
3982
The heap dumping functionality (below) uses a callback
3983
for each object. While it would seem that a buffered approach
3984
would provide better throughput, tests do
3985
not show this to be the case--possibly due to locality of
3986
memory reference or array access overhead.
3987
</rationale>
3988
3989
<issue>
3990
Still under investigation as to if java.lang.ref references
3991
are reported as a different type of reference.
3992
</issue>
3993
3994
<issue>
3995
Should or can an indication of the cost or relative cost of
3996
these operations be included?
3997
</issue>
3998
3999
</intro>
4000
4001
<callback id="jvmtiHeapIterationCallback" since="1.1">
4002
<jint/>
4003
<synopsis>Heap Iteration Callback</synopsis>
4004
<description>
4005
Agent supplied callback function.
4006
Describes (but does not pass in) an object in the heap.
4007
<p/>
4008
This function should return a bit vector of the desired
4009
<datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4010
This will determine if the entire iteration should be aborted
4011
(the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4012
<p/>
4013
See the <internallink id="heapCallbacks">heap callback
4014
function restrictions</internallink>.
4015
</description>
4016
<parameters>
4017
<param id="class_tag">
4018
<jlong/>
4019
<description>
4020
The tag of the class of object (zero if the class is not tagged).
4021
If the object represents a runtime class,
4022
the <code>class_tag</code> is the tag
4023
associated with <code>java.lang.Class</code>
4024
(zero if <code>java.lang.Class</code> is not tagged).
4025
</description>
4026
</param>
4027
<param id="size">
4028
<jlong/>
4029
<description>
4030
Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
4031
</description>
4032
</param>
4033
<param id="tag_ptr">
4034
<outptr><jlong/></outptr>
4035
<description>
4036
The object tag value, or zero if the object is not tagged.
4037
To set the tag value to be associated with the object
4038
the agent sets the <code>jlong</code> pointed to by the parameter.
4039
</description>
4040
</param>
4041
<param id="length">
4042
<jint/>
4043
<description>
4044
If this object is an array, the length of the array. Otherwise negative one (-1).
4045
</description>
4046
</param>
4047
<param id="user_data">
4048
<outptr><void/></outptr>
4049
<description>
4050
The user supplied data that was passed into the iteration function.
4051
</description>
4052
</param>
4053
</parameters>
4054
</callback>
4055
4056
<callback id="jvmtiHeapReferenceCallback" since="1.1">
4057
<jint/>
4058
<synopsis>Heap Reference Callback</synopsis>
4059
<description>
4060
Agent supplied callback function.
4061
Describes a reference from an object or the VM (the referrer) to another object
4062
(the referree) or a heap root to a referree.
4063
<p/>
4064
This function should return a bit vector of the desired
4065
<datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4066
This will determine if the objects referenced by the referree
4067
should be visited or if the entire iteration should be aborted.
4068
<p/>
4069
See the <internallink id="heapCallbacks">heap callback
4070
function restrictions</internallink>.
4071
</description>
4072
<parameters>
4073
<param id="reference_kind">
4074
<enum>jvmtiHeapReferenceKind</enum>
4075
<description>
4076
The kind of reference.
4077
</description>
4078
</param>
4079
<param id="reference_info">
4080
<inptr>
4081
<struct>jvmtiHeapReferenceInfo</struct>
4082
</inptr>
4083
<description>
4084
Details about the reference.
4085
Set when the <datalink id="jvmtiHeapReferenceCallback.reference_kind">reference_kind</datalink> is
4086
<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/>,
4087
<datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>,
4088
<datalink id="JVMTI_HEAP_REFERENCE_ARRAY_ELEMENT"/>,
4089
<datalink id="JVMTI_HEAP_REFERENCE_CONSTANT_POOL"/>,
4090
<datalink id="JVMTI_HEAP_REFERENCE_STACK_LOCAL"/>,
4091
or <datalink id="JVMTI_HEAP_REFERENCE_JNI_LOCAL"/>.
4092
Otherwise <code>NULL</code>.
4093
</description>
4094
</param>
4095
<param id="class_tag">
4096
<jlong/>
4097
<description>
4098
The tag of the class of referree object (zero if the class is not tagged).
4099
If the referree object represents a runtime class,
4100
the <code>class_tag</code> is the tag
4101
associated with <code>java.lang.Class</code>
4102
(zero if <code>java.lang.Class</code> is not tagged).
4103
</description>
4104
</param>
4105
<param id="referrer_class_tag">
4106
<jlong/>
4107
<description>
4108
The tag of the class of the referrer object (zero if the class is not tagged
4109
or the referree is a heap root). If the referrer object represents a runtime
4110
class, the <code>referrer_class_tag</code> is the tag associated with
4111
the <code>java.lang.Class</code>
4112
(zero if <code>java.lang.Class</code> is not tagged).
4113
</description>
4114
</param>
4115
<param id="size">
4116
<jlong/>
4117
<description>
4118
Size of the referree object (in bytes).
4119
See <functionlink id="GetObjectSize"/>.
4120
</description>
4121
</param>
4122
<param id="tag_ptr">
4123
<outptr><jlong/></outptr>
4124
<description>
4125
Points to the referree object tag value, or zero if the object is not
4126
tagged.
4127
To set the tag value to be associated with the object
4128
the agent sets the <code>jlong</code> pointed to by the parameter.
4129
</description>
4130
</param>
4131
<param id="referrer_tag_ptr">
4132
<outptr><jlong/></outptr>
4133
<description>
4134
Points to the tag of the referrer object, or
4135
points to the zero if the referrer
4136
object is not tagged.
4137
<code>NULL</code> if the referrer in not an object (that is,
4138
this callback is reporting a heap root).
4139
To set the tag value to be associated with the referrer object
4140
the agent sets the <code>jlong</code> pointed to by the parameter.
4141
If this callback is reporting a reference from an object to itself,
4142
<code>referrer_tag_ptr == tag_ptr</code>.
4143
</description>
4144
</param>
4145
<param id="length">
4146
<jint/>
4147
<description>
4148
If this object is an array, the length of the array. Otherwise negative one (-1).
4149
</description>
4150
</param>
4151
<param id="user_data">
4152
<outptr><void/></outptr>
4153
<description>
4154
The user supplied data that was passed into the iteration function.
4155
</description>
4156
</param>
4157
</parameters>
4158
</callback>
4159
4160
<callback id="jvmtiPrimitiveFieldCallback" since="1.1">
4161
<jint/>
4162
<synopsis>Primitive Field Callback</synopsis>
4163
<description>
4164
Agent supplied callback function which
4165
describes a primitive field of an object (<i>the object</i>).
4166
A primitive field is a field whose type is a primitive type.
4167
This callback will describe a static field if the object is a class,
4168
and otherwise will describe an instance field.
4169
<p/>
4170
This function should return a bit vector of the desired
4171
<datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4172
This will determine if the entire iteration should be aborted
4173
(the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4174
<p/>
4175
See the <internallink id="heapCallbacks">heap callback
4176
function restrictions</internallink>.
4177
</description>
4178
<parameters>
4179
<param id="kind">
4180
<enum>jvmtiHeapReferenceKind</enum>
4181
<description>
4182
The kind of field -- instance or static (<datalink id="JVMTI_HEAP_REFERENCE_FIELD"/> or
4183
<datalink id="JVMTI_HEAP_REFERENCE_STATIC_FIELD"/>).
4184
</description>
4185
</param>
4186
<param id="info">
4187
<inptr>
4188
<struct>jvmtiHeapReferenceInfo</struct>
4189
</inptr>
4190
<description>
4191
Which field (the field index).
4192
</description>
4193
</param>
4194
<param id="object_class_tag">
4195
<jlong/>
4196
<description>
4197
The tag of the class of the object (zero if the class is not tagged).
4198
If the object represents a runtime class, the
4199
<code>object_class_tag</code> is the tag
4200
associated with <code>java.lang.Class</code>
4201
(zero if <code>java.lang.Class</code> is not tagged).
4202
</description>
4203
</param>
4204
<param id="object_tag_ptr">
4205
<outptr><jlong/></outptr>
4206
<description>
4207
Points to the tag of the object, or zero if the object is not
4208
tagged.
4209
To set the tag value to be associated with the object
4210
the agent sets the <code>jlong</code> pointed to by the parameter.
4211
</description>
4212
</param>
4213
<param id="value">
4214
<jvalue/>
4215
<description>
4216
The value of the field.
4217
</description>
4218
</param>
4219
<param id="value_type">
4220
<enum>jvmtiPrimitiveType</enum>
4221
<description>
4222
The type of the field.
4223
</description>
4224
</param>
4225
<param id="user_data">
4226
<outptr><void/></outptr>
4227
<description>
4228
The user supplied data that was passed into the iteration function.
4229
</description>
4230
</param>
4231
</parameters>
4232
</callback>
4233
4234
<callback id="jvmtiArrayPrimitiveValueCallback" since="1.1">
4235
<jint/>
4236
<synopsis>Array Primitive Value Callback</synopsis>
4237
<description>
4238
Agent supplied callback function.
4239
Describes the values in an array of a primitive type.
4240
<p/>
4241
This function should return a bit vector of the desired
4242
<datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4243
This will determine if the entire iteration should be aborted
4244
(the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4245
<p/>
4246
See the <internallink id="heapCallbacks">heap callback
4247
function restrictions</internallink>.
4248
</description>
4249
<parameters>
4250
<param id="class_tag">
4251
<jlong/>
4252
<description>
4253
The tag of the class of the array object (zero if the class is not tagged).
4254
</description>
4255
</param>
4256
<param id="size">
4257
<jlong/>
4258
<description>
4259
Size of the array (in bytes).
4260
See <functionlink id="GetObjectSize"/>.
4261
</description>
4262
</param>
4263
<param id="tag_ptr">
4264
<outptr><jlong/></outptr>
4265
<description>
4266
Points to the tag of the array object, or zero if the object is not
4267
tagged.
4268
To set the tag value to be associated with the object
4269
the agent sets the <code>jlong</code> pointed to by the parameter.
4270
</description>
4271
</param>
4272
<param id="element_count">
4273
<jint/>
4274
<description>
4275
The length of the primitive array.
4276
</description>
4277
</param>
4278
<param id="element_type">
4279
<enum>jvmtiPrimitiveType</enum>
4280
<description>
4281
The type of the elements of the array.
4282
</description>
4283
</param>
4284
<param id="elements">
4285
<vmbuf><void/></vmbuf>
4286
<description>
4287
The elements of the array in a packed array of <code>element_count</code>
4288
items of <code>element_type</code> size each.
4289
</description>
4290
</param>
4291
<param id="user_data">
4292
<outptr><void/></outptr>
4293
<description>
4294
The user supplied data that was passed into the iteration function.
4295
</description>
4296
</param>
4297
</parameters>
4298
</callback>
4299
4300
<callback id="jvmtiStringPrimitiveValueCallback" since="1.1">
4301
<jint/>
4302
<synopsis>String Primitive Value Callback</synopsis>
4303
<description>
4304
Agent supplied callback function.
4305
Describes the value of a java.lang.String.
4306
<p/>
4307
This function should return a bit vector of the desired
4308
<datalink id="jvmtiHeapVisitControl">visit control flags</datalink>.
4309
This will determine if the entire iteration should be aborted
4310
(the <code>JVMTI_VISIT_OBJECTS</code> flag is ignored).
4311
<p/>
4312
See the <internallink id="heapCallbacks">heap callback
4313
function restrictions</internallink>.
4314
</description>
4315
<parameters>
4316
<param id="class_tag">
4317
<jlong/>
4318
<description>
4319
The tag of the class of the String class (zero if the class is not tagged).
4320
<issue>Is this needed?</issue>
4321
</description>
4322
</param>
4323
<param id="size">
4324
<jlong/>
4325
<description>
4326
Size of the string (in bytes).
4327
See <functionlink id="GetObjectSize"/>.
4328
</description>
4329
</param>
4330
<param id="tag_ptr">
4331
<outptr><jlong/></outptr>
4332
<description>
4333
Points to the tag of the String object, or zero if the object is not
4334
tagged.
4335
To set the tag value to be associated with the object
4336
the agent sets the <code>jlong</code> pointed to by the parameter.
4337
</description>
4338
</param>
4339
<param id="value">
4340
<vmbuf><jchar/></vmbuf>
4341
<description>
4342
The value of the String, encoded as a Unicode string.
4343
</description>
4344
</param>
4345
<param id="value_length">
4346
<jint/>
4347
<description>
4348
The length of the string.
4349
The length is equal to the number of 16-bit Unicode
4350
characters in the string.
4351
</description>
4352
</param>
4353
<param id="user_data">
4354
<outptr><void/></outptr>
4355
<description>
4356
The user supplied data that was passed into the iteration function.
4357
</description>
4358
</param>
4359
</parameters>
4360
</callback>
4361
4362
4363
<callback id="jvmtiReservedCallback" since="1.1">
4364
<jint/>
4365
<synopsis>reserved for future use Callback</synopsis>
4366
<description>
4367
Placeholder -- reserved for future use.
4368
</description>
4369
<parameters>
4370
</parameters>
4371
</callback>
4372
4373
<function id="FollowReferences" num="115" since="1.1">
4374
<synopsis>Follow References</synopsis>
4375
<description>
4376
This function initiates a traversal over the objects that are
4377
directly and indirectly reachable from the specified object or,
4378
if <code>initial_object</code> is not specified, all objects
4379
reachable from the heap roots.
4380
The heap root are the set of system classes,
4381
JNI globals, references from thread stacks, and other objects used as roots
4382
for the purposes of garbage collection.
4383
<p/>
4384
This function operates by traversing the reference graph.
4385
Let <i>A</i>, <i>B</i>, ... represent objects.
4386
When a reference from <i>A</i> to <i>B</i> is traversed,
4387
when a reference from a heap root to <i>B</i> is traversed,
4388
or when <i>B</i> is specified as the <paramlink id="initial_object"/>,
4389
then <i>B</i> is said to be <i>visited</i>.
4390
A reference from <i>A</i> to <i>B</i> is not traversed until <i>A</i>
4391
is visited.
4392
References are reported in the same order that the references are traversed.
4393
Object references are reported by invoking the agent supplied
4394
callback function <functionlink id="jvmtiHeapReferenceCallback"/>.
4395
In a reference from <i>A</i> to <i>B</i>, <i>A</i> is known
4396
as the <i>referrer</i> and <i>B</i> as the <i>referree</i>.
4397
The callback is invoked exactly once for each reference from a referrer;
4398
this is true even if there are reference cycles or multiple paths to
4399
the referrer.
4400
There may be more than one reference between a referrer and a referree,
4401
each reference is reported.
4402
These references may be distinguished by examining the
4403
<datalink
4404
id="jvmtiHeapReferenceCallback.reference_kind"><code>reference_kind</code></datalink>
4405
and
4406
<datalink
4407
id="jvmtiHeapReferenceCallback.reference_info"><code>reference_info</code></datalink>
4408
parameters of the <functionlink id="jvmtiHeapReferenceCallback"/> callback.
4409
<p/>
4410
This function reports a Java programming language view of object references,
4411
not a virtual machine implementation view. The following object references
4412
are reported when they are non-null:
4413
<ul>
4414
<li>Instance objects report references to each non-primitive instance fields
4415
(including inherited fields).</li>
4416
<li>Instance objects report a reference to the object type (class).</li>
4417
<li>Classes report a reference to the superclass and directly
4418
implemented/extended interfaces.</li>
4419
<li>Classes report a reference to the class loader, protection domain,
4420
signers, and resolved entries in the constant pool.</li>
4421
<li>Classes report a reference to each directly declared non-primitive
4422
static field.</li>
4423
<li>Arrays report a reference to the array type (class) and each
4424
array element.</li>
4425
<li>Primitive arrays report a reference to the array type.</li>
4426
</ul>
4427
<p/>
4428
This function can also be used to examine primitive (non-object) values.
4429
The primitive value of an array or String
4430
is reported after the object has been visited;
4431
it is reported by invoking the agent supplied callback function
4432
<functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4433
<functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4434
A primitive field
4435
is reported after the object with that field is visited;
4436
it is reported by invoking the agent supplied callback function
4437
<functionlink id="jvmtiPrimitiveFieldCallback"/>.
4438
<p/>
4439
Whether a callback is provided or is <code>NULL</code> only determines
4440
whether the callback will be invoked, it does not influence
4441
which objects are visited nor does it influence whether other callbacks
4442
will be invoked.
4443
However, the
4444
<datalink id="jvmtiHeapVisitControl">visit control flags</datalink>
4445
returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4446
do determine if the objects referenced by the
4447
current object as visited.
4448
The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4449
and <paramlink id="klass"/> provided as parameters to this function
4450
do not control which objects are visited but they do control which
4451
objects and primitive values are reported by the callbacks.
4452
For example, if the only callback that was set is
4453
<fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code>
4454
is set to the array of bytes class, then only arrays of byte will be
4455
reported.
4456
The table below summarizes this:
4457
<p/>
4458
<table>
4459
<tr>
4460
<th/>
4461
<th>
4462
Controls objects visited
4463
</th>
4464
<th>
4465
Controls objects reported
4466
</th>
4467
<th>
4468
Controls primitives reported
4469
</th>
4470
</tr>
4471
<tr>
4472
<th align="left">
4473
the
4474
<datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4475
returned by <functionlink id="jvmtiHeapReferenceCallback"/>
4476
</th>
4477
<td>
4478
<b>Yes</b>
4479
</td>
4480
<td>
4481
<b>Yes</b>, since visits are controlled
4482
</td>
4483
<td>
4484
<b>Yes</b>, since visits are controlled
4485
</td>
4486
</tr>
4487
<tr>
4488
<th align="left">
4489
<fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/>
4490
in <paramlink id="callbacks"/> set
4491
</th>
4492
<td>
4493
No
4494
</td>
4495
<td>
4496
<b>Yes</b>
4497
</td>
4498
<td>
4499
No
4500
</td>
4501
</tr>
4502
<tr>
4503
<th align="left">
4504
<paramlink id="heap_filter"/>
4505
</th>
4506
<td>
4507
No
4508
</td>
4509
<td>
4510
<b>Yes</b>
4511
</td>
4512
<td>
4513
<b>Yes</b>
4514
</td>
4515
</tr>
4516
<tr>
4517
<th align="left">
4518
<paramlink id="klass"/>
4519
</th>
4520
<td>
4521
No
4522
</td>
4523
<td>
4524
<b>Yes</b>
4525
</td>
4526
<td>
4527
<b>Yes</b>
4528
</td>
4529
</tr>
4530
</table>
4531
<p/>
4532
During the execution of this function the state of the heap
4533
does not change: no objects are allocated, no objects are
4534
garbage collected, and the state of objects (including
4535
held values) does not change.
4536
As a result, threads executing Java
4537
programming language code, threads attempting to resume the
4538
execution of Java programming language code, and threads
4539
attempting to execute JNI functions are typically stalled.
4540
</description>
4541
<origin>new</origin>
4542
<capabilities>
4543
<required id="can_tag_objects"></required>
4544
</capabilities>
4545
<parameters>
4546
<param id="heap_filter">
4547
<jint/>
4548
<description>
4549
This bit vector of
4550
<datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4551
restricts the objects for which the callback function is called.
4552
This applies to both the object and primitive callbacks.
4553
</description>
4554
</param>
4555
<param id="klass">
4556
<ptrtype>
4557
<jclass/>
4558
<nullok>callbacks are not limited to instances of a particular
4559
class</nullok>
4560
</ptrtype>
4561
<description>
4562
Callbacks are only reported when the object is an instance of
4563
this class.
4564
Objects which are instances of a subclass of <code>klass</code>
4565
are not reported.
4566
If <code>klass</code> is an interface, no objects are reported.
4567
This applies to both the object and primitive callbacks.
4568
</description>
4569
</param>
4570
<param id="initial_object">
4571
<ptrtype>
4572
<jobject/>
4573
<nullok>references are followed from the heap roots</nullok>
4574
</ptrtype>
4575
<description>
4576
The object to follow
4577
</description>
4578
</param>
4579
<param id="callbacks">
4580
<inptr>
4581
<struct>jvmtiHeapCallbacks</struct>
4582
</inptr>
4583
<description>
4584
Structure defining the set of callback functions.
4585
</description>
4586
</param>
4587
<param id="user_data">
4588
<inbuf>
4589
<void/>
4590
<nullok><code>NULL</code> is passed as the user supplied data</nullok>
4591
</inbuf>
4592
<description>
4593
User supplied data to be passed to the callback.
4594
</description>
4595
</param>
4596
</parameters>
4597
<errors>
4598
<error id="JVMTI_ERROR_INVALID_CLASS">
4599
<paramlink id="klass"/> is not a valid class.
4600
</error>
4601
<error id="JVMTI_ERROR_INVALID_OBJECT">
4602
<paramlink id="initial_object"/> is not a valid object.
4603
</error>
4604
</errors>
4605
</function>
4606
4607
4608
<function id="IterateThroughHeap" num="116" since="1.1">
4609
<synopsis>Iterate Through Heap</synopsis>
4610
<description>
4611
Initiate an iteration over all objects in the heap.
4612
This includes both reachable and
4613
unreachable objects. Objects are visited in no particular order.
4614
<p/>
4615
Heap objects are reported by invoking the agent supplied
4616
callback function <functionlink id="jvmtiHeapIterationCallback"/>.
4617
References between objects are not reported.
4618
If only reachable objects are desired, or if object reference information
4619
is needed, use <functionlink id="FollowReferences"/>.
4620
<p/>
4621
This function can also be used to examine primitive (non-object) values.
4622
The primitive value of an array or String
4623
is reported after the object has been visited;
4624
it is reported by invoking the agent supplied callback function
4625
<functionlink id="jvmtiArrayPrimitiveValueCallback"/> or
4626
<functionlink id="jvmtiStringPrimitiveValueCallback"/>.
4627
A primitive field
4628
is reported after the object with that field is visited;
4629
it is reported by invoking the agent supplied
4630
callback function
4631
<functionlink id="jvmtiPrimitiveFieldCallback"/>.
4632
<p/>
4633
Unless the iteration is aborted by the
4634
<datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4635
returned by a callback, all objects in the heap are visited.
4636
Whether a callback is provided or is <code>NULL</code> only determines
4637
whether the callback will be invoked, it does not influence
4638
which objects are visited nor does it influence whether other callbacks
4639
will be invoked.
4640
The <datalink id="jvmtiHeapFilter">heap filter flags</datalink>
4641
and <paramlink id="klass"/> provided as parameters to this function
4642
do not control which objects are visited but they do control which
4643
objects and primitive values are reported by the callbacks.
4644
For example, if the only callback that was set is
4645
<fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/> and <code>klass</code>
4646
is set to the array of bytes class, then only arrays of byte will be
4647
reported. The table below summarizes this (contrast this with
4648
<functionlink id="FollowReferences"/>):
4649
<p/>
4650
<table>
4651
<tr>
4652
<th/>
4653
<th>
4654
Controls objects visited
4655
</th>
4656
<th>
4657
Controls objects reported
4658
</th>
4659
<th>
4660
Controls primitives reported
4661
</th>
4662
</tr>
4663
<tr>
4664
<th align="left">
4665
the
4666
<datalink id="jvmtiHeapVisitControl">Heap Visit Control Flags</datalink>
4667
returned by <functionlink id="jvmtiHeapIterationCallback"/>
4668
</th>
4669
<td>
4670
No<br/>(unless they abort the iteration)
4671
</td>
4672
<td>
4673
No<br/>(unless they abort the iteration)
4674
</td>
4675
<td>
4676
No<br/>(unless they abort the iteration)
4677
</td>
4678
</tr>
4679
<tr>
4680
<th align="left">
4681
<fieldlink id="array_primitive_value_callback" struct="jvmtiHeapCallbacks"/>
4682
in <paramlink id="callbacks"/> set
4683
</th>
4684
<td>
4685
No
4686
</td>
4687
<td>
4688
<b>Yes</b>
4689
</td>
4690
<td>
4691
No
4692
</td>
4693
</tr>
4694
<tr>
4695
<th align="left">
4696
<paramlink id="heap_filter"/>
4697
</th>
4698
<td>
4699
No
4700
</td>
4701
<td>
4702
<b>Yes</b>
4703
</td>
4704
<td>
4705
<b>Yes</b>
4706
</td>
4707
</tr>
4708
<tr>
4709
<th align="left">
4710
<paramlink id="klass"/>
4711
</th>
4712
<td>
4713
No
4714
</td>
4715
<td>
4716
<b>Yes</b>
4717
</td>
4718
<td>
4719
<b>Yes</b>
4720
</td>
4721
</tr>
4722
</table>
4723
<p/>
4724
During the execution of this function the state of the heap
4725
does not change: no objects are allocated, no objects are
4726
garbage collected, and the state of objects (including
4727
held values) does not change.
4728
As a result, threads executing Java
4729
programming language code, threads attempting to resume the
4730
execution of Java programming language code, and threads
4731
attempting to execute JNI functions are typically stalled.
4732
</description>
4733
<origin>new</origin>
4734
<capabilities>
4735
<required id="can_tag_objects"></required>
4736
</capabilities>
4737
<parameters>
4738
<param id="heap_filter">
4739
<jint/>
4740
<description>
4741
This bit vector of
4742
<datalink id="jvmtiHeapFilter">heap filter flags</datalink>.
4743
restricts the objects for which the callback function is called.
4744
This applies to both the object and primitive callbacks.
4745
</description>
4746
</param>
4747
<param id="klass">
4748
<ptrtype>
4749
<jclass/>
4750
<nullok>callbacks are not limited to instances of a particular class</nullok>
4751
</ptrtype>
4752
<description>
4753
Callbacks are only reported when the object is an instance of
4754
this class.
4755
Objects which are instances of a subclass of <code>klass</code>
4756
are not reported.
4757
If <code>klass</code> is an interface, no objects are reported.
4758
This applies to both the object and primitive callbacks.
4759
</description>
4760
</param>
4761
<param id="callbacks">
4762
<inptr>
4763
<struct>jvmtiHeapCallbacks</struct>
4764
</inptr>
4765
<description>
4766
Structure defining the set callback functions.
4767
</description>
4768
</param>
4769
<param id="user_data">
4770
<inbuf>
4771
<void/>
4772
<nullok><code>NULL</code> is passed as the user supplied data</nullok>
4773
</inbuf>
4774
<description>
4775
User supplied data to be passed to the callback.
4776
</description>
4777
</param>
4778
</parameters>
4779
<errors>
4780
<error id="JVMTI_ERROR_INVALID_CLASS">
4781
<paramlink id="klass"/> is not a valid class.
4782
</error>
4783
</errors>
4784
</function>
4785
4786
<function id="GetTag" phase="start" num="106">
4787
<synopsis>Get Tag</synopsis>
4788
<description>
4789
Retrieve the tag associated with an object.
4790
The tag is a long value typically used to store a
4791
unique identifier or pointer to object information.
4792
The tag is set with
4793
<functionlink id="SetTag"></functionlink>.
4794
Objects for which no tags have been set return a
4795
tag value of zero.
4796
</description>
4797
<origin>new</origin>
4798
<capabilities>
4799
<required id="can_tag_objects"></required>
4800
</capabilities>
4801
<parameters>
4802
<param id="object">
4803
<jobject/>
4804
<description>
4805
The object whose tag is to be retrieved.
4806
</description>
4807
</param>
4808
<param id="tag_ptr">
4809
<outptr><jlong/></outptr>
4810
<description>
4811
On return, the referenced long is set to the value
4812
of the tag.
4813
</description>
4814
</param>
4815
</parameters>
4816
<errors>
4817
</errors>
4818
</function>
4819
4820
<function id="SetTag" phase="start" num="107">
4821
<synopsis>Set Tag</synopsis>
4822
<description>
4823
Set the tag associated with an object.
4824
The tag is a long value typically used to store a
4825
unique identifier or pointer to object information.
4826
The tag is visible with
4827
<functionlink id="GetTag"></functionlink>.
4828
</description>
4829
<origin>new</origin>
4830
<capabilities>
4831
<required id="can_tag_objects"></required>
4832
</capabilities>
4833
<parameters>
4834
<param id="object">
4835
<jobject/>
4836
<description>
4837
The object whose tag is to be set.
4838
</description>
4839
</param>
4840
<param id="tag">
4841
<jlong/>
4842
<description>
4843
The new value of the tag.
4844
</description>
4845
</param>
4846
</parameters>
4847
<errors>
4848
</errors>
4849
</function>
4850
4851
<function id="GetObjectsWithTags" num="114">
4852
<synopsis>Get Objects With Tags</synopsis>
4853
<description>
4854
Return objects in the heap with the specified tags.
4855
The format is parallel arrays of objects and tags.
4856
</description>
4857
<origin>new</origin>
4858
<capabilities>
4859
<required id="can_tag_objects"></required>
4860
</capabilities>
4861
<parameters>
4862
<param id="tag_count">
4863
<jint min="0"/>
4864
<description>
4865
Number of tags to scan for.
4866
</description>
4867
</param>
4868
<param id="tags">
4869
<inbuf incount="tag_count">
4870
<jlong/>
4871
</inbuf>
4872
<description>
4873
Scan for objects with these tags.
4874
Zero is not permitted in this array.
4875
</description>
4876
</param>
4877
<param id="count_ptr">
4878
<outptr>
4879
<jint/>
4880
</outptr>
4881
<description>
4882
Return the number of objects with any of the tags
4883
in <paramlink id="tags"/>.
4884
</description>
4885
</param>
4886
<param id="object_result_ptr">
4887
<allocbuf outcount="count_ptr">
4888
<jobject/>
4889
<nullok>this information is not returned</nullok>
4890
</allocbuf>
4891
<description>
4892
Returns the array of objects with any of the tags
4893
in <paramlink id="tags"/>.
4894
</description>
4895
</param>
4896
<param id="tag_result_ptr">
4897
<allocbuf outcount="count_ptr">
4898
<jlong/>
4899
<nullok>this information is not returned</nullok>
4900
</allocbuf>
4901
<description>
4902
For each object in <paramlink id="object_result_ptr"/>,
4903
return the tag at the corresponding index.
4904
</description>
4905
</param>
4906
</parameters>
4907
<errors>
4908
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
4909
Zero is present in <paramlink id="tags"></paramlink>.
4910
</error>
4911
</errors>
4912
</function>
4913
4914
<function id="ForceGarbageCollection" num="108">
4915
<synopsis>Force Garbage Collection</synopsis>
4916
<description>
4917
Force the VM to perform a garbage collection.
4918
The garbage collection is as complete as possible.
4919
This function does not cause finalizers to be run.
4920
This function does not return until the garbage collection
4921
is finished.
4922
<p/>
4923
Although garbage collection is as complete
4924
as possible there is no guarantee that all
4925
<eventlink id="ObjectFree"/>
4926
events will have been
4927
sent by the time that this function
4928
returns. In particular, an object may be
4929
prevented from being freed because it
4930
is awaiting finalization.
4931
</description>
4932
<origin>new</origin>
4933
<capabilities>
4934
</capabilities>
4935
<parameters>
4936
</parameters>
4937
<errors>
4938
</errors>
4939
</function>
4940
4941
4942
</category>
4943
4944
<category id="Heap_1_0" label="Heap (1.0)">
4945
<intro>
4946
<b>
4947
These functions and data types were introduced in the original
4948
<jvmti/> version 1.0 and have been superseded by more
4949
</b>
4950
<internallink id="Heap"><b>powerful and flexible versions</b></internallink>
4951
<b>
4952
which:
4953
</b>
4954
<ul>
4955
<li>
4956
<b>
4957
Allow access to primitive values (the value of Strings, arrays,
4958
and primitive fields)
4959
</b>
4960
</li>
4961
<li>
4962
<b>
4963
Allow the tag of the referrer to be set, thus enabling more
4964
efficient localized reference graph building
4965
</b>
4966
</li>
4967
<li>
4968
<b>
4969
Provide more extensive filtering abilities
4970
</b>
4971
</li>
4972
<li>
4973
<b>
4974
Are extensible, allowing their abilities to grow in future versions of <jvmti/>
4975
</b>
4976
</li>
4977
</ul>
4978
<p/>
4979
<b>Please use the </b>
4980
<internallink id="Heap"><b>current Heap functions</b></internallink>.
4981
<p/>
4982
<constants id="jvmtiHeapObjectFilter" label="Heap Object Filter Enumeration" kind="enum">
4983
<constant id="JVMTI_HEAP_OBJECT_TAGGED" num="1">
4984
Tagged objects only.
4985
</constant>
4986
<constant id="JVMTI_HEAP_OBJECT_UNTAGGED" num="2">
4987
Untagged objects only.
4988
</constant>
4989
<constant id="JVMTI_HEAP_OBJECT_EITHER" num="3">
4990
Either tagged or untagged objects.
4991
</constant>
4992
</constants>
4993
4994
<constants id="jvmtiHeapRootKind" label="Heap Root Kind Enumeration" kind="enum">
4995
<constant id="JVMTI_HEAP_ROOT_JNI_GLOBAL" num="1">
4996
JNI global reference.
4997
</constant>
4998
<constant id="JVMTI_HEAP_ROOT_SYSTEM_CLASS" num="2">
4999
System class.
5000
</constant>
5001
<constant id="JVMTI_HEAP_ROOT_MONITOR" num="3">
5002
Monitor.
5003
</constant>
5004
<constant id="JVMTI_HEAP_ROOT_STACK_LOCAL" num="4">
5005
Stack local.
5006
</constant>
5007
<constant id="JVMTI_HEAP_ROOT_JNI_LOCAL" num="5">
5008
JNI local reference.
5009
</constant>
5010
<constant id="JVMTI_HEAP_ROOT_THREAD" num="6">
5011
Thread.
5012
</constant>
5013
<constant id="JVMTI_HEAP_ROOT_OTHER" num="7">
5014
Other.
5015
</constant>
5016
</constants>
5017
5018
<constants id="jvmtiObjectReferenceKind" label="Object Reference Enumeration" kind="enum">
5019
<constant id="JVMTI_REFERENCE_CLASS" num="1">
5020
Reference from an object to its class.
5021
</constant>
5022
<constant id="JVMTI_REFERENCE_FIELD" num="2">
5023
Reference from an object to the value of one of its instance fields.
5024
For references of this kind the <code>referrer_index</code>
5025
parameter to the <internallink id="jvmtiObjectReferenceCallback">
5026
jvmtiObjectReferenceCallback</internallink> is the index of the
5027
the instance field. The index is based on the order of all the
5028
object's fields. This includes all fields of the directly declared
5029
static and instance fields in the class, and includes all fields (both
5030
public and private) fields declared in superclasses and superinterfaces.
5031
The index is thus calculated by summing the index of the field in the directly
5032
declared class (see <functionlink id="GetClassFields"/>), with the total
5033
number of fields (both public and private) declared in all superclasses
5034
and superinterfaces. The index starts at zero.
5035
</constant>
5036
<constant id="JVMTI_REFERENCE_ARRAY_ELEMENT" num="3">
5037
Reference from an array to one of its elements.
5038
For references of this kind the <code>referrer_index</code>
5039
parameter to the <internallink id="jvmtiObjectReferenceCallback">
5040
jvmtiObjectReferenceCallback</internallink> is the array index.
5041
</constant>
5042
<constant id="JVMTI_REFERENCE_CLASS_LOADER" num="4">
5043
Reference from a class to its class loader.
5044
</constant>
5045
<constant id="JVMTI_REFERENCE_SIGNERS" num="5">
5046
Reference from a class to its signers array.
5047
</constant>
5048
<constant id="JVMTI_REFERENCE_PROTECTION_DOMAIN" num="6">
5049
Reference from a class to its protection domain.
5050
</constant>
5051
<constant id="JVMTI_REFERENCE_INTERFACE" num="7">
5052
Reference from a class to one of its interfaces.
5053
</constant>
5054
<constant id="JVMTI_REFERENCE_STATIC_FIELD" num="8">
5055
Reference from a class to the value of one of its static fields.
5056
For references of this kind the <code>referrer_index</code>
5057
parameter to the <internallink id="jvmtiObjectReferenceCallback">
5058
jvmtiObjectReferenceCallback</internallink> is the index of the
5059
the static field. The index is based on the order of all the
5060
object's fields. This includes all fields of the directly declared
5061
static and instance fields in the class, and includes all fields (both
5062
public and private) fields declared in superclasses and superinterfaces.
5063
The index is thus calculated by summing the index of the field in the directly
5064
declared class (see <functionlink id="GetClassFields"/>), with the total
5065
number of fields (both public and private) declared in all superclasses
5066
and superinterfaces. The index starts at zero.
5067
Note: this definition differs from that in the <jvmti/> 1.0 Specification.
5068
<rationale>No known implementations used the 1.0 definition.</rationale>
5069
</constant>
5070
<constant id="JVMTI_REFERENCE_CONSTANT_POOL" num="9">
5071
Reference from a class to a resolved entry in the constant pool.
5072
For references of this kind the <code>referrer_index</code>
5073
parameter to the <internallink id="jvmtiObjectReferenceCallback">
5074
jvmtiObjectReferenceCallback</internallink> is the index into
5075
constant pool table of the class, starting at 1. See
5076
<vmspec chapter="4.4"/>.
5077
</constant>
5078
</constants>
5079
5080
<constants id="jvmtiIterationControl" label="Iteration Control Enumeration" kind="enum">
5081
<constant id="JVMTI_ITERATION_CONTINUE" num="1">
5082
Continue the iteration.
5083
If this is a reference iteration, follow the references of this object.
5084
</constant>
5085
<constant id="JVMTI_ITERATION_IGNORE" num="2">
5086
Continue the iteration.
5087
If this is a reference iteration, ignore the references of this object.
5088
</constant>
5089
<constant id="JVMTI_ITERATION_ABORT" num="0">
5090
Abort the iteration.
5091
</constant>
5092
</constants>
5093
</intro>
5094
5095
<callback id="jvmtiHeapObjectCallback">
5096
<enum>jvmtiIterationControl</enum>
5097
<synopsis>Heap Object Callback</synopsis>
5098
<description>
5099
Agent supplied callback function.
5100
Describes (but does not pass in) an object in the heap.
5101
<p/>
5102
Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5103
or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5104
<p/>
5105
See the <internallink id="heapCallbacks">heap callback
5106
function restrictions</internallink>.
5107
</description>
5108
<parameters>
5109
<param id="class_tag">
5110
<jlong/>
5111
<description>
5112
The tag of the class of object (zero if the class is not tagged).
5113
If the object represents a runtime class,
5114
the <code>class_tag</code> is the tag
5115
associated with <code>java.lang.Class</code>
5116
(zero if <code>java.lang.Class</code> is not tagged).
5117
</description>
5118
</param>
5119
<param id="size">
5120
<jlong/>
5121
<description>
5122
Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5123
</description>
5124
</param>
5125
<param id="tag_ptr">
5126
<outptr><jlong/></outptr>
5127
<description>
5128
The object tag value, or zero if the object is not tagged.
5129
To set the tag value to be associated with the object
5130
the agent sets the <code>jlong</code> pointed to by the parameter.
5131
</description>
5132
</param>
5133
<param id="user_data">
5134
<outptr><void/></outptr>
5135
<description>
5136
The user supplied data that was passed into the iteration function.
5137
</description>
5138
</param>
5139
</parameters>
5140
</callback>
5141
5142
<callback id="jvmtiHeapRootCallback">
5143
<enum>jvmtiIterationControl</enum>
5144
<synopsis>Heap Root Object Callback</synopsis>
5145
<description>
5146
Agent supplied callback function.
5147
Describes (but does not pass in) an object that is a root for the purposes
5148
of garbage collection.
5149
<p/>
5150
Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5151
<code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5152
references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5153
<p/>
5154
See the <internallink id="heapCallbacks">heap callback
5155
function restrictions</internallink>.
5156
</description>
5157
<parameters>
5158
<param id="root_kind">
5159
<enum>jvmtiHeapRootKind</enum>
5160
<description>
5161
The kind of heap root.
5162
</description>
5163
</param>
5164
<param id="class_tag">
5165
<jlong/>
5166
<description>
5167
The tag of the class of object (zero if the class is not tagged).
5168
If the object represents a runtime class, the <code>class_tag</code> is the tag
5169
associated with <code>java.lang.Class</code>
5170
(zero if <code>java.lang.Class</code> is not tagged).
5171
</description>
5172
</param>
5173
<param id="size">
5174
<jlong/>
5175
<description>
5176
Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5177
</description>
5178
</param>
5179
<param id="tag_ptr">
5180
<outptr><jlong/></outptr>
5181
<description>
5182
The object tag value, or zero if the object is not tagged.
5183
To set the tag value to be associated with the object
5184
the agent sets the <code>jlong</code> pointed to by the parameter.
5185
</description>
5186
</param>
5187
<param id="user_data">
5188
<outptr><void/></outptr>
5189
<description>
5190
The user supplied data that was passed into the iteration function.
5191
</description>
5192
</param>
5193
</parameters>
5194
</callback>
5195
5196
<callback id="jvmtiStackReferenceCallback">
5197
<enum>jvmtiIterationControl</enum>
5198
<synopsis>Stack Reference Object Callback</synopsis>
5199
<description>
5200
Agent supplied callback function.
5201
Describes (but does not pass in) an object on the stack that is a root for
5202
the purposes of garbage collection.
5203
<p/>
5204
Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5205
<code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5206
references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5207
<p/>
5208
See the <internallink id="heapCallbacks">heap callback
5209
function restrictions</internallink>.
5210
</description>
5211
<parameters>
5212
<param id="root_kind">
5213
<enum>jvmtiHeapRootKind</enum>
5214
<description>
5215
The kind of root (either <code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or
5216
<code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>).
5217
</description>
5218
</param>
5219
<param id="class_tag">
5220
<jlong/>
5221
<description>
5222
The tag of the class of object (zero if the class is not tagged).
5223
If the object represents a runtime class, the <code>class_tag</code> is the tag
5224
associated with <code>java.lang.Class</code>
5225
(zero if <code>java.lang.Class</code> is not tagged).
5226
</description>
5227
</param>
5228
<param id="size">
5229
<jlong/>
5230
<description>
5231
Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
5232
</description>
5233
</param>
5234
<param id="tag_ptr">
5235
<outptr><jlong/></outptr>
5236
<description>
5237
The object tag value, or zero if the object is not tagged.
5238
To set the tag value to be associated with the object
5239
the agent sets the <code>jlong</code> pointed to by the parameter.
5240
</description>
5241
</param>
5242
<param id="thread_tag">
5243
<jlong/>
5244
<description>
5245
The tag of the thread corresponding to this stack, zero if not tagged.
5246
</description>
5247
</param>
5248
<param id="depth">
5249
<jint/>
5250
<description>
5251
The depth of the frame.
5252
</description>
5253
</param>
5254
<param id="method">
5255
<jmethodID/>
5256
<description>
5257
The method executing in this frame.
5258
</description>
5259
</param>
5260
<param id="slot">
5261
<jint/>
5262
<description>
5263
The slot number.
5264
</description>
5265
</param>
5266
<param id="user_data">
5267
<outptr><void/></outptr>
5268
<description>
5269
The user supplied data that was passed into the iteration function.
5270
</description>
5271
</param>
5272
</parameters>
5273
</callback>
5274
5275
<callback id="jvmtiObjectReferenceCallback">
5276
<enum>jvmtiIterationControl</enum>
5277
<synopsis>Object Reference Callback</synopsis>
5278
<description>
5279
Agent supplied callback function.
5280
Describes a reference from an object (the referrer) to another object
5281
(the referree).
5282
<p/>
5283
Return value should be <code>JVMTI_ITERATION_CONTINUE</code> to continue iteration,
5284
<code>JVMTI_ITERATION_IGNORE</code> to continue iteration without pursuing
5285
references from referree object or <code>JVMTI_ITERATION_ABORT</code> to stop iteration.
5286
<p/>
5287
See the <internallink id="heapCallbacks">heap callback
5288
function restrictions</internallink>.
5289
</description>
5290
<parameters>
5291
<param id="reference_kind">
5292
<enum>jvmtiObjectReferenceKind</enum>
5293
<description>
5294
The type of reference.
5295
</description>
5296
</param>
5297
<param id="class_tag">
5298
<jlong/>
5299
<description>
5300
The tag of the class of referree object (zero if the class is not tagged).
5301
If the referree object represents a runtime class,
5302
the <code>class_tag</code> is the tag
5303
associated with <code>java.lang.Class</code>
5304
(zero if <code>java.lang.Class</code> is not tagged).
5305
</description>
5306
</param>
5307
<param id="size">
5308
<jlong/>
5309
<description>
5310
Size of the referree object (in bytes).
5311
See <functionlink id="GetObjectSize"/>.
5312
</description>
5313
</param>
5314
<param id="tag_ptr">
5315
<outptr><jlong/></outptr>
5316
<description>
5317
The referree object tag value, or zero if the object is not
5318
tagged.
5319
To set the tag value to be associated with the object
5320
the agent sets the <code>jlong</code> pointed to by the parameter.
5321
</description>
5322
</param>
5323
<param id="referrer_tag">
5324
<jlong/>
5325
<description>
5326
The tag of the referrer object, or zero if the referrer
5327
object is not tagged.
5328
</description>
5329
</param>
5330
<param id="referrer_index">
5331
<jint/>
5332
<description>
5333
For references of type <code>JVMTI_REFERENCE_FIELD</code> or
5334
<code>JVMTI_REFERENCE_STATIC_FIELD</code> the index
5335
of the field in the referrer object. The index is based on the
5336
order of all the object's fields - see <internallink
5337
id="JVMTI_REFERENCE_FIELD">JVMTI_REFERENCE_FIELD</internallink>
5338
or <internallink
5339
id="JVMTI_REFERENCE_STATIC_FIELD">JVMTI_REFERENCE_STATIC_FIELD
5340
</internallink> for further description.
5341
<p/>
5342
For references of type <code>JVMTI_REFERENCE_ARRAY_ELEMENT</code>
5343
the array index - see <internallink id="JVMTI_REFERENCE_ARRAY_ELEMENT">
5344
JVMTI_REFERENCE_ARRAY_ELEMENT</internallink> for further description.
5345
<p/>
5346
For references of type <code>JVMTI_REFERENCE_CONSTANT_POOL</code>
5347
the index into the constant pool of the class - see
5348
<internallink id="JVMTI_REFERENCE_CONSTANT_POOL">
5349
JVMTI_REFERENCE_CONSTANT_POOL</internallink> for further
5350
description.
5351
<p/>
5352
For references of other kinds the <code>referrer_index</code> is
5353
<code>-1</code>.
5354
</description>
5355
</param>
5356
<param id="user_data">
5357
<outptr><void/></outptr>
5358
<description>
5359
The user supplied data that was passed into the iteration function.
5360
</description>
5361
</param>
5362
</parameters>
5363
</callback>
5364
5365
<function id="IterateOverObjectsReachableFromObject" num="109">
5366
<synopsis>Iterate Over Objects Reachable From Object</synopsis>
5367
<description>
5368
This function iterates over all objects that are directly
5369
and indirectly reachable from the specified object.
5370
For each object <i>A</i> (known
5371
as the referrer) with a reference to object <i>B</i> the specified
5372
callback function is called to describe the object reference.
5373
The callback is called exactly once for each reference from a referrer;
5374
this is true even if there are reference cycles or multiple paths to
5375
the referrer.
5376
There may be more than one reference between a referrer and a referree,
5377
These may be distinguished by the
5378
<datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and
5379
<datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>.
5380
The callback for an object will always occur after the callback for
5381
its referrer.
5382
<p/>
5383
See <functionlink id="FollowReferences"/> for the object
5384
references which are reported.
5385
<p/>
5386
During the execution of this function the state of the heap
5387
does not change: no objects are allocated, no objects are
5388
garbage collected, and the state of objects (including
5389
held values) does not change.
5390
As a result, threads executing Java
5391
programming language code, threads attempting to resume the
5392
execution of Java programming language code, and threads
5393
attempting to execute JNI functions are typically stalled.
5394
</description>
5395
<origin>new</origin>
5396
<capabilities>
5397
<required id="can_tag_objects"></required>
5398
</capabilities>
5399
<parameters>
5400
<param id="object">
5401
<jobject/>
5402
<description>
5403
The object
5404
</description>
5405
</param>
5406
<param id="object_reference_callback">
5407
<ptrtype>
5408
<struct>jvmtiObjectReferenceCallback</struct>
5409
</ptrtype>
5410
<description>
5411
The callback to be called to describe each
5412
object reference.
5413
</description>
5414
</param>
5415
<param id="user_data">
5416
<inbuf>
5417
<void/>
5418
<nullok><code>NULL</code> is passed as the user supplied data</nullok>
5419
</inbuf>
5420
<description>
5421
User supplied data to be passed to the callback.
5422
</description>
5423
</param>
5424
</parameters>
5425
<errors>
5426
</errors>
5427
</function>
5428
5429
<function id="IterateOverReachableObjects" num="110">
5430
<synopsis>Iterate Over Reachable Objects</synopsis>
5431
<description>
5432
This function iterates over the root objects and all objects that
5433
are directly and indirectly reachable from the root objects.
5434
The root objects comprise the set of system classes,
5435
JNI globals, references from thread stacks, and other objects used as roots
5436
for the purposes of garbage collection.
5437
<p/>
5438
For each root the <paramlink id="heap_root_callback"></paramlink>
5439
or <paramlink id="stack_ref_callback"></paramlink> callback is called.
5440
An object can be a root object for more than one reason and in that case
5441
the appropriate callback is called for each reason.
5442
<p/>
5443
For each object reference the <paramlink id="object_ref_callback"></paramlink>
5444
callback function is called to describe the object reference.
5445
The callback is called exactly once for each reference from a referrer;
5446
this is true even if there are reference cycles or multiple paths to
5447
the referrer.
5448
There may be more than one reference between a referrer and a referree,
5449
These may be distinguished by the
5450
<datalink id="jvmtiObjectReferenceCallback.reference_kind"></datalink> and
5451
<datalink id="jvmtiObjectReferenceCallback.referrer_index"></datalink>.
5452
The callback for an object will always occur after the callback for
5453
its referrer.
5454
<p/>
5455
See <functionlink id="FollowReferences"/> for the object
5456
references which are reported.
5457
<p/>
5458
Roots are always reported to the profiler before any object references
5459
are reported. In other words, the <paramlink id="object_ref_callback"></paramlink>
5460
callback will not be called until the appropriate callback has been called
5461
for all roots. If the <paramlink id="object_ref_callback"></paramlink> callback is
5462
specified as <code>NULL</code> then this function returns after
5463
reporting the root objects to the profiler.
5464
<p/>
5465
During the execution of this function the state of the heap
5466
does not change: no objects are allocated, no objects are
5467
garbage collected, and the state of objects (including
5468
held values) does not change.
5469
As a result, threads executing Java
5470
programming language code, threads attempting to resume the
5471
execution of Java programming language code, and threads
5472
attempting to execute JNI functions are typically stalled.
5473
</description>
5474
<origin>new</origin>
5475
<capabilities>
5476
<required id="can_tag_objects"></required>
5477
</capabilities>
5478
<parameters>
5479
<param id="heap_root_callback">
5480
<ptrtype>
5481
<struct>jvmtiHeapRootCallback</struct>
5482
<nullok>do not report heap roots</nullok>
5483
</ptrtype>
5484
<description>
5485
The callback function to be called for each heap root of type
5486
<code>JVMTI_HEAP_ROOT_JNI_GLOBAL</code>,
5487
<code>JVMTI_HEAP_ROOT_SYSTEM_CLASS</code>,
5488
<code>JVMTI_HEAP_ROOT_MONITOR</code>,
5489
<code>JVMTI_HEAP_ROOT_THREAD</code>, or
5490
<code>JVMTI_HEAP_ROOT_OTHER</code>.
5491
</description>
5492
</param>
5493
<param id="stack_ref_callback">
5494
<ptrtype>
5495
<struct>jvmtiStackReferenceCallback</struct>
5496
<nullok>do not report stack references</nullok>
5497
</ptrtype>
5498
<description>
5499
The callback function to be called for each heap root of
5500
<code>JVMTI_HEAP_ROOT_STACK_LOCAL</code> or
5501
<code>JVMTI_HEAP_ROOT_JNI_LOCAL</code>.
5502
</description>
5503
</param>
5504
<param id="object_ref_callback">
5505
<ptrtype>
5506
<struct>jvmtiObjectReferenceCallback</struct>
5507
<nullok>do not follow references from the root objects</nullok>
5508
</ptrtype>
5509
<description>
5510
The callback function to be called for each object reference.
5511
</description>
5512
</param>
5513
<param id="user_data">
5514
<inbuf>
5515
<void/>
5516
<nullok><code>NULL</code> is passed as the user supplied data</nullok>
5517
</inbuf>
5518
<description>
5519
User supplied data to be passed to the callback.
5520
</description>
5521
</param>
5522
</parameters>
5523
<errors>
5524
</errors>
5525
</function>
5526
5527
<function id="IterateOverHeap" num="111">
5528
<synopsis>Iterate Over Heap</synopsis>
5529
<description>
5530
Iterate over all objects in the heap. This includes both reachable and
5531
unreachable objects.
5532
<p/>
5533
The <paramlink id="object_filter"></paramlink> parameter indicates the
5534
objects for which the callback function is called. If this parameter
5535
is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be
5536
called for every object that is tagged. If the parameter is
5537
<code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be
5538
for objects that are not tagged. If the parameter
5539
is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be
5540
called for every object in the heap, irrespective of whether it is
5541
tagged or not.
5542
<p/>
5543
During the execution of this function the state of the heap
5544
does not change: no objects are allocated, no objects are
5545
garbage collected, and the state of objects (including
5546
held values) does not change.
5547
As a result, threads executing Java
5548
programming language code, threads attempting to resume the
5549
execution of Java programming language code, and threads
5550
attempting to execute JNI functions are typically stalled.
5551
</description>
5552
<origin>new</origin>
5553
<capabilities>
5554
<required id="can_tag_objects"></required>
5555
</capabilities>
5556
<parameters>
5557
<param id="object_filter">
5558
<enum>jvmtiHeapObjectFilter</enum>
5559
<description>
5560
Indicates the objects for which the callback function is called.
5561
</description>
5562
</param>
5563
<param id="heap_object_callback">
5564
<ptrtype>
5565
<struct>jvmtiHeapObjectCallback</struct>
5566
</ptrtype>
5567
<description>
5568
The iterator function to be called for each
5569
object matching the <paramlink id="object_filter"/>.
5570
</description>
5571
</param>
5572
<param id="user_data">
5573
<inbuf>
5574
<void/>
5575
<nullok><code>NULL</code> is passed as the user supplied data</nullok>
5576
</inbuf>
5577
<description>
5578
User supplied data to be passed to the callback.
5579
</description>
5580
</param>
5581
</parameters>
5582
<errors>
5583
</errors>
5584
</function>
5585
5586
<function id="IterateOverInstancesOfClass" num="112">
5587
<synopsis>Iterate Over Instances Of Class</synopsis>
5588
<description>
5589
Iterate over all objects in the heap that are instances of the specified class.
5590
This includes direct instances of the specified class and
5591
instances of all subclasses of the specified class.
5592
This includes both reachable and unreachable objects.
5593
<p/>
5594
The <paramlink id="object_filter"></paramlink> parameter indicates the
5595
objects for which the callback function is called. If this parameter
5596
is <code>JVMTI_HEAP_OBJECT_TAGGED</code> then the callback will only be
5597
called for every object that is tagged. If the parameter is
5598
<code>JVMTI_HEAP_OBJECT_UNTAGGED</code> then the callback will only be
5599
called for objects that are not tagged. If the parameter
5600
is <code>JVMTI_HEAP_OBJECT_EITHER</code> then the callback will be
5601
called for every object in the heap, irrespective of whether it is
5602
tagged or not.
5603
<p/>
5604
During the execution of this function the state of the heap
5605
does not change: no objects are allocated, no objects are
5606
garbage collected, and the state of objects (including
5607
held values) does not change.
5608
As a result, threads executing Java
5609
programming language code, threads attempting to resume the
5610
execution of Java programming language code, and threads
5611
attempting to execute JNI functions are typically stalled.
5612
</description>
5613
<origin>new</origin>
5614
<capabilities>
5615
<required id="can_tag_objects"></required>
5616
</capabilities>
5617
<parameters>
5618
<param id="klass">
5619
<jclass/>
5620
<description>
5621
Iterate over objects of this class only.
5622
</description>
5623
</param>
5624
<param id="object_filter">
5625
<enum>jvmtiHeapObjectFilter</enum>
5626
<description>
5627
Indicates the objects for which the callback function is called.
5628
</description>
5629
</param>
5630
<param id="heap_object_callback">
5631
<ptrtype>
5632
<struct>jvmtiHeapObjectCallback</struct>
5633
</ptrtype>
5634
<description>
5635
The iterator function to be called for each
5636
<paramlink id="klass"/> instance matching
5637
the <paramlink id="object_filter"/>.
5638
</description>
5639
</param>
5640
<param id="user_data">
5641
<inbuf>
5642
<void/>
5643
<nullok><code>NULL</code> is passed as the user supplied data</nullok>
5644
</inbuf>
5645
<description>
5646
User supplied data to be passed to the callback.
5647
</description>
5648
</param>
5649
</parameters>
5650
<errors>
5651
</errors>
5652
</function>
5653
5654
</category>
5655
5656
<category id="local" label="Local Variable">
5657
5658
<intro>
5659
These functions are used to retrieve or set the value of a local variable.
5660
The variable is identified by the depth of the frame containing its
5661
value and the variable's slot number within that frame.
5662
The mapping of variables to
5663
slot numbers can be obtained with the function
5664
<functionlink id="GetLocalVariableTable"></functionlink>.
5665
</intro>
5666
5667
<function id="GetLocalObject" num="21">
5668
<synopsis>Get Local Variable - Object</synopsis>
5669
<description>
5670
This function can be used to retrieve the value of a local
5671
variable whose type is <code>Object</code> or a subclass of <code>Object</code>.
5672
</description>
5673
<origin>jvmdi</origin>
5674
<capabilities>
5675
<required id="can_access_local_variables"></required>
5676
</capabilities>
5677
<parameters>
5678
<param id="thread">
5679
<jthread null="current" frame="frame"/>
5680
<description>
5681
The thread of the frame containing the variable's value.
5682
</description>
5683
</param>
5684
<param id="depth">
5685
<jframeID thread="thread"/>
5686
<description>
5687
The depth of the frame containing the variable's value.
5688
</description>
5689
</param>
5690
<param id="slot">
5691
<jint/>
5692
<description>
5693
The variable's slot number.
5694
</description>
5695
</param>
5696
<param id="value_ptr">
5697
<outptr><jobject/></outptr>
5698
<description>
5699
On return, points to the variable's value.
5700
</description>
5701
</param>
5702
</parameters>
5703
<errors>
5704
<error id="JVMTI_ERROR_INVALID_SLOT">
5705
Invalid <code>slot</code>.
5706
</error>
5707
<error id="JVMTI_ERROR_TYPE_MISMATCH">
5708
The variable type is not
5709
<code>Object</code> or a subclass of <code>Object</code>.
5710
</error>
5711
<error id="JVMTI_ERROR_OPAQUE_FRAME">
5712
Not a visible frame
5713
</error>
5714
</errors>
5715
</function>
5716
5717
<function id="GetLocalInstance" num="155" since="1.2">
5718
<synopsis>Get Local Instance</synopsis>
5719
<description>
5720
This function can be used to retrieve the value of the local object
5721
variable at slot 0 (the "<code>this</code>" object) from non-static
5722
frames. This function can retrieve the "<code>this</code>" object from
5723
native method frames, whereas <code>GetLocalObject()</code> would
5724
return <code>JVMTI_ERROR_OPAQUE_FRAME</code> in those cases.
5725
</description>
5726
<origin>new</origin>
5727
<capabilities>
5728
<required id="can_access_local_variables"></required>
5729
</capabilities>
5730
<parameters>
5731
<param id="thread">
5732
<jthread null="current" frame="frame"/>
5733
<description>
5734
The thread of the frame containing the variable's value.
5735
</description>
5736
</param>
5737
<param id="depth">
5738
<jframeID thread="thread"/>
5739
<description>
5740
The depth of the frame containing the variable's value.
5741
</description>
5742
</param>
5743
<param id="value_ptr">
5744
<outptr><jobject/></outptr>
5745
<description>
5746
On return, points to the variable's value.
5747
</description>
5748
</param>
5749
</parameters>
5750
<errors>
5751
<error id="JVMTI_ERROR_INVALID_SLOT">
5752
If the specified frame is a static method frame.
5753
</error>
5754
</errors>
5755
</function>
5756
<function id="GetLocalInt" num="22">
5757
<synopsis>Get Local Variable - Int</synopsis>
5758
<description>
5759
This function can be used to retrieve the value of a local
5760
variable whose type is <code>int</code>,
5761
<code>short</code>, <code>char</code>, <code>byte</code>, or
5762
<code>boolean</code>.
5763
</description>
5764
<origin>jvmdi</origin>
5765
<capabilities>
5766
<required id="can_access_local_variables"></required>
5767
</capabilities>
5768
<parameters>
5769
<param id="thread">
5770
<jthread null="current" frame="frame"/>
5771
<description>
5772
The thread of the frame containing the variable's value.
5773
</description>
5774
</param>
5775
<param id="depth">
5776
<jframeID thread="thread"/>
5777
<description>
5778
The depth of the frame containing the variable's value.
5779
</description>
5780
</param>
5781
<param id="slot">
5782
<jint/>
5783
<description>
5784
The variable's slot number.
5785
</description>
5786
</param>
5787
<param id="value_ptr">
5788
<outptr><jint/></outptr>
5789
<description>
5790
On return, points to the variable's value.
5791
</description>
5792
</param>
5793
</parameters>
5794
<errors>
5795
<error id="JVMTI_ERROR_INVALID_SLOT">
5796
Invalid <code>slot</code>.
5797
</error>
5798
<error id="JVMTI_ERROR_TYPE_MISMATCH">
5799
The variable type is not
5800
<code>int</code>, <code>short</code>,
5801
<code>char</code>, <code>byte</code>, or
5802
<code>boolean</code>.
5803
</error>
5804
<error id="JVMTI_ERROR_OPAQUE_FRAME">
5805
Not a visible frame
5806
</error>
5807
</errors>
5808
</function>
5809
5810
<function id="GetLocalLong" num="23">
5811
<synopsis>Get Local Variable - Long</synopsis>
5812
<description>
5813
This function can be used to retrieve the value of a local
5814
variable whose type is <code>long</code>.
5815
</description>
5816
<origin>jvmdi</origin>
5817
<capabilities>
5818
<required id="can_access_local_variables"></required>
5819
</capabilities>
5820
<parameters>
5821
<param id="thread">
5822
<jthread null="current" frame="frame"/>
5823
<description>
5824
The thread of the frame containing the variable's value.
5825
</description>
5826
</param>
5827
<param id="depth">
5828
<jframeID thread="thread"/>
5829
<description>
5830
The depth of the frame containing the variable's value.
5831
</description>
5832
</param>
5833
<param id="slot">
5834
<jint/>
5835
<description>
5836
The variable's slot number.
5837
</description>
5838
</param>
5839
<param id="value_ptr">
5840
<outptr><jlong/></outptr>
5841
<description>
5842
On return, points to the variable's value.
5843
</description>
5844
</param>
5845
</parameters>
5846
<errors>
5847
<error id="JVMTI_ERROR_INVALID_SLOT">
5848
Invalid <code>slot</code>.
5849
</error>
5850
<error id="JVMTI_ERROR_TYPE_MISMATCH">
5851
The variable type is not <code>long</code>.
5852
</error>
5853
<error id="JVMTI_ERROR_OPAQUE_FRAME">
5854
Not a visible frame
5855
</error>
5856
</errors>
5857
</function>
5858
5859
<function id="GetLocalFloat" num="24">
5860
<synopsis>Get Local Variable - Float</synopsis>
5861
<description>
5862
This function can be used to retrieve the value of a local
5863
variable whose type is <code>float</code>.
5864
</description>
5865
<origin>jvmdi</origin>
5866
<capabilities>
5867
<required id="can_access_local_variables"></required>
5868
</capabilities>
5869
<parameters>
5870
<param id="thread">
5871
<jthread null="current" frame="frame"/>
5872
<description>
5873
The thread of the frame containing the variable's value.
5874
</description>
5875
</param>
5876
<param id="depth">
5877
<jframeID thread="thread"/>
5878
<description>
5879
The depth of the frame containing the variable's value.
5880
</description>
5881
</param>
5882
<param id="slot">
5883
<jint/>
5884
<description>
5885
The variable's slot number.
5886
</description>
5887
</param>
5888
<param id="value_ptr">
5889
<outptr><jfloat/></outptr>
5890
<description>
5891
On return, points to the variable's value.
5892
</description>
5893
</param>
5894
</parameters>
5895
<errors>
5896
<error id="JVMTI_ERROR_INVALID_SLOT">
5897
Invalid <code>slot</code>.
5898
</error>
5899
<error id="JVMTI_ERROR_TYPE_MISMATCH">
5900
The variable type is not <code>float</code>.
5901
</error>
5902
<error id="JVMTI_ERROR_OPAQUE_FRAME">
5903
Not a visible frame
5904
</error>
5905
</errors>
5906
</function>
5907
5908
<function id="GetLocalDouble" num="25">
5909
<synopsis>Get Local Variable - Double</synopsis>
5910
<description>
5911
This function can be used to retrieve the value of a local
5912
variable whose type is <code>long</code>.
5913
</description>
5914
<origin>jvmdi</origin>
5915
<capabilities>
5916
<required id="can_access_local_variables"></required>
5917
</capabilities>
5918
<parameters>
5919
<param id="thread">
5920
<jthread null="current" frame="frame"/>
5921
<description>
5922
The thread of the frame containing the variable's value.
5923
</description>
5924
</param>
5925
<param id="depth">
5926
<jframeID thread="thread"/>
5927
<description>
5928
The depth of the frame containing the variable's value.
5929
</description>
5930
</param>
5931
<param id="slot">
5932
<jint/>
5933
<description>
5934
The variable's slot number.
5935
</description>
5936
</param>
5937
<param id="value_ptr">
5938
<outptr><jdouble/></outptr>
5939
<description>
5940
On return, points to the variable's value.
5941
</description>
5942
</param>
5943
</parameters>
5944
<errors>
5945
<error id="JVMTI_ERROR_INVALID_SLOT">
5946
Invalid <code>slot</code>.
5947
</error>
5948
<error id="JVMTI_ERROR_TYPE_MISMATCH">
5949
The variable type is not <code>double</code>.
5950
</error>
5951
<error id="JVMTI_ERROR_OPAQUE_FRAME">
5952
Not a visible frame
5953
</error>
5954
</errors>
5955
</function>
5956
5957
<function id="SetLocalObject" num="26">
5958
<synopsis>Set Local Variable - Object</synopsis>
5959
<description>
5960
This function can be used to set the value of a local
5961
variable whose type is <code>Object</code> or a subclass of <code>Object</code>.
5962
</description>
5963
<origin>jvmdi</origin>
5964
<capabilities>
5965
<required id="can_access_local_variables"></required>
5966
</capabilities>
5967
<parameters>
5968
<param id="thread">
5969
<jthread null="current" frame="frame"/>
5970
<description>
5971
The thread of the frame containing the variable's value.
5972
</description>
5973
</param>
5974
<param id="depth">
5975
<jframeID thread="thread"/>
5976
<description>
5977
The depth of the frame containing the variable's value.
5978
</description>
5979
</param>
5980
<param id="slot">
5981
<jint/>
5982
<description>
5983
The variable's slot number.
5984
</description>
5985
</param>
5986
<param id="value">
5987
<jobject/>
5988
<description>
5989
The new value for the variable.
5990
</description>
5991
</param>
5992
</parameters>
5993
<errors>
5994
<error id="JVMTI_ERROR_INVALID_SLOT">
5995
Invalid <code>slot</code>.
5996
</error>
5997
<error id="JVMTI_ERROR_TYPE_MISMATCH">
5998
The variable type is not
5999
<code>Object</code> or a subclass of <code>Object</code>.
6000
</error>
6001
<error id="JVMTI_ERROR_TYPE_MISMATCH">
6002
The supplied <paramlink id="value"/> is not compatible
6003
with the variable type.
6004
</error>
6005
<error id="JVMTI_ERROR_OPAQUE_FRAME">
6006
Not a visible frame
6007
</error>
6008
</errors>
6009
</function>
6010
6011
<function id="SetLocalInt" num="27">
6012
<synopsis>Set Local Variable - Int</synopsis>
6013
<description>
6014
This function can be used to set the value of a local
6015
variable whose type is <code>int</code>,
6016
<code>short</code>, <code>char</code>, <code>byte</code>, or
6017
<code>boolean</code>.
6018
</description>
6019
<origin>jvmdi</origin>
6020
<capabilities>
6021
<required id="can_access_local_variables"></required>
6022
</capabilities>
6023
<parameters>
6024
<param id="thread">
6025
<jthread null="current" frame="frame"/>
6026
<description>
6027
The thread of the frame containing the variable's value.
6028
</description>
6029
</param>
6030
<param id="depth">
6031
<jframeID thread="thread"/>
6032
<description>
6033
The depth of the frame containing the variable's value.
6034
</description>
6035
</param>
6036
<param id="slot">
6037
<jint/>
6038
<description>
6039
The variable's slot number.
6040
</description>
6041
</param>
6042
<param id="value">
6043
<jint/>
6044
<description>
6045
The new value for the variable.
6046
</description>
6047
</param>
6048
</parameters>
6049
<errors>
6050
<error id="JVMTI_ERROR_INVALID_SLOT">
6051
Invalid <code>slot</code>.
6052
</error>
6053
<error id="JVMTI_ERROR_TYPE_MISMATCH">
6054
The variable type is not
6055
<code>int</code>, <code>short</code>,
6056
<code>char</code>, <code>byte</code>, or
6057
<code>boolean</code>.
6058
</error>
6059
<error id="JVMTI_ERROR_OPAQUE_FRAME">
6060
Not a visible frame
6061
</error>
6062
</errors>
6063
</function>
6064
6065
<function id="SetLocalLong" num="28">
6066
<synopsis>Set Local Variable - Long</synopsis>
6067
<description>
6068
This function can be used to set the value of a local
6069
variable whose type is <code>long</code>.
6070
</description>
6071
<origin>jvmdi</origin>
6072
<capabilities>
6073
<required id="can_access_local_variables"></required>
6074
</capabilities>
6075
<parameters>
6076
<param id="thread">
6077
<jthread null="current" frame="frame"/>
6078
<description>
6079
The thread of the frame containing the variable's value.
6080
</description>
6081
</param>
6082
<param id="depth">
6083
<jframeID thread="thread"/>
6084
<description>
6085
The depth of the frame containing the variable's value.
6086
</description>
6087
</param>
6088
<param id="slot">
6089
<jint/>
6090
<description>
6091
The variable's slot number.
6092
</description>
6093
</param>
6094
<param id="value">
6095
<jlong/>
6096
<description>
6097
The new value for the variable.
6098
</description>
6099
</param>
6100
</parameters>
6101
<errors>
6102
<error id="JVMTI_ERROR_INVALID_SLOT">
6103
Invalid <code>slot</code>.
6104
</error>
6105
<error id="JVMTI_ERROR_TYPE_MISMATCH">
6106
The variable type is not <code>long</code>.
6107
</error>
6108
<error id="JVMTI_ERROR_OPAQUE_FRAME">
6109
Not a visible frame
6110
</error>
6111
</errors>
6112
</function>
6113
6114
<function id="SetLocalFloat" num="29">
6115
<synopsis>Set Local Variable - Float</synopsis>
6116
<description>
6117
This function can be used to set the value of a local
6118
variable whose type is <code>float</code>.
6119
</description>
6120
<origin>jvmdi</origin>
6121
<capabilities>
6122
<required id="can_access_local_variables"></required>
6123
</capabilities>
6124
<parameters>
6125
<param id="thread">
6126
<jthread null="current" frame="frame"/>
6127
<description>
6128
The thread of the frame containing the variable's value.
6129
</description>
6130
</param>
6131
<param id="depth">
6132
<jframeID thread="thread"/>
6133
<description>
6134
The depth of the frame containing the variable's value.
6135
</description>
6136
</param>
6137
<param id="slot">
6138
<jint/>
6139
<description>
6140
The variable's slot number.
6141
</description>
6142
</param>
6143
<param id="value">
6144
<jfloat/>
6145
<description>
6146
The new value for the variable.
6147
</description>
6148
</param>
6149
</parameters>
6150
<errors>
6151
<error id="JVMTI_ERROR_INVALID_SLOT">
6152
Invalid <code>slot</code>.
6153
</error>
6154
<error id="JVMTI_ERROR_TYPE_MISMATCH">
6155
The variable type is not <code>float</code>.
6156
</error>
6157
<error id="JVMTI_ERROR_OPAQUE_FRAME">
6158
Not a visible frame
6159
</error>
6160
</errors>
6161
</function>
6162
6163
<function id="SetLocalDouble" num="30">
6164
<synopsis>Set Local Variable - Double</synopsis>
6165
<description>
6166
This function can be used to set the value of a local
6167
variable whose type is <code>double</code>.
6168
</description>
6169
<origin>jvmdi</origin>
6170
<capabilities>
6171
<required id="can_access_local_variables"></required>
6172
</capabilities>
6173
<parameters>
6174
<param id="thread">
6175
<jthread null="current" frame="frame"/>
6176
<description>
6177
The thread of the frame containing the variable's value.
6178
</description>
6179
</param>
6180
<param id="depth">
6181
<jframeID thread="thread"/>
6182
<description>
6183
The depth of the frame containing the variable's value.
6184
</description>
6185
</param>
6186
<param id="slot">
6187
<jint/>
6188
<description>
6189
The variable's slot number.
6190
</description>
6191
</param>
6192
<param id="value">
6193
<jdouble/>
6194
<description>
6195
The new value for the variable.
6196
</description>
6197
</param>
6198
</parameters>
6199
<errors>
6200
<error id="JVMTI_ERROR_INVALID_SLOT">
6201
Invalid <code>slot</code>.
6202
</error>
6203
<error id="JVMTI_ERROR_TYPE_MISMATCH">
6204
The variable type is not <code>double</code>.
6205
</error>
6206
<error id="JVMTI_ERROR_OPAQUE_FRAME">
6207
Not a visible frame
6208
</error>
6209
</errors>
6210
</function>
6211
</category>
6212
6213
<category id="breakpointCategory" label="Breakpoint">
6214
6215
<intro>
6216
</intro>
6217
6218
<function id="SetBreakpoint" num="38">
6219
<synopsis>Set Breakpoint</synopsis>
6220
<description>
6221
Set a breakpoint at the instruction indicated by
6222
<code>method</code> and <code>location</code>.
6223
An instruction can only have one breakpoint.
6224
<p/>
6225
Whenever the designated instruction is about to be executed, a
6226
<eventlink id="Breakpoint"></eventlink> event is generated.
6227
</description>
6228
<origin>jvmdi</origin>
6229
<capabilities>
6230
<required id="can_generate_breakpoint_events"></required>
6231
</capabilities>
6232
<parameters>
6233
<param id="klass">
6234
<jclass method="method"/>
6235
<description>
6236
The class in which to set the breakpoint
6237
</description>
6238
</param>
6239
<param id="method">
6240
<jmethodID class="klass"/>
6241
<description>
6242
The method in which to set the breakpoint
6243
</description>
6244
</param>
6245
<param id="location">
6246
<jlocation/>
6247
<description>
6248
the index of the instruction at which to set the breakpoint
6249
6250
</description>
6251
</param>
6252
</parameters>
6253
<errors>
6254
<error id="JVMTI_ERROR_DUPLICATE">
6255
The designated bytecode already has a breakpoint.
6256
</error>
6257
</errors>
6258
</function>
6259
6260
<function id="ClearBreakpoint" num="39">
6261
<synopsis>Clear Breakpoint</synopsis>
6262
<description>
6263
Clear the breakpoint at the bytecode indicated by
6264
<code>method</code> and <code>location</code>.
6265
</description>
6266
<origin>jvmdi</origin>
6267
<capabilities>
6268
<required id="can_generate_breakpoint_events"></required>
6269
</capabilities>
6270
<parameters>
6271
<param id="klass">
6272
<jclass method="method"/>
6273
<description>
6274
The class in which to clear the breakpoint
6275
</description>
6276
</param>
6277
<param id="method">
6278
<jmethodID class="klass"/>
6279
<description>
6280
The method in which to clear the breakpoint
6281
</description>
6282
</param>
6283
<param id="location">
6284
<jlocation/>
6285
<description>
6286
the index of the instruction at which to clear the breakpoint
6287
</description>
6288
</param>
6289
</parameters>
6290
<errors>
6291
<error id="JVMTI_ERROR_NOT_FOUND">
6292
There's no breakpoint at the designated bytecode.
6293
</error>
6294
</errors>
6295
</function>
6296
6297
</category>
6298
6299
<category id="fieldWatch" label="Watched Field">
6300
6301
<intro>
6302
</intro>
6303
6304
<function id="SetFieldAccessWatch" num="41">
6305
<synopsis>Set Field Access Watch</synopsis>
6306
<description>
6307
Generate a <eventlink id="FieldAccess"></eventlink> event
6308
when the field specified
6309
by <code>klass</code> and
6310
<code>field</code> is about to be accessed.
6311
An event will be generated for each access of the field
6312
until it is canceled with
6313
<functionlink id="ClearFieldAccessWatch"></functionlink>.
6314
Field accesses from Java programming language code or from JNI code are watched,
6315
fields modified by other means are not watched.
6316
Note that <jvmti/> users should be aware that their own field accesses
6317
will trigger the watch.
6318
A field can only have one field access watch set.
6319
Modification of a field is not considered an access--use
6320
<functionlink id="SetFieldModificationWatch"></functionlink>
6321
to monitor modifications.
6322
</description>
6323
<origin>jvmdi</origin>
6324
<capabilities>
6325
<required id="can_generate_field_access_events"></required>
6326
</capabilities>
6327
<parameters>
6328
<param id="klass">
6329
<jclass field="field"/>
6330
<description>
6331
The class containing the field to watch
6332
</description>
6333
</param>
6334
<param id="field">
6335
<jfieldID class="klass"/>
6336
<description>
6337
The field to watch
6338
6339
</description>
6340
</param>
6341
</parameters>
6342
<errors>
6343
<error id="JVMTI_ERROR_DUPLICATE">
6344
The designated field is already being watched for accesses.
6345
</error>
6346
</errors>
6347
</function>
6348
6349
<function id="ClearFieldAccessWatch" num="42">
6350
<synopsis>Clear Field Access Watch</synopsis>
6351
<description>
6352
Cancel a field access watch previously set by
6353
<functionlink id="SetFieldAccessWatch"></functionlink>, on the
6354
field specified
6355
by <code>klass</code> and
6356
<code>field</code>.
6357
</description>
6358
<origin>jvmdi</origin>
6359
<capabilities>
6360
<required id="can_generate_field_access_events"></required>
6361
</capabilities>
6362
<parameters>
6363
<param id="klass">
6364
<jclass field="field"/>
6365
<description>
6366
The class containing the field to watch
6367
</description>
6368
</param>
6369
<param id="field">
6370
<jfieldID class="klass"/>
6371
<description>
6372
The field to watch
6373
6374
</description>
6375
</param>
6376
</parameters>
6377
<errors>
6378
<error id="JVMTI_ERROR_NOT_FOUND">
6379
The designated field is not being watched for accesses.
6380
</error>
6381
</errors>
6382
</function>
6383
6384
<function id="SetFieldModificationWatch" num="43">
6385
<synopsis>Set Field Modification Watch</synopsis>
6386
<description>
6387
Generate a <eventlink id="FieldModification"></eventlink> event
6388
when the field specified
6389
by <code>klass</code> and
6390
<code>field</code> is about to be modified.
6391
An event will be generated for each modification of the field
6392
until it is canceled with
6393
<functionlink id="ClearFieldModificationWatch"></functionlink>.
6394
Field modifications from Java programming language code or from JNI code are watched,
6395
fields modified by other means are not watched.
6396
Note that <jvmti/> users should be aware that their own field modifications
6397
will trigger the watch.
6398
A field can only have one field modification watch set.
6399
</description>
6400
<origin>jvmdi</origin>
6401
<capabilities>
6402
<required id="can_generate_field_modification_events"></required>
6403
</capabilities>
6404
<parameters>
6405
<param id="klass">
6406
<jclass field="field"/>
6407
<description>
6408
The class containing the field to watch
6409
</description>
6410
</param>
6411
<param id="field">
6412
<jfieldID class="klass"/>
6413
<description>
6414
The field to watch
6415
6416
</description>
6417
</param>
6418
</parameters>
6419
<errors>
6420
<error id="JVMTI_ERROR_DUPLICATE">
6421
The designated field is already being watched for modifications.
6422
</error>
6423
</errors>
6424
</function>
6425
6426
<function id="ClearFieldModificationWatch" num="44">
6427
<synopsis>Clear Field Modification Watch</synopsis>
6428
<description>
6429
6430
Cancel a field modification watch previously set by
6431
<functionlink id="SetFieldModificationWatch"></functionlink>, on the
6432
field specified
6433
by <code>klass</code> and
6434
<code>field</code>.
6435
</description>
6436
<origin>jvmdi</origin>
6437
<capabilities>
6438
<required id="can_generate_field_modification_events"></required>
6439
</capabilities>
6440
<parameters>
6441
<param id="klass">
6442
<jclass field="field"/>
6443
<description>
6444
The class containing the field to watch
6445
</description>
6446
</param>
6447
<param id="field">
6448
<jfieldID class="klass"/>
6449
<description>
6450
The field to watch
6451
6452
</description>
6453
</param>
6454
</parameters>
6455
<errors>
6456
<error id="JVMTI_ERROR_NOT_FOUND">
6457
The designated field is not being watched for modifications.
6458
</error>
6459
</errors>
6460
</function>
6461
</category>
6462
6463
<category id="class" label="Class">
6464
6465
<intro>
6466
</intro>
6467
6468
<function id="GetLoadedClasses" jkernel="yes" num="78">
6469
<synopsis>Get Loaded Classes</synopsis>
6470
<description>
6471
Return an array of all classes loaded in the virtual machine.
6472
The number of classes in the array is returned via
6473
<code>class_count_ptr</code>, and the array itself via
6474
<code>classes_ptr</code>.
6475
<p/>
6476
Array classes of all types (including arrays of primitive types) are
6477
included in the returned list. Primitive classes (for example,
6478
<code>java.lang.Integer.TYPE</code>) are <i>not</i> included in this list.
6479
</description>
6480
<origin>jvmdi</origin>
6481
<capabilities>
6482
</capabilities>
6483
<parameters>
6484
<param id="class_count_ptr">
6485
<outptr><jint/></outptr>
6486
<description>
6487
On return, points to the number of classes.
6488
</description>
6489
</param>
6490
<param id="classes_ptr">
6491
<allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6492
<description>
6493
On return, points to an array of references, one
6494
for each class.
6495
</description>
6496
</param>
6497
</parameters>
6498
<errors>
6499
</errors>
6500
</function>
6501
6502
<function id="GetClassLoaderClasses" jkernel="yes" num="79">
6503
<synopsis>Get Classloader Classes</synopsis>
6504
<description>
6505
Returns an array of those classes for which this class loader has
6506
been recorded as an initiating loader. Each
6507
class in the returned array was created by this class loader,
6508
either by defining it directly or by delegation to another class loader.
6509
See <vmspec chapter="5.3"/>.
6510
<p/>
6511
For JDK version 1.1 implementations that don't
6512
recognize the distinction between initiating and defining class loaders,
6513
this function should return all classes loaded in the virtual machine.
6514
The number of classes in the array is returned via
6515
<code>class_count_ptr</code>, and the array itself via
6516
<code>classes_ptr</code>.
6517
</description>
6518
<origin>jvmdi</origin>
6519
<capabilities>
6520
</capabilities>
6521
<parameters>
6522
<param id="initiating_loader">
6523
<ptrtype>
6524
<jobject/>
6525
<nullok>the classes initiated by the bootstrap loader will be returned</nullok>
6526
</ptrtype>
6527
<description>
6528
An initiating class loader.
6529
</description>
6530
</param>
6531
<param id="class_count_ptr">
6532
<outptr><jint/></outptr>
6533
<description>
6534
On return, points to the number of classes.
6535
</description>
6536
</param>
6537
<param id="classes_ptr">
6538
<allocbuf outcount="class_count_ptr"><jclass/></allocbuf>
6539
<description>
6540
On return, points to an array of references, one
6541
for each class.
6542
</description>
6543
</param>
6544
</parameters>
6545
<errors>
6546
</errors>
6547
</function>
6548
6549
<function id="GetClassSignature" phase="start" num="48">
6550
<synopsis>Get Class Signature</synopsis>
6551
<description>
6552
For the class indicated by <code>klass</code>, return the
6553
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/types.html#wp16432">JNI
6554
type signature</externallink>
6555
and the generic signature of the class.
6556
For example, <code>java.util.List</code> is <code>"Ljava/util/List;"</code>
6557
and <code>int[]</code> is <code>"[I"</code>
6558
The returned name for primitive classes
6559
is the type signature character of the corresponding primitive type.
6560
For example, <code>java.lang.Integer.TYPE</code> is <code>"I"</code>.
6561
</description>
6562
<origin>jvmdiClone</origin>
6563
<capabilities>
6564
</capabilities>
6565
<parameters>
6566
<param id="klass">
6567
<jclass/>
6568
<description>
6569
The class to query.
6570
</description>
6571
</param>
6572
<param id="signature_ptr">
6573
<allocbuf>
6574
<char/>
6575
<nullok>the signature is not returned</nullok>
6576
</allocbuf>
6577
<description>
6578
On return, points to the JNI type signature of the class, encoded as a
6579
<internallink id="mUTF">modified UTF-8</internallink> string.
6580
</description>
6581
</param>
6582
<param id="generic_ptr">
6583
<allocbuf>
6584
<char/>
6585
<nullok>the generic signature is not returned</nullok>
6586
</allocbuf>
6587
<description>
6588
On return, points to the generic signature of the class, encoded as a
6589
<internallink id="mUTF">modified UTF-8</internallink> string.
6590
If there is no generic signature attribute for the class, then,
6591
on return, points to <code>NULL</code>.
6592
</description>
6593
</param>
6594
</parameters>
6595
<errors>
6596
</errors>
6597
</function>
6598
6599
<function id="GetClassStatus" phase="start" num="49">
6600
<synopsis>Get Class Status</synopsis>
6601
<description>
6602
Get the status of the class. Zero or more of the following bits can be
6603
set.
6604
<constants id="jvmtiClassStatus" label="Class Status Flags" kind="bits">
6605
<constant id="JVMTI_CLASS_STATUS_VERIFIED" num="1">
6606
Class bytecodes have been verified
6607
</constant>
6608
<constant id="JVMTI_CLASS_STATUS_PREPARED" num="2">
6609
Class preparation is complete
6610
</constant>
6611
<constant id="JVMTI_CLASS_STATUS_INITIALIZED" num="4">
6612
Class initialization is complete. Static initializer has been run.
6613
</constant>
6614
<constant id="JVMTI_CLASS_STATUS_ERROR" num="8">
6615
Error during initialization makes class unusable
6616
</constant>
6617
<constant id="JVMTI_CLASS_STATUS_ARRAY" num="16">
6618
Class is an array. If set, all other bits are zero.
6619
</constant>
6620
<constant id="JVMTI_CLASS_STATUS_PRIMITIVE" num="32">
6621
Class is a primitive class (for example, <code>java.lang.Integer.TYPE</code>).
6622
If set, all other bits are zero.
6623
</constant>
6624
</constants>
6625
</description>
6626
<origin>jvmdi</origin>
6627
<capabilities>
6628
</capabilities>
6629
<parameters>
6630
<param id="klass">
6631
<jclass/>
6632
<description>
6633
The class to query.
6634
</description>
6635
</param>
6636
<param id="status_ptr">
6637
<outptr><jint/></outptr>
6638
<description>
6639
On return, points to the current state of this class as one or
6640
more of the <internallink id="jvmtiClassStatus">class status flags</internallink>.
6641
</description>
6642
</param>
6643
</parameters>
6644
<errors>
6645
</errors>
6646
</function>
6647
6648
<function id="GetSourceFileName" phase="start" num="50">
6649
<synopsis>Get Source File Name</synopsis>
6650
<description>
6651
For the class indicated by <code>klass</code>, return the source file
6652
name via <code>source_name_ptr</code>. The returned string
6653
is a file name only and never contains a directory name.
6654
<p/>
6655
For primitive classes (for example, <code>java.lang.Integer.TYPE</code>)
6656
and for arrays this function returns
6657
<errorlink id="JVMTI_ERROR_ABSENT_INFORMATION"></errorlink>.
6658
</description>
6659
<origin>jvmdi</origin>
6660
<capabilities>
6661
<required id="can_get_source_file_name"></required>
6662
</capabilities>
6663
<parameters>
6664
<param id="klass">
6665
<jclass/>
6666
<description>
6667
The class to query.
6668
</description>
6669
</param>
6670
<param id="source_name_ptr">
6671
<allocbuf><char/></allocbuf>
6672
<description>
6673
On return, points to the class's source file name, encoded as a
6674
<internallink id="mUTF">modified UTF-8</internallink> string.
6675
</description>
6676
</param>
6677
</parameters>
6678
<errors>
6679
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
6680
Class information does not include a source file name. This includes
6681
cases where the class is an array class or primitive class.
6682
</error>
6683
</errors>
6684
</function>
6685
6686
<function id="GetClassModifiers" phase="start" num="51">
6687
<synopsis>Get Class Modifiers</synopsis>
6688
<description>
6689
For the class indicated by <code>klass</code>, return the access
6690
flags
6691
via <code>modifiers_ptr</code>.
6692
Access flags are defined in <vmspec chapter="4"/>.
6693
<p/>
6694
If the class is an array class, then its public, private, and protected
6695
modifiers are the same as those of its component type. For arrays of
6696
primitives, this component type is represented by one of the primitive
6697
classes (for example, <code>java.lang.Integer.TYPE</code>).
6698
<p/>
6699
If the class is a primitive class, its public modifier is always true,
6700
and its protected and private modifiers are always false.
6701
<p/>
6702
If the class is an array class or a primitive class then its final
6703
modifier is always true and its interface modifier is always false.
6704
The values of its other modifiers are not determined by this specification.
6705
6706
</description>
6707
<origin>jvmdi</origin>
6708
<capabilities>
6709
</capabilities>
6710
<parameters>
6711
<param id="klass">
6712
<jclass/>
6713
<description>
6714
The class to query.
6715
</description>
6716
</param>
6717
<param id="modifiers_ptr">
6718
<outptr><jint/></outptr>
6719
<description>
6720
On return, points to the current access flags of this class.
6721
6722
</description>
6723
</param>
6724
</parameters>
6725
<errors>
6726
</errors>
6727
</function>
6728
6729
<function id="GetClassMethods" phase="start" num="52">
6730
<synopsis>Get Class Methods</synopsis>
6731
<description>
6732
For the class indicated by <code>klass</code>, return a count of
6733
methods via <code>method_count_ptr</code> and a list of
6734
method IDs via <code>methods_ptr</code>. The method list contains
6735
constructors and static initializers as well as true methods.
6736
Only directly declared methods are returned (not inherited methods).
6737
An empty method list is returned for array classes and primitive classes
6738
(for example, <code>java.lang.Integer.TYPE</code>).
6739
</description>
6740
<origin>jvmdi</origin>
6741
<capabilities>
6742
<capability id="can_maintain_original_method_order"/>
6743
</capabilities>
6744
<parameters>
6745
<param id="klass">
6746
<jclass/>
6747
<description>
6748
The class to query.
6749
</description>
6750
</param>
6751
<param id="method_count_ptr">
6752
<outptr><jint/></outptr>
6753
<description>
6754
On return, points to the number of methods declared in this class.
6755
</description>
6756
</param>
6757
<param id="methods_ptr">
6758
<allocbuf outcount="method_count_ptr"><jmethodID class="klass"/></allocbuf>
6759
<description>
6760
On return, points to the method ID array.
6761
</description>
6762
</param>
6763
</parameters>
6764
<errors>
6765
<error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
6766
<paramlink id="klass"></paramlink> is not prepared.
6767
</error>
6768
</errors>
6769
</function>
6770
6771
<function id="GetClassFields" phase="start" num="53">
6772
<synopsis>Get Class Fields</synopsis>
6773
<description>
6774
For the class indicated by <code>klass</code>, return a count of fields
6775
via <code>field_count_ptr</code> and a list of field IDs via
6776
<code>fields_ptr</code>.
6777
Only directly declared fields are returned (not inherited fields).
6778
Fields are returned in the order they occur in the class file.
6779
An empty field list is returned for array classes and primitive classes
6780
(for example, <code>java.lang.Integer.TYPE</code>).
6781
Use JNI to determine the length of an array.
6782
</description>
6783
<origin>jvmdi</origin>
6784
<capabilities>
6785
</capabilities>
6786
<parameters>
6787
<param id="klass">
6788
<jclass/>
6789
<description>
6790
The class to query.
6791
</description>
6792
</param>
6793
<param id="field_count_ptr">
6794
<outptr><jint/></outptr>
6795
<description>
6796
On return, points to the number of fields declared in this class.
6797
</description>
6798
</param>
6799
<param id="fields_ptr">
6800
<allocbuf outcount="field_count_ptr"><jfieldID/></allocbuf>
6801
<description>
6802
On return, points to the field ID array.
6803
</description>
6804
</param>
6805
</parameters>
6806
<errors>
6807
<error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
6808
<paramlink id="klass"></paramlink> is not prepared.
6809
</error>
6810
</errors>
6811
</function>
6812
6813
<function id="GetImplementedInterfaces" phase="start" num="54">
6814
<synopsis>Get Implemented Interfaces</synopsis>
6815
<description>
6816
Return the direct super-interfaces of this class. For a class, this
6817
function returns the interfaces declared in its <code>implements</code>
6818
clause. For an interface, this function returns the interfaces declared in
6819
its <code>extends</code> clause.
6820
An empty interface list is returned for array classes and primitive classes
6821
(for example, <code>java.lang.Integer.TYPE</code>).
6822
</description>
6823
<origin>jvmdi</origin>
6824
<capabilities>
6825
</capabilities>
6826
<parameters>
6827
<param id="klass">
6828
<jclass/>
6829
<description>
6830
The class to query.
6831
</description>
6832
</param>
6833
<param id="interface_count_ptr">
6834
<outptr><jint/></outptr>
6835
<description>
6836
On return, points to the number of interfaces.
6837
</description>
6838
</param>
6839
<param id="interfaces_ptr">
6840
<allocbuf outcount="interface_count_ptr"><jclass/></allocbuf>
6841
<description>
6842
On return, points to the interface array.
6843
</description>
6844
</param>
6845
</parameters>
6846
<errors>
6847
<error id="JVMTI_ERROR_CLASS_NOT_PREPARED">
6848
<paramlink id="klass"></paramlink> is not prepared.
6849
</error>
6850
</errors>
6851
</function>
6852
6853
<function id="GetClassVersionNumbers" phase="start" num="145" since="1.1">
6854
<synopsis>Get Class Version Numbers</synopsis>
6855
<description>
6856
For the class indicated by <code>klass</code>,
6857
return the minor and major version numbers,
6858
as defined in
6859
<vmspec chapter="4"/>.
6860
</description>
6861
<origin>new</origin>
6862
<capabilities>
6863
</capabilities>
6864
<parameters>
6865
<param id="klass">
6866
<jclass/>
6867
<description>
6868
The class to query.
6869
</description>
6870
</param>
6871
<param id="minor_version_ptr">
6872
<outptr><jint/></outptr>
6873
<description>
6874
On return, points to the value of the
6875
<code>minor_version</code> item of the
6876
Class File Format.
6877
Note: to be consistent with the Class File Format,
6878
the minor version number is the first parameter.
6879
</description>
6880
</param>
6881
<param id="major_version_ptr">
6882
<outptr><jint/></outptr>
6883
<description>
6884
On return, points to the value of the
6885
<code>major_version</code> item of the
6886
Class File Format.
6887
</description>
6888
</param>
6889
</parameters>
6890
<errors>
6891
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
6892
The class is a primitive or array class.
6893
</error>
6894
</errors>
6895
</function>
6896
6897
<function id="GetConstantPool" phase="start" num="146" since="1.1">
6898
<synopsis>Get Constant Pool</synopsis>
6899
<description>
6900
For the class indicated by <code>klass</code>,
6901
return the raw bytes of the constant pool in the format of the
6902
<code>constant_pool</code> item of
6903
<vmspec chapter="4"/>.
6904
The format of the constant pool may differ between versions
6905
of the Class File Format, so, the
6906
<functionlink id="GetClassVersionNumbers">minor and major
6907
class version numbers</functionlink> should be checked for
6908
compatibility.
6909
<p/>
6910
The returned constant pool might not have the same layout or
6911
contents as the constant pool in the defining class file.
6912
The constant pool returned by GetConstantPool() may have
6913
more or fewer entries than the defining constant pool.
6914
Entries may be in a different order.
6915
The constant pool returned by GetConstantPool() will match the
6916
constant pool used by
6917
<functionlink id="GetBytecodes">GetBytecodes()</functionlink>.
6918
That is, the bytecodes returned by GetBytecodes() will have
6919
constant pool indices which refer to constant pool entries returned
6920
by GetConstantPool().
6921
Note that since <functionlink id="RetransformClasses"/>
6922
and <functionlink id="RedefineClasses"/> can change
6923
the constant pool, the constant pool returned by this function
6924
can change accordingly. Thus, the correspondence between
6925
GetConstantPool() and GetBytecodes() does not hold if there
6926
is an intervening class retransformation or redefinition.
6927
The value of a constant pool entry used by a given bytecode will
6928
match that of the defining class file (even if the indices don't match).
6929
Constant pool entries which are not used directly or indirectly by
6930
bytecodes (for example, UTF-8 strings associated with annotations) are
6931
not required to exist in the returned constant pool.
6932
</description>
6933
<origin>new</origin>
6934
<capabilities>
6935
<required id="can_get_constant_pool"></required>
6936
</capabilities>
6937
<parameters>
6938
<param id="klass">
6939
<jclass/>
6940
<description>
6941
The class to query.
6942
</description>
6943
</param>
6944
<param id="constant_pool_count_ptr">
6945
<outptr><jint/></outptr>
6946
<description>
6947
On return, points to the number of entries
6948
in the constant pool table plus one.
6949
This corresponds to the <code>constant_pool_count</code>
6950
item of the Class File Format.
6951
</description>
6952
</param>
6953
<param id="constant_pool_byte_count_ptr">
6954
<outptr><jint/></outptr>
6955
<description>
6956
On return, points to the number of bytes
6957
in the returned raw constant pool.
6958
</description>
6959
</param>
6960
<param id="constant_pool_bytes_ptr">
6961
<allocbuf outcount="constant_pool_byte_count_ptr"><uchar/></allocbuf>
6962
<description>
6963
On return, points to the raw constant pool, that is the bytes
6964
defined by the <code>constant_pool</code> item of the
6965
Class File Format
6966
</description>
6967
</param>
6968
</parameters>
6969
<errors>
6970
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
6971
The class is a primitive or array class.
6972
</error>
6973
</errors>
6974
</function>
6975
6976
<function id="IsInterface" phase="start" num="55">
6977
<synopsis>Is Interface</synopsis>
6978
<description>
6979
Determines whether a class object reference represents an interface.
6980
The <code>jboolean</code> result is
6981
<code>JNI_TRUE</code> if the "class" is actually an interface,
6982
<code>JNI_FALSE</code> otherwise.
6983
</description>
6984
<origin>jvmdi</origin>
6985
<capabilities>
6986
</capabilities>
6987
<parameters>
6988
<param id="klass">
6989
<jclass/>
6990
<description>
6991
The class to query.
6992
</description>
6993
</param>
6994
<param id="is_interface_ptr">
6995
<outptr><jboolean/></outptr>
6996
<description>
6997
On return, points to the boolean result of this function.
6998
6999
</description>
7000
</param>
7001
</parameters>
7002
<errors>
7003
</errors>
7004
</function>
7005
7006
<function id="IsArrayClass" phase="start" num="56">
7007
<synopsis>Is Array Class</synopsis>
7008
<description>
7009
Determines whether a class object reference represents an array.
7010
The <code>jboolean</code> result is
7011
<code>JNI_TRUE</code> if the class is an array,
7012
<code>JNI_FALSE</code> otherwise.
7013
</description>
7014
<origin>jvmdi</origin>
7015
<capabilities>
7016
</capabilities>
7017
<parameters>
7018
<param id="klass">
7019
<jclass/>
7020
<description>
7021
The class to query.
7022
</description>
7023
</param>
7024
<param id="is_array_class_ptr">
7025
<outptr><jboolean/></outptr>
7026
<description>
7027
On return, points to the boolean result of this function.
7028
7029
</description>
7030
</param>
7031
</parameters>
7032
<errors>
7033
</errors>
7034
</function>
7035
7036
<function id="IsModifiableClass" jkernel="yes" phase="start" num="45" since="1.1">
7037
<synopsis>Is Modifiable Class</synopsis>
7038
<description>
7039
Determines whether a class is modifiable.
7040
If a class is modifiable (<paramlink id="is_modifiable_class_ptr"/>
7041
returns <code>JNI_TRUE</code>) the class can be
7042
redefined with <functionlink id="RedefineClasses"/> (assuming
7043
the agent possesses the
7044
<fieldlink id="can_redefine_classes" struct="jvmtiCapabilities"/>
7045
capability) or
7046
retransformed with <functionlink id="RetransformClasses"/> (assuming
7047
the agent possesses the
7048
<fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
7049
capability).
7050
If a class is not modifiable (<paramlink id="is_modifiable_class_ptr"/>
7051
returns <code>JNI_FALSE</code>) the class can be neither
7052
redefined nor retransformed.
7053
<p/>
7054
Primitive classes (for example, <code>java.lang.Integer.TYPE</code>)
7055
and array classes are never modifiable.
7056
<p/>
7057
</description>
7058
<origin>new</origin>
7059
<capabilities>
7060
<capability id="can_redefine_any_class">
7061
If possessed then all classes (except primitive and array classes)
7062
are modifiable.
7063
</capability>
7064
<capability id="can_redefine_classes">
7065
No effect on the result of the function.
7066
But must additionally be possessed to modify the class with
7067
<functionlink id="RedefineClasses"/>.
7068
</capability>
7069
<capability id="can_retransform_classes">
7070
No effect on the result of the function.
7071
But must additionally be possessed to modify the class with
7072
<functionlink id="RetransformClasses"/>.
7073
</capability>
7074
</capabilities>
7075
<parameters>
7076
<param id="klass">
7077
<jclass/>
7078
<description>
7079
The class to query.
7080
</description>
7081
</param>
7082
<param id="is_modifiable_class_ptr">
7083
<outptr><jboolean/></outptr>
7084
<description>
7085
On return, points to the boolean result of this function.
7086
</description>
7087
</param>
7088
</parameters>
7089
<errors>
7090
</errors>
7091
</function>
7092
7093
<function id="GetClassLoader" phase="start" num="57">
7094
<synopsis>Get Class Loader</synopsis>
7095
<description>
7096
For the class indicated by <code>klass</code>, return via
7097
<code>classloader_ptr</code> a reference to the class loader for the
7098
class.
7099
</description>
7100
<origin>jvmdi</origin>
7101
<capabilities>
7102
</capabilities>
7103
<parameters>
7104
<param id="klass">
7105
<jclass/>
7106
<description>
7107
The class to query.
7108
</description>
7109
</param>
7110
<param id="classloader_ptr">
7111
<outptr><jobject/></outptr>
7112
<description>
7113
On return, points to the class loader that loaded
7114
this class.
7115
If the class was not created by a class loader
7116
or if the class loader is the bootstrap class loader,
7117
points to <code>NULL</code>.
7118
</description>
7119
</param>
7120
</parameters>
7121
<errors>
7122
</errors>
7123
7124
</function>
7125
7126
<function id="GetSourceDebugExtension" phase="start" num="90">
7127
<synopsis>Get Source Debug Extension</synopsis>
7128
<description>
7129
For the class indicated by <code>klass</code>, return the debug
7130
extension via <code>source_debug_extension_ptr</code>.
7131
The returned string
7132
contains exactly the debug extension information present in the
7133
class file of <code>klass</code>.
7134
</description>
7135
<origin>jvmdi</origin>
7136
<capabilities>
7137
<required id="can_get_source_debug_extension"></required>
7138
</capabilities>
7139
<parameters>
7140
<param id="klass">
7141
<jclass/>
7142
<description>
7143
The class to query.
7144
</description>
7145
</param>
7146
<param id="source_debug_extension_ptr">
7147
<allocbuf><char/></allocbuf>
7148
<description>
7149
On return, points to the class's debug extension, encoded as a
7150
<internallink id="mUTF">modified UTF-8</internallink> string.
7151
</description>
7152
</param>
7153
</parameters>
7154
<errors>
7155
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
7156
Class information does not include a debug extension.
7157
</error>
7158
</errors>
7159
</function>
7160
7161
<function id="RetransformClasses" jkernel="yes" num="152" since="1.1">
7162
<synopsis>Retransform Classes</synopsis>
7163
<description>
7164
This function facilitates the
7165
<internallink id="bci">bytecode instrumentation</internallink>
7166
of already loaded classes.
7167
To replace the class definition without reference to the existing
7168
bytecodes, as one might do when recompiling from source for
7169
fix-and-continue debugging, <functionlink id="RedefineClasses"/>
7170
function should be used instead.
7171
<p/>
7172
When classes are initially loaded or when they are
7173
<functionlink id="RedefineClasses">redefined</functionlink>,
7174
the initial class file bytes can be transformed with the
7175
<eventlink id="ClassFileLoadHook"/> event.
7176
This function reruns the transformation process
7177
(whether or not a transformation has previously occurred).
7178
This retransformation follows these steps:
7179
<ul>
7180
<li>starting from the initial class file bytes
7181
</li>
7182
<li>for each <fieldlink id="can_retransform_classes"
7183
struct="jvmtiCapabilities">retransformation
7184
incapable</fieldlink>
7185
agent which received a
7186
<code>ClassFileLoadHook</code> event during the previous
7187
load or redefine, the bytes it returned
7188
(via the <code>new_class_data</code> parameter)
7189
are reused as the output of the transformation;
7190
note that this is equivalent to reapplying
7191
the previous transformation, unaltered. except that
7192
the <code>ClassFileLoadHook</code> event
7193
is <b>not</b> sent to these agents
7194
</li>
7195
<li>for each <fieldlink id="can_retransform_classes"
7196
struct="jvmtiCapabilities">retransformation
7197
capable</fieldlink>
7198
agent, the <code>ClassFileLoadHook</code> event is sent,
7199
allowing a new transformation to be applied
7200
</li>
7201
<li>the transformed class file bytes are installed as the new
7202
definition of the class
7203
</li>
7204
</ul>
7205
See the <eventlink id="ClassFileLoadHook"/> event for more details.
7206
<p/>
7207
The initial class file bytes represent the bytes passed to
7208
<code>ClassLoader.defineClass</code>
7209
or <code>RedefineClasses</code> (before any transformations
7210
were applied), however they may not exactly match them.
7211
The constant pool may differ in ways described in
7212
<functionlink id="GetConstantPool"/>.
7213
Constant pool indices in the bytecodes of methods will correspond.
7214
Some attributes may not be present.
7215
Where order is not meaningful, for example the order of methods,
7216
order may not be preserved.
7217
<p/>
7218
Retransformation can cause new versions of methods to be installed.
7219
Old method versions may become
7220
<internallink id="obsoleteMethods">obsolete</internallink>
7221
The new method version will be used on new invokes.
7222
If a method has active stack frames, those active frames continue to
7223
run the bytecodes of the original method version.
7224
<p/>
7225
This function does not cause any initialization except that which
7226
would occur under the customary JVM semantics.
7227
In other words, retransforming a class does not cause its initializers to be
7228
run. The values of static fields will remain as they were
7229
prior to the call.
7230
<p/>
7231
Threads need not be suspended.
7232
<p/>
7233
All breakpoints in the class are cleared.
7234
<p/>
7235
All attributes are updated.
7236
<p/>
7237
Instances of the retransformed class are not affected -- fields retain their
7238
previous values.
7239
<functionlink id="GetTag">Tags</functionlink> on the instances are
7240
also unaffected.
7241
<p/>
7242
In response to this call, no events other than the
7243
<eventlink id="ClassFileLoadHook"/> event
7244
will be sent.
7245
<p/>
7246
The retransformation may change method bodies, the constant pool and attributes.
7247
The retransformation must not add, remove or rename fields or methods, change the
7248
signatures of methods, change modifiers, or change inheritance.
7249
These restrictions may be lifted in future versions.
7250
See the error return description below for information on error codes
7251
returned if an unsupported retransformation is attempted.
7252
The class file bytes are not verified or installed until they have passed
7253
through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7254
returned error code reflects the result of the transformations.
7255
If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7256
none of the classes to be retransformed will have a new definition installed.
7257
When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7258
all of the classes to be retransformed will have their new definitions installed.
7259
</description>
7260
<origin>new</origin>
7261
<capabilities>
7262
<required id="can_retransform_classes"></required>
7263
<capability id="can_retransform_any_class"></capability>
7264
</capabilities>
7265
<parameters>
7266
<param id="class_count">
7267
<jint min="0"/>
7268
<description>
7269
The number of classes to be retransformed.
7270
</description>
7271
</param>
7272
<param id="classes">
7273
<inbuf incount="class_count"><jclass/></inbuf>
7274
<description>
7275
The array of classes to be retransformed.
7276
</description>
7277
</param>
7278
</parameters>
7279
<errors>
7280
<error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7281
One of the <paramlink id="classes"/> cannot be modified.
7282
See <functionlink id="IsModifiableClass"/>.
7283
</error>
7284
<error id="JVMTI_ERROR_INVALID_CLASS">
7285
One of the <paramlink id="classes"/> is not a valid class.
7286
</error>
7287
<error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7288
A retransformed class file has a version number not supported by this VM.
7289
</error>
7290
<error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7291
A retransformed class file is malformed (The VM would return a <code>ClassFormatError</code>).
7292
</error>
7293
<error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7294
The retransformed class file definitions would lead to a circular definition
7295
(the VM would return a <code>ClassCircularityError</code>).
7296
</error>
7297
<error id="JVMTI_ERROR_FAILS_VERIFICATION">
7298
The retransformed class file bytes fail verification.
7299
</error>
7300
<error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7301
The class name defined in a retransformed class file is
7302
different from the name in the old class object.
7303
</error>
7304
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7305
A retransformed class file would require adding a method.
7306
</error>
7307
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7308
A retransformed class file changes a field.
7309
</error>
7310
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7311
A direct superclass is different for a retransformed class file,
7312
or the set of directly implemented
7313
interfaces is different.
7314
</error>
7315
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7316
A retransformed class file does not declare a method
7317
declared in the old class version.
7318
</error>
7319
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7320
A retransformed class file has different class modifiers.
7321
</error>
7322
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7323
A method in the retransformed class file has different modifiers
7324
than its counterpart in the old class version.
7325
</error>
7326
</errors>
7327
</function>
7328
7329
<function id="RedefineClasses" jkernel="yes" num="87">
7330
<synopsis>Redefine Classes</synopsis>
7331
<typedef id="jvmtiClassDefinition" label="Class redefinition description">
7332
<field id="klass">
7333
<jclass/>
7334
<description>
7335
Class object for this class
7336
</description>
7337
</field>
7338
<field id="class_byte_count">
7339
<jint/>
7340
<description>
7341
Number of bytes defining class (below)
7342
</description>
7343
</field>
7344
<field id="class_bytes">
7345
<inbuf incount="class_byte_count"><uchar/></inbuf>
7346
<description>
7347
Bytes defining class (in <vmspec chapter="4"/>)
7348
</description>
7349
</field>
7350
</typedef>
7351
<description>
7352
All classes given are redefined according to the definitions
7353
supplied.
7354
This function is used to replace the definition of a class
7355
with a new definition, as might be needed in fix-and-continue
7356
debugging.
7357
Where the existing class file bytes are to be transformed, for
7358
example in
7359
<internallink id="bci">bytecode instrumentation</internallink>,
7360
<functionlink id="RetransformClasses"/> should be used.
7361
<p/>
7362
Redefinition can cause new versions of methods to be installed.
7363
Old method versions may become
7364
<internallink id="obsoleteMethods">obsolete</internallink>
7365
The new method version will be used on new invokes.
7366
If a method has active stack frames, those active frames continue to
7367
run the bytecodes of the original method version.
7368
If resetting of stack frames is desired, use
7369
<functionlink id="PopFrame"></functionlink>
7370
to pop frames with obsolete method versions.
7371
<p/>
7372
This function does not cause any initialization except that which
7373
would occur under the customary JVM semantics.
7374
In other words, redefining a class does not cause its initializers to be
7375
run. The values of static fields will remain as they were
7376
prior to the call.
7377
<p/>
7378
Threads need not be suspended.
7379
<p/>
7380
All breakpoints in the class are cleared.
7381
<p/>
7382
All attributes are updated.
7383
<p/>
7384
Instances of the redefined class are not affected -- fields retain their
7385
previous values.
7386
<functionlink id="GetTag">Tags</functionlink> on the instances are
7387
also unaffected.
7388
<p/>
7389
In response to this call, the <jvmti/> event
7390
<eventlink id="ClassFileLoadHook">Class File Load Hook</eventlink>
7391
will be sent (if enabled), but no other <jvmti/> events will be sent.
7392
<p/>
7393
The redefinition may change method bodies, the constant pool and attributes.
7394
The redefinition must not add, remove or rename fields or methods, change the
7395
signatures of methods, change modifiers, or change inheritance.
7396
These restrictions may be lifted in future versions.
7397
See the error return description below for information on error codes
7398
returned if an unsupported redefinition is attempted.
7399
The class file bytes are not verified or installed until they have passed
7400
through the chain of <eventlink id="ClassFileLoadHook"/> events, thus the
7401
returned error code reflects the result of the transformations applied
7402
to the bytes passed into <paramlink id="class_definitions"/>.
7403
If any error code is returned other than <code>JVMTI_ERROR_NONE</code>,
7404
none of the classes to be redefined will have a new definition installed.
7405
When this function returns (with the error code of <code>JVMTI_ERROR_NONE</code>)
7406
all of the classes to be redefined will have their new definitions installed.
7407
</description>
7408
<origin>jvmdi</origin>
7409
<capabilities>
7410
<required id="can_redefine_classes"></required>
7411
<capability id="can_redefine_any_class"></capability>
7412
</capabilities>
7413
<parameters>
7414
<param id="class_count">
7415
<jint min="0"/>
7416
<description>
7417
The number of classes specified in <code>class_definitions</code>
7418
</description>
7419
</param>
7420
<param id="class_definitions">
7421
<inbuf incount="class_count"><struct>jvmtiClassDefinition</struct></inbuf>
7422
<description>
7423
The array of new class definitions
7424
</description>
7425
</param>
7426
</parameters>
7427
<errors>
7428
<error id="JVMTI_ERROR_NULL_POINTER">
7429
One of <code>class_bytes</code> is <code>NULL</code>.
7430
</error>
7431
<error id="JVMTI_ERROR_UNMODIFIABLE_CLASS">
7432
An element of <code>class_definitions</code> cannot be modified.
7433
See <functionlink id="IsModifiableClass"/>.
7434
</error>
7435
<error id="JVMTI_ERROR_INVALID_CLASS">
7436
An element of <code>class_definitions</code> is not a valid class.
7437
</error>
7438
<error id="JVMTI_ERROR_UNSUPPORTED_VERSION">
7439
A new class file has a version number not supported by this VM.
7440
</error>
7441
<error id="JVMTI_ERROR_INVALID_CLASS_FORMAT">
7442
A new class file is malformed (The VM would return a <code>ClassFormatError</code>).
7443
</error>
7444
<error id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION">
7445
The new class file definitions would lead to a circular definition
7446
(the VM would return a <code>ClassCircularityError</code>).
7447
</error>
7448
<error id="JVMTI_ERROR_FAILS_VERIFICATION">
7449
The class bytes fail verification.
7450
</error>
7451
<error id="JVMTI_ERROR_NAMES_DONT_MATCH">
7452
The class name defined in a new class file is
7453
different from the name in the old class object.
7454
</error>
7455
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED">
7456
A new class file would require adding a method.
7457
</error>
7458
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED">
7459
A new class version changes a field.
7460
</error>
7461
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED">
7462
A direct superclass is different for a new class
7463
version, or the set of directly implemented
7464
interfaces is different.
7465
</error>
7466
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED">
7467
A new class version does not declare a method
7468
declared in the old class version.
7469
</error>
7470
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED">
7471
A new class version has different modifiers.
7472
</error>
7473
<error id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED">
7474
A method in the new class version has different modifiers
7475
than its counterpart in the old class version.
7476
</error>
7477
</errors>
7478
</function>
7479
7480
</category>
7481
7482
<category id="object" label="Object">
7483
7484
<function id="GetObjectSize" jkernel="yes" phase="start" num="154">
7485
<synopsis>Get Object Size</synopsis>
7486
<description>
7487
For the object indicated by <code>object</code>,
7488
return via <code>size_ptr</code> the size of the object.
7489
This size is an implementation-specific approximation of
7490
the amount of storage consumed by this object.
7491
It may include some or all of the object's overhead, and thus
7492
is useful for comparison within an implementation but not
7493
between implementations.
7494
The estimate may change during a single invocation of the JVM.
7495
</description>
7496
<origin>new</origin>
7497
<capabilities>
7498
</capabilities>
7499
<parameters>
7500
<param id="object">
7501
<jobject/>
7502
<description>
7503
The object to query.
7504
</description>
7505
</param>
7506
<param id="size_ptr">
7507
<outptr><jlong/></outptr>
7508
<description>
7509
On return, points to the object's size in bytes.
7510
</description>
7511
</param>
7512
</parameters>
7513
<errors>
7514
</errors>
7515
</function>
7516
7517
<function id="GetObjectHashCode" phase="start" num="58">
7518
<synopsis>Get Object Hash Code</synopsis>
7519
<description>
7520
For the object indicated by <code>object</code>,
7521
return via <code>hash_code_ptr</code> a hash code.
7522
This hash code could be used to maintain a hash table of object references,
7523
however, on some implementations this can cause significant performance
7524
impacts--in most cases
7525
<internallink id="Heap">tags</internallink>
7526
will be a more efficient means of associating information with objects.
7527
This function guarantees
7528
the same hash code value for a particular object throughout its life
7529
</description>
7530
<origin>jvmdi</origin>
7531
<capabilities>
7532
</capabilities>
7533
<parameters>
7534
<param id="object">
7535
<jobject/>
7536
<description>
7537
The object to query.
7538
</description>
7539
</param>
7540
<param id="hash_code_ptr">
7541
<outptr><jint/></outptr>
7542
<description>
7543
On return, points to the object's hash code.
7544
</description>
7545
</param>
7546
</parameters>
7547
<errors>
7548
</errors>
7549
</function>
7550
7551
<function id="GetObjectMonitorUsage" num="59">
7552
<synopsis>Get Object Monitor Usage</synopsis>
7553
<typedef id="jvmtiMonitorUsage" label="Object monitor usage information">
7554
<field id="owner">
7555
<jthread/>
7556
<description>
7557
The thread owning this monitor, or <code>NULL</code> if unused
7558
</description>
7559
</field>
7560
<field id="entry_count">
7561
<jint/>
7562
<description>
7563
The number of times the owning thread has entered the monitor
7564
</description>
7565
</field>
7566
<field id="waiter_count">
7567
<jint/>
7568
<description>
7569
The number of threads waiting to own this monitor
7570
</description>
7571
</field>
7572
<field id="waiters">
7573
<allocfieldbuf><jthread/></allocfieldbuf>
7574
<description>
7575
The <code>waiter_count</code> waiting threads
7576
</description>
7577
</field>
7578
<field id="notify_waiter_count">
7579
<jint/>
7580
<description>
7581
The number of threads waiting to be notified by this monitor
7582
</description>
7583
</field>
7584
<field id="notify_waiters">
7585
<allocfieldbuf><jthread/></allocfieldbuf>
7586
<description>
7587
The <code>notify_waiter_count</code> threads waiting to be notified
7588
</description>
7589
</field>
7590
</typedef>
7591
<description>
7592
Get information about the object's monitor.
7593
The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
7594
are filled in with information about usage of the monitor.
7595
<todo>
7596
Decide and then clarify suspend requirements.
7597
</todo>
7598
</description>
7599
<origin>jvmdi</origin>
7600
<capabilities>
7601
<required id="can_get_monitor_info"></required>
7602
</capabilities>
7603
<parameters>
7604
<param id="object">
7605
<jobject/>
7606
<description>
7607
The object to query.
7608
</description>
7609
</param>
7610
<param id="info_ptr">
7611
<outptr><struct>jvmtiMonitorUsage</struct></outptr>
7612
<description>
7613
On return, filled with monitor information for the
7614
specified object.
7615
</description>
7616
</param>
7617
</parameters>
7618
<errors>
7619
</errors>
7620
</function>
7621
7622
<elide>
7623
<function id="GetObjectMonitors" num="116">
7624
<synopsis>Get Object Monitors</synopsis>
7625
<description>
7626
Return the list of object monitors.
7627
<p/>
7628
Note: details about each monitor can be examined with
7629
<functionlink id="GetObjectMonitorUsage"></functionlink>.
7630
</description>
7631
<origin>new</origin>
7632
<capabilities>
7633
<required id="can_get_monitor_info"></required>
7634
</capabilities>
7635
<parameters>
7636
<param id="monitorCnt">
7637
<outptr><jint/></outptr>
7638
<description>
7639
On return, pointer to the number
7640
of monitors returned in <code>monitors_ptr</code>.
7641
</description>
7642
</param>
7643
<param id="monitors_ptr">
7644
<allocbuf outcount="monitorCnt"><jobject/></allocbuf>
7645
<description>
7646
On return, pointer to the monitor list.
7647
</description>
7648
</param>
7649
</parameters>
7650
<errors>
7651
</errors>
7652
</function>
7653
</elide>
7654
7655
</category>
7656
7657
<category id="fieldCategory" label="Field">
7658
7659
<intro>
7660
</intro>
7661
7662
<function id="GetFieldName" phase="start" num="60">
7663
<synopsis>Get Field Name (and Signature)</synopsis>
7664
<description>
7665
For the field indicated by <paramlink id="klass"/> and <paramlink id="field"/>,
7666
return the field name via <paramlink id="name_ptr"/> and field signature via
7667
<paramlink id="signature_ptr"/>.
7668
<p/>
7669
Field signatures are defined in the JNI Specification and
7670
are referred to as <code>field descriptors</code> in
7671
<vmspec chapter="4.3.2"/>.
7672
</description>
7673
<origin>jvmdiClone</origin>
7674
<capabilities>
7675
</capabilities>
7676
<parameters>
7677
<param id="klass">
7678
<jclass field="field"/>
7679
<description>
7680
The class of the field to query.
7681
</description>
7682
</param>
7683
<param id="field">
7684
<jfieldID class="klass"/>
7685
<description>
7686
The field to query.
7687
</description>
7688
</param>
7689
<param id="name_ptr">
7690
<allocbuf>
7691
<char/>
7692
<nullok>the name is not returned</nullok>
7693
</allocbuf>
7694
<description>
7695
On return, points to the field name, encoded as a
7696
<internallink id="mUTF">modified UTF-8</internallink> string.
7697
</description>
7698
</param>
7699
<param id="signature_ptr">
7700
<allocbuf>
7701
<char/>
7702
<nullok>the signature is not returned</nullok>
7703
</allocbuf>
7704
<description>
7705
On return, points to the field signature, encoded as a
7706
<internallink id="mUTF">modified UTF-8</internallink> string.
7707
</description>
7708
</param>
7709
<param id="generic_ptr">
7710
<allocbuf>
7711
<char/>
7712
<nullok>the generic signature is not returned</nullok>
7713
</allocbuf>
7714
<description>
7715
On return, points to the generic signature of the field, encoded as a
7716
<internallink id="mUTF">modified UTF-8</internallink> string.
7717
If there is no generic signature attribute for the field, then,
7718
on return, points to <code>NULL</code>.
7719
</description>
7720
</param>
7721
</parameters>
7722
<errors>
7723
</errors>
7724
</function>
7725
7726
<function id="GetFieldDeclaringClass" phase="start" num="61">
7727
<synopsis>Get Field Declaring Class</synopsis>
7728
<description>
7729
For the field indicated by <code>klass</code> and <code>field</code>
7730
return the class that defined it via <code>declaring_class_ptr</code>.
7731
The declaring class will either be <code>klass</code>, a superclass, or
7732
an implemented interface.
7733
</description>
7734
<origin>jvmdi</origin>
7735
<capabilities>
7736
</capabilities>
7737
<parameters>
7738
<param id="klass">
7739
<jclass field="field"/>
7740
<description>
7741
The class to query.
7742
</description>
7743
</param>
7744
<param id="field">
7745
<jfieldID class="klass"/>
7746
<description>
7747
The field to query.
7748
</description>
7749
</param>
7750
<param id="declaring_class_ptr">
7751
<outptr><jclass/></outptr>
7752
<description>
7753
On return, points to the declaring class
7754
</description>
7755
</param>
7756
</parameters>
7757
<errors>
7758
</errors>
7759
</function>
7760
7761
<function id="GetFieldModifiers" phase="start" num="62">
7762
<synopsis>Get Field Modifiers</synopsis>
7763
<description>
7764
For the field indicated by <code>klass</code> and <code>field</code>
7765
return the access flags via <code>modifiers_ptr</code>.
7766
Access flags are defined in <vmspec chapter="4"/>.
7767
</description>
7768
<origin>jvmdi</origin>
7769
<capabilities>
7770
</capabilities>
7771
<parameters>
7772
<param id="klass">
7773
<jclass field="field"/>
7774
<description>
7775
The class to query.
7776
</description>
7777
</param>
7778
<param id="field">
7779
<jfieldID class="klass"/>
7780
<description>
7781
The field to query.
7782
</description>
7783
</param>
7784
<param id="modifiers_ptr">
7785
<outptr><jint/></outptr>
7786
<description>
7787
On return, points to the access flags.
7788
</description>
7789
</param>
7790
</parameters>
7791
<errors>
7792
</errors>
7793
</function>
7794
7795
<function id="IsFieldSynthetic" phase="start" num="63">
7796
<synopsis>Is Field Synthetic</synopsis>
7797
<description>
7798
For the field indicated by <code>klass</code> and <code>field</code>, return a
7799
value indicating whether the field is synthetic via <code>is_synthetic_ptr</code>.
7800
Synthetic fields are generated by the compiler but not present in the
7801
original source code.
7802
</description>
7803
<origin>jvmdi</origin>
7804
<capabilities>
7805
<required id="can_get_synthetic_attribute"></required>
7806
</capabilities>
7807
<parameters>
7808
<param id="klass">
7809
<jclass field="field"/>
7810
<description>
7811
The class of the field to query.
7812
</description>
7813
</param>
7814
<param id="field">
7815
<jfieldID class="klass"/>
7816
<description>
7817
The field to query.
7818
</description>
7819
</param>
7820
<param id="is_synthetic_ptr">
7821
<outptr><jboolean/></outptr>
7822
<description>
7823
On return, points to the boolean result of this function.
7824
</description>
7825
</param>
7826
</parameters>
7827
<errors>
7828
</errors>
7829
</function>
7830
7831
</category>
7832
7833
<category id="method" label="Method">
7834
7835
<intro>
7836
These functions provide information about a method (represented as a
7837
<typelink id="jmethodID"/>) and set how methods are processed.
7838
</intro>
7839
7840
<intro id="obsoleteMethods" label="Obsolete Methods">
7841
The functions <functionlink id="RetransformClasses"/> and
7842
<functionlink id="RedefineClasses"/> can cause new versions
7843
of methods to be installed.
7844
An original version of a method is considered equivalent
7845
to the new version if:
7846
<ul>
7847
<li>their bytecodes are the same except for indices into the
7848
constant pool and </li>
7849
<li>the referenced constants are equal.</li>
7850
</ul>
7851
An original method version which is not equivalent to the
7852
new method version is called obsolete and is assigned a new method ID;
7853
the original method ID now refers to the new method version.
7854
A method ID can be tested for obsolescence with
7855
<functionlink id="IsMethodObsolete"/>.
7856
</intro>
7857
7858
<function id="GetMethodName" phase="start" num="64">
7859
<synopsis>Get Method Name (and Signature)</synopsis>
7860
<description>
7861
For the method indicated by <code>method</code>,
7862
return the method name via <code>name_ptr</code> and method signature via
7863
<code>signature_ptr</code>.
7864
<p/>
7865
Method signatures are defined in the JNI Specification and are
7866
referred to as <code>method descriptors</code> in
7867
<vmspec chapter="4.3.3"/>.
7868
Note this is different
7869
than method signatures as defined in the <i>Java Language Specification</i>.
7870
</description>
7871
<origin>jvmdiClone</origin>
7872
<capabilities>
7873
</capabilities>
7874
<parameters>
7875
<param id="method">
7876
<jmethodID/>
7877
<description>
7878
The method to query.
7879
</description>
7880
</param>
7881
<param id="name_ptr">
7882
<allocbuf>
7883
<char/>
7884
<nullok>the name is not returned</nullok>
7885
</allocbuf>
7886
<description>
7887
On return, points to the method name, encoded as a
7888
<internallink id="mUTF">modified UTF-8</internallink> string.
7889
</description>
7890
</param>
7891
<param id="signature_ptr">
7892
<allocbuf>
7893
<char/>
7894
<nullok>the signature is not returned</nullok>
7895
</allocbuf>
7896
<description>
7897
On return, points to the method signature, encoded as a
7898
<internallink id="mUTF">modified UTF-8</internallink> string.
7899
</description>
7900
</param>
7901
<param id="generic_ptr">
7902
<allocbuf>
7903
<char/>
7904
<nullok>the generic signature is not returned</nullok>
7905
</allocbuf>
7906
<description>
7907
On return, points to the generic signature of the method, encoded as a
7908
<internallink id="mUTF">modified UTF-8</internallink> string.
7909
If there is no generic signature attribute for the method, then,
7910
on return, points to <code>NULL</code>.
7911
</description>
7912
</param>
7913
</parameters>
7914
<errors>
7915
</errors>
7916
</function>
7917
7918
<function id="GetMethodDeclaringClass" phase="start" num="65">
7919
<synopsis>Get Method Declaring Class</synopsis>
7920
<description>
7921
For the method indicated by <code>method</code>,
7922
return the class that defined it via <code>declaring_class_ptr</code>.
7923
</description>
7924
<origin>jvmdi</origin>
7925
<capabilities>
7926
</capabilities>
7927
<parameters>
7928
<param id="klass">
7929
<jclass method="method"/>
7930
<description>
7931
The class to query.
7932
</description>
7933
</param>
7934
<param id="method">
7935
<jmethodID class="klass"/>
7936
<description>
7937
The method to query.
7938
</description>
7939
</param>
7940
<param id="declaring_class_ptr">
7941
<outptr><jclass/></outptr>
7942
<description>
7943
On return, points to the declaring class
7944
</description>
7945
</param>
7946
</parameters>
7947
<errors>
7948
</errors>
7949
</function>
7950
7951
<function id="GetMethodModifiers" phase="start" num="66">
7952
<synopsis>Get Method Modifiers</synopsis>
7953
<description>
7954
For the method indicated by <code>method</code>,
7955
return the access flags via <code>modifiers_ptr</code>.
7956
Access flags are defined in <vmspec chapter="4"/>.
7957
</description>
7958
<origin>jvmdi</origin>
7959
<capabilities>
7960
</capabilities>
7961
<parameters>
7962
<param id="klass">
7963
<jclass method="method"/>
7964
<description>
7965
The class to query.
7966
</description>
7967
</param>
7968
<param id="method">
7969
<jmethodID class="klass"/>
7970
<description>
7971
The method to query.
7972
</description>
7973
</param>
7974
<param id="modifiers_ptr">
7975
<outptr><jint/></outptr>
7976
<description>
7977
On return, points to the access flags.
7978
</description>
7979
</param>
7980
</parameters>
7981
<errors>
7982
</errors>
7983
</function>
7984
7985
<function id="GetMaxLocals" phase="start" num="68">
7986
<synopsis>Get Max Locals</synopsis>
7987
<description>
7988
For the method indicated by <code>method</code>,
7989
return the number of local variable slots used by the method,
7990
including the local variables used to pass parameters to the
7991
method on its invocation.
7992
<p/>
7993
See <code>max_locals</code> in <vmspec chapter="4.7.3"/>.
7994
</description>
7995
<origin>jvmdi</origin>
7996
<capabilities>
7997
</capabilities>
7998
<parameters>
7999
<param id="klass">
8000
<jclass method="method"/>
8001
<description>
8002
The class to query.
8003
</description>
8004
</param>
8005
<param id="method">
8006
<jmethodID class="klass" native="error"/>
8007
<description>
8008
The method to query.
8009
</description>
8010
</param>
8011
<param id="max_ptr">
8012
<outptr><jint/></outptr>
8013
<description>
8014
On return, points to the maximum number of local slots
8015
</description>
8016
</param>
8017
</parameters>
8018
<errors>
8019
</errors>
8020
</function>
8021
8022
<function id="GetArgumentsSize" phase="start" num="69">
8023
<synopsis>Get Arguments Size</synopsis>
8024
<description>
8025
For the method indicated by <code>method</code>,
8026
return via <code>max_ptr</code> the number of local variable slots used
8027
by the method's arguments.
8028
Note that two-word arguments use two slots.
8029
</description>
8030
<origin>jvmdi</origin>
8031
<capabilities>
8032
</capabilities>
8033
<parameters>
8034
<param id="klass">
8035
<jclass method="method"/>
8036
<description>
8037
The class to query.
8038
</description>
8039
</param>
8040
<param id="method">
8041
<jmethodID class="klass" native="error"/>
8042
<description>
8043
The method to query.
8044
</description>
8045
</param>
8046
<param id="size_ptr">
8047
<outptr><jint/></outptr>
8048
<description>
8049
On return, points to the number of argument slots
8050
</description>
8051
</param>
8052
</parameters>
8053
<errors>
8054
</errors>
8055
</function>
8056
8057
<function id="GetLineNumberTable" phase="start" num="70">
8058
<synopsis>Get Line Number Table</synopsis>
8059
<typedef id="jvmtiLineNumberEntry" label="Line number table entry">
8060
<field id="start_location">
8061
<jlocation/>
8062
<description>
8063
the <datalink id="jlocation"></datalink> where the line begins
8064
</description>
8065
</field>
8066
<field id="line_number">
8067
<jint/>
8068
<description>
8069
the line number
8070
</description>
8071
</field>
8072
</typedef>
8073
<description>
8074
For the method indicated by <code>method</code>,
8075
return a table of source line number entries. The size of the table is
8076
returned via <code>entry_count_ptr</code> and the table itself is
8077
returned via <code>table_ptr</code>.
8078
</description>
8079
<origin>jvmdi</origin>
8080
<capabilities>
8081
<required id="can_get_line_numbers"></required>
8082
</capabilities>
8083
<parameters>
8084
<param id="klass">
8085
<jclass method="method"/>
8086
<description>
8087
The class to query.
8088
</description>
8089
</param>
8090
<param id="method">
8091
<jmethodID class="klass" native="error"/>
8092
<description>
8093
The method to query.
8094
</description>
8095
</param>
8096
<param id="entry_count_ptr">
8097
<outptr><jint/></outptr>
8098
<description>
8099
On return, points to the number of entries in the table
8100
</description>
8101
</param>
8102
<param id="table_ptr">
8103
<allocbuf outcount="entry_count_ptr"><struct>jvmtiLineNumberEntry</struct></allocbuf>
8104
<description>
8105
On return, points to the line number table pointer.
8106
</description>
8107
</param>
8108
</parameters>
8109
<errors>
8110
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
8111
Class information does not include line numbers.
8112
</error>
8113
</errors>
8114
</function>
8115
8116
<function id="GetMethodLocation" phase="start" num="71">
8117
<synopsis>Get Method Location</synopsis>
8118
<description>
8119
For the method indicated by <code>method</code>,
8120
return the beginning and ending addresses through
8121
<code>start_location_ptr</code> and <code>end_location_ptr</code>. In a
8122
conventional byte code indexing scheme,
8123
<code>start_location_ptr</code> will always point to zero
8124
and <code>end_location_ptr</code>
8125
will always point to the byte code count minus one.
8126
</description>
8127
<origin>jvmdi</origin>
8128
<capabilities>
8129
</capabilities>
8130
<parameters>
8131
<param id="klass">
8132
<jclass method="method"/>
8133
<description>
8134
The class to query.
8135
</description>
8136
</param>
8137
<param id="method">
8138
<jmethodID class="klass" native="error"/>
8139
<description>
8140
The method to query.
8141
</description>
8142
</param>
8143
<param id="start_location_ptr">
8144
<outptr><jlocation/></outptr>
8145
<description>
8146
On return, points to the first location, or
8147
<code>-1</code> if location information is not available.
8148
If the information is available and
8149
<functionlink id="GetJLocationFormat"></functionlink>
8150
returns <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>
8151
then this will always be zero.
8152
</description>
8153
</param>
8154
<param id="end_location_ptr">
8155
<outptr><jlocation/></outptr>
8156
<description>
8157
On return, points to the last location,
8158
or <code>-1</code> if location information is not available.
8159
</description>
8160
</param>
8161
</parameters>
8162
<errors>
8163
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
8164
Class information does not include method sizes.
8165
</error>
8166
</errors>
8167
</function>
8168
8169
<function id="GetLocalVariableTable" num="72">
8170
<synopsis>Get Local Variable Table</synopsis>
8171
<typedef id="jvmtiLocalVariableEntry" label="Local variable table entry">
8172
<field id="start_location">
8173
<jlocation/>
8174
<description>
8175
The code array index where the local variable is first valid
8176
(that is, where it must have a value).
8177
</description>
8178
</field>
8179
<field id="length">
8180
<jint/>
8181
<description>
8182
The length of the valid section for this local variable.
8183
The last code array index where the local variable is valid
8184
is <code>start_location + length</code>.
8185
</description>
8186
</field>
8187
<field id="name">
8188
<allocfieldbuf><char/></allocfieldbuf>
8189
<description>
8190
The local variable name, encoded as a
8191
<internallink id="mUTF">modified UTF-8</internallink> string.
8192
</description>
8193
</field>
8194
<field id="signature">
8195
<allocfieldbuf><char/></allocfieldbuf>
8196
<description>
8197
The local variable's type signature, encoded as a
8198
<internallink id="mUTF">modified UTF-8</internallink> string.
8199
The signature format is the same as that defined in
8200
<vmspec chapter="4.3.2"/>.
8201
</description>
8202
</field>
8203
<field id="generic_signature">
8204
<allocfieldbuf><char/></allocfieldbuf>
8205
<description>
8206
The local variable's generic signature, encoded as a
8207
<internallink id="mUTF">modified UTF-8</internallink> string.
8208
The value of this field will be <code>NULL</code> for any local
8209
variable which does not have a generic type.
8210
</description>
8211
</field>
8212
<field id="slot">
8213
<jint/>
8214
<description>
8215
The local variable's slot. See <internallink id="local">Local Variables</internallink>.
8216
</description>
8217
</field>
8218
</typedef>
8219
<description>
8220
Return local variable information.
8221
</description>
8222
<origin>jvmdiClone</origin>
8223
<capabilities>
8224
<required id="can_access_local_variables"></required>
8225
</capabilities>
8226
<parameters>
8227
<param id="method">
8228
<jmethodID native="error"/>
8229
<description>
8230
The method to query.
8231
</description>
8232
</param>
8233
<param id="entry_count_ptr">
8234
<outptr><jint/></outptr>
8235
<description>
8236
On return, points to the number of entries in the table
8237
</description>
8238
</param>
8239
<param id="table_ptr">
8240
<allocbuf outcount="entry_count_ptr"><struct>jvmtiLocalVariableEntry</struct></allocbuf>
8241
<description>
8242
On return, points to an array of local variable table entries.
8243
</description>
8244
</param>
8245
</parameters>
8246
<errors>
8247
<error id="JVMTI_ERROR_ABSENT_INFORMATION">
8248
Class information does not include local variable
8249
information.
8250
</error>
8251
</errors>
8252
</function>
8253
8254
<function id="GetBytecodes" phase="start" num="75">
8255
<synopsis>Get Bytecodes</synopsis>
8256
<description>
8257
For the method indicated by <code>method</code>,
8258
return the byte codes that implement the method. The number of
8259
bytecodes is returned via <code>bytecode_count_ptr</code>. The byte codes
8260
themselves are returned via <code>bytecodes_ptr</code>.
8261
</description>
8262
<origin>jvmdi</origin>
8263
<capabilities>
8264
<required id="can_get_bytecodes"></required>
8265
</capabilities>
8266
<parameters>
8267
<param id="klass">
8268
<jclass method="method"/>
8269
<description>
8270
The class to query.
8271
</description>
8272
</param>
8273
<param id="method">
8274
<jmethodID class="klass" native="error"/>
8275
<description>
8276
The method to query.
8277
</description>
8278
</param>
8279
<param id="bytecode_count_ptr">
8280
<outptr><jint/></outptr>
8281
<description>
8282
On return, points to the length of the byte code array
8283
</description>
8284
</param>
8285
<param id="bytecodes_ptr">
8286
<allocbuf outcount="bytecode_count_ptr"><uchar/></allocbuf>
8287
<description>
8288
On return, points to the pointer to the byte code array
8289
</description>
8290
</param>
8291
</parameters>
8292
<errors>
8293
</errors>
8294
</function>
8295
8296
<function id="IsMethodNative" phase="start" num="76">
8297
<synopsis>Is Method Native</synopsis>
8298
<description>
8299
For the method indicated by <code>method</code>, return a
8300
value indicating whether the method is native via <code>is_native_ptr</code>
8301
</description>
8302
<origin>jvmdi</origin>
8303
<capabilities>
8304
</capabilities>
8305
<parameters>
8306
<param id="klass">
8307
<jclass method="method"/>
8308
<description>
8309
The class to query.
8310
</description>
8311
</param>
8312
<param id="method">
8313
<jmethodID class="klass"/>
8314
<description>
8315
The method to query.
8316
</description>
8317
</param>
8318
<param id="is_native_ptr">
8319
<outptr><jboolean/></outptr>
8320
<description>
8321
On return, points to the boolean result of this function.
8322
</description>
8323
</param>
8324
</parameters>
8325
<errors>
8326
</errors>
8327
</function>
8328
8329
<function id="IsMethodSynthetic" phase="start" num="77">
8330
<synopsis>Is Method Synthetic</synopsis>
8331
<description>
8332
For the method indicated by <code>method</code>, return a
8333
value indicating whether the method is synthetic via <code>is_synthetic_ptr</code>.
8334
Synthetic methods are generated by the compiler but not present in the
8335
original source code.
8336
</description>
8337
<origin>jvmdi</origin>
8338
<capabilities>
8339
<required id="can_get_synthetic_attribute"></required>
8340
</capabilities>
8341
<parameters>
8342
<param id="klass">
8343
<jclass method="method"/>
8344
<description>
8345
The class to query.
8346
</description>
8347
</param>
8348
<param id="method">
8349
<jmethodID class="klass"/>
8350
<description>
8351
The method to query.
8352
</description>
8353
</param>
8354
<param id="is_synthetic_ptr">
8355
<outptr><jboolean/></outptr>
8356
<description>
8357
On return, points to the boolean result of this function.
8358
</description>
8359
</param>
8360
</parameters>
8361
<errors>
8362
</errors>
8363
</function>
8364
8365
<function id="IsMethodObsolete" phase="start" num="91">
8366
<synopsis>Is Method Obsolete</synopsis>
8367
<description>
8368
Determine if a method ID refers to an
8369
<internallink id="obsoleteMethods">obsolete</internallink>
8370
method version.
8371
</description>
8372
<origin>jvmdi</origin>
8373
<capabilities>
8374
</capabilities>
8375
<parameters>
8376
<param id="klass">
8377
<jclass method="method"/>
8378
<description>
8379
The class to query.
8380
</description>
8381
</param>
8382
<param id="method">
8383
<jmethodID class="klass"/>
8384
<description>
8385
The method ID to query.
8386
</description>
8387
</param>
8388
<param id="is_obsolete_ptr">
8389
<outptr><jboolean/></outptr>
8390
<description>
8391
On return, points to the boolean result of this function.
8392
</description>
8393
</param>
8394
</parameters>
8395
<errors>
8396
</errors>
8397
</function>
8398
8399
<function id="SetNativeMethodPrefix" jkernel="yes" phase="any" num="73" since="1.1">
8400
<synopsis>Set Native Method Prefix</synopsis>
8401
<description>
8402
This function modifies the failure handling of
8403
native method resolution by allowing retry
8404
with a prefix applied to the name.
8405
When used with the
8406
<eventlink id="ClassFileLoadHook">ClassFileLoadHook
8407
event</eventlink>, it enables native methods to be
8408
<internallink id="bci">instrumented</internallink>.
8409
<p/>
8410
Since native methods cannot be directly instrumented
8411
(they have no bytecodes), they must be wrapped with
8412
a non-native method which can be instrumented.
8413
For example, if we had:
8414
<example>
8415
native boolean foo(int x);</example>
8416
<p/>
8417
We could transform the class file (with the
8418
ClassFileLoadHook event) so that this becomes:
8419
<example>
8420
boolean foo(int x) {
8421
<i>... record entry to foo ...</i>
8422
return wrapped_foo(x);
8423
}
8424
8425
native boolean wrapped_foo(int x);</example>
8426
<p/>
8427
Where foo becomes a wrapper for the actual native method
8428
with the appended prefix "wrapped_". Note that
8429
"wrapped_" would be a poor choice of prefix since it
8430
might conceivably form the name of an existing method
8431
thus something like "$$$MyAgentWrapped$$$_" would be
8432
better but would make these examples less readable.
8433
<p/>
8434
The wrapper will allow data to be collected on the native
8435
method call, but now the problem becomes linking up the
8436
wrapped method with the native implementation.
8437
That is, the method <code>wrapped_foo</code> needs to be
8438
resolved to the native implementation of <code>foo</code>,
8439
which might be:
8440
<example>
8441
Java_somePackage_someClass_foo(JNIEnv* env, jint x)</example>
8442
<p/>
8443
This function allows the prefix to be specified and the
8444
proper resolution to occur.
8445
Specifically, when the standard resolution fails, the
8446
resolution is retried taking the prefix into consideration.
8447
There are two ways that resolution occurs, explicit
8448
resolution with the JNI function <code>RegisterNatives</code>
8449
and the normal automatic resolution. For
8450
<code>RegisterNatives</code>, the VM will attempt this
8451
association:
8452
<example>
8453
method(foo) -> nativeImplementation(foo)</example>
8454
<p/>
8455
When this fails, the resolution will be retried with
8456
the specified prefix prepended to the method name,
8457
yielding the correct resolution:
8458
<example>
8459
method(wrapped_foo) -> nativeImplementation(foo)</example>
8460
<p/>
8461
For automatic resolution, the VM will attempt:
8462
<example>
8463
method(wrapped_foo) -> nativeImplementation(wrapped_foo)</example>
8464
<p/>
8465
When this fails, the resolution will be retried with
8466
the specified prefix deleted from the implementation name,
8467
yielding the correct resolution:
8468
<example>
8469
method(wrapped_foo) -> nativeImplementation(foo)</example>
8470
<p/>
8471
Note that since the prefix is only used when standard
8472
resolution fails, native methods can be wrapped selectively.
8473
<p/>
8474
Since each <jvmti/> environment is independent and
8475
can do its own transformation of the bytecodes, more
8476
than one layer of wrappers may be applied. Thus each
8477
environment needs its own prefix. Since transformations
8478
are applied in order, the prefixes, if applied, will
8479
be applied in the same order.
8480
The order of transformation application is described in
8481
the <eventlink id="ClassFileLoadHook"/> event.
8482
Thus if three environments applied
8483
wrappers, <code>foo</code> might become
8484
<code>$env3_$env2_$env1_foo</code>. But if, say,
8485
the second environment did not apply a wrapper to
8486
<code>foo</code> it would be just
8487
<code>$env3_$env1_foo</code>. To be able to
8488
efficiently determine the sequence of prefixes,
8489
an intermediate prefix is only applied if its non-native
8490
wrapper exists. Thus, in the last example, even though
8491
<code>$env1_foo</code> is not a native method, the
8492
<code>$env1_</code> prefix is applied since
8493
<code>$env1_foo</code> exists.
8494
<p/>
8495
Since the prefixes are used at resolution time
8496
and since resolution may be arbitrarily delayed, a
8497
native method prefix must remain set as long as there
8498
are corresponding prefixed native methods.
8499
</description>
8500
<origin>new</origin>
8501
<capabilities>
8502
<required id="can_set_native_method_prefix"></required>
8503
</capabilities>
8504
<parameters>
8505
<param id="prefix">
8506
<inbuf>
8507
<char/>
8508
<nullok>
8509
any existing prefix in this environment is cancelled
8510
</nullok>
8511
</inbuf>
8512
<description>
8513
The prefix to apply, encoded as a
8514
<internallink id="mUTF">modified UTF-8</internallink> string.
8515
</description>
8516
</param>
8517
</parameters>
8518
<errors>
8519
</errors>
8520
</function>
8521
8522
<function id="SetNativeMethodPrefixes" jkernel="yes" phase="any" num="74" since="1.1">
8523
<synopsis>Set Native Method Prefixes</synopsis>
8524
<description>
8525
For a normal agent, <functionlink id="SetNativeMethodPrefix"/>
8526
will provide all needed native method prefixing.
8527
For a meta-agent that performs multiple independent class
8528
file transformations (for example as a proxy for another
8529
layer of agents) this function allows each transformation
8530
to have its own prefix.
8531
The prefixes are applied in the order supplied and are
8532
processed in the same manor as described for the
8533
application of prefixes from multiple <jvmti/> environments
8534
in <functionlink id="SetNativeMethodPrefix"/>.
8535
<p/>
8536
Any previous prefixes are replaced. Thus, calling this
8537
function with a <paramlink id="prefix_count"/> of <code>0</code>
8538
disables prefixing in this environment.
8539
<p/>
8540
<functionlink id="SetNativeMethodPrefix"/> and this function
8541
are the two ways to set the prefixes.
8542
Calling <code>SetNativeMethodPrefix</code> with
8543
a prefix is the same as calling this function with
8544
<paramlink id="prefix_count"/> of <code>1</code>.
8545
Calling <code>SetNativeMethodPrefix</code> with
8546
<code>NULL</code> is the same as calling this function with
8547
<paramlink id="prefix_count"/> of <code>0</code>.
8548
</description>
8549
<origin>new</origin>
8550
<capabilities>
8551
<required id="can_set_native_method_prefix"></required>
8552
</capabilities>
8553
<parameters>
8554
<param id="prefix_count">
8555
<jint min="0"/>
8556
<description>
8557
The number of prefixes to apply.
8558
</description>
8559
</param>
8560
<param id="prefixes">
8561
<agentbuf>
8562
<char/>
8563
</agentbuf>
8564
<description>
8565
The prefixes to apply for this environment, each encoded as a
8566
<internallink id="mUTF">modified UTF-8</internallink> string.
8567
</description>
8568
</param>
8569
</parameters>
8570
<errors>
8571
</errors>
8572
</function>
8573
8574
</category>
8575
8576
<category id="RawMonitors" label="Raw Monitor">
8577
8578
<function id="CreateRawMonitor" phase="onload" callbacksafe="safe" num="31">
8579
<synopsis>Create Raw Monitor</synopsis>
8580
<description>
8581
Create a raw monitor.
8582
</description>
8583
<origin>jvmdi</origin>
8584
<capabilities>
8585
</capabilities>
8586
<parameters>
8587
<param id="name">
8588
<inbuf><char/></inbuf>
8589
<description>
8590
A name to identify the monitor, encoded as a
8591
<internallink id="mUTF">modified UTF-8</internallink> string.
8592
</description>
8593
</param>
8594
<param id="monitor_ptr">
8595
<outptr><jrawMonitorID/></outptr>
8596
<description>
8597
On return, points to the created monitor.
8598
</description>
8599
</param>
8600
</parameters>
8601
<errors>
8602
</errors>
8603
</function>
8604
8605
<function id="DestroyRawMonitor" phase="onload" callbacksafe="safe" num="32">
8606
<synopsis>Destroy Raw Monitor</synopsis>
8607
<description>
8608
Destroy the raw monitor.
8609
If the monitor being destroyed has been entered by this thread, it will be
8610
exited before it is destroyed.
8611
If the monitor being destroyed has been entered by another thread,
8612
an error will be returned and the monitor will not be destroyed.
8613
</description>
8614
<origin>jvmdi</origin>
8615
<capabilities>
8616
</capabilities>
8617
<parameters>
8618
<param id="monitor">
8619
<jrawMonitorID/>
8620
<description>
8621
The monitor
8622
</description>
8623
</param>
8624
</parameters>
8625
<errors>
8626
<error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8627
Not monitor owner
8628
</error>
8629
</errors>
8630
</function>
8631
8632
<function id="RawMonitorEnter" phase="any" callbacksafe="safe" impl="innative notrace" num="33">
8633
<synopsis>Raw Monitor Enter</synopsis>
8634
<description>
8635
Gain exclusive ownership of a raw monitor.
8636
The same thread may enter a monitor more then once.
8637
The thread must
8638
<functionlink id="RawMonitorExit">exit</functionlink>
8639
the monitor the same number of times as it is entered.
8640
If a monitor is entered during <code>OnLoad</code> (before attached threads exist)
8641
and has not exited when attached threads come into existence, the enter
8642
is considered to have occurred on the main thread.
8643
</description>
8644
<origin>jvmdi</origin>
8645
<capabilities>
8646
</capabilities>
8647
<parameters>
8648
<param id="monitor">
8649
<jrawMonitorID/>
8650
<description>
8651
The monitor
8652
</description>
8653
</param>
8654
</parameters>
8655
<errors>
8656
</errors>
8657
</function>
8658
8659
<function id="RawMonitorExit" phase="any" callbacksafe="safe" impl="innative notrace" num="34">
8660
<synopsis>Raw Monitor Exit</synopsis>
8661
<description>
8662
Release exclusive ownership of a raw monitor.
8663
</description>
8664
<origin>jvmdi</origin>
8665
<capabilities>
8666
</capabilities>
8667
<parameters>
8668
<param id="monitor">
8669
<jrawMonitorID/>
8670
<description>
8671
The monitor
8672
</description>
8673
</param>
8674
</parameters>
8675
<errors>
8676
<error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8677
Not monitor owner
8678
</error>
8679
</errors>
8680
</function>
8681
8682
<function id="RawMonitorWait" phase="any" callbacksafe="safe" impl="innative notrace" num="35">
8683
<synopsis>Raw Monitor Wait</synopsis>
8684
<description>
8685
Wait for notification of the raw monitor.
8686
<p/>
8687
Causes the current thread to wait until either another thread calls
8688
<functionlink id="RawMonitorNotify"/> or
8689
<functionlink id="RawMonitorNotifyAll"/>
8690
for the specified raw monitor, or the specified
8691
<paramlink id="millis">timeout</paramlink>
8692
has elapsed.
8693
</description>
8694
<origin>jvmdi</origin>
8695
<capabilities>
8696
</capabilities>
8697
<parameters>
8698
<param id="monitor">
8699
<jrawMonitorID/>
8700
<description>
8701
The monitor
8702
</description>
8703
</param>
8704
<param id="millis">
8705
<jlong/>
8706
<description>
8707
The timeout, in milliseconds. If the timeout is
8708
zero, then real time is not taken into consideration
8709
and the thread simply waits until notified.
8710
</description>
8711
</param>
8712
</parameters>
8713
<errors>
8714
<error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8715
Not monitor owner
8716
</error>
8717
<error id="JVMTI_ERROR_INTERRUPT">
8718
Wait was interrupted, try again
8719
</error>
8720
</errors>
8721
</function>
8722
8723
<function id="RawMonitorNotify" phase="any" callbacksafe="safe" impl="notrace" num="36">
8724
<synopsis>Raw Monitor Notify</synopsis>
8725
<description>
8726
Notify a single thread waiting on the raw monitor.
8727
</description>
8728
<origin>jvmdi</origin>
8729
<capabilities>
8730
</capabilities>
8731
<parameters>
8732
<param id="monitor">
8733
<jrawMonitorID/>
8734
<description>
8735
The monitor
8736
</description>
8737
</param>
8738
</parameters>
8739
<errors>
8740
<error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8741
Not monitor owner
8742
</error>
8743
</errors>
8744
</function>
8745
8746
<function id="RawMonitorNotifyAll" phase="any" callbacksafe="safe" impl="notrace" num="37">
8747
<synopsis>Raw Monitor Notify All</synopsis>
8748
<description>
8749
Notify all threads waiting on the raw monitor.
8750
</description>
8751
<origin>jvmdi</origin>
8752
<capabilities>
8753
</capabilities>
8754
<parameters>
8755
<param id="monitor">
8756
<jrawMonitorID/>
8757
<description>
8758
The monitor
8759
</description>
8760
</param>
8761
</parameters>
8762
<errors>
8763
<error id="JVMTI_ERROR_NOT_MONITOR_OWNER">
8764
Not monitor owner
8765
</error>
8766
</errors>
8767
</function>
8768
8769
<elide>
8770
<function id="GetRawMonitorUse" num="118">
8771
<synopsis>Get Raw Monitor Use</synopsis>
8772
<description>
8773
The fields of the <functionlink id="jvmtiMonitorUsage"></functionlink> structure
8774
are filled in with information about usage of the raw monitor.
8775
</description>
8776
<origin>new</origin>
8777
<capabilities>
8778
<required id="can_get_raw_monitor_usage"></required>
8779
</capabilities>
8780
<parameters>
8781
<param id="monitor">
8782
<jrawMonitorID/>
8783
<description>
8784
the raw monitor to query.
8785
</description>
8786
</param>
8787
<param id="info_ptr">
8788
<outptr><struct>jvmtiMonitorUsage</struct></outptr>
8789
<description>
8790
On return, filled with monitor information for the
8791
specified raw monitor.
8792
</description>
8793
</param>
8794
</parameters>
8795
<errors>
8796
</errors>
8797
</function>
8798
8799
<function id="GetRawMonitors" num="119">
8800
<synopsis>Get Raw Monitors</synopsis>
8801
<description>
8802
Return the list of raw monitors.
8803
<p/>
8804
Note: details about each monitor can be examined with
8805
<functionlink id="GetRawMonitorUse"></functionlink>.
8806
</description>
8807
<origin>new</origin>
8808
<capabilities>
8809
<required id="can_get_raw_monitor_usage"></required>
8810
</capabilities>
8811
<parameters>
8812
<param id="monitorCnt">
8813
<outptr><jint/></outptr>
8814
<description>
8815
On return, pointer to the number
8816
of monitors returned in <code>monitors_ptr</code>.
8817
</description>
8818
</param>
8819
<param id="monitors_ptr">
8820
<allocbuf outcount="monitorCnt"><jrawMonitorID/></allocbuf>
8821
<description>
8822
On return, pointer to the monitor list.
8823
</description>
8824
</param>
8825
</parameters>
8826
<errors>
8827
</errors>
8828
</function>
8829
</elide>
8830
</category>
8831
8832
<category id="jniIntercept" label="JNI Function Interception">
8833
8834
<intro>
8835
Provides the ability to intercept and resend
8836
Java Native Interface (JNI) function calls
8837
by manipulating the JNI function table.
8838
See <externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/functions.html">JNI
8839
Functions</externallink> in the <i>Java Native Interface Specification</i>.
8840
<p/>
8841
The following example illustrates intercepting the
8842
<code>NewGlobalRef</code> JNI call in order to count reference
8843
creation.
8844
<example>
8845
JNIEnv original_jni_Functions;
8846
JNIEnv redirected_jni_Functions;
8847
int my_global_ref_count = 0;
8848
8849
jobject
8850
MyNewGlobalRef(JNIEnv *jni_env, jobject lobj) {
8851
++my_global_ref_count;
8852
return originalJNIFunctions-&gt;NewGlobalRef(env, lobj);
8853
}
8854
8855
void
8856
myInit() {
8857
jvmtiError err;
8858
8859
err = (*jvmti_env)-&gt;GetJNIFunctionTable(jvmti_env, &amp;original_jni_Functions);
8860
if (err != JVMTI_ERROR_NONE) {
8861
die();
8862
}
8863
err = (*jvmti_env)-&gt;GetJNIFunctionTable(jvmti_env, &amp;redirected_jni_Functions);
8864
if (err != JVMTI_ERROR_NONE) {
8865
die();
8866
}
8867
redirectedJNIFunctions-&gt;NewGlobalRef = MyNewGlobalRef;
8868
err = (*jvmti_env)-&gt;SetJNIFunctionTable(jvmti_env, redirected_jni_Functions);
8869
if (err != JVMTI_ERROR_NONE) {
8870
die();
8871
}
8872
}
8873
</example>
8874
Sometime after <code>myInit</code> is called the user's JNI
8875
code is executed which makes the call to create a new global
8876
reference. Instead of going to the normal JNI implementation
8877
the call goes to <code>myNewGlobalRef</code>. Note that a
8878
copy of the original function table is kept so that the normal
8879
JNI function can be called after the data is collected.
8880
Note also that any JNI functions which are not overwritten
8881
will behave normally.
8882
<todo>
8883
check that the example compiles and executes.
8884
</todo>
8885
</intro>
8886
8887
<function id="SetJNIFunctionTable" phase="start" num="120">
8888
<synopsis>Set JNI Function Table</synopsis>
8889
<description>
8890
Set the JNI function table
8891
in all current and future JNI environments.
8892
As a result, all future JNI calls are directed to the specified functions.
8893
Use <functionlink id="GetJNIFunctionTable"></functionlink> to get the
8894
function table to pass to this function.
8895
For this function to take effect the the updated table entries must be
8896
used by the JNI clients.
8897
Since the table is defined <code>const</code> some compilers may optimize
8898
away the access to the table, thus preventing this function from taking
8899
effect.
8900
The table is copied--changes to the local copy of the
8901
table have no effect.
8902
This function affects only the function table, all other aspects of the environment are
8903
unaffected.
8904
See the examples <internallink id="jniIntercept">above</internallink>.
8905
</description>
8906
<origin>new</origin>
8907
<capabilities>
8908
</capabilities>
8909
<parameters>
8910
<param id="function_table">
8911
<inptr>
8912
<struct>jniNativeInterface</struct>
8913
</inptr>
8914
<description>
8915
Points to the new JNI function table.
8916
</description>
8917
</param>
8918
</parameters>
8919
<errors>
8920
</errors>
8921
</function>
8922
8923
<function id="GetJNIFunctionTable" phase="start" num="121">
8924
<synopsis>Get JNI Function Table</synopsis>
8925
<description>
8926
Get the JNI function table.
8927
The JNI function table is copied into allocated memory.
8928
If <functionlink id="SetJNIFunctionTable"></functionlink>
8929
has been called, the modified (not the original) function
8930
table is returned.
8931
Only the function table is copied, no other aspects of the environment
8932
are copied.
8933
See the examples <internallink id="jniIntercept">above</internallink>.
8934
</description>
8935
<origin>new</origin>
8936
<capabilities>
8937
</capabilities>
8938
<parameters>
8939
<param id="function_table">
8940
<allocbuf>
8941
<struct>jniNativeInterface</struct>
8942
</allocbuf>
8943
<description>
8944
On return, <code>*function_table</code>
8945
points a newly allocated copy of the JNI function table.
8946
</description>
8947
</param>
8948
</parameters>
8949
<errors>
8950
</errors>
8951
</function>
8952
8953
</category>
8954
8955
<category id="eventManagement" label="Event Management">
8956
8957
<function id="SetEventCallbacks" jkernel="yes" phase="onload" num="122">
8958
<synopsis>Set Event Callbacks</synopsis>
8959
<description>
8960
Set the functions to be called for each event.
8961
The callbacks are specified by supplying a replacement function table.
8962
The function table is copied--changes to the local copy of the
8963
table have no effect.
8964
This is an atomic action, all callbacks are set at once.
8965
No events are sent before this function is called.
8966
When an entry is <code>NULL</code> or when the event is beyond
8967
<paramlink id="size_of_callbacks"></paramlink> no event is sent.
8968
Details on events are
8969
described <internallink id="EventSection">later</internallink> in this document.
8970
An event must be enabled and have a callback in order to be
8971
sent--the order in which this function and
8972
<functionlink id="SetEventNotificationMode"></functionlink>
8973
are called does not affect the result.
8974
</description>
8975
<origin>new</origin>
8976
<capabilities>
8977
</capabilities>
8978
<parameters>
8979
<param id="callbacks">
8980
<inptr>
8981
<struct>jvmtiEventCallbacks</struct>
8982
<nullok>remove the existing callbacks</nullok>
8983
</inptr>
8984
<description>
8985
The new event callbacks.
8986
</description>
8987
</param>
8988
<param id="size_of_callbacks">
8989
<jint min="0"/>
8990
<description>
8991
<code>sizeof(jvmtiEventCallbacks)</code>--for version
8992
compatibility.
8993
</description>
8994
</param>
8995
</parameters>
8996
<errors>
8997
</errors>
8998
</function>
8999
9000
<function id="SetEventNotificationMode" jkernel="yes" phase="onload" num="2">
9001
<synopsis>Set Event Notification Mode</synopsis>
9002
<description>
9003
Control the generation of events.
9004
<constants id="jvmtiEventMode" label="Event Enable/Disable" kind="enum">
9005
<constant id="JVMTI_ENABLE" num="1">
9006
If <paramlink id="mode"></paramlink> is <code>JVMTI_ENABLE</code>,
9007
the event <paramlink id="event_type"></paramlink> will be enabled
9008
</constant>
9009
<constant id="JVMTI_DISABLE" num="0">
9010
If <paramlink id="mode"></paramlink> is <code>JVMTI_DISABLE</code>,
9011
the event <paramlink id="event_type"></paramlink> will be disabled
9012
</constant>
9013
</constants>
9014
If <code>thread</code> is <code>NULL</code>,
9015
the event is enabled or disabled globally; otherwise, it is
9016
enabled or disabled for a particular thread.
9017
An event is generated for
9018
a particular thread if it is enabled either at the thread or global
9019
levels.
9020
<p/>
9021
See <internallink id="EventIndex">below</internallink> for information on specific events.
9022
<p/>
9023
The following events cannot be controlled at the thread
9024
level through this function.
9025
<ul>
9026
<li><eventlink id="VMInit"></eventlink></li>
9027
<li><eventlink id="VMStart"></eventlink></li>
9028
<li><eventlink id="VMDeath"></eventlink></li>
9029
<li><eventlink id="ThreadStart"></eventlink></li>
9030
<li><eventlink id="CompiledMethodLoad"></eventlink></li>
9031
<li><eventlink id="CompiledMethodUnload"></eventlink></li>
9032
<li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9033
<li><eventlink id="DataDumpRequest"></eventlink></li>
9034
</ul>
9035
<p/>
9036
Initially, no events are enabled at either the thread level
9037
or the global level.
9038
<p/>
9039
Any needed capabilities (see Event Enabling Capabilities below) must be possessed
9040
before calling this function.
9041
<p/>
9042
Details on events are
9043
described <internallink id="EventSection">below</internallink>.
9044
</description>
9045
<origin>jvmdiClone</origin>
9046
<eventcapabilities></eventcapabilities>
9047
<parameters>
9048
<param id="mode">
9049
<enum>jvmtiEventMode</enum>
9050
<description>
9051
<code>JVMTI_ENABLE</code> or <code>JVMTI_DISABLE</code>
9052
</description>
9053
</param>
9054
<param id="event_type">
9055
<enum>jvmtiEvent</enum>
9056
<description>
9057
the event to control
9058
</description>
9059
</param>
9060
<param id="event_thread">
9061
<ptrtype>
9062
<jthread impl="noconvert"/>
9063
<nullok>event is controlled at the global level</nullok>
9064
</ptrtype>
9065
<description>
9066
The thread to control
9067
</description>
9068
</param>
9069
<param id="...">
9070
<varargs/>
9071
<description>
9072
for future expansion
9073
</description>
9074
</param>
9075
</parameters>
9076
<errors>
9077
<error id="JVMTI_ERROR_INVALID_THREAD">
9078
<paramlink id="event_thread"/> is non-<code>NULL</code> and is not a valid thread.
9079
</error>
9080
<error id="JVMTI_ERROR_THREAD_NOT_ALIVE">
9081
<paramlink id="event_thread"/> is non-<code>NULL</code> and is not live (has not been started or is now dead).
9082
</error>
9083
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9084
thread level control was attempted on events which do not
9085
permit thread level control.
9086
</error>
9087
<error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9088
The Required Event Enabling Capability is not possessed.
9089
</error>
9090
</errors>
9091
</function>
9092
9093
<function id="GenerateEvents" num="123">
9094
<synopsis>Generate Events</synopsis>
9095
<description>
9096
Generate events to represent the current state of the VM.
9097
For example, if <paramlink id="event_type"/> is
9098
<code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code>,
9099
a <eventlink id="CompiledMethodLoad"></eventlink> event will be
9100
sent for each currently compiled method.
9101
Methods that were loaded and now have been unloaded are not sent.
9102
The history of what events have previously been sent does not
9103
effect what events are sent by this function--for example,
9104
all currently compiled methods
9105
will be sent each time this function is called.
9106
<p/>
9107
This function is useful when
9108
events may have been missed due to the agent attaching after program
9109
execution begins; this function generates the missed events.
9110
<p/>
9111
Attempts to execute Java programming language code or
9112
JNI functions may be paused until this function returns -
9113
so neither should be called from the thread sending the event.
9114
This function returns only after the missed events have been
9115
sent, processed and have returned.
9116
The event may be sent on a different thread than the thread
9117
on which the event occurred.
9118
The callback for the event must be set with
9119
<functionlink id="SetEventCallbacks"></functionlink>
9120
and the event must be enabled with
9121
<functionlink id="SetEventNotificationMode"></functionlink>
9122
or the events will not occur.
9123
If the VM no longer has the information to generate some or
9124
all of the requested events, the events are simply not sent -
9125
no error is returned.
9126
<p/>
9127
Only the following events are supported:
9128
<ul>
9129
<li><eventlink id="CompiledMethodLoad"></eventlink></li>
9130
<li><eventlink id="DynamicCodeGenerated"></eventlink></li>
9131
</ul>
9132
</description>
9133
<origin>new</origin>
9134
<capabilities>
9135
<capability id="can_generate_compiled_method_load_events"></capability>
9136
</capabilities>
9137
<parameters>
9138
<param id="event_type">
9139
<enum>jvmtiEvent</enum>
9140
<description>
9141
The type of event to generate. Must be one of these:
9142
<ul>
9143
<li><eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink></li>
9144
<li><eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink></li>
9145
</ul>
9146
</description>
9147
</param>
9148
</parameters>
9149
<errors>
9150
<error id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY">
9151
<paramlink id="event_type"/> is
9152
<eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9153
and <fieldlink id="can_generate_compiled_method_load_events" struct="jvmtiCapabilities"></fieldlink>
9154
is <code>false</code>.
9155
</error>
9156
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9157
<paramlink id="event_type"/> is other than
9158
<eventlink id="CompiledMethodLoad"><code>JVMTI_EVENT_COMPILED_METHOD_LOAD</code></eventlink>
9159
or <eventlink id="DynamicCodeGenerated"><code>JVMTI_EVENT_DYNAMIC_CODE_GENERATED</code></eventlink>.
9160
</error>
9161
</errors>
9162
</function>
9163
9164
</category>
9165
9166
<category id="extension" label="Extension Mechanism">
9167
9168
<intro>
9169
These functions
9170
allow a <jvmti/> implementation to provide functions and events
9171
beyond those defined in this specification.
9172
<p/>
9173
Both extension functions and extension events have parameters
9174
each of which has a 'type' and 'kind' chosen from the following tables:
9175
9176
<constants id="jvmtiParamTypes" label="Extension Function/Event Parameter Types" kind="enum">
9177
<constant id="JVMTI_TYPE_JBYTE" num="101">
9178
Java programming language primitive type - <code>byte</code>.
9179
JNI type <code>jbyte</code>.
9180
</constant>
9181
<constant id="JVMTI_TYPE_JCHAR" num="102">
9182
Java programming language primitive type - <code>char</code>.
9183
JNI type <code>jchar</code>.
9184
</constant>
9185
<constant id="JVMTI_TYPE_JSHORT" num="103">
9186
Java programming language primitive type - <code>short</code>.
9187
JNI type <code>jshort</code>.
9188
</constant>
9189
<constant id="JVMTI_TYPE_JINT" num="104">
9190
Java programming language primitive type - <code>int</code>.
9191
JNI type <datalink id="jint"></datalink>.
9192
</constant>
9193
<constant id="JVMTI_TYPE_JLONG" num="105">
9194
Java programming language primitive type - <code>long</code>.
9195
JNI type <datalink id="jlong"></datalink>.
9196
</constant>
9197
<constant id="JVMTI_TYPE_JFLOAT" num="106">
9198
Java programming language primitive type - <code>float</code>.
9199
JNI type <datalink id="jfloat"></datalink>.
9200
</constant>
9201
<constant id="JVMTI_TYPE_JDOUBLE" num="107">
9202
Java programming language primitive type - <code>double</code>.
9203
JNI type <datalink id="jdouble"></datalink>.
9204
</constant>
9205
<constant id="JVMTI_TYPE_JBOOLEAN" num="108">
9206
Java programming language primitive type - <code>boolean</code>.
9207
JNI type <datalink id="jboolean"></datalink>.
9208
</constant>
9209
<constant id="JVMTI_TYPE_JOBJECT" num="109">
9210
Java programming language object type - <code>java.lang.Object</code>.
9211
JNI type <datalink id="jobject"></datalink>.
9212
Returned values are JNI local references and must be managed.
9213
</constant>
9214
<constant id="JVMTI_TYPE_JTHREAD" num="110">
9215
Java programming language object type - <code>java.lang.Thread</code>.
9216
<jvmti/> type <datalink id="jthread"></datalink>.
9217
Returned values are JNI local references and must be managed.
9218
</constant>
9219
<constant id="JVMTI_TYPE_JCLASS" num="111">
9220
Java programming language object type - <code>java.lang.Class</code>.
9221
JNI type <datalink id="jclass"></datalink>.
9222
Returned values are JNI local references and must be managed.
9223
</constant>
9224
<constant id="JVMTI_TYPE_JVALUE" num="112">
9225
Union of all Java programming language primitive and object types -
9226
JNI type <datalink id="jvalue"></datalink>.
9227
Returned values which represent object types are JNI local references and must be managed.
9228
</constant>
9229
<constant id="JVMTI_TYPE_JFIELDID" num="113">
9230
Java programming language field identifier -
9231
JNI type <datalink id="jfieldID"></datalink>.
9232
</constant>
9233
<constant id="JVMTI_TYPE_JMETHODID" num="114">
9234
Java programming language method identifier -
9235
JNI type <datalink id="jmethodID"></datalink>.
9236
</constant>
9237
<constant id="JVMTI_TYPE_CCHAR" num="115">
9238
C programming language type - <code>char</code>.
9239
</constant>
9240
<constant id="JVMTI_TYPE_CVOID" num="116">
9241
C programming language type - <code>void</code>.
9242
</constant>
9243
<constant id="JVMTI_TYPE_JNIENV" num="117">
9244
JNI environment - <code>JNIEnv</code>.
9245
Should be used with the correct <datalink id="jvmtiParamKind"/> to make it a pointer type.
9246
</constant>
9247
</constants>
9248
9249
<constants id="jvmtiParamKind" label="Extension Function/Event Parameter Kinds" kind="enum">
9250
<constant id="JVMTI_KIND_IN" num="91">
9251
Ingoing argument - <code>foo</code>.
9252
</constant>
9253
<constant id="JVMTI_KIND_IN_PTR" num="92">
9254
Ingoing pointer argument - <code>const foo*</code>.
9255
</constant>
9256
<constant id="JVMTI_KIND_IN_BUF" num="93">
9257
Ingoing array argument - <code>const foo*</code>.
9258
</constant>
9259
<constant id="JVMTI_KIND_ALLOC_BUF" num="94">
9260
Outgoing allocated array argument - <code>foo**</code>.
9261
Free with <code>Deallocate</code>.
9262
</constant>
9263
<constant id="JVMTI_KIND_ALLOC_ALLOC_BUF" num="95">
9264
Outgoing allocated array of allocated arrays argument - <code>foo***</code>.
9265
Free with <code>Deallocate</code>.
9266
</constant>
9267
<constant id="JVMTI_KIND_OUT" num="96">
9268
Outgoing argument - <code>foo*</code>.
9269
</constant>
9270
<constant id="JVMTI_KIND_OUT_BUF" num="97">
9271
Outgoing array argument (pre-allocated by agent) - <code>foo*</code>.
9272
Do not <code>Deallocate</code>.
9273
</constant>
9274
</constants>
9275
9276
</intro>
9277
9278
<typedef id="jvmtiParamInfo" label="Extension Function/Event Parameter Info">
9279
<field id="name">
9280
<allocfieldbuf><char/></allocfieldbuf>
9281
<description>
9282
The parameter name, encoded as a
9283
<internallink id="mUTF">modified UTF-8</internallink> string
9284
</description>
9285
</field>
9286
<field id="kind">
9287
<enum>jvmtiParamKind</enum>
9288
<description>
9289
The kind of the parameter - type modifiers
9290
</description>
9291
</field>
9292
<field id="base_type">
9293
<enum>jvmtiParamTypes</enum>
9294
<description>
9295
The base type of the parameter - modified by <code>kind</code>
9296
</description>
9297
</field>
9298
<field id="null_ok">
9299
<jboolean/>
9300
<description>
9301
Is a <code>NULL</code> argument permitted? Applies only to pointer and object types.
9302
</description>
9303
</field>
9304
</typedef>
9305
9306
<callback id="jvmtiExtensionFunction">
9307
<enum>jvmtiError</enum>
9308
<synopsis>Extension Function</synopsis>
9309
<description>
9310
This is the implementation-specific extension function.
9311
</description>
9312
<parameters>
9313
<param id="jvmti_env">
9314
<outptr>
9315
<struct>jvmtiEnv</struct>
9316
</outptr>
9317
<description>
9318
The <jvmti/> environment is the only fixed parameter for extension functions.
9319
</description>
9320
</param>
9321
<param id="...">
9322
<varargs/>
9323
<description>
9324
The extension function-specific parameters
9325
</description>
9326
</param>
9327
</parameters>
9328
</callback>
9329
9330
<function id="GetExtensionFunctions" phase="onload" num="124">
9331
<synopsis>Get Extension Functions</synopsis>
9332
9333
<typedef id="jvmtiExtensionFunctionInfo" label="Extension Function Info">
9334
<field id="func">
9335
<ptrtype>
9336
<struct>jvmtiExtensionFunction</struct>
9337
</ptrtype>
9338
<description>
9339
The actual function to call
9340
</description>
9341
</field>
9342
<field id="id">
9343
<allocfieldbuf><char/></allocfieldbuf>
9344
<description>
9345
The identifier for the extension function, encoded as a
9346
<internallink id="mUTF">modified UTF-8</internallink> string.
9347
Uses package name conventions.
9348
For example, <code>com.sun.hotspot.bar</code>
9349
</description>
9350
</field>
9351
<field id="short_description">
9352
<allocfieldbuf><char/></allocfieldbuf>
9353
<description>
9354
A one sentence description of the function, encoded as a
9355
<internallink id="mUTF">modified UTF-8</internallink> string.
9356
</description>
9357
</field>
9358
<field id="param_count">
9359
<jint/>
9360
<description>
9361
The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9362
</description>
9363
</field>
9364
<field id="params">
9365
<allocfieldbuf outcount="param_count">
9366
<struct>jvmtiParamInfo</struct>
9367
</allocfieldbuf>
9368
<description>
9369
Array of
9370
<fieldlink id="param_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9371
parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9372
</description>
9373
</field>
9374
<field id="error_count">
9375
<jint/>
9376
<description>
9377
The number of possible error returns (excluding universal errors)
9378
</description>
9379
</field>
9380
<field id="errors">
9381
<allocfieldbuf outcount="error_count">
9382
<enum>jvmtiError</enum>
9383
</allocfieldbuf>
9384
<description>
9385
Array of <fieldlink id="error_count" struct="jvmtiExtensionFunctionInfo"></fieldlink>
9386
possible errors
9387
</description>
9388
</field>
9389
</typedef>
9390
9391
<description>
9392
Returns the set of extension functions.
9393
</description>
9394
<origin>new</origin>
9395
<capabilities>
9396
</capabilities>
9397
<parameters>
9398
<param id="extension_count_ptr">
9399
<outptr><jint/></outptr>
9400
<description>
9401
On return, points to the number of extension functions
9402
</description>
9403
</param>
9404
<param id="extensions">
9405
<allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionFunctionInfo</struct></allocbuf>
9406
<description>
9407
Returns an array of extension function info, one per function
9408
</description>
9409
</param>
9410
</parameters>
9411
<errors>
9412
</errors>
9413
</function>
9414
9415
<function id="GetExtensionEvents" phase="onload" num="125">
9416
<synopsis>Get Extension Events</synopsis>
9417
9418
<typedef id="jvmtiExtensionEventInfo" label="Extension Event Info">
9419
<field id="extension_event_index">
9420
<jint/>
9421
<description>
9422
The identifying index of the event
9423
</description>
9424
</field>
9425
<field id="id">
9426
<allocfieldbuf><char/></allocfieldbuf>
9427
<description>
9428
The identifier for the extension event, encoded as a
9429
<internallink id="mUTF">modified UTF-8</internallink> string.
9430
Uses package name conventions.
9431
For example, <code>com.sun.hotspot.bar</code>
9432
</description>
9433
</field>
9434
<field id="short_description">
9435
<allocfieldbuf><char/></allocfieldbuf>
9436
<description>
9437
A one sentence description of the event, encoded as a
9438
<internallink id="mUTF">modified UTF-8</internallink> string.
9439
</description>
9440
</field>
9441
<field id="param_count">
9442
<jint/>
9443
<description>
9444
The number of parameters excluding <code>jvmtiEnv *jvmti_env</code>
9445
</description>
9446
</field>
9447
<field id="params">
9448
<allocfieldbuf outcount="param_count">
9449
<struct>jvmtiParamInfo</struct>
9450
</allocfieldbuf>
9451
<description>
9452
Array of
9453
<fieldlink id="param_count" struct="jvmtiExtensionEventInfo"></fieldlink>
9454
parameters (<code>jvmtiEnv *jvmti_env</code> excluded)
9455
</description>
9456
</field>
9457
</typedef>
9458
9459
<description>
9460
Returns the set of extension events.
9461
</description>
9462
<origin>new</origin>
9463
<capabilities>
9464
</capabilities>
9465
<parameters>
9466
<param id="extension_count_ptr">
9467
<outptr><jint/></outptr>
9468
<description>
9469
On return, points to the number of extension events
9470
</description>
9471
</param>
9472
<param id="extensions">
9473
<allocbuf outcount="extension_count_ptr"><struct>jvmtiExtensionEventInfo</struct></allocbuf>
9474
<description>
9475
Returns an array of extension event info, one per event
9476
</description>
9477
</param>
9478
</parameters>
9479
<errors>
9480
</errors>
9481
</function>
9482
9483
<callback id="jvmtiExtensionEvent">
9484
<void/>
9485
<synopsis>Extension Event</synopsis>
9486
<description>
9487
This is the implementation-specific event.
9488
The event handler is set with
9489
<functionlink id="SetExtensionEventCallback"/>.
9490
<p/>
9491
Event handlers for extension events must be declared varargs to match this definition.
9492
Failure to do so could result in calling convention mismatch and undefined behavior
9493
on some platforms.
9494
<p/>
9495
For example, if the <code>jvmtiParamInfo</code>
9496
returned by <functionlink id="GetExtensionEvents"/> indicates that
9497
there is a <code>jint</code> parameter, the event handler should be
9498
declared:
9499
<example>
9500
void JNICALL myHandler(jvmtiEnv* jvmti_env, jint myInt, ...)
9501
</example>
9502
Note the terminal "<code>...</code>" which indicates varargs.
9503
</description>
9504
<parameters>
9505
<param id="jvmti_env">
9506
<outptr>
9507
<struct>jvmtiEnv</struct>
9508
</outptr>
9509
<description>
9510
The <jvmti/> environment is the only fixed parameter for extension events.
9511
</description>
9512
</param>
9513
<param id="...">
9514
<varargs/>
9515
<description>
9516
The extension event-specific parameters
9517
</description>
9518
</param>
9519
</parameters>
9520
</callback>
9521
9522
<function id="SetExtensionEventCallback" phase="onload" num="126">
9523
<synopsis>Set Extension Event Callback</synopsis>
9524
9525
<description>
9526
Sets the callback function for an extension event and
9527
enables the event. Or, if the callback is <code>NULL</code>, disables
9528
the event. Note that unlike standard events, setting
9529
the callback and enabling the event are a single operation.
9530
</description>
9531
<origin>new</origin>
9532
<capabilities>
9533
</capabilities>
9534
<parameters>
9535
<param id="extension_event_index">
9536
<jint/>
9537
<description>
9538
Identifies which callback to set.
9539
This index is the
9540
<fieldlink id="extension_event_index" struct="jvmtiExtensionEventInfo"></fieldlink>
9541
field of
9542
<datalink id="jvmtiExtensionEventInfo"/>.
9543
</description>
9544
</param>
9545
<param id="callback">
9546
<ptrtype>
9547
<struct>jvmtiExtensionEvent</struct>
9548
<nullok>disable the event</nullok>
9549
</ptrtype>
9550
<description>
9551
If <code>callback</code> is non-<code>NULL</code>,
9552
set <code>callback</code> to be the event callback function
9553
and enable the event.
9554
</description>
9555
</param>
9556
</parameters>
9557
<errors>
9558
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
9559
<paramlink id="extension_event_index"/> is not an
9560
<fieldlink id="extension_event_index"
9561
struct="jvmtiExtensionEventInfo"/>
9562
returned by
9563
<functionlink id="GetExtensionEvents"/>
9564
</error>
9565
</errors>
9566
</function>
9567
9568
</category>
9569
9570
<category id="capability" label="Capability">
9571
9572
<intro>
9573
The capabilities functions allow you to change the
9574
functionality available to <jvmti/>--that is,
9575
which <jvmti/>
9576
functions can be called, what events can be generated,
9577
and what functionality these events and functions can
9578
provide.
9579
<p/>
9580
The "Capabilities" section of each function and event describe which
9581
capabilities, if any, they are associated with. "Required Functionality"
9582
means it is available for use and no capabilities must be added to use it.
9583
"Optional Functionality" means the agent must possess the capability
9584
before it can be used.
9585
To possess a capability, the agent must
9586
<functionlink id="AddCapabilities">add the capability</functionlink>.
9587
"Optional Features" describe capabilities which,
9588
if added, extend the feature set.
9589
<p/>
9590
The potentially available capabilities of each <jvmti/> implementation are different.
9591
Depending on the implementation, a capability:
9592
<ul>
9593
<li>may never be added</li>
9594
<li>may be added in either the <code>OnLoad</code> or live phase in any environment</li>
9595
<li>may be added only during the <code>OnLoad</code> phase</li>
9596
<li>may be possessed by only one environment at a time</li>
9597
<li>may be possessed by only one environment at a time,
9598
and only during the <code>OnLoad</code> phase</li>
9599
<li>and so on ...</li>
9600
</ul>
9601
Frequently, the addition of a capability may incur a cost in execution speed, start up
9602
time, and/or memory footprint. Note that the overhead of using a capability
9603
is completely different than the overhead of possessing a capability.
9604
Take single stepping as an example. When single stepping is on (that
9605
is, when the event is enabled and thus actively sending events)
9606
the overhead of sending and processing an event
9607
on each instruction is huge in any implementation.
9608
However, the overhead of possessing the capability may be small or large,
9609
depending on the implementation. Also, when and if a capability is potentially
9610
available depends on the implementation. Some examples:
9611
<ul>
9612
<li>One VM might perform all execution by compiling bytecodes into
9613
native code and be unable to generate single step instructions.
9614
In this implementation the capability can not be added.</li>
9615
<li>Another VM may be able to switch execution to a single stepping
9616
interpreter at any time. In this implementation, having the capability has no
9617
overhead and could be added at any time.</li>
9618
<li>Yet another VM might be able to choose a bytecode compiling or single stepping capable interpreted
9619
execution engine at start up, but be unable to switch between them.
9620
In this implementation the capability would need to be added
9621
during the <code>OnLoad</code> phase (before bytecode
9622
execution begins) and would have a large impact on execution speed
9623
even if single stepping was never used.</li>
9624
<li>Still another VM might be able to add an "is single stepping on" check
9625
into compiled bytecodes or a generated interpreter. Again in this implementation
9626
the capability would need to be added during the <code>OnLoad</code> phase but the overhead (a test
9627
and branch on each instruction) would be considerably less.</li>
9628
</ul>
9629
<p/>
9630
Each <jvmti/> <internallink id="environments">environment</internallink>
9631
has its own set of capabilities.
9632
Initially, that set is empty.
9633
Any desired capability must be added.
9634
If possible, capabilities should be added during the <code>OnLoad</code> phase. For most
9635
virtual machines certain capabilities require special set up for
9636
the virtual machine and this set up must happen
9637
during the <code>OnLoad</code> phase, before the virtual machine begins execution.
9638
Once a capability is added, it can
9639
only be removed if explicitly relinquished by the environment.
9640
<p/>
9641
The agent can,
9642
<functionlink id="GetPotentialCapabilities">determine what
9643
capabilities this VM can potentially provide</functionlink>,
9644
<functionlink id="AddCapabilities">add the capabilities
9645
to be used</functionlink>,
9646
<functionlink id="RelinquishCapabilities">release capabilities
9647
which are no longer needed</functionlink>, and
9648
<functionlink id="GetCapabilities">examine the currently available
9649
capabilities</functionlink>.
9650
</intro>
9651
9652
<intro id="capabilityExamples" label="Capability Examples">
9653
For example, a freshly started agent (in the <code>OnLoad</code> function)
9654
wants to enable all possible capabilities.
9655
Note that, in general, this is not advisable as the agent may suffer
9656
a performance penalty for functionality it is not using.
9657
The code might look like this in C:
9658
<example>
9659
jvmtiCapabilities capa;
9660
jvmtiError err;
9661
9662
err = (*jvmti)-&gt;GetPotentialCapabilities(jvmti, &amp;capa);
9663
if (err == JVMTI_ERROR_NONE) {
9664
err = (*jvmti)-&gt;AddCapabilities(jvmti, &amp;capa);
9665
</example>
9666
For example, if an agent wants to check if it can get
9667
the bytecodes of a method (that is, it wants to check
9668
if it previously added this capability and has not
9669
relinquished it), the code might
9670
look like this in C:
9671
<example>
9672
jvmtiCapabilities capa;
9673
jvmtiError err;
9674
9675
err = (*jvmti)-&gt;GetCapabilities(jvmti, &amp;capa);
9676
if (err == JVMTI_ERROR_NONE) {
9677
if (capa.can_get_bytecodes) { ... } }
9678
</example>
9679
</intro>
9680
9681
<capabilitiestypedef id="jvmtiCapabilities" label="The Capabilities Structure">
9682
<description>
9683
The functions in this category use this capabilities structure
9684
which contains boolean flags corresponding to each capability:
9685
</description>
9686
<capabilityfield id="can_tag_objects">
9687
<description>
9688
Can set and get tags, as described in the
9689
<internallink id="Heap">Heap category</internallink>.
9690
</description>
9691
</capabilityfield>
9692
<capabilityfield id="can_generate_field_modification_events">
9693
<description>
9694
Can set watchpoints on field modification -
9695
<functionlink id="SetFieldModificationWatch"></functionlink>
9696
</description>
9697
</capabilityfield>
9698
<capabilityfield id="can_generate_field_access_events">
9699
<description>
9700
Can set watchpoints on field access -
9701
<functionlink id="SetFieldAccessWatch"></functionlink>
9702
</description>
9703
</capabilityfield>
9704
<capabilityfield id="can_get_bytecodes">
9705
<description>
9706
Can get bytecodes of a method <functionlink id="GetBytecodes"></functionlink>
9707
</description>
9708
</capabilityfield>
9709
<capabilityfield id="can_get_synthetic_attribute">
9710
<description>
9711
Can test if a field or method is synthetic -
9712
<functionlink id="IsFieldSynthetic"></functionlink> and
9713
<functionlink id="IsMethodSynthetic"></functionlink>
9714
</description>
9715
</capabilityfield>
9716
<capabilityfield id="can_get_owned_monitor_info">
9717
<description>
9718
Can get information about ownership of monitors -
9719
<functionlink id="GetOwnedMonitorInfo"></functionlink>
9720
</description>
9721
</capabilityfield>
9722
<capabilityfield id="can_get_current_contended_monitor">
9723
<description>
9724
Can <functionlink id="GetCurrentContendedMonitor"></functionlink>
9725
</description>
9726
</capabilityfield>
9727
<capabilityfield id="can_get_monitor_info">
9728
<description>
9729
Can <functionlink id="GetObjectMonitorUsage"></functionlink>
9730
</description>
9731
</capabilityfield>
9732
<capabilityfield id="can_pop_frame">
9733
<description>
9734
Can pop frames off the stack - <functionlink id="PopFrame"></functionlink>
9735
</description>
9736
</capabilityfield>
9737
<capabilityfield id="can_redefine_classes">
9738
<description>
9739
Can redefine classes with <functionlink id="RedefineClasses"/>.
9740
</description>
9741
</capabilityfield>
9742
<capabilityfield id="can_signal_thread">
9743
<description>
9744
Can send stop or interrupt to threads
9745
</description>
9746
</capabilityfield>
9747
<capabilityfield id="can_get_source_file_name">
9748
<description>
9749
Can get the source file name of a class
9750
</description>
9751
</capabilityfield>
9752
<capabilityfield id="can_get_line_numbers">
9753
<description>
9754
Can get the line number table of a method
9755
</description>
9756
</capabilityfield>
9757
<capabilityfield id="can_get_source_debug_extension">
9758
<description>
9759
Can get the source debug extension of a class
9760
</description>
9761
</capabilityfield>
9762
<capabilityfield id="can_access_local_variables">
9763
<description>
9764
Can set and get local variables
9765
</description>
9766
</capabilityfield>
9767
<capabilityfield id="can_maintain_original_method_order">
9768
<description>
9769
Can return methods in the order they occur in the class file
9770
</description>
9771
</capabilityfield>
9772
<capabilityfield id="can_generate_single_step_events">
9773
<description>
9774
Can get <eventlink id="SingleStep">single step</eventlink> events
9775
</description>
9776
</capabilityfield>
9777
<capabilityfield id="can_generate_exception_events">
9778
<description>
9779
Can get <eventlink id="Exception">exception thrown</eventlink> and
9780
<eventlink id="ExceptionCatch">exception catch</eventlink> events
9781
</description>
9782
</capabilityfield>
9783
<capabilityfield id="can_generate_frame_pop_events">
9784
<description>
9785
Can <functionlink id="NotifyFramePop">set</functionlink> and thus get
9786
<eventlink id="FramePop"></eventlink> events
9787
</description>
9788
</capabilityfield>
9789
<capabilityfield id="can_generate_breakpoint_events">
9790
<description>
9791
Can <functionlink id="SetBreakpoint">set</functionlink> and thus get
9792
<eventlink id="Breakpoint"></eventlink> events
9793
</description>
9794
</capabilityfield>
9795
<capabilityfield id="can_suspend">
9796
<description>
9797
Can suspend and resume threads
9798
</description>
9799
</capabilityfield>
9800
<capabilityfield id="can_redefine_any_class">
9801
<description>
9802
Can modify (retransform or redefine) any non-primitive non-array class.
9803
See <functionlink id="IsModifiableClass"/>.
9804
</description>
9805
</capabilityfield>
9806
<capabilityfield id="can_get_current_thread_cpu_time">
9807
<description>
9808
Can <functionlink id="GetCurrentThreadCpuTime">get</functionlink>
9809
current thread CPU time
9810
</description>
9811
</capabilityfield>
9812
<capabilityfield id="can_get_thread_cpu_time">
9813
<description>
9814
Can <functionlink id="GetThreadCpuTime">get</functionlink>
9815
thread CPU time
9816
</description>
9817
</capabilityfield>
9818
<capabilityfield id="can_generate_method_entry_events"
9819
disp1="can_generate" disp2="_method_entry_events"
9820
>
9821
<description>
9822
Can generate method entry events on entering a method
9823
</description>
9824
</capabilityfield>
9825
<capabilityfield id="can_generate_method_exit_events"
9826
disp1="can_generate" disp2="_method_exit_events"
9827
>
9828
<description>
9829
Can generate method exit events on leaving a method
9830
</description>
9831
</capabilityfield>
9832
<capabilityfield id="can_generate_all_class_hook_events"
9833
disp1="can_generate" disp2="_all_class_hook_events"
9834
>
9835
<description>
9836
Can generate ClassFileLoadHook events for every loaded class.
9837
</description>
9838
</capabilityfield>
9839
<capabilityfield id="can_generate_compiled_method_load_events"
9840
disp1="can_generate" disp2="_compiled_method_load_events"
9841
>
9842
<description>
9843
Can generate events when a method is compiled or unloaded
9844
</description>
9845
</capabilityfield>
9846
<capabilityfield id="can_generate_monitor_events"
9847
disp1="can_generate" disp2="_monitor_events"
9848
>
9849
<description>
9850
Can generate events on monitor activity
9851
</description>
9852
</capabilityfield>
9853
<capabilityfield id="can_generate_vm_object_alloc_events"
9854
disp1="can_generate" disp2="_vm_object_alloc_events"
9855
>
9856
<description>
9857
Can generate events on VM allocation of an object
9858
</description>
9859
</capabilityfield>
9860
<capabilityfield id="can_generate_native_method_bind_events"
9861
disp1="can_generate" disp2="_native_method_bind_events"
9862
>
9863
<description>
9864
Can generate events when a native method is bound to its
9865
implementation
9866
</description>
9867
</capabilityfield>
9868
<capabilityfield id="can_generate_garbage_collection_events"
9869
disp1="can_generate" disp2="_garbage_collection_events"
9870
>
9871
<description>
9872
Can generate events when garbage collection begins or ends
9873
</description>
9874
</capabilityfield>
9875
<capabilityfield id="can_generate_object_free_events"
9876
disp1="can_generate" disp2="_object_free_events"
9877
>
9878
<description>
9879
Can generate events when the garbage collector frees an object
9880
</description>
9881
</capabilityfield>
9882
<capabilityfield id="can_force_early_return" since="1.1">
9883
<description>
9884
Can return early from a method, as described in the
9885
<internallink id="ForceEarlyReturn">Force Early Return category</internallink>.
9886
</description>
9887
</capabilityfield>
9888
<capabilityfield id="can_get_owned_monitor_stack_depth_info" since="1.1">
9889
<description>
9890
Can get information about owned monitors with stack depth -
9891
<functionlink id="GetOwnedMonitorStackDepthInfo"></functionlink>
9892
</description>
9893
</capabilityfield>
9894
<capabilityfield id="can_get_constant_pool" since="1.1">
9895
<description>
9896
Can get the constant pool of a class -
9897
<functionlink id="GetConstantPool"></functionlink>
9898
</description>
9899
</capabilityfield>
9900
<capabilityfield id="can_set_native_method_prefix" since="1.1">
9901
<description>
9902
Can set prefix to be applied when native method cannot be resolved -
9903
<functionlink id="SetNativeMethodPrefix"/> and
9904
<functionlink id="SetNativeMethodPrefixes"/>
9905
</description>
9906
</capabilityfield>
9907
<capabilityfield id="can_retransform_classes" since="1.1">
9908
<description>
9909
Can retransform classes with <functionlink id="RetransformClasses"/>.
9910
In addition to the restrictions imposed by the specific
9911
implementation on this capability (see the
9912
<internallink id="capability">Capability</internallink> section),
9913
this capability must be set before the
9914
<eventlink id="ClassFileLoadHook"/> event is enabled for the
9915
first time in this environment.
9916
An environment that possesses this capability at the time that
9917
<code>ClassFileLoadHook</code> is enabled for the first time is
9918
said to be <i>retransformation capable</i>.
9919
An environment that does not possess this capability at the time that
9920
<code>ClassFileLoadHook</code> is enabled for the first time is
9921
said to be <i>retransformation incapable</i>.
9922
</description>
9923
</capabilityfield>
9924
<capabilityfield id="can_retransform_any_class" since="1.1">
9925
<description>
9926
<functionlink id="RetransformClasses"/> can be called on any class
9927
(<fieldlink id="can_retransform_classes" struct="jvmtiCapabilities"/>
9928
must also be set)
9929
</description>
9930
</capabilityfield>
9931
<capabilityfield id="can_generate_resource_exhaustion_heap_events" since="1.1">
9932
<description>
9933
Can generate events when the VM is unable to allocate memory from
9934
the <tm>Java</tm> platform heap.
9935
See <eventlink id="ResourceExhausted"/>.
9936
</description>
9937
</capabilityfield>
9938
<capabilityfield id="can_generate_resource_exhaustion_threads_events" since="1.1">
9939
<description>
9940
Can generate events when the VM is unable to create a thread.
9941
See <eventlink id="ResourceExhausted"/>.
9942
</description>
9943
</capabilityfield>
9944
</capabilitiestypedef>
9945
9946
<function id="GetPotentialCapabilities" jkernel="yes" phase="onload" num="140">
9947
<synopsis>Get Potential Capabilities</synopsis>
9948
<description>
9949
Returns via <paramlink id="capabilities_ptr"></paramlink> the <jvmti/>
9950
features that can potentially be possessed by this environment
9951
at this time.
9952
The returned capabilities differ from the complete set of capabilities
9953
implemented by the VM in two cases: another environment possesses
9954
capabilities that can only be possessed by one environment, or the
9955
current <functionlink id="GetPhase">phase</functionlink> is live,
9956
and certain capabilities can only be added during the <code>OnLoad</code> phase.
9957
The <functionlink id="AddCapabilities"></functionlink> function
9958
may be used to set any or all or these capabilities.
9959
Currently possessed capabilities are included.
9960
<p/>
9961
Typically this function is used in the <code>OnLoad</code> function.
9962
Some virtual machines may allow a limited set of capabilities to be
9963
added in the live phase.
9964
In this case, the set of potentially available capabilities
9965
will likely differ from the <code>OnLoad</code> phase set.
9966
<p/>
9967
See the
9968
<internallink id="capabilityExamples">Capability Examples</internallink>.
9969
</description>
9970
<origin>new</origin>
9971
<capabilities>
9972
</capabilities>
9973
<parameters>
9974
<param id="capabilities_ptr">
9975
<outptr><struct>jvmtiCapabilities</struct></outptr>
9976
<description>
9977
On return, points to the <jvmti/> capabilities that may be added.
9978
</description>
9979
</param>
9980
</parameters>
9981
<errors>
9982
</errors>
9983
</function>
9984
9985
<elide>
9986
<function id="EstimateCostOfCapabilities" phase="onload" num="141">
9987
<synopsis>Estimate Cost Of Capabilities</synopsis>
9988
<description>
9989
<issue>There is strong opposition to this function. The concern is
9990
that it would be difficult or impossible to provide meaningful
9991
numbers, as the amount of impact is conditional on many factors
9992
that a single number could not represent. There is doubt that
9993
conditional implementations would be used or are even a good idea.
9994
The thought is that release documentation for the implementation
9995
would be the best means of exposing this information.
9996
Unless new arguments are presented, I intend to remove this
9997
function in the next revision.
9998
</issue>
9999
<p/>
10000
Return via the <paramlink id="time_impact_ptr"></paramlink> and
10001
<paramlink id="space_impact_ptr"></paramlink> an estimate of the impact
10002
of adding the capabilities pointed to by
10003
<paramlink id="capabilities_ptr"></paramlink>.
10004
The returned estimates are in percentage of additional overhead, thus
10005
a time impact of 100 mean the application might run
10006
at half the speed.
10007
The estimates are very rough approximations and are not guaranteed.
10008
Note also, that the estimates are of the impact of having the
10009
capability available--when and if it is used the impact may be
10010
much greater.
10011
Estimates can be for a single capability or for a set of
10012
capabilities. Note that the costs are not necessarily additive,
10013
adding support for one capability might make another available
10014
for free or conversely having two capabilities at once may
10015
have multiplicative impact.
10016
Estimates are relative to the current set of capabilities -
10017
that is, how much more impact given the currently possessed capabilities.
10018
<p/>
10019
Typically this function is used in the OnLoad function,
10020
some virtual machines may allow a limited set of capabilities to be
10021
added in the live phase.
10022
In this case, the set of potentially available capabilities
10023
will likely differ from the OnLoad phase set.
10024
<p/>
10025
See the
10026
<internallink id="capabilityExamples">Capability Examples</internallink>.
10027
</description>
10028
<origin>new</origin>
10029
<capabilities>
10030
</capabilities>
10031
<parameters>
10032
<param id="capabilities_ptr">
10033
<inptr><struct>jvmtiCapabilities</struct></inptr>
10034
<description>
10035
points to the <jvmti/> capabilities to evaluate.
10036
</description>
10037
</param>
10038
<param id="time_impact_ptr">
10039
<outptr><jint/></outptr>
10040
<description>
10041
On return, points to the estimated percentage increase in
10042
run time if this capability was added.
10043
</description>
10044
</param>
10045
<param id="space_impact_ptr">
10046
<outptr><jint/></outptr>
10047
<description>
10048
On return, points to the estimated percentage increase in
10049
memory space used if this capability was added.
10050
</description>
10051
</param>
10052
</parameters>
10053
<errors>
10054
<error id="JVMTI_ERROR_NOT_AVAILABLE">
10055
The desired capabilities are not even potentially available.
10056
</error>
10057
</errors>
10058
</function>
10059
</elide>
10060
10061
<function id="AddCapabilities" jkernel="yes" phase="onload" num="142">
10062
<synopsis>Add Capabilities</synopsis>
10063
<description>
10064
Set new capabilities by adding the capabilities
10065
whose values are set to one (<code>1</code>) in
10066
<code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10067
All previous capabilities are retained.
10068
Typically this function is used in the <code>OnLoad</code> function.
10069
Some virtual machines may allow a limited set of capabilities to be
10070
added in the live phase.
10071
<p/>
10072
See the
10073
<internallink id="capabilityExamples">Capability Examples</internallink>.
10074
</description>
10075
<origin>new</origin>
10076
<capabilities>
10077
</capabilities>
10078
<parameters>
10079
<param id="capabilities_ptr">
10080
<inptr><struct>jvmtiCapabilities</struct></inptr>
10081
<description>
10082
Points to the <jvmti/> capabilities to add.
10083
</description>
10084
</param>
10085
</parameters>
10086
<errors>
10087
<error id="JVMTI_ERROR_NOT_AVAILABLE">
10088
The desired capabilities are not even potentially available.
10089
</error>
10090
</errors>
10091
</function>
10092
10093
10094
<function id="RelinquishCapabilities" phase="onload" num="143">
10095
<synopsis>Relinquish Capabilities</synopsis>
10096
<description>
10097
Relinquish the capabilities
10098
whose values are set to one (<code>1</code>) in
10099
<code>*</code><paramlink id="capabilities_ptr"></paramlink>.
10100
Some implementations may allow only one environment to have a capability
10101
(see the <internallink id="capability">capability introduction</internallink>).
10102
This function releases capabilities
10103
so that they may be used by other agents.
10104
All other capabilities are retained.
10105
The capability will no longer be present in <functionlink id="GetCapabilities"></functionlink>.
10106
Attempting to relinquish a capability that the agent does not possess is not an error.
10107
<issue>
10108
It is possible for the agent to be actively using capabilities
10109
which are being relinquished. For example, a thread is currently
10110
suspended and can_suspend is being relinquished or an event is currently
10111
enabled and can_generate_whatever is being relinquished.
10112
There are three possible ways we could spec this:
10113
<ul>
10114
<li>relinquish automatically releases them</li>
10115
<li>relinquish checks and returns some error code if held</li>
10116
<li>it is the agent's responsibility and it is not checked</li>
10117
</ul>
10118
One of these should be chosen.
10119
</issue>
10120
</description>
10121
<origin>new</origin>
10122
<capabilities>
10123
</capabilities>
10124
<parameters>
10125
<param id="capabilities_ptr">
10126
<inptr><struct>jvmtiCapabilities</struct></inptr>
10127
<description>
10128
Points to the <jvmti/> capabilities to relinquish.
10129
</description>
10130
</param>
10131
</parameters>
10132
<errors>
10133
</errors>
10134
</function>
10135
10136
10137
10138
<function id="GetCapabilities" jkernel="yes" phase="any" num="89">
10139
<synopsis>Get Capabilities</synopsis>
10140
<description>
10141
Returns via <paramlink id="capabilities_ptr"></paramlink> the optional <jvmti/>
10142
features which this environment currently possesses.
10143
Each possessed capability is indicated by a one (<code>1</code>) in the
10144
corresponding field of the <internallink id="jvmtiCapabilities">capabilities
10145
structure</internallink>.
10146
An environment does not possess a capability unless it has been successfully added with
10147
<functionlink id="AddCapabilities"/>.
10148
An environment only loses possession of a capability if it has been relinquished with
10149
<functionlink id="RelinquishCapabilities"/>. Thus, this function returns the net result
10150
of the <code>AddCapabilities</code> and <code>RelinquishCapabilities</code> calls which
10151
have been made.
10152
<p/>
10153
See the
10154
<internallink id="capabilityExamples">Capability Examples</internallink>.
10155
</description>
10156
<origin>jvmdiClone</origin>
10157
<capabilities>
10158
</capabilities>
10159
<parameters>
10160
<param id="capabilities_ptr">
10161
<outptr><struct>jvmtiCapabilities</struct></outptr>
10162
<description>
10163
On return, points to the <jvmti/> capabilities.
10164
</description>
10165
</param>
10166
</parameters>
10167
<errors>
10168
</errors>
10169
</function>
10170
10171
</category>
10172
10173
10174
<category id="timers" label="Timers">
10175
10176
<intro>
10177
These functions provide timing information.
10178
The resolution at which the time is updated is not specified.
10179
They provides nanosecond precision, but not necessarily nanosecond accuracy.
10180
Details about the timers, such as their maximum values, can be accessed with
10181
the timer information functions.
10182
</intro>
10183
10184
<typedef id="jvmtiTimerInfo" label="Timer Info">
10185
<description>
10186
The information function for each timer returns this data structure.
10187
</description>
10188
<field id="max_value">
10189
<jlong/>
10190
<description>
10191
The maximum value the timer can reach.
10192
After this value is reached the timer wraps back to zero.
10193
This is an unsigned value. If tested or printed as a jlong (signed value)
10194
it may appear to be a negative number.
10195
</description>
10196
</field>
10197
<field id="may_skip_forward">
10198
<jboolean/>
10199
<description>
10200
If true, the timer can be externally adjusted and as a result skip forward.
10201
If false, the timer value will never increase faster than real time.
10202
</description>
10203
</field>
10204
<field id="may_skip_backward">
10205
<jboolean/>
10206
<description>
10207
If true, the timer can be externally adjusted and as a result skip backward.
10208
If false, the timer value will be monotonically increasing.
10209
</description>
10210
</field>
10211
<field id="kind">
10212
<enum>jvmtiTimerKind</enum>
10213
<description>
10214
The kind of timer.
10215
On a platform that does not distinguish between user and system time, <datalink
10216
id="JVMTI_TIMER_TOTAL_CPU"><code>JVMTI_TIMER_TOTAL_CPU</code></datalink>
10217
is returned.
10218
</description>
10219
</field>
10220
<field id="reserved1">
10221
<jlong/>
10222
<description>
10223
Reserved for future use.
10224
</description>
10225
</field>
10226
<field id="reserved2">
10227
<jlong/>
10228
<description>
10229
Reserved for future use.
10230
</description>
10231
</field>
10232
</typedef>
10233
10234
<intro>
10235
Where the timer kind is --
10236
10237
<constants id="jvmtiTimerKind" label="Timer Kinds" kind="enum">
10238
<constant id="JVMTI_TIMER_USER_CPU" num="30">
10239
CPU time that a thread is in user mode.
10240
</constant>
10241
<constant id="JVMTI_TIMER_TOTAL_CPU" num="31">
10242
CPU time that a thread is in user or system mode.
10243
</constant>
10244
<constant id="JVMTI_TIMER_ELAPSED" num="32">
10245
Elapsed time.
10246
</constant>
10247
</constants>
10248
</intro>
10249
10250
<function id="GetCurrentThreadCpuTimerInfo" callbacksafe="safe" impl="innative notrace" phase="start" num="134">
10251
<synopsis>Get Current Thread CPU Timer Information</synopsis>
10252
<description>
10253
Get information about the
10254
<functionlink id="GetCurrentThreadCpuTime"/> timer.
10255
The fields of the <datalink id="jvmtiTimerInfo"/> structure
10256
are filled in with details about the timer.
10257
This information is specific to the platform and the implementation of
10258
<functionlink id="GetCurrentThreadCpuTime"/> and thus
10259
does not vary by thread nor does it vary
10260
during a particular invocation of the VM.
10261
<p/>
10262
Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10263
and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10264
returned by <code>GetCurrentThreadCpuTimerInfo</code>
10265
and <functionlink id="GetThreadCpuTimerInfo"/>
10266
may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10267
</description>
10268
<origin>new</origin>
10269
<capabilities>
10270
<required id="can_get_current_thread_cpu_time">
10271
Can get current thread CPU time.
10272
</required>
10273
</capabilities>
10274
<parameters>
10275
<param id="info_ptr">
10276
<outptr><struct>jvmtiTimerInfo</struct></outptr>
10277
<description>
10278
On return, filled with information describing the time
10279
returned by <functionlink id="GetCurrentThreadCpuTime"/>.
10280
</description>
10281
</param>
10282
</parameters>
10283
<errors>
10284
</errors>
10285
</function>
10286
10287
<function id="GetCurrentThreadCpuTime" callbacksafe="safe" impl="innative notrace" phase="start" num="135">
10288
<synopsis>Get Current Thread CPU Time</synopsis>
10289
<description>
10290
Return the CPU time utilized by the current thread.
10291
<p/>
10292
Note that the <functionlink id="GetThreadCpuTime"/>
10293
function provides CPU time for any thread, including
10294
the current thread. <code>GetCurrentThreadCpuTime</code>
10295
exists to support platforms which cannot
10296
supply CPU time for threads other than the current
10297
thread or which have more accurate information for
10298
the current thread (see
10299
<functionlink id="GetCurrentThreadCpuTimerInfo"/> vs
10300
<functionlink id="GetThreadCpuTimerInfo"/>).
10301
On many platforms this call will be equivalent to:
10302
<example>
10303
GetThreadCpuTime(env, NULL, nanos_ptr)
10304
</example>
10305
</description>
10306
<origin>new</origin>
10307
<capabilities>
10308
<required id="can_get_current_thread_cpu_time">
10309
Can get current thread CPU time.
10310
<p/>
10311
If this capability is enabled after threads have started,
10312
the implementation may choose any time up
10313
to and including the time that the capability is enabled
10314
as the point where CPU time collection starts.
10315
<p/>
10316
This capability must be potentially available on any
10317
platform where
10318
<internallink id="jvmtiCapabilities.can_get_thread_cpu_time"><code>can_get_thread_cpu_time</code></internallink>
10319
is potentially available.
10320
</required>
10321
</capabilities>
10322
<parameters>
10323
<param id="nanos_ptr">
10324
<outptr><jlong/></outptr>
10325
<description>
10326
On return, points to the CPU time used by this thread
10327
in nanoseconds.
10328
This is an unsigned value. If tested or printed as a jlong (signed value)
10329
it may appear to be a negative number.
10330
</description>
10331
</param>
10332
</parameters>
10333
<errors>
10334
</errors>
10335
</function>
10336
10337
<function id="GetThreadCpuTimerInfo" num="136">
10338
<synopsis>Get Thread CPU Timer Information</synopsis>
10339
<description>
10340
Get information about the
10341
<functionlink id="GetThreadCpuTime"/> timer.
10342
The fields of the <datalink id="jvmtiTimerInfo"/> structure
10343
are filled in with details about the timer.
10344
This information is specific to the platform and the implementation of
10345
<functionlink id="GetThreadCpuTime"/> and thus
10346
does not vary by thread nor does it vary
10347
during a particular invocation of the VM.
10348
<p/>
10349
Note that the implementations of <functionlink id="GetCurrentThreadCpuTime"/>
10350
and <functionlink id="GetThreadCpuTime"/> may differ, and thus the values
10351
returned by <functionlink id="GetCurrentThreadCpuTimerInfo"/>
10352
and <code>GetThreadCpuTimerInfo</code>
10353
may differ -- see <functionlink id="GetCurrentThreadCpuTime"/> for more information.
10354
</description>
10355
<origin>new</origin>
10356
<capabilities>
10357
<required id="can_get_thread_cpu_time">
10358
Can get thread CPU time.
10359
</required>
10360
</capabilities>
10361
<parameters>
10362
<param id="info_ptr">
10363
<outptr><struct>jvmtiTimerInfo</struct></outptr>
10364
<description>
10365
On return, filled with information describing the time
10366
returned by <functionlink id="GetThreadCpuTime"/>.
10367
</description>
10368
</param>
10369
</parameters>
10370
<errors>
10371
</errors>
10372
</function>
10373
10374
<function id="GetThreadCpuTime" num="137">
10375
<synopsis>Get Thread CPU Time</synopsis>
10376
<description>
10377
Return the CPU time utilized by the specified thread.
10378
<p/>
10379
Get information about this timer with
10380
<functionlink id="GetThreadCpuTimerInfo"/>.
10381
</description>
10382
<origin>new</origin>
10383
<capabilities>
10384
<required id="can_get_thread_cpu_time">
10385
Can get thread CPU time.
10386
<p/>
10387
If this capability is enabled after threads have started,
10388
the implementation may choose any time up
10389
to and including the time that the capability is enabled
10390
as the point where CPU time collection starts.
10391
</required>
10392
</capabilities>
10393
<parameters>
10394
<param id="thread">
10395
<jthread null="current"/>
10396
<description>
10397
The thread to query.
10398
</description>
10399
</param>
10400
<param id="nanos_ptr">
10401
<outptr><jlong/></outptr>
10402
<description>
10403
On return, points to the CPU time used by the specified thread
10404
in nanoseconds.
10405
This is an unsigned value. If tested or printed as a jlong (signed value)
10406
it may appear to be a negative number.
10407
</description>
10408
</param>
10409
</parameters>
10410
<errors>
10411
</errors>
10412
</function>
10413
10414
<function id="GetTimerInfo" phase="any" callbacksafe="safe" num="138">
10415
<synopsis>Get Timer Information</synopsis>
10416
<description>
10417
Get information about the
10418
<functionlink id="GetTime"/> timer.
10419
The fields of the <datalink id="jvmtiTimerInfo"/> structure
10420
are filled in with details about the timer.
10421
This information will not change during a particular invocation of the VM.
10422
</description>
10423
<origin>new</origin>
10424
<capabilities>
10425
</capabilities>
10426
<parameters>
10427
<param id="info_ptr">
10428
<outptr><struct>jvmtiTimerInfo</struct></outptr>
10429
<description>
10430
On return, filled with information describing the time
10431
returned by <functionlink id="GetTime"/>.
10432
</description>
10433
</param>
10434
</parameters>
10435
<errors>
10436
</errors>
10437
</function>
10438
10439
<function id="GetTime" phase="any" callbacksafe="safe" num="139">
10440
<synopsis>Get Time</synopsis>
10441
<description>
10442
Return the current value of the system timer, in nanoseconds.
10443
<p/>
10444
The value returned represents nanoseconds since some fixed but
10445
arbitrary time (perhaps in the future, so values may be
10446
negative). This function provides nanosecond precision, but not
10447
necessarily nanosecond accuracy. No guarantees are made about
10448
how frequently values change.
10449
<p/>
10450
Get information about this timer with
10451
<functionlink id="GetTimerInfo"/>.
10452
</description>
10453
<origin>new</origin>
10454
<capabilities>
10455
</capabilities>
10456
<parameters>
10457
<param id="nanos_ptr">
10458
<outptr><jlong/></outptr>
10459
<description>
10460
On return, points to the time in nanoseconds.
10461
This is an unsigned value. If tested or printed as a jlong (signed value)
10462
it may appear to be a negative number.
10463
</description>
10464
</param>
10465
</parameters>
10466
<errors>
10467
</errors>
10468
</function>
10469
10470
<function id="GetAvailableProcessors" phase="any" num="144">
10471
<synopsis>Get Available Processors</synopsis>
10472
<description>
10473
Returns the number of processors available to the Java virtual machine.
10474
<p/>
10475
This value may change during a particular invocation of the virtual machine.
10476
Applications that are sensitive to the number of available processors should
10477
therefore occasionally poll this property.
10478
</description>
10479
<origin>new</origin>
10480
<capabilities>
10481
</capabilities>
10482
<parameters>
10483
<param id="processor_count_ptr">
10484
<outptr><jint/></outptr>
10485
<description>
10486
On return, points to the maximum number of processors available to the
10487
virtual machine; never smaller than one.
10488
</description>
10489
</param>
10490
</parameters>
10491
<errors>
10492
</errors>
10493
</function>
10494
10495
</category>
10496
10497
10498
<category id="classLoaderSearch" label="Class Loader Search">
10499
10500
<intro>
10501
These functions allow the agent to add to the locations that a class loader searches for a class.
10502
This is useful for installing instrumentation under the correct class loader.
10503
</intro>
10504
10505
<function id="AddToBootstrapClassLoaderSearch" jkernel="yes" phase="onload" num="149">
10506
<synopsis>Add To Bootstrap Class Loader Search</synopsis>
10507
<description>
10508
This function can be used to cause instrumentation classes to be defined by the
10509
bootstrap class loader. See <vmspec chapter="5.3.1"/>.
10510
After the bootstrap
10511
class loader unsuccessfully searches for a class, the specified platform-dependent
10512
search path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in
10513
the <paramlink id="segment"/>. This function may be called multiple times to add multiple segments,
10514
the segments will be searched in the order that this function was called.
10515
<p/>
10516
In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10517
search path segment to be searched after the bootstrap class loader unsuccessfully searches
10518
for a class. The segment is typically a directory or JAR file.
10519
<p/>
10520
In the live phase the <paramlink id="segment"/> may be used to specify any platform-dependent
10521
path to a <externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jar/jar.html">
10522
JAR file</externallink>. The agent should take care that the JAR file does not
10523
contain any classes or resources other than those to be defined by the bootstrap
10524
class loader for the purposes of instrumentation.
10525
<p/>
10526
<vmspec/> specifies that a subsequent attempt to resolve a symbolic
10527
reference that the Java virtual machine has previously unsuccessfully attempted
10528
to resolve always fails with the same error that was thrown as a result of the
10529
initial resolution attempt. Consequently, if the JAR file contains an entry
10530
that corresponds to a class for which the Java virtual machine has
10531
unsuccessfully attempted to resolve a reference, then subsequent attempts to
10532
resolve that reference will fail with the same error as the initial attempt.
10533
</description>
10534
<origin>new</origin>
10535
<capabilities>
10536
</capabilities>
10537
<parameters>
10538
<param id="segment">
10539
<inbuf><char/></inbuf>
10540
<description>
10541
The platform-dependent search path segment, encoded as a
10542
<internallink id="mUTF">modified UTF-8</internallink> string.
10543
</description>
10544
</param>
10545
</parameters>
10546
<errors>
10547
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
10548
<paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
10549
existing JAR file is an invalid path.
10550
</error>
10551
</errors>
10552
</function>
10553
10554
<function id="AddToSystemClassLoaderSearch" jkernel="yes" phase="onload" num="151" since="1.1">
10555
<synopsis>Add To System Class Loader Search</synopsis>
10556
<description>
10557
This function can be used to cause instrumentation classes to be
10558
defined by the system class loader. See <vmspec chapter="5.3.2"/>.
10559
After the class loader unsuccessfully searches for a class, the specified platform-dependent search
10560
path <paramlink id="segment"/> will be searched as well. Only one segment may be specified in the
10561
<paramlink id="segment"/>. This function may be called multiple times to add multiple segments, the
10562
segments will be searched in the order that this function was called.
10563
<p/>
10564
In the <code>OnLoad</code> phase the function may be used to specify any platform-dependent
10565
search path segment to be searched after the system class loader unsuccessfully searches
10566
for a class. The segment is typically a directory or JAR file.
10567
<p/>
10568
In the live phase the <paramlink id="segment"/> is a platform-dependent path to a <externallink
10569
id="http://docs.oracle.com/javase/7/docs/technotes/guides/jar/jar.html">JAR file</externallink> to be
10570
searched after the system class loader unsuccessfully searches for a class. The agent should
10571
take care that the JAR file does not contain any classes or resources other than those to be
10572
defined by the system class loader for the purposes of instrumentation.
10573
<p/>
10574
In the live phase the system class loader supports adding a JAR file to be searched if
10575
the system class loader implements a method name <code>appendToClassPathForInstrumentation</code>
10576
which takes a single parameter of type <code>java.lang.String</code>. The method is not required
10577
to have <code>public</code> access.
10578
<p/>
10579
<vmspec/> specifies that a subsequent attempt to resolve a symbolic
10580
reference that the Java virtual machine has previously unsuccessfully attempted
10581
to resolve always fails with the same error that was thrown as a result of the
10582
initial resolution attempt. Consequently, if the JAR file contains an entry
10583
that corresponds to a class for which the Java virtual machine has
10584
unsuccessfully attempted to resolve a reference, then subsequent attempts to
10585
resolve that reference will fail with the same error as the initial attempt.
10586
</description>
10587
<origin>new</origin>
10588
<capabilities>
10589
</capabilities>
10590
<parameters>
10591
<param id="segment">
10592
<inbuf><char/></inbuf>
10593
<description>
10594
The platform-dependent search path segment, encoded as a
10595
<internallink id="mUTF">modified UTF-8</internallink> string.
10596
</description>
10597
</param>
10598
</parameters>
10599
<errors>
10600
<error id="JVMTI_ERROR_ILLEGAL_ARGUMENT">
10601
<paramlink id="segment"/> is an invalid path. In the live phase, anything other than an
10602
existing JAR file is an invalid path.
10603
</error>
10604
<error id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED">
10605
Operation not supported by the system class loader.
10606
</error>
10607
</errors>
10608
</function>
10609
10610
</category>
10611
10612
10613
<category id="props" label="System Properties">
10614
10615
<intro>
10616
These functions get and set system properties.
10617
</intro>
10618
10619
<function id="GetSystemProperties" phase="onload" num="130">
10620
<synopsis>Get System Properties</synopsis>
10621
<description>
10622
The list of VM system property keys which may be used with
10623
<functionlink id="GetSystemProperty"/> is returned.
10624
It is strongly recommended that virtual machines provide the
10625
following property keys:
10626
<ul>
10627
<li><code>java.vm.vendor</code></li>
10628
<li><code>java.vm.version</code></li>
10629
<li><code>java.vm.name</code></li>
10630
<li><code>java.vm.info</code></li>
10631
<li><code>java.library.path</code></li>
10632
<li><code>java.class.path</code></li>
10633
</ul>
10634
Provides access to system properties defined by and used
10635
by the VM.
10636
Properties set on the command-line are included.
10637
This allows getting and setting of these properties
10638
before the VM even begins executing bytecodes.
10639
Since this is a VM view of system properties, the set of available
10640
properties will usually be different than that
10641
in <code>java.lang.System.getProperties</code>.
10642
JNI method invocation may be used to access
10643
<code>java.lang.System.getProperties</code>.
10644
<p/>
10645
The set of properties may grow during execution.
10646
</description>
10647
<origin>new</origin>
10648
<capabilities>
10649
</capabilities>
10650
<parameters>
10651
<param id="count_ptr">
10652
<outptr><jint/></outptr>
10653
<description>
10654
On return, points to the number of property keys returned.
10655
</description>
10656
</param>
10657
<param id="property_ptr">
10658
<allocallocbuf outcount="count_ptr"><char/></allocallocbuf>
10659
<description>
10660
On return, points to an array of property keys, encoded as
10661
<internallink id="mUTF">modified UTF-8</internallink> strings.
10662
</description>
10663
</param>
10664
</parameters>
10665
<errors>
10666
</errors>
10667
</function>
10668
10669
<function id="GetSystemProperty" phase="onload" num="131">
10670
<synopsis>Get System Property</synopsis>
10671
<description>
10672
Return a VM system property value given the property key.
10673
<p/>
10674
The function <functionlink id="GetSystemProperties"/>
10675
returns the set of property keys which may be used.
10676
The properties which can be retrieved may grow during
10677
execution.
10678
<p/>
10679
Since this is a VM view of system properties, the values
10680
of properties may differ from that returned by
10681
<code>java.lang.System.getProperty(String)</code>.
10682
A typical VM might copy the values of the VM system
10683
properties into the <code>Properties</code> held by
10684
<code>java.lang.System</code> during the initialization
10685
of that class. Thereafter any changes to the VM system
10686
properties (with <functionlink id="SetSystemProperty"/>)
10687
or the <code>java.lang.System</code> system properties
10688
(with <code>java.lang.System.setProperty(String,String)</code>)
10689
would cause the values to diverge.
10690
JNI method invocation may be used to access
10691
<code>java.lang.System.getProperty(String)</code>.
10692
</description>
10693
<origin>new</origin>
10694
<capabilities>
10695
</capabilities>
10696
<parameters>
10697
<param id="property">
10698
<inbuf><char/></inbuf>
10699
<description>
10700
The key of the property to retrieve, encoded as a
10701
<internallink id="mUTF">modified UTF-8</internallink> string.
10702
</description>
10703
</param>
10704
<param id="value_ptr">
10705
<allocbuf><char/></allocbuf>
10706
<description>
10707
On return, points to the property value, encoded as a
10708
<internallink id="mUTF">modified UTF-8</internallink> string.
10709
</description>
10710
</param>
10711
</parameters>
10712
<errors>
10713
<error id="JVMTI_ERROR_NOT_AVAILABLE">
10714
This property is not available.
10715
Use <functionlink id="GetSystemProperties"/> to find available properties.
10716
</error>
10717
</errors>
10718
</function>
10719
10720
<function id="SetSystemProperty" phase="onloadOnly" num="132">
10721
<synopsis>Set System Property</synopsis>
10722
<description>
10723
Set a VM system property value.
10724
<p/>
10725
The function <functionlink id="GetSystemProperties"/>
10726
returns the set of property keys, some of these may be settable.
10727
See <functionlink id="GetSystemProperty"/>.
10728
</description>
10729
<origin>new</origin>
10730
<capabilities>
10731
</capabilities>
10732
<parameters>
10733
<param id="property">
10734
<inbuf><char/></inbuf>
10735
<description>
10736
The key of the property, encoded as a
10737
<internallink id="mUTF">modified UTF-8</internallink> string.
10738
</description>
10739
</param>
10740
<param id="value_ptr">
10741
<inbuf>
10742
<char/>
10743
<nullok>
10744
do not set the value, but return <errorlink id="JVMTI_ERROR_NOT_AVAILABLE"/>
10745
if the property is not writeable
10746
</nullok>
10747
</inbuf>
10748
<description>
10749
The property value to set, encoded as a
10750
<internallink id="mUTF">modified UTF-8</internallink> string.
10751
</description>
10752
</param>
10753
</parameters>
10754
<errors>
10755
<error id="JVMTI_ERROR_NOT_AVAILABLE">
10756
This property is not available or is not writeable.
10757
</error>
10758
</errors>
10759
</function>
10760
10761
</category>
10762
10763
<category id="general" label="General">
10764
10765
<intro>
10766
</intro>
10767
10768
<function id="GetPhase" jkernel="yes" phase="any" num="133">
10769
<synopsis>Get Phase</synopsis>
10770
<description>
10771
Return the current phase of VM execution.
10772
The phases proceed in sequence:
10773
<constants id="jvmtiPhase" label="Phases of execution" kind="enum">
10774
<constant id="JVMTI_PHASE_ONLOAD" num="1">
10775
<code>OnLoad</code> phase: while in the
10776
<internallink id="onload"><code>Agent_OnLoad</code></internallink>
10777
or, for statically linked agents, the <internallink id="onload">
10778
<code>Agent_OnLoad_&lt;agent-lib-name&gt;
10779
</code></internallink> function.
10780
</constant>
10781
<constant id="JVMTI_PHASE_PRIMORDIAL" num="2">
10782
Primordial phase: between return from <code>Agent_OnLoad</code>
10783
or <code>Agent_OnLoad_&lt;agent-lib-name&gt;</code> and the
10784
<code>VMStart</code> event.
10785
</constant>
10786
<constant id="JVMTI_PHASE_START" num="6">
10787
Start phase: when the <eventlink id="VMStart"><code>VMStart</code></eventlink> event
10788
is sent and until the <code>VMInit</code> event is sent.
10789
</constant>
10790
<constant id="JVMTI_PHASE_LIVE" num="4">
10791
Live phase: when the <eventlink id="VMInit"><code>VMInit</code></eventlink> event is sent
10792
and until the <eventlink id="VMDeath"></eventlink> event returns.
10793
</constant>
10794
<constant id="JVMTI_PHASE_DEAD" num="8">
10795
Dead phase: after the <eventlink id="VMDeath"></eventlink> event returns or after
10796
start-up failure.
10797
</constant>
10798
</constants>
10799
In the case of start-up failure the VM will proceed directly to the dead
10800
phase skipping intermediate phases and neither a <code>VMInit</code> nor
10801
<code>VMDeath</code> event will be sent.
10802
<p/>
10803
Most <jvmti/> functions operate only in the live phase.
10804
The following functions operate in either the <code>OnLoad</code> or live phases:
10805
<functionphaselist phase="onload"/>
10806
The following functions operate in only the <code>OnLoad</code> phase:
10807
<functionphaselist phase="onloadOnly"/>
10808
The following functions operate in the start or live phases:
10809
<functionphaselist phase="start"/>
10810
The following functions operate in any phase:
10811
<functionphaselist phase="any"/>
10812
JNI functions (except the Invocation API) must only be used in the start or live phases.
10813
<p/>
10814
Most <jvmti/> events are sent only in the live phase.
10815
The following events operate in others phases:
10816
<eventphaselist phase="start"/>
10817
<eventphaselist phase="any"/>
10818
</description>
10819
<origin>new</origin>
10820
<capabilities>
10821
</capabilities>
10822
<parameters>
10823
<param id="phase_ptr">
10824
<outptr><enum>jvmtiPhase</enum></outptr>
10825
<description>
10826
On return, points to the phase.
10827
</description>
10828
</param>
10829
</parameters>
10830
<errors>
10831
</errors>
10832
</function>
10833
10834
<function id="DisposeEnvironment" jkernel="yes" phase="any" num="127">
10835
<synopsis>Dispose Environment</synopsis>
10836
<description>
10837
Shutdown a <jvmti/> connection created with JNI <code>GetEnv</code>
10838
(see <internallink id="environments"><jvmti/> Environments</internallink>).
10839
Dispose of any resources held by the environment.
10840
<issue>
10841
What resources are reclaimed? What is undone?
10842
Breakpoints,watchpoints removed?
10843
</issue>
10844
Threads suspended by this environment are not resumed by this call,
10845
this must be done explicitly by the agent.
10846
Memory allocated by this environment via calls to <jvmti/> functions
10847
is not released, this can be done explicitly by the agent
10848
by calling <functionlink id="Deallocate"/>.
10849
Raw monitors created by this environment are not destroyed,
10850
this can be done explicitly by the agent
10851
by calling <functionlink id="DestroyRawMonitor"/>.
10852
The state of threads waiting on raw monitors created by this environment
10853
are not affected.
10854
<p/>
10855
Any <functionlink id="SetNativeMethodPrefix">native method
10856
prefixes</functionlink> for this environment will be unset;
10857
the agent must remove any prefixed native methods before
10858
dispose is called.
10859
<p/>
10860
Any <internallink id="capability">capabilities</internallink>
10861
held by this environment are relinquished.
10862
<p/>
10863
Events enabled by this environment will no longer be sent, however
10864
event handlers currently running will continue to run. Caution must
10865
be exercised in the design of event handlers whose environment may
10866
be disposed and thus become invalid during their execution.
10867
<p/>
10868
This environment may not be used after this call.
10869
This call returns to the caller.
10870
</description>
10871
<origin>new</origin>
10872
<capabilities>
10873
</capabilities>
10874
<parameters>
10875
</parameters>
10876
<errors>
10877
</errors>
10878
</function>
10879
10880
<function id="SetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="148">
10881
<synopsis>Set Environment Local Storage</synopsis>
10882
<description>
10883
The VM stores a pointer value associated with each environment.
10884
This pointer value is called <i>environment-local storage</i>.
10885
This value is <code>NULL</code> unless set with this function.
10886
Agents can allocate memory in which they store environment specific
10887
information. By setting environment-local storage it can then be
10888
accessed with
10889
<functionlink id="GetEnvironmentLocalStorage"></functionlink>.
10890
<p/>
10891
Called by the agent to set the value of the <jvmti/>
10892
environment-local storage. <jvmti/> supplies to the agent a pointer-size
10893
environment-local storage that can be used to record per-environment
10894
information.
10895
</description>
10896
<origin>new</origin>
10897
<capabilities>
10898
</capabilities>
10899
<parameters>
10900
<param id="data">
10901
<inbuf>
10902
<void/>
10903
<nullok>value is set to <code>NULL</code></nullok>
10904
</inbuf>
10905
<description>
10906
The value to be entered into the environment-local storage.
10907
</description>
10908
</param>
10909
</parameters>
10910
<errors>
10911
</errors>
10912
</function>
10913
10914
<function id="GetEnvironmentLocalStorage" jkernel="yes" phase="any" callbacksafe="safe" impl="innative notrace" num="147">
10915
<synopsis>Get Environment Local Storage</synopsis>
10916
<description>
10917
Called by the agent to get the value of the <jvmti/> environment-local
10918
storage.
10919
</description>
10920
<origin>new</origin>
10921
<capabilities>
10922
</capabilities>
10923
<parameters>
10924
<param id="data_ptr">
10925
<agentbuf><void/></agentbuf>
10926
<description>
10927
Pointer through which the value of the environment local
10928
storage is returned.
10929
If environment-local storage has not been set with
10930
<functionlink id="SetEnvironmentLocalStorage"></functionlink> returned
10931
pointer is <code>NULL</code>.
10932
</description>
10933
</param>
10934
</parameters>
10935
<errors>
10936
</errors>
10937
</function>
10938
10939
<function id="GetVersionNumber" jkernel="yes" phase="any" num="88">
10940
<synopsis>Get Version Number</synopsis>
10941
<description>
10942
Return the <jvmti/> version via <code>version_ptr</code>.
10943
The return value is the version identifier.
10944
The version identifier includes major, minor and micro
10945
version as well as the interface type.
10946
<constants id="jvmtiVersionInterfaceTypes" label="Version Interface Types" kind="bits">
10947
<constant id="JVMTI_VERSION_INTERFACE_JNI" num="0x00000000">
10948
Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for JNI.
10949
</constant>
10950
<constant id="JVMTI_VERSION_INTERFACE_JVMTI" num="0x30000000">
10951
Value of <code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> for <jvmti/>.
10952
</constant>
10953
</constants>
10954
<constants id="jvmtiVersionMasks" label="Version Masks" kind="bits">
10955
<constant id="JVMTI_VERSION_MASK_INTERFACE_TYPE" num="0x70000000">
10956
Mask to extract interface type.
10957
The value of the version returned by this function masked with
10958
<code>JVMTI_VERSION_MASK_INTERFACE_TYPE</code> is always
10959
<code>JVMTI_VERSION_INTERFACE_JVMTI</code>
10960
since this is a <jvmti/> function.
10961
</constant>
10962
<constant id="JVMTI_VERSION_MASK_MAJOR" num="0x0FFF0000">
10963
Mask to extract major version number.
10964
</constant>
10965
<constant id="JVMTI_VERSION_MASK_MINOR" num="0x0000FF00">
10966
Mask to extract minor version number.
10967
</constant>
10968
<constant id="JVMTI_VERSION_MASK_MICRO" num="0x000000FF">
10969
Mask to extract micro version number.
10970
</constant>
10971
</constants>
10972
<constants id="jvmtiVersionShifts" label="Version Shifts" kind="bits">
10973
<constant id="JVMTI_VERSION_SHIFT_MAJOR" num="16">
10974
Shift to extract major version number.
10975
</constant>
10976
<constant id="JVMTI_VERSION_SHIFT_MINOR" num="8">
10977
Shift to extract minor version number.
10978
</constant>
10979
<constant id="JVMTI_VERSION_SHIFT_MICRO" num="0">
10980
Shift to extract micro version number.
10981
</constant>
10982
</constants>
10983
</description>
10984
<origin>jvmdi</origin>
10985
<capabilities>
10986
</capabilities>
10987
<parameters>
10988
<param id="version_ptr">
10989
<outptr><jint/></outptr>
10990
<description>
10991
On return, points to the <jvmti/> version.
10992
</description>
10993
</param>
10994
</parameters>
10995
<errors>
10996
</errors>
10997
</function>
10998
10999
11000
<function id="GetErrorName" phase="any" num="128">
11001
<synopsis>Get Error Name</synopsis>
11002
<description>
11003
Return the symbolic name for an
11004
<internallink id="ErrorSection">error code</internallink>.
11005
<p/>
11006
For example
11007
<code>GetErrorName(env, JVMTI_ERROR_NONE, &amp;err_name)</code>
11008
would return in <code>err_name</code> the string
11009
<code>"JVMTI_ERROR_NONE"</code>.
11010
</description>
11011
<origin>new</origin>
11012
<capabilities>
11013
</capabilities>
11014
<parameters>
11015
<param id="error">
11016
<enum>jvmtiError</enum>
11017
<description>
11018
The error code.
11019
</description>
11020
</param>
11021
<param id="name_ptr">
11022
<allocbuf><char/></allocbuf>
11023
<description>
11024
On return, points to the error name.
11025
The name is encoded as a
11026
<internallink id="mUTF">modified UTF-8</internallink> string,
11027
but is restricted to the ASCII subset.
11028
</description>
11029
</param>
11030
</parameters>
11031
<errors>
11032
</errors>
11033
</function>
11034
11035
<function id="SetVerboseFlag" phase="any" num="150">
11036
<synopsis>Set Verbose Flag</synopsis>
11037
<description>
11038
<constants id="jvmtiVerboseFlag" label="Verbose Flag Enumeration" kind="enum">
11039
<constant id="JVMTI_VERBOSE_OTHER" num="0">
11040
Verbose output other than the below.
11041
</constant>
11042
<constant id="JVMTI_VERBOSE_GC" num="1">
11043
Verbose garbage collector output, like that specified with <code>-verbose:gc</code>.
11044
</constant>
11045
<constant id="JVMTI_VERBOSE_CLASS" num="2">
11046
Verbose class loading output, like that specified with <code>-verbose:class</code>.
11047
</constant>
11048
<constant id="JVMTI_VERBOSE_JNI" num="4">
11049
Verbose JNI output, like that specified with <code>-verbose:jni</code>.
11050
</constant>
11051
</constants>
11052
Control verbose output.
11053
This is the output which typically is sent to <code>stderr</code>.
11054
</description>
11055
<origin>new</origin>
11056
<capabilities>
11057
</capabilities>
11058
<parameters>
11059
<param id="flag">
11060
<enum>jvmtiVerboseFlag</enum>
11061
<description>
11062
Which verbose flag to set.
11063
</description>
11064
</param>
11065
<param id="value">
11066
<jboolean/>
11067
<description>
11068
New value of the flag.
11069
</description>
11070
</param>
11071
</parameters>
11072
<errors>
11073
</errors>
11074
</function>
11075
11076
11077
<function id="GetJLocationFormat" phase="any" num="129">
11078
<synopsis>Get JLocation Format</synopsis>
11079
<description>
11080
Although the greatest functionality is achieved with location information
11081
referencing the virtual machine bytecode index, the definition of
11082
<code>jlocation</code> has intentionally been left unconstrained to allow VM
11083
implementations that do not have this information.
11084
<p/>
11085
This function describes the representation of <code>jlocation</code> used in this VM.
11086
If the returned format is <datalink id="JVMTI_JLOCATION_JVMBCI"></datalink>,
11087
<code>jlocation</code>s can
11088
be used as in indices into the array returned by
11089
<functionlink id="GetBytecodes"></functionlink>.
11090
<constants id="jvmtiJlocationFormat" label="JLocation Format Enumeration" kind="enum">
11091
<constant id="JVMTI_JLOCATION_JVMBCI" num="1">
11092
<code>jlocation</code> values represent virtual machine
11093
bytecode indices--that is, offsets into the
11094
virtual machine code for a method.
11095
</constant>
11096
<constant id="JVMTI_JLOCATION_MACHINEPC" num="2">
11097
<code>jlocation</code> values represent native machine
11098
program counter values.
11099
</constant>
11100
<constant id="JVMTI_JLOCATION_OTHER" num="0">
11101
<code>jlocation</code> values have some other representation.
11102
</constant>
11103
</constants>
11104
</description>
11105
<origin>new</origin>
11106
<capabilities>
11107
</capabilities>
11108
<parameters>
11109
<param id="format_ptr">
11110
<outptr><enum>jvmtiJlocationFormat</enum></outptr>
11111
<description>
11112
On return, points to the format identifier for <code>jlocation</code> values.
11113
</description>
11114
</param>
11115
</parameters>
11116
<errors>
11117
</errors>
11118
</function>
11119
11120
</category>
11121
11122
</functionsection>
11123
11124
<errorsection label="Error Reference">
11125
<intro>
11126
Every <jvmti/> function returns a <b><code>jvmtiError</code></b> error code.
11127
<p/>
11128
It is the responsibility of the agent to call <jvmti/> functions with
11129
valid parameters and in the proper context (calling thread is attached,
11130
phase is correct, etc.).
11131
Detecting some error conditions may be difficult, inefficient, or
11132
impossible for an implementation.
11133
The errors listed in
11134
<internallink id="reqerrors">Function Specific Required Errors</internallink>
11135
must be detected by the implementation.
11136
All other errors represent the recommended response to the error
11137
condition.
11138
</intro>
11139
11140
<errorcategory id="universal-error" label="Universal Errors">
11141
<intro>
11142
The following errors may be returned by any function
11143
</intro>
11144
11145
<errorid id="JVMTI_ERROR_NONE" num="0">
11146
No error has occurred. This is the error code that is returned
11147
on successful completion of the function.
11148
</errorid>
11149
<errorid id="JVMTI_ERROR_NULL_POINTER" num="100">
11150
Pointer is unexpectedly <code>NULL</code>.
11151
</errorid>
11152
<errorid id="JVMTI_ERROR_OUT_OF_MEMORY" num="110">
11153
The function attempted to allocate memory and no more memory was
11154
available for allocation.
11155
</errorid>
11156
<errorid id="JVMTI_ERROR_ACCESS_DENIED" num="111">
11157
The desired functionality has not been enabled in this virtual machine.
11158
</errorid>
11159
<errorid id="JVMTI_ERROR_UNATTACHED_THREAD" num="115">
11160
The thread being used to call this function is not attached
11161
to the virtual machine. Calls must be made from attached threads.
11162
See <code>AttachCurrentThread</code> in the JNI invocation API.
11163
</errorid>
11164
<errorid id="JVMTI_ERROR_INVALID_ENVIRONMENT" num="116">
11165
The <jvmti/> environment provided is no longer connected or is
11166
not an environment.
11167
</errorid>
11168
<errorid id="JVMTI_ERROR_WRONG_PHASE" num="112">
11169
The desired functionality is not available in the current
11170
<functionlink id="GetPhase">phase</functionlink>.
11171
Always returned if the virtual machine has completed running.
11172
</errorid>
11173
<errorid id="JVMTI_ERROR_INTERNAL" num="113">
11174
An unexpected internal error has occurred.
11175
</errorid>
11176
</errorcategory>
11177
11178
<errorcategory id="reqerrors" label="Function Specific Required Errors">
11179
<intro>
11180
The following errors are returned by some <jvmti/> functions and must
11181
be returned by the implementation when the condition occurs.
11182
</intro>
11183
11184
<errorid id="JVMTI_ERROR_INVALID_PRIORITY" num="12">
11185
Invalid priority.
11186
</errorid>
11187
<errorid id="JVMTI_ERROR_THREAD_NOT_SUSPENDED" num="13">
11188
Thread was not suspended.
11189
</errorid>
11190
<errorid id="JVMTI_ERROR_THREAD_SUSPENDED" num="14">
11191
Thread already suspended.
11192
</errorid>
11193
<errorid id="JVMTI_ERROR_THREAD_NOT_ALIVE" num="15">
11194
This operation requires the thread to be alive--that is,
11195
it must be started and not yet have died.
11196
</errorid>
11197
<errorid id="JVMTI_ERROR_CLASS_NOT_PREPARED" num="22">
11198
The class has been loaded but not yet prepared.
11199
</errorid>
11200
<errorid id="JVMTI_ERROR_NO_MORE_FRAMES" num="31">
11201
There are no Java programming language or JNI stack frames at the specified depth.
11202
</errorid>
11203
<errorid id="JVMTI_ERROR_OPAQUE_FRAME" num="32">
11204
Information about the frame is not available (e.g. for native frames).
11205
</errorid>
11206
<errorid id="JVMTI_ERROR_DUPLICATE" num="40">
11207
Item already set.
11208
</errorid>
11209
<errorid id="JVMTI_ERROR_NOT_FOUND" num="41">
11210
Desired element (e.g. field or breakpoint) not found
11211
</errorid>
11212
<errorid id="JVMTI_ERROR_NOT_MONITOR_OWNER" num="51">
11213
This thread doesn't own the raw monitor.
11214
</errorid>
11215
<errorid id="JVMTI_ERROR_INTERRUPT" num="52">
11216
The call has been interrupted before completion.
11217
</errorid>
11218
<errorid id="JVMTI_ERROR_UNMODIFIABLE_CLASS" num="79">
11219
The class cannot be modified.
11220
</errorid>
11221
<errorid id="JVMTI_ERROR_NOT_AVAILABLE" num="98">
11222
The functionality is not available in this virtual machine.
11223
</errorid>
11224
<errorid id="JVMTI_ERROR_ABSENT_INFORMATION" num="101">
11225
The requested information is not available.
11226
</errorid>
11227
<errorid id="JVMTI_ERROR_INVALID_EVENT_TYPE" num="102">
11228
The specified event type ID is not recognized.
11229
</errorid>
11230
<errorid id="JVMTI_ERROR_NATIVE_METHOD" num="104">
11231
The requested information is not available for native method.
11232
</errorid>
11233
<errorid id="JVMTI_ERROR_CLASS_LOADER_UNSUPPORTED" num="106">
11234
The class loader does not support this operation.
11235
</errorid>
11236
</errorcategory>
11237
11238
<errorcategory id="function-specific-errors" label="Function Specific Agent Errors">
11239
<intro>
11240
The following errors are returned by some <jvmti/> functions.
11241
They are returned in the event of invalid parameters passed by the
11242
agent or usage in an invalid context.
11243
An implementation is not required to detect these errors.
11244
</intro>
11245
11246
<errorid id="JVMTI_ERROR_INVALID_THREAD" num="10">
11247
The passed thread is not a valid thread.
11248
</errorid>
11249
<errorid id="JVMTI_ERROR_INVALID_FIELDID" num="25">
11250
Invalid field.
11251
</errorid>
11252
<errorid id="JVMTI_ERROR_INVALID_METHODID" num="23">
11253
Invalid method.
11254
</errorid>
11255
<errorid id="JVMTI_ERROR_INVALID_LOCATION" num="24">
11256
Invalid location.
11257
</errorid>
11258
<errorid id="JVMTI_ERROR_INVALID_OBJECT" num="20">
11259
Invalid object.
11260
</errorid>
11261
<errorid id="JVMTI_ERROR_INVALID_CLASS" num="21">
11262
Invalid class.
11263
</errorid>
11264
<errorid id="JVMTI_ERROR_TYPE_MISMATCH" num="34">
11265
The variable is not an appropriate type for the function used.
11266
</errorid>
11267
<errorid id="JVMTI_ERROR_INVALID_SLOT" num="35">
11268
Invalid slot.
11269
</errorid>
11270
<errorid id="JVMTI_ERROR_MUST_POSSESS_CAPABILITY" num="99">
11271
The capability being used is false in this environment.
11272
</errorid>
11273
<errorid id="JVMTI_ERROR_INVALID_THREAD_GROUP" num="11">
11274
Thread group invalid.
11275
</errorid>
11276
<errorid id="JVMTI_ERROR_INVALID_MONITOR" num="50">
11277
Invalid raw monitor.
11278
</errorid>
11279
<errorid id="JVMTI_ERROR_ILLEGAL_ARGUMENT" num="103">
11280
Illegal argument.
11281
</errorid>
11282
<errorid id="JVMTI_ERROR_INVALID_TYPESTATE" num="65">
11283
The state of the thread has been modified, and is now inconsistent.
11284
</errorid>
11285
<errorid id="JVMTI_ERROR_UNSUPPORTED_VERSION" num="68">
11286
A new class file has a version number not supported by this VM.
11287
</errorid>
11288
<errorid id="JVMTI_ERROR_INVALID_CLASS_FORMAT" num="60">
11289
A new class file is malformed (the VM would return a <code>ClassFormatError</code>).
11290
</errorid>
11291
<errorid id="JVMTI_ERROR_CIRCULAR_CLASS_DEFINITION" num="61">
11292
The new class file definitions would lead to a circular
11293
definition (the VM would return a <code>ClassCircularityError</code>).
11294
</errorid>
11295
<errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_ADDED" num="63">
11296
A new class file would require adding a method.
11297
</errorid>
11298
<errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED" num="64">
11299
A new class version changes a field.
11300
</errorid>
11301
<errorid id="JVMTI_ERROR_FAILS_VERIFICATION" num="62">
11302
The class bytes fail verification.
11303
</errorid>
11304
<errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED" num="66">
11305
A direct superclass is different for the new class
11306
version, or the set of directly implemented
11307
interfaces is different.
11308
</errorid>
11309
<errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_DELETED" num="67">
11310
A new class version does not declare a method
11311
declared in the old class version.
11312
</errorid>
11313
<errorid id="JVMTI_ERROR_NAMES_DONT_MATCH" num="69">
11314
The class name defined in the new class file is
11315
different from the name in the old class object.
11316
</errorid>
11317
<errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED" num="70">
11318
A new class version has different modifiers.
11319
</errorid>
11320
<errorid id="JVMTI_ERROR_UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED" num="71">
11321
A method in the new class version has different modifiers
11322
than its counterpart in the old class version.
11323
</errorid>
11324
</errorcategory>
11325
</errorsection>
11326
11327
<eventsection label="Events">
11328
<intro label="Handling Events" id="eventIntro">
11329
Agents can be informed of many events that occur in application
11330
programs.
11331
<p/>
11332
To handle events, designate a set of callback functions with
11333
<functionlink id="SetEventCallbacks"></functionlink>.
11334
For each event the corresponding callback function will be
11335
called.
11336
Arguments to the callback function provide additional
11337
information about the event.
11338
<p/>
11339
The callback function is usually called from within an application
11340
thread. The <jvmti/> implementation does not
11341
queue events in any way. This means
11342
that event callback functions must be written
11343
carefully. Here are some general guidelines. See
11344
the individual event descriptions for further
11345
suggestions.
11346
<p/>
11347
<ul>
11348
<li>Any exception thrown during the execution of an event callback can
11349
overwrite any current pending exception in the current application thread.
11350
Care must be taken to preserve a pending exception
11351
when an event callback makes a JNI call that might generate an exception.
11352
</li>
11353
<li>Event callback functions must be re-entrant. The <jvmti/> implementation does
11354
not queue events. If an agent needs to process events one at a time, it
11355
can use a raw monitor inside the
11356
event callback functions to serialize event processing.
11357
</li>
11358
<li>Event callback functions that execute JNI's FindClass function to load
11359
classes need to note that FindClass locates the class loader associated
11360
with the current native method. For the purposes of class loading, an
11361
event callback that includes a JNI environment as a parameter to the
11362
callback will treated as if it is a native call, where the native method
11363
is in the class of the event thread's current frame.
11364
</li>
11365
</ul>
11366
<p/>
11367
Some <jvmti/> events identify objects with JNI references.
11368
All references
11369
in <jvmti/> events are JNI local references and will become invalid
11370
after the event callback returns.
11371
Unless stated otherwise, memory referenced by pointers sent in event
11372
callbacks may not be referenced after the event callback returns.
11373
<p/>
11374
Except where stated otherwise, events are delivered on the thread
11375
that caused the event.
11376
Events are sent at the time they occur.
11377
The specification for each event includes the set of
11378
<functionlink id="GetPhase">phases</functionlink> in which it can be sent;
11379
if an event triggering activity occurs during another phase, no event
11380
is sent.
11381
<p/>
11382
A thread that generates an event does not change its execution status
11383
(for example, the event does not cause the thread to be suspended).
11384
If an agent wishes the event to result in suspension, then the agent
11385
is responsible for explicitly suspending the thread with
11386
<functionlink id="SuspendThread"></functionlink>.
11387
<p/>
11388
If an event is enabled in multiple environments, the event will be sent
11389
to each agent in the order that the environments were created.
11390
</intro>
11391
11392
<intro label="Enabling Events" id="enablingevents">
11393
All events are initially disabled. In order to receive any
11394
event:
11395
<ul>
11396
<li>
11397
If the event requires a capability, that capability must
11398
be added with
11399
<functionlink id="AddCapabilities"></functionlink>.
11400
</li>
11401
<li>
11402
A callback for the event must be set with
11403
<functionlink id="SetEventCallbacks"></functionlink>.
11404
</li>
11405
<li>
11406
The event must be enabled with
11407
<functionlink id="SetEventNotificationMode"></functionlink>.
11408
</li>
11409
</ul>
11410
</intro>
11411
11412
<intro label="Multiple Co-located Events" id="eventorder">
11413
In many situations it is possible for multiple events to occur
11414
at the same location in one thread. When this happens, all the events
11415
are reported through the event callbacks in the order specified in this section.
11416
<p/>
11417
If the current location is at the entry point of a method, the
11418
<eventlink id="MethodEntry"></eventlink> event is reported before
11419
any other event at the current location in the same thread.
11420
<p/>
11421
If an exception catch has been detected at the current location,
11422
either because it is the beginning of a catch clause or a native method
11423
that cleared a pending exception has returned, the
11424
<code>exceptionCatch</code> event is reported before
11425
any other event at the current location in the same thread.
11426
<p/>
11427
If a <code>singleStep</code> event or
11428
<code>breakpoint</code> event is triggered at the
11429
current location, the event is defined to occur
11430
immediately before the code at the current location is executed.
11431
These events are reported before any events which are triggered
11432
by the execution of code at the current location in the same
11433
thread (specifically:
11434
<code>exception</code>,
11435
<code>fieldAccess</code>, and
11436
<code>fieldModification</code>).
11437
If both a step and breakpoint event are triggered for the same thread and
11438
location, the step event is reported before the breakpoint event.
11439
<p/>
11440
If the current location is the exit point of a method (that is, the last
11441
location before returning to the caller), the
11442
<eventlink id="MethodExit"></eventlink> event and
11443
the <eventlink id="FramePop"></eventlink> event (if requested)
11444
are reported after all other events at the current location in the same
11445
thread. There is no specified ordering of these two events
11446
with respect to each other.
11447
<p/>
11448
Co-located events can be triggered during the processing of some other
11449
event by the agent at the same location in the same thread.
11450
If such an event, of type <i>y</i>, is triggered during the processing of
11451
an event of type <i>x</i>, and if <i>x</i>
11452
precedes <i>y</i> in the ordering specified above, the co-located event
11453
<i>y</i> is reported for the current thread and location. If <i>x</i> does not precede
11454
<i>y</i>, <i>y</i> is not reported for the current thread and location.
11455
For example, if a breakpoint is set at the current location
11456
during the processing of <eventlink id="SingleStep"></eventlink>,
11457
that breakpoint will be reported before the thread moves off the current
11458
location.
11459
<p/>The following events are never considered to be co-located with
11460
other events.
11461
<ul>
11462
<li><eventlink id="VMStart"></eventlink></li>
11463
<li><eventlink id="VMInit"></eventlink></li>
11464
<li><eventlink id="VMDeath"></eventlink></li>
11465
<li><eventlink id="ThreadStart"></eventlink></li>
11466
<li><eventlink id="ThreadEnd"></eventlink></li>
11467
<li><eventlink id="ClassLoad"></eventlink></li>
11468
<li><eventlink id="ClassPrepare"></eventlink></li>
11469
</ul>
11470
</intro>
11471
11472
<intro label="Event Callbacks" id="jvmtiEventCallbacks">
11473
The event callback structure below is used to specify the handler function
11474
for events. It is set with the
11475
<functionlink id="SetEventCallbacks"></functionlink> function.
11476
</intro>
11477
11478
<event label="Single Step"
11479
id="SingleStep" const="JVMTI_EVENT_SINGLE_STEP" filtered="thread" num="60">
11480
<description>
11481
Single step events allow the agent to trace thread execution
11482
at the finest granularity allowed by the VM. A single step event is
11483
generated whenever a thread reaches a new location.
11484
Typically, single step events represent the completion of one VM
11485
instruction as defined in <vmspec/>. However, some implementations
11486
may define locations differently. In any case the
11487
<code>method</code> and <code>location</code>
11488
parameters uniquely identify the current location and allow
11489
the mapping to source file and line number when that information is
11490
available.
11491
<p/>
11492
No single step events are generated from within native methods.
11493
</description>
11494
<origin>jvmdi</origin>
11495
<capabilities>
11496
<required id="can_generate_single_step_events"></required>
11497
</capabilities>
11498
<parameters>
11499
<param id="jni_env">
11500
<outptr>
11501
<struct>JNIEnv</struct>
11502
</outptr>
11503
<description>
11504
The JNI environment of the event (current) thread
11505
</description>
11506
</param>
11507
<param id="thread">
11508
<jthread/>
11509
<description>
11510
Thread about to execution a new instruction
11511
</description>
11512
</param>
11513
<param id="klass">
11514
<jclass method="method"/>
11515
<description>
11516
Class of the method about to execute a new instruction
11517
</description>
11518
</param>
11519
<param id="method">
11520
<jmethodID class="klass"/>
11521
<description>
11522
Method about to execute a new instruction
11523
</description>
11524
</param>
11525
<param id="location">
11526
<jlocation/>
11527
<description>
11528
Location of the new instruction
11529
</description>
11530
</param>
11531
</parameters>
11532
</event>
11533
11534
<event label="Breakpoint"
11535
id="Breakpoint" const="JVMTI_EVENT_BREAKPOINT" filtered="thread" num="62">
11536
<description>
11537
Breakpoint events are generated whenever a thread reaches a location
11538
designated as a breakpoint with <functionlink id="SetBreakpoint"></functionlink>.
11539
The <code>method</code> and <code>location</code>
11540
parameters uniquely identify the current location and allow
11541
the mapping to source file and line number when that information is
11542
available.
11543
</description>
11544
<origin>jvmdi</origin>
11545
<capabilities>
11546
<required id="can_generate_breakpoint_events"></required>
11547
</capabilities>
11548
<parameters>
11549
<param id="jni_env">
11550
<outptr>
11551
<struct>JNIEnv</struct>
11552
</outptr>
11553
<description>
11554
The JNI environment of the event (current) thread.
11555
</description>
11556
</param>
11557
<param id="thread">
11558
<jthread/>
11559
<description>
11560
Thread that hit the breakpoint
11561
</description>
11562
</param>
11563
<param id="klass">
11564
<jclass method="method"/>
11565
<description>
11566
Class of the method that hit the breakpoint
11567
</description>
11568
</param>
11569
<param id="method">
11570
<jmethodID class="klass"/>
11571
<description>
11572
Method that hit the breakpoint
11573
</description>
11574
</param>
11575
<param id="location">
11576
<jlocation/>
11577
<description>
11578
location of the breakpoint
11579
</description>
11580
</param>
11581
</parameters>
11582
</event>
11583
11584
<event label="Field Access"
11585
id="FieldAccess" const="JVMTI_EVENT_FIELD_ACCESS" filtered="thread" num="63">
11586
<description>
11587
Field access events are generated whenever a thread accesses
11588
a field that was designated as a watchpoint
11589
with <functionlink id="SetFieldAccessWatch"></functionlink>.
11590
The <code>method</code> and <code>location</code>
11591
parameters uniquely identify the current location and allow
11592
the mapping to source file and line number when that information is
11593
available.
11594
</description>
11595
<origin>jvmdi</origin>
11596
<capabilities>
11597
<required id="can_generate_field_access_events"></required>
11598
</capabilities>
11599
<parameters>
11600
<param id="jni_env">
11601
<outptr>
11602
<struct>JNIEnv</struct>
11603
</outptr>
11604
<description>
11605
The JNI environment of the event (current) thread
11606
</description>
11607
</param>
11608
<param id="thread">
11609
<jthread/>
11610
<description>
11611
Thread accessing the field
11612
</description>
11613
</param>
11614
<param id="klass">
11615
<jclass method="method"/>
11616
<description>
11617
Class of the method where the access is occurring
11618
</description>
11619
</param>
11620
<param id="method">
11621
<jmethodID class="klass"/>
11622
<description>
11623
Method where the access is occurring
11624
</description>
11625
</param>
11626
<param id="location">
11627
<jlocation/>
11628
<description>
11629
Location where the access is occurring
11630
</description>
11631
</param>
11632
<param id="field_klass">
11633
<jclass field="field"/>
11634
<description>
11635
Class of the field being accessed
11636
</description>
11637
</param>
11638
<param id="object">
11639
<jobject/>
11640
<description>
11641
Object with the field being accessed if the field is an
11642
instance field; <code>NULL</code> otherwise
11643
</description>
11644
</param>
11645
<param id="field">
11646
<jfieldID class="field_klass"/>
11647
<description>
11648
Field being accessed
11649
</description>
11650
</param>
11651
</parameters>
11652
</event>
11653
11654
<event label="Field Modification"
11655
id="FieldModification" const="JVMTI_EVENT_FIELD_MODIFICATION" filtered="thread" num="64">
11656
<description>
11657
Field modification events are generated whenever a thread modifies
11658
a field that was designated as a watchpoint
11659
with <functionlink id="SetFieldModificationWatch"></functionlink>.
11660
The <code>method</code> and <code>location</code>
11661
parameters uniquely identify the current location and allow
11662
the mapping to source file and line number when that information is
11663
available.
11664
</description>
11665
<origin>jvmdi</origin>
11666
<capabilities>
11667
<required id="can_generate_field_modification_events"></required>
11668
</capabilities>
11669
<parameters>
11670
<param id="jni_env">
11671
<outptr>
11672
<struct>JNIEnv</struct>
11673
</outptr>
11674
<description>
11675
The JNI environment of the event (current) thread
11676
</description>
11677
</param>
11678
<param id="thread">
11679
<jthread/>
11680
<description>
11681
Thread modifying the field
11682
</description>
11683
</param>
11684
<param id="klass">
11685
<jclass method="method"/>
11686
<description>
11687
Class of the method where the modification is occurring
11688
</description>
11689
</param>
11690
<param id="method">
11691
<jmethodID class="klass"/>
11692
<description>
11693
Method where the modification is occurring
11694
</description>
11695
</param>
11696
<param id="location">
11697
<jlocation/>
11698
<description>
11699
Location where the modification is occurring
11700
</description>
11701
</param>
11702
<param id="field_klass">
11703
<jclass field="field"/>
11704
<description>
11705
Class of the field being modified
11706
</description>
11707
</param>
11708
<param id="object">
11709
<jobject/>
11710
<description>
11711
Object with the field being modified if the field is an
11712
instance field; <code>NULL</code> otherwise
11713
</description>
11714
</param>
11715
<param id="field">
11716
<jfieldID class="field_klass"/>
11717
<description>
11718
Field being modified
11719
</description>
11720
</param>
11721
<param id="signature_type">
11722
<char/>
11723
<description>
11724
Signature type of the new value
11725
</description>
11726
</param>
11727
<param id="new_value">
11728
<jvalue/>
11729
<description>
11730
The new value
11731
</description>
11732
</param>
11733
</parameters>
11734
</event>
11735
11736
<event label="Frame Pop"
11737
id="FramePop" const="JVMTI_EVENT_FRAME_POP" filtered="thread" num="61">
11738
<description>
11739
Frame pop events are generated upon exit from a single method
11740
in a single frame as specified
11741
in a call to <functionlink id="NotifyFramePop"></functionlink>.
11742
This is true whether termination is caused by
11743
executing its return instruction
11744
or by throwing an exception to its caller
11745
(see <paramlink id="was_popped_by_exception"></paramlink>).
11746
However, frame pops caused by the <functionlink id="PopFrame"/>
11747
function are not reported.
11748
<p/>
11749
The location reported by <functionlink id="GetFrameLocation"></functionlink>
11750
identifies the executable location in the returning method,
11751
immediately prior to the return.
11752
</description>
11753
<origin>jvmdi</origin>
11754
<capabilities>
11755
<required id="can_generate_frame_pop_events"></required>
11756
</capabilities>
11757
<parameters>
11758
<param id="jni_env">
11759
<outptr>
11760
<struct>JNIEnv</struct>
11761
</outptr>
11762
<description>
11763
The JNI environment of the event (current) thread
11764
</description>
11765
</param>
11766
<param id="thread">
11767
<jthread/>
11768
<description>
11769
Thread that is popping the frame
11770
</description>
11771
</param>
11772
<param id="klass">
11773
<jclass method="method"/>
11774
<description>
11775
Class of the method being popped
11776
</description>
11777
</param>
11778
<param id="method">
11779
<jmethodID class="klass"/>
11780
<description>
11781
Method being popped
11782
</description>
11783
</param>
11784
<param id="was_popped_by_exception">
11785
<jboolean/>
11786
<description>
11787
True if frame was popped by a thrown exception.
11788
False if method exited through its return instruction.
11789
</description>
11790
</param>
11791
</parameters>
11792
</event>
11793
11794
<event label="Method Entry"
11795
id="MethodEntry" const="JVMTI_EVENT_METHOD_ENTRY" filtered="thread" num="65">
11796
<description>
11797
Method entry events are generated upon entry of Java
11798
programming language methods (including native methods).
11799
<p/>
11800
The location reported by <functionlink id="GetFrameLocation"></functionlink>
11801
identifies the initial executable location in
11802
the method.
11803
<p/>
11804
Enabling method
11805
entry or exit events will significantly degrade performance on many platforms and is thus
11806
not advised for performance critical usage (such as profiling).
11807
<internallink id="bci">Bytecode instrumentation</internallink> should be
11808
used in these cases.
11809
</description>
11810
<origin>jvmdi</origin>
11811
<capabilities>
11812
<required id="can_generate_method_entry_events"></required>
11813
</capabilities>
11814
<parameters>
11815
<param id="jni_env">
11816
<outptr>
11817
<struct>JNIEnv</struct>
11818
</outptr>
11819
<description>
11820
The JNI environment of the event (current) thread
11821
</description>
11822
</param>
11823
<param id="thread">
11824
<jthread/>
11825
<description>
11826
Thread entering the method
11827
</description>
11828
</param>
11829
<param id="klass">
11830
<jclass method="method"/>
11831
<description>
11832
Class of the method being entered
11833
</description>
11834
</param>
11835
<param id="method">
11836
<jmethodID class="klass"/>
11837
<description>
11838
Method being entered
11839
</description>
11840
</param>
11841
</parameters>
11842
</event>
11843
11844
<event label="Method Exit"
11845
id="MethodExit" const="JVMTI_EVENT_METHOD_EXIT" filtered="thread" num="66">
11846
<description>
11847
Method exit events are generated upon exit from Java
11848
programming language methods (including native methods).
11849
This is true whether termination is caused by
11850
executing its return instruction
11851
or by throwing an exception to its caller
11852
(see <paramlink id="was_popped_by_exception"></paramlink>).
11853
<p/>
11854
The <code>method</code> field uniquely identifies the
11855
method being entered or exited. The <code>frame</code> field provides
11856
access to the stack frame for the method.
11857
<p/>
11858
The location reported by <functionlink id="GetFrameLocation"></functionlink>
11859
identifies the executable location in the returning method
11860
immediately prior to the return.
11861
<p/>
11862
Enabling method
11863
entry or exit events will significantly degrade performance on many platforms and is thus
11864
not advised for performance critical usage (such as profiling).
11865
<internallink id="bci">Bytecode instrumentation</internallink> should be
11866
used in these cases.
11867
</description>
11868
<origin>jvmdi</origin>
11869
<capabilities>
11870
<required id="can_generate_method_exit_events"></required>
11871
</capabilities>
11872
<parameters>
11873
<param id="jni_env">
11874
<outptr>
11875
<struct>JNIEnv</struct>
11876
</outptr>
11877
<description>
11878
The JNI environment of the event (current) thread
11879
</description>
11880
</param>
11881
<param id="thread">
11882
<jthread/>
11883
<description>
11884
Thread exiting the method
11885
</description>
11886
</param>
11887
<param id="klass">
11888
<jclass method="method"/>
11889
<description>
11890
Class of the method being exited
11891
</description>
11892
</param>
11893
<param id="method">
11894
<jmethodID class="klass"/>
11895
<description>
11896
Method being exited
11897
</description>
11898
</param>
11899
<param id="was_popped_by_exception">
11900
<jboolean/>
11901
<description>
11902
True if frame was popped by a thrown exception.
11903
False if method exited through its return instruction.
11904
</description>
11905
</param>
11906
<param id="return_value">
11907
<jvalue/>
11908
<description>
11909
The return value of the method being exited.
11910
Undefined and should not be used if
11911
<paramlink id="was_popped_by_exception"></paramlink>
11912
is true.
11913
</description>
11914
</param>
11915
</parameters>
11916
</event>
11917
11918
<event label="Native Method Bind" phase="any"
11919
id="NativeMethodBind" const="JVMTI_EVENT_NATIVE_METHOD_BIND" num="67">
11920
<description>
11921
A Native Method Bind event is sent when a VM binds a
11922
Java programming language native method
11923
to the address of a function that implements the native method.
11924
This will occur when the native method is called for the first time
11925
and also occurs when the JNI function <code>RegisterNatives</code> is called.
11926
This event allows the bind to be redirected to an agent-specified
11927
proxy function.
11928
This event is not sent when the native method is unbound.
11929
Typically, this proxy function will need to be specific to a
11930
particular method or, to handle the general case, automatically
11931
generated assembly code, since after instrumentation code is
11932
executed the function at the original binding
11933
address will usually be invoked.
11934
The original binding can be restored or the redirection changed
11935
by use of the JNI function <code>RegisterNatives</code>.
11936
Some events may be sent during the primordial phase, JNI and
11937
most of <jvmti/> cannot be used at this time but the method and
11938
address can be saved for use later.
11939
</description>
11940
<origin>new</origin>
11941
<capabilities>
11942
<required id="can_generate_native_method_bind_events"></required>
11943
</capabilities>
11944
<parameters>
11945
<param id="jni_env">
11946
<outptr>
11947
<struct>JNIEnv</struct>
11948
</outptr>
11949
<description>
11950
The JNI environment of the event (current) thread
11951
Will be <code>NULL</code> if sent during the primordial
11952
<functionlink id="GetPhase">phase</functionlink>.
11953
</description>
11954
</param>
11955
<param id="thread">
11956
<jthread/>
11957
<description>
11958
Thread requesting the bind
11959
</description>
11960
</param>
11961
<param id="klass">
11962
<jclass method="method"/>
11963
<description>
11964
Class of the method being bound
11965
</description>
11966
</param>
11967
<param id="method">
11968
<jmethodID class="klass"/>
11969
<description>
11970
Native method being bound
11971
</description>
11972
</param>
11973
<param id="address">
11974
<outptr><void/></outptr>
11975
<description>
11976
The address the VM is about to bind to--that is, the
11977
address of the implementation of the native method
11978
</description>
11979
</param>
11980
<param id="new_address_ptr">
11981
<agentbuf><void/></agentbuf>
11982
<description>
11983
if the referenced address is changed (that is, if
11984
<code>*new_address_ptr</code> is set), the binding
11985
will instead be made to the supplied address.
11986
</description>
11987
</param>
11988
</parameters>
11989
</event>
11990
11991
<event label="Exception"
11992
id="Exception" const="JVMTI_EVENT_EXCEPTION" filtered="thread" num="58">
11993
<description>
11994
Exception events are generated whenever an exception is first detected
11995
in a Java programming language method.
11996
Where "exception" means any <code>java.lang.Throwable</code>.
11997
The exception may have been thrown by a Java programming language or native
11998
method, but in the case of native methods, the event is not generated
11999
until the exception is first seen by a Java programming language method. If an exception is
12000
set and cleared in a native method (and thus is never visible to Java programming language code),
12001
no exception event is generated.
12002
<p/>
12003
The <code>method</code> and <code>location</code>
12004
parameters uniquely identify the current location
12005
(where the exception was detected) and allow
12006
the mapping to source file and line number when that information is
12007
available. The <code>exception</code> field identifies the thrown
12008
exception object. The <code>catch_method</code>
12009
and <code>catch_location</code> identify the location of the catch clause,
12010
if any, that handles the thrown exception. If there is no such catch clause,
12011
each field is set to 0. There is no guarantee that the thread will ever
12012
reach this catch clause. If there are native methods on the call stack
12013
between the throw location and the catch clause, the exception may
12014
be reset by one of those native methods.
12015
Similarly, exceptions that are reported as uncaught (<code>catch_klass</code>
12016
et al. set to 0) may in fact be caught by native code.
12017
Agents can check for these occurrences by monitoring
12018
<eventlink id="ExceptionCatch"></eventlink> events.
12019
Note that finally clauses are implemented as catch and re-throw. Therefore they
12020
will be reported in the catch location.
12021
</description>
12022
<origin>jvmdi</origin>
12023
<capabilities>
12024
<required id="can_generate_exception_events"></required>
12025
</capabilities>
12026
<parameters>
12027
<param id="jni_env">
12028
<outptr>
12029
<struct>JNIEnv</struct>
12030
</outptr>
12031
<description>
12032
The JNI environment of the event (current) thread
12033
</description>
12034
</param>
12035
<param id="thread">
12036
<jthread/>
12037
<description>
12038
Thread generating the exception
12039
</description>
12040
</param>
12041
<param id="klass">
12042
<jclass method="method"/>
12043
<description>
12044
Class generating the exception
12045
</description>
12046
</param>
12047
<param id="method">
12048
<jmethodID class="klass"/>
12049
<description>
12050
Method generating the exception
12051
</description>
12052
</param>
12053
<param id="location">
12054
<jlocation/>
12055
<description>
12056
Location where exception occurred
12057
</description>
12058
</param>
12059
<param id="exception">
12060
<jobject/>
12061
<description>
12062
The exception being thrown
12063
</description>
12064
</param>
12065
<param id="catch_klass">
12066
<jclass method="catch_method"/>
12067
<description>
12068
Class that will catch the exception, or <code>NULL</code> if no known catch
12069
</description>
12070
</param>
12071
<param id="catch_method">
12072
<jmethodID class="catch_klass"/>
12073
<description>
12074
Method that will catch the exception, or <code>NULL</code> if no known catch
12075
</description>
12076
</param>
12077
<param id="catch_location">
12078
<jlocation/>
12079
<description>
12080
location which will catch the exception or zero if no known catch
12081
</description>
12082
</param>
12083
</parameters>
12084
</event>
12085
12086
<event label="Exception Catch"
12087
id="ExceptionCatch" const="JVMTI_EVENT_EXCEPTION_CATCH" filtered="thread" num="59">
12088
<description>
12089
Exception catch events are generated whenever a thrown exception is caught.
12090
Where "exception" means any <code>java.lang.Throwable</code>.
12091
If the exception is caught in a Java programming language method, the event is generated
12092
when the catch clause is reached. If the exception is caught in a native
12093
method, the event is generated as soon as control is returned to a Java programming language
12094
method. Exception catch events are generated for any exception for which
12095
a throw was detected in a Java programming language method.
12096
Note that finally clauses are implemented as catch and re-throw. Therefore they
12097
will generate exception catch events.
12098
<p/>
12099
The <code>method</code> and <code>location</code>
12100
parameters uniquely identify the current location
12101
and allow the mapping to source file and line number when that information is
12102
available. For exceptions caught in a Java programming language method, the
12103
<code>exception</code> object identifies the exception object. Exceptions
12104
caught in native methods are not necessarily available by the time the
12105
exception catch is reported, so the <code>exception</code> field is set
12106
to <code>NULL</code>.
12107
</description>
12108
<origin>jvmdi</origin>
12109
<capabilities>
12110
<required id="can_generate_exception_events"></required>
12111
</capabilities>
12112
<parameters>
12113
<param id="jni_env">
12114
<outptr>
12115
<struct>JNIEnv</struct>
12116
</outptr>
12117
<description>
12118
The JNI environment of the event (current) thread
12119
</description>
12120
</param>
12121
<param id="thread">
12122
<jthread/>
12123
<description>
12124
Thread catching the exception
12125
</description>
12126
</param>
12127
<param id="klass">
12128
<jclass method="method"/>
12129
<description>
12130
Class catching the exception
12131
</description>
12132
</param>
12133
<param id="method">
12134
<jmethodID class="klass"/>
12135
<description>
12136
Method catching the exception
12137
</description>
12138
</param>
12139
<param id="location">
12140
<jlocation/>
12141
<description>
12142
Location where exception is being caught
12143
</description>
12144
</param>
12145
<param id="exception">
12146
<jobject/>
12147
<description>
12148
Exception being caught
12149
</description>
12150
</param>
12151
</parameters>
12152
</event>
12153
12154
<event label="Thread Start"
12155
id="ThreadStart" const="JVMTI_EVENT_THREAD_START" num="52" phase="start">
12156
<description>
12157
Thread start events are generated by a new thread before its initial
12158
method executes.
12159
<p/>
12160
A thread may be listed in the array returned by
12161
<functionlink id="GetAllThreads"></functionlink>
12162
before its thread start event is generated.
12163
It is possible for other events to be generated
12164
on a thread before its thread start event.
12165
<p/>
12166
The event is sent on the newly started <paramlink id="thread"></paramlink>.
12167
</description>
12168
<origin>jvmdi</origin>
12169
<capabilities>
12170
</capabilities>
12171
<parameters>
12172
<param id="jni_env">
12173
<outptr>
12174
<struct>JNIEnv</struct>
12175
</outptr>
12176
<description>
12177
The JNI environment of the event (current) thread.
12178
</description>
12179
</param>
12180
<param id="thread">
12181
<jthread/>
12182
<description>
12183
Thread starting
12184
</description>
12185
</param>
12186
</parameters>
12187
</event>
12188
12189
<event label="Thread End"
12190
id="ThreadEnd" const="JVMTI_EVENT_THREAD_END" filtered="thread" num="53" phase="start">
12191
<description>
12192
Thread end events are generated by a terminating thread
12193
after its initial method has finished execution.
12194
<p/>
12195
A thread may be listed in the array returned by
12196
<functionlink id="GetAllThreads"></functionlink>
12197
after its thread end event is generated.
12198
No events are generated on a thread
12199
after its thread end event.
12200
<p/>
12201
The event is sent on the dying <paramlink id="thread"></paramlink>.
12202
</description>
12203
<origin>jvmdi</origin>
12204
<capabilities>
12205
</capabilities>
12206
<parameters>
12207
<param id="jni_env">
12208
<outptr>
12209
<struct>JNIEnv</struct>
12210
</outptr>
12211
<description>
12212
The JNI environment of the event (current) thread.
12213
</description>
12214
</param>
12215
<param id="thread">
12216
<jthread/>
12217
<description>
12218
Thread ending
12219
</description>
12220
</param>
12221
</parameters>
12222
</event>
12223
12224
<event label="Class Load"
12225
id="ClassLoad" const="JVMTI_EVENT_CLASS_LOAD" filtered="thread" phase="start" num="55">
12226
<description>
12227
A class load event is generated when a class is first loaded. The order
12228
of class load events generated by a particular thread are guaranteed
12229
to match the order of class loading within that thread.
12230
Array class creation does not generate a class load event.
12231
The creation of a primitive class (for example, java.lang.Integer.TYPE)
12232
does not generate a class load event.
12233
<p/>
12234
This event is sent at an early stage in loading the class. As
12235
a result the class should be used carefully. Note, for example,
12236
that methods and fields are not yet loaded, so queries for methods,
12237
fields, subclasses, and so on will not give correct results.
12238
See "Loading of Classes and Interfaces" in the <i>Java Language
12239
Specification</i>. For most
12240
purposes the <eventlink id="ClassPrepare"></eventlink> event will
12241
be more useful.
12242
</description>
12243
<origin>jvmdi</origin>
12244
<capabilities>
12245
</capabilities>
12246
<parameters>
12247
<param id="jni_env">
12248
<outptr>
12249
<struct>JNIEnv</struct>
12250
</outptr>
12251
<description>
12252
The JNI environment of the event (current) thread
12253
</description>
12254
</param>
12255
<param id="thread">
12256
<jthread/>
12257
<description>
12258
Thread loading the class
12259
</description>
12260
</param>
12261
<param id="klass">
12262
<jclass/>
12263
<description>
12264
Class being loaded
12265
</description>
12266
</param>
12267
</parameters>
12268
</event>
12269
12270
<elide>
12271
<event label="Class Unload"
12272
id="ClassUnload" const="JVMTI_EVENT_CLASS_UNLOAD" num="57">
12273
<description>
12274
A class unload event is generated when the class is about to be unloaded.
12275
Class unload events take place during garbage collection and must be
12276
handled extremely carefully. The garbage collector holds many locks
12277
and has suspended all other threads, so the event handler cannot depend
12278
on the ability to acquire any locks. The class unload event handler should
12279
do as little as possible, perhaps by queuing information to be processed
12280
later. In particular, the <code>jclass</code> should be used only in
12281
the JNI function <code>isSameObject</code> or in the following <jvmti/> functions:
12282
<ul>
12283
<li><functionlink id="GetClassSignature"></functionlink></li>
12284
<li><functionlink id="GetSourceFileName"></functionlink></li>
12285
<li><functionlink id="IsInterface"></functionlink></li>
12286
<li><functionlink id="IsArrayClass"></functionlink></li>
12287
</ul>
12288
</description>
12289
<origin>jvmdi</origin>
12290
<capabilities>
12291
</capabilities>
12292
<parameters>
12293
<param id="jni_env">
12294
<outptr>
12295
<struct>JNIEnv</struct>
12296
</outptr>
12297
<description>
12298
The JNI environment of the event (current) thread
12299
</description>
12300
</param>
12301
<param id="thread">
12302
<jthread/>
12303
<description>
12304
Thread generating the class unload
12305
</description>
12306
</param>
12307
<param id="klass">
12308
<jclass/>
12309
<description>
12310
Class being unloaded
12311
</description>
12312
</param>
12313
</parameters>
12314
</event>
12315
</elide>
12316
12317
<event label="Class Prepare"
12318
id="ClassPrepare" const="JVMTI_EVENT_CLASS_PREPARE" filtered="thread" phase="start" num="56">
12319
<description>
12320
A class prepare event is generated when class preparation is complete.
12321
At this point, class fields, methods, and implemented interfaces are
12322
available, and no code from the class has been executed. Since array
12323
classes never have fields or methods, class prepare events are not
12324
generated for them. Class prepare events are not generated for
12325
primitive classes (for example, <code>java.lang.Integer.TYPE</code>).
12326
</description>
12327
<origin>jvmdi</origin>
12328
<capabilities>
12329
</capabilities>
12330
<parameters>
12331
<param id="jni_env">
12332
<outptr>
12333
<struct>JNIEnv</struct>
12334
</outptr>
12335
<description>
12336
The JNI environment of the event (current) thread
12337
</description>
12338
</param>
12339
<param id="thread">
12340
<jthread/>
12341
<description>
12342
Thread generating the class prepare
12343
</description>
12344
</param>
12345
<param id="klass">
12346
<jclass/>
12347
<description>
12348
Class being prepared
12349
</description>
12350
</param>
12351
</parameters>
12352
</event>
12353
12354
<event label="Class File Load Hook" phase="any"
12355
id="ClassFileLoadHook" const="JVMTI_EVENT_CLASS_FILE_LOAD_HOOK" num="54">
12356
<description>
12357
This event is sent when the VM obtains class file data,
12358
but before it constructs
12359
the in-memory representation for that class.
12360
This event is also sent when the class is being modified by the
12361
<functionlink id="RetransformClasses"/> function or
12362
the <functionlink id="RedefineClasses"/> function,
12363
called in any <jvmti/> environment.
12364
The agent can instrument
12365
the existing class file data sent by the VM to include profiling/debugging hooks.
12366
See the description of
12367
<internallink id="bci">bytecode instrumentation</internallink>
12368
for usage information.
12369
<p/>
12370
This event may be sent before the VM is initialized (the primordial
12371
<functionlink id="GetPhase">phase</functionlink>). During this time
12372
no VM resources should be created. Some classes might not be compatible
12373
with the function (eg. ROMized classes) and this event will not be
12374
generated for these classes.
12375
<p/>
12376
The agent must allocate the space for the modified
12377
class file data buffer
12378
using the memory allocation function
12379
<functionlink id="Allocate"></functionlink> because the
12380
VM is responsible for freeing the new class file data buffer
12381
using <functionlink id="Deallocate"></functionlink>.
12382
Note that <functionlink id="Allocate"></functionlink>
12383
is permitted during the primordial phase.
12384
<p/>
12385
If the agent wishes to modify the class file, it must set
12386
<code>new_class_data</code> to point
12387
to the newly instrumented class file data buffer and set
12388
<code>new_class_data_len</code> to the length of that
12389
buffer before returning
12390
from this call. If no modification is desired, the agent simply
12391
does not set <code>new_class_data</code>. If multiple agents
12392
have enabled this event the results are chained. That is, if
12393
<code>new_class_data</code> has been set, it becomes the
12394
<code>class_data</code> for the next agent.
12395
<p/>
12396
The order that this event is sent to each environment differs
12397
from other events.
12398
This event is sent to environments in the following order:
12399
<ul>
12400
<li><fieldlink id="can_retransform_classes"
12401
struct="jvmtiCapabilities">retransformation
12402
incapable</fieldlink>
12403
environments, in the
12404
order in which they were created
12405
</li>
12406
<li><fieldlink id="can_retransform_classes"
12407
struct="jvmtiCapabilities">retransformation
12408
capable</fieldlink>
12409
environments, in the
12410
order in which they were created
12411
</li>
12412
</ul>
12413
When triggered by <functionlink id="RetransformClasses"/>,
12414
this event is sent only to <fieldlink id="can_retransform_classes"
12415
struct="jvmtiCapabilities">retransformation
12416
capable</fieldlink>
12417
environments.
12418
</description>
12419
<origin>jvmpi</origin>
12420
<capabilities>
12421
<capability id="can_generate_all_class_hook_events"></capability>
12422
</capabilities>
12423
<parameters>
12424
<param id="jni_env">
12425
<outptr>
12426
<struct>JNIEnv</struct>
12427
</outptr>
12428
<description>
12429
The JNI environment of the event (current) thread.
12430
Will be <code>NULL</code> if sent during the primordial
12431
<functionlink id="GetPhase">phase</functionlink>.
12432
</description>
12433
</param>
12434
<param id="class_being_redefined">
12435
<jclass/>
12436
<description>
12437
The class being
12438
<functionlink id="RedefineClasses">redefined</functionlink> or
12439
<functionlink id="RetransformClasses">retransformed</functionlink>.
12440
<code>NULL</code> if sent by class load.
12441
</description>
12442
</param>
12443
<param id="loader">
12444
<jobject/>
12445
<description>
12446
The class loader loading the class.
12447
<code>NULL</code> if the bootstrap class loader.
12448
</description>
12449
</param>
12450
<param id="name">
12451
<vmbuf><char/></vmbuf>
12452
<description>
12453
Name of class being loaded as a VM internal qualified name
12454
(for example, "java/util/List"), encoded as a
12455
<internallink id="mUTF">modified UTF-8</internallink> string.
12456
Note: if the class is defined with a <code>NULL</code> name or
12457
without a name specified, <code>name</code> will be <code>NULL</code>.
12458
</description>
12459
</param>
12460
<param id="protection_domain">
12461
<jobject/>
12462
<description>
12463
The <code>ProtectionDomain</code> of the class.
12464
</description>
12465
</param>
12466
<param id="class_data_len">
12467
<jint/>
12468
<description>
12469
Length of current class file data buffer.
12470
</description>
12471
</param>
12472
<param id="class_data">
12473
<vmbuf><uchar/></vmbuf>
12474
<description>
12475
Pointer to the current class file data buffer.
12476
</description>
12477
</param>
12478
<param id="new_class_data_len">
12479
<outptr><jint/></outptr>
12480
<description>
12481
Pointer to the length of the new class file data buffer.
12482
</description>
12483
</param>
12484
<param id="new_class_data">
12485
<agentbuf incount="new_class_data_len"><uchar/></agentbuf>
12486
<description>
12487
Pointer to the pointer to the instrumented class file data buffer.
12488
</description>
12489
</param>
12490
</parameters>
12491
</event>
12492
12493
<event label="VM Start Event"
12494
id="VMStart" const="JVMTI_EVENT_VM_START" num="57" phase="start">
12495
<description>
12496
The VM initialization event signals the start of the VM.
12497
At this time JNI is live but the VM is not yet fully initialized.
12498
Once this event is generated, the agent is free to call any JNI function.
12499
This event signals the beginning of the start phase,
12500
<jvmti/> functions permitted in the start phase may be called.
12501
<p/>
12502
In the case of VM start-up failure, this event will not be sent.
12503
</description>
12504
<origin>jvmdi</origin>
12505
<capabilities>
12506
</capabilities>
12507
<parameters>
12508
<param id="jni_env">
12509
<outptr>
12510
<struct>JNIEnv</struct>
12511
</outptr>
12512
<description>
12513
The JNI environment of the event (current) thread.
12514
</description>
12515
</param>
12516
</parameters>
12517
</event>
12518
12519
<event label="VM Initialization Event"
12520
id="VMInit" const="JVMTI_EVENT_VM_INIT" num="50">
12521
<description>
12522
The VM initialization event signals the completion of VM initialization. Once
12523
this event is generated, the agent is free to call any JNI or <jvmti/>
12524
function. The VM initialization event can be preceded by or can be concurrent
12525
with other events, but
12526
the preceding events should be handled carefully, if at all, because the
12527
VM has not completed its initialization. The thread start event for the
12528
main application thread is guaranteed not to occur until after the
12529
handler for the VM initialization event returns.
12530
<p/>
12531
In the case of VM start-up failure, this event will not be sent.
12532
</description>
12533
<origin>jvmdi</origin>
12534
<capabilities>
12535
</capabilities>
12536
<parameters>
12537
<param id="jni_env">
12538
<outptr>
12539
<struct>JNIEnv</struct>
12540
</outptr>
12541
<description>
12542
The JNI environment of the event (current) thread.
12543
</description>
12544
</param>
12545
<param id="thread">
12546
<jthread/>
12547
<description>
12548
The initial thread
12549
</description>
12550
</param>
12551
</parameters>
12552
</event>
12553
12554
<event label="VM Death Event"
12555
id="VMDeath" const="JVMTI_EVENT_VM_DEATH" num="51">
12556
<description>
12557
The VM death event notifies the agent of the termination of the VM.
12558
No events will occur after the VMDeath event.
12559
<p/>
12560
In the case of VM start-up failure, this event will not be sent.
12561
Note that <internallink id="onunload">Agent_OnUnload</internallink>
12562
will still be called in these cases.
12563
</description>
12564
<origin>jvmdi</origin>
12565
<capabilities>
12566
</capabilities>
12567
<parameters>
12568
<param id="jni_env">
12569
<outptr>
12570
<struct>JNIEnv</struct>
12571
</outptr>
12572
<description>
12573
The JNI environment of the event (current) thread
12574
</description>
12575
</param>
12576
</parameters>
12577
</event>
12578
12579
<event label="Compiled Method Load"
12580
id="CompiledMethodLoad" const="JVMTI_EVENT_COMPILED_METHOD_LOAD" num="68">
12581
<description>
12582
Sent when a method is compiled and loaded into memory by the VM.
12583
If it is unloaded, the <eventlink id="CompiledMethodUnload"/> event is sent.
12584
If it is moved, the <eventlink id="CompiledMethodUnload"/> event is sent,
12585
followed by a new <code>CompiledMethodLoad</code> event.
12586
Note that a single method may have multiple compiled forms, and that
12587
this event will be sent for each form.
12588
Note also that several methods may be inlined into a single
12589
address range, and that this event will be sent for each method.
12590
<p/>
12591
These events can be sent after their initial occurrence with
12592
<functionlink id="GenerateEvents"></functionlink>.
12593
</description>
12594
<origin>jvmpi</origin>
12595
<typedef id="jvmtiAddrLocationMap" label="Native address to location entry">
12596
<field id="start_address">
12597
<vmbuf><void/></vmbuf>
12598
<description>
12599
Starting native address of code corresponding to a location
12600
</description>
12601
</field>
12602
<field id="location">
12603
<jlocation/>
12604
<description>
12605
Corresponding location. See
12606
<functionlink id="GetJLocationFormat"></functionlink>
12607
for the meaning of location.
12608
</description>
12609
</field>
12610
</typedef>
12611
<capabilities>
12612
<required id="can_generate_compiled_method_load_events"></required>
12613
</capabilities>
12614
<parameters>
12615
<param id="klass">
12616
<jclass method="method"/>
12617
<description>
12618
Class of the method being compiled and loaded
12619
</description>
12620
</param>
12621
<param id="method">
12622
<jmethodID class="klass"/>
12623
<description>
12624
Method being compiled and loaded
12625
</description>
12626
</param>
12627
<param id="code_size">
12628
<jint/>
12629
<description>
12630
Size of compiled code
12631
</description>
12632
</param>
12633
<param id="code_addr">
12634
<vmbuf><void/></vmbuf>
12635
<description>
12636
Address where compiled method code is loaded
12637
</description>
12638
</param>
12639
<param id="map_length">
12640
<jint/>
12641
<description>
12642
Number of <typelink id="jvmtiAddrLocationMap"></typelink>
12643
entries in the address map.
12644
Zero if mapping information cannot be supplied.
12645
</description>
12646
</param>
12647
<param id="map">
12648
<vmbuf><struct>jvmtiAddrLocationMap</struct></vmbuf>
12649
<description>
12650
Map from native addresses to location.
12651
The native address range of each entry is from
12652
<fieldlink id="start_address" struct="jvmtiAddrLocationMap"></fieldlink>
12653
to <code>start_address-1</code> of the next entry.
12654
<code>NULL</code> if mapping information cannot be supplied.
12655
</description>
12656
</param>
12657
<param id="compile_info">
12658
<vmbuf><void/></vmbuf>
12659
<description>
12660
VM-specific compilation information.
12661
The referenced compile information is managed by the VM
12662
and must not depend on the agent for collection.
12663
A VM implementation defines the content and lifetime
12664
of the information.
12665
</description>
12666
</param>
12667
</parameters>
12668
</event>
12669
12670
<event label="Compiled Method Unload"
12671
id="CompiledMethodUnload" const="JVMTI_EVENT_COMPILED_METHOD_UNLOAD" num="69">
12672
<description>
12673
Sent when a compiled method is unloaded from memory.
12674
This event might not be sent on the thread which performed the unload.
12675
This event may be sent sometime after the unload occurs, but
12676
will be sent before the memory is reused
12677
by a newly generated compiled method. This event may be sent after
12678
the class is unloaded.
12679
</description>
12680
<origin>jvmpi</origin>
12681
<capabilities>
12682
<required id="can_generate_compiled_method_load_events"></required>
12683
</capabilities>
12684
<parameters>
12685
<param id="klass">
12686
<jclass method="method"/>
12687
<description>
12688
Class of the compiled method being unloaded.
12689
</description>
12690
</param>
12691
<param id="method">
12692
<jmethodID class="klass"/>
12693
<description>
12694
Compiled method being unloaded.
12695
For identification of the compiled method only -- the class
12696
may be unloaded and therefore the method should not be used
12697
as an argument to further JNI or <jvmti/> functions.
12698
</description>
12699
</param>
12700
<param id="code_addr">
12701
<vmbuf><void/></vmbuf>
12702
<description>
12703
Address where compiled method code was loaded.
12704
For identification of the compiled method only --
12705
the space may have been reclaimed.
12706
</description>
12707
</param>
12708
</parameters>
12709
</event>
12710
12711
<event label="Dynamic Code Generated" phase="any"
12712
id="DynamicCodeGenerated" const="JVMTI_EVENT_DYNAMIC_CODE_GENERATED" num="70">
12713
<description>
12714
Sent when a component of the virtual machine is generated dynamically.
12715
This does not correspond to Java programming language code that is
12716
compiled--see <eventlink id="CompiledMethodLoad"></eventlink>.
12717
This is for native code--for example, an interpreter that is generated
12718
differently depending on command-line options.
12719
<p/>
12720
Note that this event has no controlling capability.
12721
If a VM cannot generate these events, it simply does not send any.
12722
<p/>
12723
These events can be sent after their initial occurrence with
12724
<functionlink id="GenerateEvents"></functionlink>.
12725
</description>
12726
<origin>jvmpi</origin>
12727
<capabilities>
12728
</capabilities>
12729
<parameters>
12730
<param id="name">
12731
<vmbuf><char/></vmbuf>
12732
<description>
12733
Name of the code, encoded as a
12734
<internallink id="mUTF">modified UTF-8</internallink> string.
12735
Intended for display to an end-user.
12736
The name might not be unique.
12737
</description>
12738
</param>
12739
<param id="address">
12740
<vmbuf><void/></vmbuf>
12741
<description>
12742
Native address of the code
12743
</description>
12744
</param>
12745
<param id="length">
12746
<jint/>
12747
<description>
12748
Length in bytes of the code
12749
</description>
12750
</param>
12751
</parameters>
12752
</event>
12753
12754
<event label="Data Dump Request"
12755
id="DataDumpRequest" const="JVMTI_EVENT_DATA_DUMP_REQUEST" num="71">
12756
<description>
12757
Sent by the VM to request the agent to dump its data. This
12758
is just a hint and the agent need not react to this event.
12759
This is useful for processing command-line signals from users. For
12760
example, in the Java 2 SDK a CTRL-Break on Win32 and a CTRL-\ on Solaris
12761
causes the VM to send this event to the agent.
12762
</description>
12763
<origin>jvmpi</origin>
12764
<capabilities>
12765
</capabilities>
12766
<parameters>
12767
</parameters>
12768
</event>
12769
12770
<event label="Monitor Contended Enter"
12771
id="MonitorContendedEnter" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTER" filtered="thread" num="75">
12772
<description>
12773
Sent when a thread is attempting to enter a Java programming language
12774
monitor already acquired by another thread.
12775
</description>
12776
<origin>jvmpi</origin>
12777
<capabilities>
12778
<required id="can_generate_monitor_events"></required>
12779
</capabilities>
12780
<parameters>
12781
<param id="jni_env">
12782
<outptr>
12783
<struct>JNIEnv</struct>
12784
</outptr>
12785
<description>
12786
The JNI environment of the event (current) thread
12787
</description>
12788
</param>
12789
<param id="thread">
12790
<jthread/>
12791
<description>
12792
JNI local reference to the thread
12793
attempting to enter the monitor
12794
</description>
12795
</param>
12796
<param id="object">
12797
<jobject/>
12798
<description>
12799
JNI local reference to the monitor
12800
</description>
12801
</param>
12802
</parameters>
12803
</event>
12804
12805
<event label="Monitor Contended Entered"
12806
id="MonitorContendedEntered" const="JVMTI_EVENT_MONITOR_CONTENDED_ENTERED" filtered="thread" num="76">
12807
<description>
12808
Sent when a thread enters a Java programming language
12809
monitor after waiting for it to be released by another thread.
12810
</description>
12811
<origin>jvmpi</origin>
12812
<capabilities>
12813
<required id="can_generate_monitor_events"></required>
12814
</capabilities>
12815
<parameters>
12816
<param id="jni_env">
12817
<outptr>
12818
<struct>JNIEnv</struct>
12819
</outptr>
12820
<description>
12821
The JNI environment of the event (current) thread
12822
</description>
12823
</param>
12824
<param id="thread">
12825
<jthread/>
12826
<description>
12827
JNI local reference to the thread entering
12828
the monitor
12829
</description>
12830
</param>
12831
<param id="object">
12832
<jobject/>
12833
<description>
12834
JNI local reference to the monitor
12835
</description>
12836
</param>
12837
</parameters>
12838
</event>
12839
12840
<event label="Monitor Wait"
12841
id="MonitorWait" const="JVMTI_EVENT_MONITOR_WAIT" filtered="thread" num="73">
12842
<description>
12843
Sent when a thread is about to wait on an object.
12844
</description>
12845
<origin>jvmpi</origin>
12846
<capabilities>
12847
<required id="can_generate_monitor_events"></required>
12848
</capabilities>
12849
<parameters>
12850
<param id="jni_env">
12851
<outptr>
12852
<struct>JNIEnv</struct>
12853
</outptr>
12854
<description>
12855
The JNI environment of the event (current) thread
12856
</description>
12857
</param>
12858
<param id="thread">
12859
<jthread/>
12860
<description>
12861
JNI local reference to the thread about to wait
12862
</description>
12863
</param>
12864
<param id="object">
12865
<jobject/>
12866
<description>
12867
JNI local reference to the monitor
12868
</description>
12869
</param>
12870
<param id="timeout">
12871
<jlong/>
12872
<description>
12873
The number of milliseconds the thread will wait
12874
</description>
12875
</param>
12876
</parameters>
12877
</event>
12878
12879
<event label="Monitor Waited"
12880
id="MonitorWaited" const="JVMTI_EVENT_MONITOR_WAITED" filtered="thread" num="74">
12881
<description>
12882
Sent when a thread finishes waiting on an object.
12883
</description>
12884
<origin>jvmpi</origin>
12885
<capabilities>
12886
<required id="can_generate_monitor_events"></required>
12887
</capabilities>
12888
<parameters>
12889
<param id="jni_env">
12890
<outptr>
12891
<struct>JNIEnv</struct>
12892
</outptr>
12893
<description>
12894
The JNI environment of the event (current) thread
12895
</description>
12896
</param>
12897
<param id="thread">
12898
<jthread/>
12899
<description>
12900
JNI local reference to the thread that was finished waiting
12901
</description>
12902
</param>
12903
<param id="object">
12904
<jobject/>
12905
<description>
12906
JNI local reference to the monitor.
12907
</description>
12908
</param>
12909
<param id="timed_out">
12910
<jboolean/>
12911
<description>
12912
True if the monitor timed out
12913
</description>
12914
</param>
12915
</parameters>
12916
</event>
12917
12918
<event label="Resource Exhausted"
12919
id="ResourceExhausted" const="JVMTI_EVENT_RESOURCE_EXHAUSTED" num="80"
12920
since="1.1">
12921
<description>
12922
Sent when a VM resource needed by a running application has been exhausted.
12923
Except as required by the optional capabilities, the set of resources
12924
which report exhaustion is implementation dependent.
12925
<p/>
12926
The following bit flags define the properties of the resource exhaustion:
12927
<constants id="jvmtiResourceExhaustionFlags"
12928
label="Resource Exhaustion Flags"
12929
kind="bits"
12930
since="1.1">
12931
<constant id="JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR" num="0x0001">
12932
After this event returns, the VM will throw a
12933
<code>java.lang.OutOfMemoryError</code>.
12934
</constant>
12935
<constant id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP" num="0x0002">
12936
The VM was unable to allocate memory from the <tm>Java</tm>
12937
platform <i>heap</i>.
12938
The <i>heap</i> is the runtime
12939
data area from which memory for all class instances and
12940
arrays are allocated.
12941
</constant>
12942
<constant id="JVMTI_RESOURCE_EXHAUSTED_THREADS" num="0x0004">
12943
The VM was unable to create a thread.
12944
</constant>
12945
</constants>
12946
</description>
12947
<origin>new</origin>
12948
<capabilities>
12949
<capability id="can_generate_resource_exhaustion_heap_events">
12950
Can generate events when the VM is unable to allocate memory from the
12951
<internallink id="JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP">heap</internallink>.
12952
</capability>
12953
<capability id="can_generate_resource_exhaustion_threads_events">
12954
Can generate events when the VM is unable to
12955
<internallink id="JVMTI_RESOURCE_EXHAUSTED_THREADS">create
12956
a thread</internallink>.
12957
</capability>
12958
</capabilities>
12959
<parameters>
12960
<param id="jni_env">
12961
<outptr>
12962
<struct>JNIEnv</struct>
12963
</outptr>
12964
<description>
12965
The JNI environment of the event (current) thread
12966
</description>
12967
</param>
12968
<param id="flags">
12969
<jint/>
12970
<description>
12971
Flags defining the properties of the of resource exhaustion
12972
as specified by the
12973
<internallink id="jvmtiResourceExhaustionFlags">Resource
12974
Exhaustion Flags</internallink>.
12975
</description>
12976
</param>
12977
<param id="reserved">
12978
<vmbuf><void/></vmbuf>
12979
<description>
12980
Reserved.
12981
</description>
12982
</param>
12983
<param id="description">
12984
<vmbuf><char/></vmbuf>
12985
<description>
12986
Description of the resource exhaustion, encoded as a
12987
<internallink id="mUTF">modified UTF-8</internallink> string.
12988
</description>
12989
</param>
12990
</parameters>
12991
</event>
12992
12993
<event label="VM Object Allocation"
12994
id="VMObjectAlloc" const="JVMTI_EVENT_VM_OBJECT_ALLOC" num="84">
12995
<description>
12996
Sent when a method causes the virtual machine to allocate an
12997
Object visible to Java programming language code and the
12998
allocation is not detectable by other intrumentation mechanisms.
12999
Generally object allocation should be detected by instrumenting
13000
the bytecodes of allocating methods.
13001
Object allocation generated in native code by JNI function
13002
calls should be detected using
13003
<internallink id="jniIntercept">JNI function interception</internallink>.
13004
Some methods might not have associated bytecodes and are not
13005
native methods, they instead are executed directly by the
13006
VM. These methods should send this event.
13007
Virtual machines which are incapable of bytecode instrumentation
13008
for some or all of their methods can send this event.
13009
<p/>
13010
Typical examples where this event might be sent:
13011
<ul>
13012
<li>Reflection -- for example, <code>java.lang.Class.newInstance()</code></li>
13013
<li>Methods not represented by bytecodes -- for example, VM intrinsics and
13014
J2ME preloaded classes</li>
13015
</ul>
13016
Cases where this event would not be generated:
13017
<ul>
13018
<li>Allocation due to bytecodes -- for example, the <code>new</code>
13019
and <code>newarray</code> VM instructions</li>
13020
<li>Allocation due to JNI function calls -- for example,
13021
<code>AllocObject</code></li>
13022
<li>Allocations during VM initialization</li>
13023
<li>VM internal objects</li>
13024
</ul>
13025
</description>
13026
<origin>new</origin>
13027
<capabilities>
13028
<required id="can_generate_vm_object_alloc_events"></required>
13029
</capabilities>
13030
<parameters>
13031
<param id="jni_env">
13032
<outptr>
13033
<struct>JNIEnv</struct>
13034
</outptr>
13035
<description>
13036
The JNI environment of the event (current) thread
13037
</description>
13038
</param>
13039
<param id="thread">
13040
<jthread/>
13041
<description>
13042
Thread allocating the object.
13043
</description>
13044
</param>
13045
<param id="object">
13046
<jobject/>
13047
<description>
13048
JNI local reference to the object that was allocated
13049
</description>
13050
</param>
13051
<param id="object_klass">
13052
<jclass/>
13053
<description>
13054
JNI local reference to the class of the object
13055
</description>
13056
</param>
13057
<param id="size">
13058
<jlong/>
13059
<description>
13060
Size of the object (in bytes). See <functionlink id="GetObjectSize"/>.
13061
</description>
13062
</param>
13063
</parameters>
13064
</event>
13065
13066
<event label="Object Free"
13067
id="ObjectFree" const="JVMTI_EVENT_OBJECT_FREE" num="83">
13068
<description>
13069
An Object Free event is sent when the garbage collector frees an object.
13070
Events are only sent for tagged objects--see
13071
<internallink id="Heap">heap functions</internallink>.
13072
<p/>
13073
The event handler must not use JNI functions and
13074
must not use <jvmti/> functions except those which
13075
specifically allow such use (see the raw monitor, memory management,
13076
and environment local storage functions).
13077
</description>
13078
<origin>new</origin>
13079
<capabilities>
13080
<required id="can_generate_object_free_events"></required>
13081
</capabilities>
13082
<parameters>
13083
<param id="tag">
13084
<jlong/>
13085
<description>
13086
The freed object's tag
13087
</description>
13088
</param>
13089
</parameters>
13090
</event>
13091
13092
<event label="Garbage Collection Start"
13093
id="GarbageCollectionStart" const="JVMTI_EVENT_GARBAGE_COLLECTION_START" num="81">
13094
<description>
13095
A Garbage Collection Start event is sent when a
13096
garbage collection pause begins.
13097
Only stop-the-world collections are reported--that is, collections during
13098
which all threads cease to modify the state of the Java virtual machine.
13099
This means that some collectors will never generate these events.
13100
This event is sent while the VM is still stopped, thus
13101
the event handler must not use JNI functions and
13102
must not use <jvmti/> functions except those which
13103
specifically allow such use (see the raw monitor, memory management,
13104
and environment local storage functions).
13105
<p/>
13106
This event is always sent as a matched pair with
13107
<eventlink id="GarbageCollectionFinish"/>
13108
(assuming both events are enabled) and no garbage collection
13109
events will occur between them.
13110
</description>
13111
<origin>new</origin>
13112
<capabilities>
13113
<required id="can_generate_garbage_collection_events"></required>
13114
</capabilities>
13115
<parameters>
13116
</parameters>
13117
</event>
13118
13119
<event label="Garbage Collection Finish"
13120
id="GarbageCollectionFinish" const="JVMTI_EVENT_GARBAGE_COLLECTION_FINISH" num="82">
13121
<description>
13122
A Garbage Collection Finish event is sent when a
13123
garbage collection pause ends.
13124
This event is sent while the VM is still stopped, thus
13125
the event handler must not use JNI functions and
13126
must not use <jvmti/> functions except those which
13127
specifically allow such use (see the raw monitor, memory management,
13128
and environment local storage functions).
13129
<p/>
13130
Some agents may need to do post garbage collection operations that
13131
require the use of the disallowed <jvmti/> or JNI functions. For these
13132
cases an agent thread can be created which waits on a raw monitor,
13133
and the handler for the Garbage Collection Finish event simply
13134
notifies the raw monitor
13135
<p/>
13136
This event is always sent as a matched pair with
13137
<eventlink id="GarbageCollectionStart"/> (assuming both events are enabled).
13138
<issue>
13139
The most important use of this event is to provide timing information,
13140
and thus additional information is not required. However,
13141
information about the collection which is "free" should be included -
13142
what that information is needs to be determined.
13143
</issue>
13144
</description>
13145
<origin>new</origin>
13146
<capabilities>
13147
<required id="can_generate_garbage_collection_events"></required>
13148
</capabilities>
13149
<parameters>
13150
</parameters>
13151
</event>
13152
13153
<elide>
13154
<event label="Verbose Output" phase="any"
13155
id="VerboseOutput" const="JVMTI_EVENT_VERBOSE_OUTPUT" num="85">
13156
<description>
13157
Send verbose messages as strings.
13158
<issue>
13159
This format is extremely fragile, as it can change with each
13160
platform, collector and version. Alternatives include:
13161
<ul>
13162
<li>building off Java programming language M and M APIs</li>
13163
<li>XML</li>
13164
<li>key/value pairs</li>
13165
<li>removing it</li>
13166
</ul>
13167
</issue>
13168
<issue>
13169
Though this seemed trivial to implement.
13170
In the RI it appears this will be quite complex.
13171
</issue>
13172
</description>
13173
<origin>new</origin>
13174
<capabilities>
13175
</capabilities>
13176
<parameters>
13177
<param id="flag">
13178
<enum>jvmtiVerboseFlag</enum>
13179
<description>
13180
Which verbose output is being sent.
13181
</description>
13182
</param>
13183
<param id="message">
13184
<vmbuf><char/></vmbuf>
13185
<description>
13186
Message text, encoded as a
13187
<internallink id="mUTF">modified UTF-8</internallink> string.
13188
</description>
13189
</param>
13190
</parameters>
13191
</event>
13192
</elide>
13193
13194
</eventsection>
13195
13196
<datasection>
13197
<intro>
13198
<jvmti/> extends the data types defined by JNI.
13199
</intro>
13200
<basetypes id="jniTypes" label="JNI Types Used in the JVM Tool Interface">
13201
<basetype id="jboolean">
13202
<description>
13203
Holds a Java programming language <code>boolean</code>.
13204
Unsigned 8 bits.
13205
</description>
13206
</basetype>
13207
<basetype id="jchar">
13208
<description>
13209
Holds a Java programming language <code>char</code>.
13210
Unsigned 16 bits.
13211
</description>
13212
</basetype>
13213
<basetype id="jint">
13214
<description>
13215
Holds a Java programming language <code>int</code>.
13216
Signed 32 bits.
13217
</description>
13218
</basetype>
13219
<basetype id="jlong">
13220
<description>
13221
Holds a Java programming language <code>long</code>.
13222
Signed 64 bits.
13223
</description>
13224
</basetype>
13225
<basetype id="jfloat">
13226
<description>
13227
Holds a Java programming language <code>float</code>.
13228
32 bits.
13229
</description>
13230
</basetype>
13231
<basetype id="jdouble">
13232
<description>
13233
Holds a Java programming language <code>double</code>.
13234
64 bits.
13235
</description>
13236
</basetype>
13237
<basetype id="jobject">
13238
<description>
13239
Holds a Java programming language object.
13240
</description>
13241
</basetype>
13242
<basetype id="jclass">
13243
<description>
13244
Holds a Java programming language class.
13245
</description>
13246
</basetype>
13247
<basetype id="jvalue">
13248
<description>
13249
Is a union of all primitive types and <code>jobject</code>. Thus, holds any Java
13250
programming language value.
13251
</description>
13252
</basetype>
13253
<basetype id="jfieldID">
13254
<description>
13255
Identifies a Java programming language field.
13256
<code>jfieldID</code>s returned by <jvmti/> functions and events may be
13257
safely stored.
13258
</description>
13259
</basetype>
13260
<basetype id="jmethodID">
13261
<description>
13262
Identifies a Java programming language method, initializer, or constructor.
13263
<code>jmethodID</code>s returned by <jvmti/> functions and events may be
13264
safely stored. However, if the class is unloaded, they become invalid
13265
and must not be used.
13266
</description>
13267
</basetype>
13268
<basetype id="JNIEnv">
13269
<description>
13270
Pointer to the JNI function table. Pointer to this (<code>JNIEnv *</code>)
13271
is a JNI environment.
13272
</description>
13273
</basetype>
13274
</basetypes>
13275
13276
<basetypes id="jvmtiTypes" label="JVM Tool Interface Base Types">
13277
<basetype id="jvmtiEnv">
13278
<description>
13279
The <jvmti/> <internallink id="environments">environment</internallink> pointer.
13280
See the <internallink id="FunctionSection">Function Section</internallink>.
13281
<code>jvmtiEnv</code> points to the
13282
<internallink id="FunctionTable">function table</internallink> pointer.
13283
</description>
13284
</basetype>
13285
<basetype id="jthread">
13286
<definition>typedef jobject jthread;</definition>
13287
<description>
13288
Subtype of <datalink id="jobject"></datalink> that holds a thread.
13289
</description>
13290
</basetype>
13291
<basetype id="jthreadGroup">
13292
<definition>typedef jobject jthreadGroup;</definition>
13293
<description>
13294
Subtype of <datalink id="jobject"></datalink> that holds a thread group.
13295
</description>
13296
</basetype>
13297
<basetype id="jlocation">
13298
<definition>typedef jlong jlocation;</definition>
13299
<description>
13300
A 64 bit value, representing a monotonically increasing
13301
executable position within a method.
13302
<code>-1</code> indicates a native method.
13303
See <functionlink id="GetJLocationFormat"></functionlink> for the format on a
13304
given VM.
13305
</description>
13306
</basetype>
13307
<basetype id="jrawMonitorID">
13308
<definition>struct _jrawMonitorID;
13309
typedef struct _jrawMonitorID *jrawMonitorID;</definition>
13310
<description>
13311
A raw monitor.
13312
</description>
13313
</basetype>
13314
<basetype id="jvmtiError">
13315
<description>
13316
Holds an error return code.
13317
See the <internallink id="ErrorSection">Error section</internallink> for possible values.
13318
<example>
13319
typedef enum {
13320
JVMTI_ERROR_NONE = 0,
13321
JVMTI_ERROR_INVALID_THREAD = 10,
13322
...
13323
} jvmtiError;
13324
</example>
13325
</description>
13326
</basetype>
13327
<basetype id="jvmtiEvent">
13328
<description>
13329
An identifier for an event type.
13330
See the <internallink id="EventSection">Event section</internallink> for possible values.
13331
It is guaranteed that future versions of this specification will
13332
never assign zero as an event type identifier.
13333
<example>
13334
typedef enum {
13335
JVMTI_EVENT_SINGLE_STEP = 1,
13336
JVMTI_EVENT_BREAKPOINT = 2,
13337
...
13338
} jvmtiEvent;
13339
</example>
13340
</description>
13341
</basetype>
13342
<basetype id="jvmtiEventCallbacks">
13343
<description>
13344
The callbacks used for events.
13345
<example>
13346
typedef struct {
13347
jvmtiEventVMInit VMInit;
13348
jvmtiEventVMDeath VMDeath;
13349
...
13350
} jvmtiEventCallbacks;
13351
</example>
13352
See <internallink id="jvmtiEventCallbacks">event callbacks</internallink>
13353
for the complete structure.
13354
<p/>
13355
Where, for example, the VM initialization callback is defined:
13356
<example>
13357
typedef void (JNICALL *jvmtiEventVMInit)
13358
(jvmtiEnv *jvmti_env,
13359
JNIEnv* jni_env,
13360
jthread thread);
13361
</example>
13362
See the individual events for the callback function definition.
13363
</description>
13364
</basetype>
13365
<basetype id="jniNativeInterface">
13366
<definition>typedef struct JNINativeInterface_ jniNativeInterface;</definition>
13367
<description>
13368
Typedef for the JNI function table <code>JNINativeInterface</code>
13369
defined in the
13370
<externallink id="http://docs.oracle.com/javase/7/docs/technotes/guides/jni/spec/functions.html#wp23720">JNI Specification</externallink>.
13371
The JNI reference implementation defines this with an underscore.
13372
</description>
13373
</basetype>
13374
</basetypes>
13375
13376
</datasection>
13377
13378
<issuessection label="Issues">
13379
<intro id="suspendRequired" label="Resolved Issue: Suspend - Required or Automatic">
13380
JVMDI requires that the agent suspend threads before calling
13381
certain sensitive functions. JVMPI requires garbage collection to be
13382
disabled before calling certain sensitive functions.
13383
It was suggested that rather than have this requirement, that
13384
VM place itself in a suitable state before performing an
13385
operation. This makes considerable sense since each VM
13386
knows its requirements and can most easily arrange a
13387
safe state.
13388
<p/>
13389
The ability to externally suspend/resume threads will, of
13390
course, remain. The ability to enable/disable garbage collection will not.
13391
<p/>
13392
This issue is resolved--suspend will not
13393
be required. The spec has been updated to reflect this.
13394
</intro>
13395
13396
<intro id="stackSampling" label="Resolved Issue: Call Stack Sampling">
13397
There are a variety of approaches to sampling call stacks.
13398
The biggest bifurcation is between VM controlled and agent
13399
controlled.
13400
<p/>
13401
This issue is resolved--agent controlled
13402
sampling will be the approach.
13403
</intro>
13404
13405
<intro id="threadRepresentation" label="Resolved Issue: Thread Representation">
13406
JVMDI represents threads as jthread. JVMPI primarily
13407
uses JNIEnv* to represent threads.
13408
<p/>
13409
The Expert Group has chosen jthread as the representation
13410
for threads in <jvmti/>.
13411
JNIEnv* is sent by
13412
events since it is needed to JNI functions. JNIEnv, per the
13413
JNI spec, are not supposed to be used outside their thread.
13414
</intro>
13415
13416
<intro id="design" label="Resolved Issue: Method Representation">
13417
The JNI spec allows an implementation to depend on jclass/jmethodID
13418
pairs, rather than simply a jmethodID, to reference a method.
13419
JVMDI, for consistency, choose the same representation.
13420
JVMPI, however, specifies that a jmethodID alone maps to a
13421
method. Both of the Sun <tm>J2SE</tm> virtual machines (Classic and <tm>HotSpot</tm>) store
13422
pointers in jmethodIDs, and as a result, a jmethodID is sufficient.
13423
In fact, any JVM implementation that supports JVMPI must have
13424
such a representation.
13425
<jvmti/> will use jmethodID as a unique representation of a method
13426
(no jclass is used).
13427
There should be efficiency gains, particularly in
13428
functionality like stack dumping, to this representation.
13429
<p/>
13430
Note that fields were not used in JVMPI and that the access profile
13431
of fields differs from methods--for implementation efficiency
13432
reasons, a jclass/jfieldID pair will still be needed for field
13433
reference.
13434
</intro>
13435
13436
<intro id="localReferenceIssue" label="Resolved Issue: Local References">
13437
Functions return local references.
13438
</intro>
13439
13440
<intro id="frameRep" label="Resolved Issue: Representation of frames">
13441
In JVMDI, a frame ID is used to represent a frame. Problem with this
13442
is that a VM must track when a frame becomes invalid, a far better
13443
approach, and the one used in <jvmti/>, is to reference frames by depth.
13444
</intro>
13445
13446
<intro id="requiredCapabilities" label="Issue: Required Capabilities">
13447
Currently, having a required capabilities means that the functionality
13448
is optional. Capabilities are useful even for required functionality
13449
since they can inform the VM is needed set-up. Thus, there should be
13450
a set of capabilities that a conformant implementation must provide
13451
(if requested during Agent_OnLoad).
13452
</intro>
13453
13454
<intro id="taghint" label="Proposal: add tag hint function">
13455
A hint of the percentage of objects that will be tagged would
13456
help the VM pick a good implementation.
13457
</intro>
13458
13459
<intro id="moreMonitorQueries" label="Request: More Monitor Quires">
13460
How difficult or easy would be to extend the monitor_info category to include
13461
<pre>
13462
- current number of monitors
13463
- enumeration of monitors
13464
- enumeration of threads waiting on a given monitor
13465
</pre>
13466
The reason for my question is the fact that current get_monitor_info support
13467
requires the agent to specify a given thread to get the info which is probably
13468
OK in the profiling/debugging space, while in the monitoring space the agent
13469
could be watching the monitor list and then decide which thread to ask for
13470
the info. You might ask why is this important for monitoring .... I think it
13471
can aid in the detection/prediction of application contention caused by hot-locks.
13472
</intro>
13473
</issuessection>
13474
13475
<changehistory id="ChangeHistory" update="09/05/07">
13476
<intro>
13477
The <jvmti/> specification is an evolving document with major, minor,
13478
and micro version numbers.
13479
A released version of the specification is uniquely identified
13480
by its major and minor version.
13481
The functions, events, and capabilities in this specification
13482
indicate a "Since" value which is the major and minor version in
13483
which it was introduced.
13484
The version of the specification implemented by the VM can
13485
be retrieved at runtime with the <functionlink id="GetVersionNumber"/>
13486
function.
13487
</intro>
13488
<change date="14 Nov 2002">
13489
Converted to XML document.
13490
</change>
13491
<change date="14 Nov 2002">
13492
Elided heap dump functions (for now) since what was there
13493
was wrong.
13494
</change>
13495
<change date="18 Nov 2002">
13496
Added detail throughout.
13497
</change>
13498
<change date="18 Nov 2002">
13499
Changed JVMTI_THREAD_STATUS_RUNNING to JVMTI_THREAD_STATUS_RUNNABLE.
13500
</change>
13501
<change date="19 Nov 2002">
13502
Added AsyncGetStackTrace.
13503
</change>
13504
<change date="19 Nov 2002">
13505
Added jframeID return to GetStackTrace.
13506
</change>
13507
<change date="19 Nov 2002">
13508
Elided GetCurrentFrame and GetCallingFrame functions (for now) since what was there
13509
since they are redundant with GetStackTrace.
13510
</change>
13511
<change date="19 Nov 2002">
13512
Elided ClearAllBreakpoints since it has always been redundant.
13513
</change>
13514
<change date="19 Nov 2002">
13515
Added GetSystemProperties.
13516
</change>
13517
<change date="19 Nov 2002">
13518
Changed the thread local storage functions to use jthread.
13519
</change>
13520
<change date="20 Nov 2002">
13521
Added GetJLocationFormat.
13522
</change>
13523
<change date="22 Nov 2002">
13524
Added events and introductory text.
13525
</change>
13526
<change date="22 Nov 2002">
13527
Cross reference type and constant definitions.
13528
</change>
13529
<change date="24 Nov 2002">
13530
Added DTD.
13531
</change>
13532
<change date="24 Nov 2002">
13533
Added capabilities function section.
13534
</change>
13535
<change date="29 Nov 2002">
13536
Assign capabilities to each function and event.
13537
</change>
13538
<change date="29 Nov 2002">
13539
Add <internallink id="jniIntercept">JNI interception functions</internallink>.
13540
</change>
13541
<change date="30 Nov 2002">
13542
Auto generate SetEventNotificationMode capabilities.
13543
</change>
13544
<change date="30 Nov 2002">
13545
Add <eventlink id="VMObjectAlloc"></eventlink> event.
13546
</change>
13547
<change date="30 Nov 2002">
13548
Add <eventlink id="DynamicCodeGenerated"></eventlink> event.
13549
</change>
13550
<change date="30 Nov 2002">
13551
Add const to declarations.
13552
</change>
13553
<change date="30 Nov 2002">
13554
Change method exit and frame pop to send on exception.
13555
</change>
13556
<change date="1 Dec 2002">
13557
Add ForceGarbageCollection.
13558
</change>
13559
<change date="2 Dec 2002">
13560
Redo Xrun section; clarify GetStackTrace and add example;
13561
Fix width problems; use "agent" consistently.
13562
</change>
13563
<change date="8 Dec 2002">
13564
Remove previous start-up intro.
13565
Add <internallink id="environments"><jvmti/> Environments</internallink>
13566
section.
13567
</change>
13568
<change date="8 Dec 2002">
13569
Add <functionlink id="DisposeEnvironment"></functionlink>.
13570
</change>
13571
<change date="9 Dec 2002">
13572
Numerous minor updates.
13573
</change>
13574
<change date="15 Dec 2002">
13575
Add heap profiling functions added:
13576
get/set annotation, iterate live objects/heap.
13577
Add heap profiling functions place holder added:
13578
heap roots.
13579
Heap profiling event added: object free.
13580
Heap profiling event redesigned: vm object allocation.
13581
Heap profiling event placeholders added: garbage collection start/finish.
13582
Native method bind event added.
13583
</change>
13584
<change date="19 Dec 2002">
13585
Revamp suspend/resume functions.
13586
Add origin information with jvmdi tag.
13587
Misc fixes.
13588
</change>
13589
<change date="24 Dec 2002">
13590
Add semantics to types.
13591
</change>
13592
<change date="27 Dec 2002">
13593
Add local reference section.
13594
Autogenerate parameter descriptions from types.
13595
</change>
13596
<change date="28 Dec 2002">
13597
Document that RunAgentThread sends threadStart.
13598
</change>
13599
<change date="29 Dec 2002">
13600
Remove redundant local ref and dealloc warning.
13601
Convert GetRawMonitorName to allocated buffer.
13602
Add GenerateEvents.
13603
</change>
13604
<change date="30 Dec 2002">
13605
Make raw monitors a type and rename to "jrawMonitorID".
13606
</change>
13607
<change date="1 Jan 2003">
13608
Include origin information.
13609
Clean-up JVMDI issue references.
13610
Remove Deallocate warnings which are now automatically generated.
13611
</change>
13612
<change date="2 Jan 2003">
13613
Fix representation issues for jthread.
13614
</change>
13615
<change date="3 Jan 2003">
13616
Make capabilities buffered out to 64 bits - and do it automatically.
13617
</change>
13618
<change date="4 Jan 2003">
13619
Make constants which are enumeration into enum types.
13620
Parameters now of enum type.
13621
Clean-up and index type section.
13622
Replace remaining datadef entities with callback.
13623
</change>
13624
<change date="7 Jan 2003">
13625
Correct GenerateEvents description.
13626
More internal semantics work.
13627
</change>
13628
<change date="9 Jan 2003">
13629
Replace previous GetSystemProperties with two functions
13630
which use allocated information instead fixed.
13631
Add SetSystemProperty.
13632
More internal semantics work.
13633
</change>
13634
<change date="12 Jan 2003">
13635
Add varargs to end of SetEventNotificationMode.
13636
</change>
13637
<change date="20 Jan 2003">
13638
Finish fixing spec to reflect that alloc sizes are jlong.
13639
</change>
13640
<change date="22 Jan 2003">
13641
Allow NULL as RunAgentThread arg.
13642
</change>
13643
<change date="22 Jan 2003">
13644
Fixed names to standardized naming convention
13645
Removed AsyncGetStackTrace.
13646
</change>
13647
<change date="29 Jan 2003">
13648
Since we are using jthread, removed GetThread.
13649
</change>
13650
<change date="31 Jan 2003">
13651
Change GetFieldName to allow NULLs like GetMethodName.
13652
</change>
13653
<change date="29 Feb 2003" version="v40">
13654
Rewrite the introductory text, adding sections on
13655
start-up, environments and bytecode instrumentation.
13656
Change the command line arguments per EG discussions.
13657
Add an introduction to the capabilities section.
13658
Add the extension mechanism category and functions.
13659
Mark for deletion, but clarified anyhow, SuspendAllThreads.
13660
Rename IterateOverLiveObjects to IterateOverReachableObjects and
13661
change the text accordingly.
13662
Clarify IterateOverHeap.
13663
Clarify CompiledMethodLoad.
13664
Discuss prerequisite state for Calling Functions.
13665
Clarify SetAllocationHooks.
13666
Added issues ("To be resolved:") through-out.
13667
And so on...
13668
</change>
13669
<change date="6 Mar 2003" version="v41">
13670
Remove struct from the call to GetOwnedMonitorInfo.
13671
Automatically generate most error documentation, remove
13672
(rather broken) hand written error doc.
13673
Better describe capability use (empty initial set).
13674
Add min value to jint params.
13675
Remove the capability can_access_thread_local_storage.
13676
Rename error JVMTI_ERROR_NOT_IMPLEMENTED to JVMTI_ERROR_MUST_POSSESS_CAPABILITY;
13677
same for *NOT_IMPLEMENTED.
13678
Description fixes.
13679
</change>
13680
<change date="8 Mar 2003" version="v42">
13681
Rename GetClassSignature to GetClassName.
13682
Rename IterateOverClassObjects to IterateOverInstancesOfClass.
13683
Remove GetMaxStack (operand stack isn't used in <jvmti/>).
13684
Description fixes: define launch-time, remove native frame pop
13685
from PopFrame, and assorted clarifications.
13686
</change>
13687
<change date="8 Mar 2003" version="v43">
13688
Fix minor editing problem.
13689
</change>
13690
<change date="10 Mar 2003" version="v44">
13691
Add phase information.
13692
Remap (compact) event numbers.
13693
</change>
13694
<change date="11 Mar 2003" version="v45">
13695
More phase information - allow "any".
13696
Elide raw monitor queries and events.
13697
Minor description fixes.
13698
</change>
13699
<change date="12 Mar 2003" version="v46">
13700
Add GetPhase.
13701
Use "phase" through document.
13702
Elide GetRawMonitorName.
13703
Elide GetObjectMonitors.
13704
</change>
13705
<change date="12 Mar 2003" version="v47">
13706
Fixes from link, XML, and spell checking.
13707
Auto-generate the callback structure.
13708
</change>
13709
<change date="13 Mar 2003" version="v48">
13710
One character XML fix.
13711
</change>
13712
<change date="13 Mar 2003" version="v49">
13713
Change function parameter names to be consistent with
13714
event parameters (fooBarBaz becomes foo_bar_baz).
13715
</change>
13716
<change date="14 Mar 2003" version="v50">
13717
Fix broken link. Fix thread markers.
13718
</change>
13719
<change date="14 Mar 2003" version="v51">
13720
Change constants so they are under 128 to workaround
13721
compiler problems.
13722
</change>
13723
<change date="23 Mar 2003" version="v52">
13724
Overhaul capabilities. Separate GetStackTrace into
13725
GetStackTrace and GetStackFrames.
13726
</change>
13727
<change date="8 Apr 2003" version="v54">
13728
Use depth instead of jframeID to reference frames.
13729
Remove the now irrelevant GetCurrentFrame, GetCallerFrame and GetStackFrames.
13730
Remove frame arg from events.
13731
</change>
13732
<change date="9 Apr 2003" version="v55">
13733
Remove GetObjectWithAnnotation since tests show bufferred approach more efficient.
13734
Add missing annotation_count to GetObjectsWithAnnotations
13735
</change>
13736
<change date="10 Apr 2003" version="v56">
13737
Remove confusing parenthetical statement in GetObjectsWithAnnotations
13738
</change>
13739
<change date="13 Apr 2003" version="v58">
13740
Replace jclass/jmethodID representation of method with simply jmethodID;
13741
Pass JvmtiEnv* as first arg of every event; remove JNIEnv* where inappropriate.
13742
Replace can_access_frames with can_access_local_variables; remove from purely stack access.
13743
Use can_get_synthetic_attribute; fix description.
13744
Clarify that zero length arrays must be deallocated.
13745
Clarify RelinquishCapabilities.
13746
Generalize JVMTI_ERROR_VM_DEAD to JVMTI_ERROR_WRONG_PHASE.
13747
</change>
13748
<change date="27 Apr 2003" version="v59">
13749
Remove lingering indirect references to OBSOLETE_METHOD_ID.
13750
</change>
13751
<change date="4 May 2003" version="v60">
13752
Allow DestroyRawMonitor during OnLoad.
13753
</change>
13754
<change date="7 May 2003" version="v61">
13755
Added not monitor owner error return to DestroyRawMonitor.
13756
</change>
13757
<change date="13 May 2003" version="v62">
13758
Clarify semantics of raw monitors.
13759
Change flags on <code>GetThreadStatus</code>.
13760
<code>GetClassLoader</code> return NULL for the bootstrap class loader.
13761
Add <code>GetClassName</code> issue.
13762
Define local variable signature.
13763
Disallow zero in annotations array of <code>GetObjectsWithAnnotations</code>.
13764
Remove over specification in <code>GetObjectsWithAnnotations</code>.
13765
Elide <code>SetAllocationHooks</code>.
13766
Elide <code>SuspendAllThreads</code>.
13767
</change>
13768
<change date="14 May 2003" version="v63">
13769
Define the data type <code>jvmtiEventCallbacks</code>.
13770
Zero length allocations return NULL.
13771
Keep SetAllocationHooks in JVMDI, but remove from <jvmti/>.
13772
Add JVMTI_THREAD_STATUS_FLAG_INTERRUPTED.
13773
</change>
13774
<change date="15 May 2003" version="v64">
13775
Better wording, per review.
13776
</change>
13777
<change date="15 May 2003" version="v65">
13778
First Alpha.
13779
Make jmethodID and jfieldID unique, jclass not used.
13780
</change>
13781
<change date="27 May 2003" version="v66">
13782
Fix minor XSLT errors.
13783
</change>
13784
<change date="13 June 2003" version="v67">
13785
Undo making jfieldID unique (jmethodID still is).
13786
</change>
13787
<change date="17 June 2003" version="v68">
13788
Changes per June 11th Expert Group meeting --
13789
Overhaul Heap functionality: single callback,
13790
remove GetHeapRoots, add reachable iterators,
13791
and rename "annotation" to "tag".
13792
NULL thread parameter on most functions is current
13793
thread.
13794
Add timers.
13795
Remove ForceExit.
13796
Add GetEnvironmentLocalStorage.
13797
Add verbose flag and event.
13798
Add AddToBootstrapClassLoaderSearch.
13799
Update ClassFileLoadHook.
13800
</change>
13801
<change date="18 June 2003" version="v69">
13802
Clean up issues sections.
13803
Rename GetClassName back to GetClassSignature and
13804
fix description.
13805
Add generic signature to GetClassSignature,
13806
GetFieldSignature, GetMethodSignature, and
13807
GetLocalVariableTable.
13808
Elide EstimateCostOfCapabilities.
13809
Clarify that the system property functions operate
13810
on the VM view of system properties.
13811
Clarify Agent_OnLoad.
13812
Remove "const" from JNIEnv* in events.
13813
Add metadata accessors.
13814
</change>
13815
<change date="18 June 2003" version="v70">
13816
Add start_depth to GetStackTrace.
13817
Move system properties to a new category.
13818
Add GetObjectSize.
13819
Remove "X" from command line flags.
13820
XML, HTML, and spell check corrections.
13821
</change>
13822
<change date="19 June 2003" version="v71">
13823
Fix JVMTI_HEAP_ROOT_THREAD to be 6.
13824
Make each synopsis match the function name.
13825
Fix unclear wording.
13826
</change>
13827
<change date="26 June 2003" version="v72">
13828
SetThreadLocalStorage and SetEnvironmentLocalStorage should allow value
13829
to be set to NULL.
13830
NotifyFramePop, GetFrameLocationm and all the local variable operations
13831
needed to have their wording about frames fixed.
13832
Grammar and clarity need to be fixed throughout.
13833
Capitalization and puntuation need to be consistent.
13834
Need micro version number and masks for accessing major, minor, and micro.
13835
The error code lists should indicate which must be returned by
13836
an implementation.
13837
The command line properties should be visible in the properties functions.
13838
Disallow popping from the current thread.
13839
Allow implementations to return opaque frame error when they cannot pop.
13840
The NativeMethodBind event should be sent during any phase.
13841
The DynamicCodeGenerated event should be sent during any phase.
13842
The following functions should be allowed to operate before VMInit:
13843
Set/GetEnvironmentLocalStorage
13844
GetMethodDeclaringClass
13845
GetClassSignature
13846
GetClassModifiers
13847
IsInterface
13848
IsArrayClass
13849
GetMethodName
13850
GetMethodModifiers
13851
GetMaxLocals
13852
GetArgumentsSize
13853
GetLineNumberTable
13854
GetMethodLocation
13855
IsMethodNative
13856
IsMethodSynthetic.
13857
Other changes (to XSL):
13858
Argument description should show asterisk after not before pointers.
13859
NotifyFramePop, GetFrameLocationm and all the local variable operations
13860
should hsve the NO_MORE_FRAMES error added.
13861
Not alive threads should have a different error return than invalid thread.
13862
</change>
13863
<change date="7 July 2003" version="v73">
13864
VerboseOutput event was missing message parameter.
13865
Minor fix-ups.
13866
</change>
13867
<change date="14 July 2003" version="v74">
13868
Technical Publications Department corrections.
13869
Allow thread and environment local storage to be set to NULL.
13870
</change>
13871
<change date="23 July 2003" version="v75">
13872
Use new Agent_OnLoad rather than overloaded JVM_OnLoad.
13873
Add JNICALL to callbacks (XSL).
13874
Document JNICALL requirement for both events and callbacks (XSL).
13875
Restrict RedefineClasses to methods and attributes.
13876
Elide the VerboseOutput event.
13877
VMObjectAlloc: restrict when event is sent and remove method parameter.
13878
Finish loose ends from Tech Pubs edit.
13879
</change>
13880
<change date="24 July 2003" version="v76">
13881
Change ClassFileLoadHook event to send the class instead of a boolean of redefine.
13882
</change>
13883
<change date="24 July 2003" version="v77">
13884
XML fixes.
13885
Minor text clarifications and corrections.
13886
</change>
13887
<change date="24 July 2003" version="v78">
13888
Remove GetExceptionHandlerTable and GetThrownExceptions from <jvmti/>.
13889
Clarify that stack frames are JVM Spec frames.
13890
Split can_get_source_info into can_get_source_file_name, can_get_line_numbers,
13891
and can_get_source_debug_extension.
13892
PopFrame cannot have a native calling method.
13893
Removed incorrect statement in GetClassloaderClasses
13894
(see <vmspec chapter="4.4"/>).
13895
</change>
13896
<change date="24 July 2003" version="v79">
13897
XML and text fixes.
13898
Move stack frame description into Stack Frame category.
13899
</change>
13900
<change date="26 July 2003" version="v80">
13901
Allow NULL (means bootstrap loader) for GetClassloaderClasses.
13902
Add new heap reference kinds for references from classes.
13903
Add timer information struct and query functions.
13904
Add AvailableProcessors.
13905
Rename GetOtherThreadCpuTime to GetThreadCpuTime.
13906
Explicitly add JVMTI_ERROR_INVALID_THREAD and JVMTI_ERROR_THREAD_NOT_ALIVE
13907
to SetEventNotification mode.
13908
Add initial thread to the VM_INIT event.
13909
Remove platform assumptions from AddToBootstrapClassLoaderSearch.
13910
</change>
13911
<change date="26 July 2003" version="v81">
13912
Grammar and clarity changes per review.
13913
</change>
13914
<change date="27 July 2003" version="v82">
13915
More grammar and clarity changes per review.
13916
Add Agent_OnUnload.
13917
</change>
13918
<change date="28 July 2003" version="v83">
13919
Change return type of Agent_OnUnload to void.
13920
</change>
13921
<change date="28 July 2003" version="v84">
13922
Rename JVMTI_REFERENCE_ARRAY to JVMTI_REFERENCE_ARRAY_ELEMENT.
13923
</change>
13924
<change date="28 July 2003" version="v85">
13925
Steal java.lang.Runtime.availableProcessors() wording for
13926
AvailableProcessors().
13927
Guarantee that zero will never be an event ID.
13928
Remove some issues which are no longer issues.
13929
Per review, rename and more completely document the timer
13930
information functions.
13931
</change>
13932
<change date="29 July 2003" version="v86">
13933
Non-spec visible change to XML controlled implementation:
13934
SetThreadLocalStorage must run in VM mode.
13935
</change>
13936
<change date="5 August 2003" version="0.1.87">
13937
Add GetErrorName.
13938
Add varargs warning to jvmtiExtensionEvent.
13939
Remove "const" on the jvmtiEnv* of jvmtiExtensionEvent.
13940
Remove unused can_get_exception_info capability.
13941
Pass jvmtiEnv* and JNIEnv* to the jvmtiStartFunction.
13942
Fix jvmtiExtensionFunctionInfo.func declared type.
13943
Extension function returns error code.
13944
Use new version numbering.
13945
</change>
13946
<change date="5 August 2003" version="0.2.88">
13947
Remove the ClassUnload event.
13948
</change>
13949
<change date="8 August 2003" version="0.2.89">
13950
Heap reference iterator callbacks return an enum that
13951
allows outgoing object references to be ignored.
13952
Allow JNIEnv as a param type to extension events/functions.
13953
</change>
13954
<change date="15 August 2003" version="0.2.90">
13955
Fix a typo.
13956
</change>
13957
<change date="2 September 2003" version="0.2.91">
13958
Remove all metadata functions: GetClassMetadata,
13959
GetFieldMetadata, and GetMethodMetadata.
13960
</change>
13961
<change date="1 October 2003" version="0.2.92">
13962
Mark the functions Allocate. Deallocate, RawMonitor*,
13963
SetEnvironmentLocalStorage, and GetEnvironmentLocalStorage
13964
as safe for use in heap callbacks and GC events.
13965
</change>
13966
<change date="24 November 2003" version="0.2.93">
13967
Add pass through opaque user data pointer to heap iterate
13968
functions and callbacks.
13969
In the CompiledMethodUnload event, send the code address.
13970
Add GarbageCollectionOccurred event.
13971
Add constant pool reference kind.
13972
Mark the functions CreateRawMonitor and DestroyRawMonitor
13973
as safe for use in heap callbacks and GC events.
13974
Clarify: VMDeath, GetCurrentThreadCpuTimerInfo,
13975
GetThreadCpuTimerInfo, IterateOverReachableObjects,
13976
IterateOverObjectsReachableFromObject, GetTime and
13977
JVMTI_ERROR_NULL_POINTER.
13978
Add missing errors to: GenerateEvents and
13979
AddToBootstrapClassLoaderSearch.
13980
Fix description of ClassFileLoadHook name parameter.
13981
In heap callbacks and GC/ObjectFree events, specify
13982
that only explicitly allowed functions can be called.
13983
Allow GetCurrentThreadCpuTimerInfo, GetCurrentThreadCpuTime,
13984
GetTimerInfo, and GetTime during callback.
13985
Allow calling SetTag/GetTag during the onload phase.
13986
SetEventNotificationMode, add: error attempted inappropriate
13987
thread level control.
13988
Remove jvmtiExceptionHandlerEntry.
13989
Fix handling of native methods on the stack --
13990
location_ptr param of GetFrameLocation, remove
13991
JVMTI_ERROR_OPAQUE_FRAME from GetFrameLocation,
13992
jvmtiFrameInfo.location, and jlocation.
13993
Remove typo (from JVMPI) implying that the MonitorWaited
13994
event is sent on sleep.
13995
</change>
13996
<change date="25 November 2003" version="0.2.94">
13997
Clarifications and typos.
13998
</change>
13999
<change date="3 December 2003" version="0.2.95">
14000
Allow NULL user_data in heap iterators.
14001
</change>
14002
<change date="28 January 2004" version="0.2.97">
14003
Add GetThreadState, deprecate GetThreadStatus.
14004
</change>
14005
<change date="29 January 2004" version="0.2.98">
14006
INVALID_SLOT and TYPE_MISMATCH errors should be optional.
14007
</change>
14008
<change date="12 February 2004" version="0.2.102">
14009
Remove MonitorContendedExit.
14010
Added JNIEnv parameter to VMObjectAlloc.
14011
Clarified definition of class_tag and referrer_index
14012
parameters to heap callbacks.
14013
</change>
14014
<change date="16 Febuary 2004" version="0.2.103">
14015
Document JAVA_TOOL_OPTIONS.
14016
</change>
14017
<change date="17 Febuary 2004" version="0.2.105">
14018
Divide start phase into primordial and start.
14019
Add VMStart event
14020
Change phase associations of functions and events.
14021
</change>
14022
<change date="18 Febuary 2004" version="0.3.6">
14023
Elide deprecated GetThreadStatus.
14024
Bump minor version, subtract 100 from micro version
14025
</change>
14026
<change date="18 Febuary 2004" version="0.3.7">
14027
Document that timer nanosecond values are unsigned.
14028
Clarify text having to do with native methods.
14029
</change>
14030
<change date="19 Febuary 2004" version="0.3.8">
14031
Fix typos.
14032
Remove elided deprecated GetThreadStatus.
14033
</change>
14034
<change date="23 Febuary 2004" version="0.3.9">
14035
Require NotifyFramePop to act on suspended threads.
14036
</change>
14037
<change date="24 Febuary 2004" version="0.3.10">
14038
Add capabilities
14039
(<internallink id="jvmtiCapabilities.can_redefine_any_class"
14040
><code>can_redefine_any_class</code></internallink>
14041
and
14042
<internallink id="jvmtiCapabilities.can_generate_all_class_hook_events"
14043
><code>can_generate_all_class_hook_events</code></internallink>)
14044
and an error (<errorlink id="JVMTI_ERROR_UNMODIFIABLE_CLASS"></errorlink>)
14045
which allow some classes to be unmodifiable.
14046
</change>
14047
<change date="28 Febuary 2004" version="0.3.11">
14048
Add JVMTI_ERROR_MUST_POSSESS_CAPABILITY to SetEventNotificationMode.
14049
</change>
14050
<change date="8 March 2004" version="0.3.12">
14051
Clarified CompiledMethodUnload so that it is clear the event
14052
may be posted after the class has been unloaded.
14053
</change>
14054
<change date="5 March 2004" version="0.3.13">
14055
Change the size parameter of VMObjectAlloc to jlong to match GetObjectSize.
14056
</change>
14057
<change date="13 March 2004" version="0.3.14">
14058
Added guideline for the use of the JNI FindClass function in event
14059
callback functions.
14060
</change>
14061
<change date="15 March 2004" version="0.3.15">
14062
Add GetAllStackTraces and GetThreadListStackTraces.
14063
</change>
14064
<change date="19 March 2004" version="0.3.16">
14065
ClassLoad and ClassPrepare events can be posted during start phase.
14066
</change>
14067
<change date="25 March 2004" version="0.3.17">
14068
Add JVMTI_ERROR_NATIVE_METHOD to GetLineNumberTable, GetLocalVariableTable,
14069
GetMaxLocals, GetArgumentsSize, GetMethodLocation, GetBytecodes.
14070
</change>
14071
<change date="29 March 2004" version="0.3.18">
14072
Return the timer kind in the timer information structure.
14073
</change>
14074
<change date="31 March 2004" version="0.3.19">
14075
Spec clarifications:
14076
JVMTI_THREAD_STATE_IN_NATIVE might not include JNI or <jvmti/>.
14077
ForceGarbageCollection does not run finalizers.
14078
The context of the specification is the Java platform.
14079
Warn about early instrumentation.
14080
</change>
14081
<change date="1 April 2004" version="0.3.20">
14082
Refinements to the above clarifications and
14083
Clarify that an error returned by Agent_OnLoad terminates the VM.
14084
</change>
14085
<change date="1 April 2004" version="0.3.21">
14086
Array class creation does not generate a class load event.
14087
</change>
14088
<change date="7 April 2004" version="0.3.22">
14089
Align thread state hierarchy more closely with java.lang.Thread.State.
14090
</change>
14091
<change date="12 April 2004" version="0.3.23">
14092
Clarify the documentation of thread state.
14093
</change>
14094
<change date="19 April 2004" version="0.3.24">
14095
Remove GarbageCollectionOccurred event -- can be done by agent.
14096
</change>
14097
<change date="22 April 2004" version="0.3.25">
14098
Define "command-line option".
14099
</change>
14100
<change date="29 April 2004" version="0.3.26">
14101
Describe the intended use of bytecode instrumentation.
14102
Fix description of extension event first parameter.
14103
</change>
14104
<change date="30 April 2004" version="0.3.27">
14105
Clarification and typos.
14106
</change>
14107
<change date="18 May 2004" version="0.3.28">
14108
Remove DataDumpRequest event.
14109
</change>
14110
<change date="18 May 2004" version="0.3.29">
14111
Clarify RawMonitorWait with zero timeout.
14112
Clarify thread state after RunAgentThread.
14113
</change>
14114
<change date="24 May 2004" version="0.3.30">
14115
Clean-up: fix bad/old links, etc.
14116
</change>
14117
<change date="30 May 2004" version="0.3.31">
14118
Clarifications including:
14119
All character strings are modified UTF-8.
14120
Agent thread visibiity.
14121
Meaning of obsolete method version.
14122
Thread invoking heap callbacks,
14123
</change>
14124
<change date="1 June 2004" version="1.0.32">
14125
Bump major.minor version numbers to "1.0".
14126
</change>
14127
<change date="2 June 2004" version="1.0.33">
14128
Clarify interaction between ForceGarbageCollection
14129
and ObjectFree.
14130
</change>
14131
<change date="6 June 2004" version="1.0.34">
14132
Restrict AddToBootstrapClassLoaderSearch and
14133
SetSystemProperty to the OnLoad phase only.
14134
</change>
14135
<change date="11 June 2004" version="1.0.35">
14136
Fix typo in SetTag.
14137
</change>
14138
<change date="18 June 2004" version="1.0.36">
14139
Fix trademarks.
14140
Add missing parameter in example GetThreadState usage.
14141
</change>
14142
<change date="4 August 2004" version="1.0.37">
14143
Copyright updates.
14144
</change>
14145
<change date="5 November 2004" version="1.0.38">
14146
Add missing function table layout.
14147
Add missing description of C++ member function format of functions.
14148
Clarify that name in CFLH can be NULL.
14149
Released as part of <tm>J2SE</tm> 5.0.
14150
</change>
14151
<change date="24 April 2005" version="1.1.47">
14152
Bump major.minor version numbers to "1.1".
14153
Add ForceEarlyReturn* functions.
14154
Add GetOwnedMonitorStackDepthInfo function.
14155
Add GetCurrentThread function.
14156
Add "since" version marker.
14157
Add AddToSystemClassLoaderSearch.
14158
Allow AddToBootstrapClassLoaderSearch be used in live phase.
14159
Fix historic rubbish in the descriptions of the heap_object_callback
14160
parameter of IterateOverHeap and IterateOverInstancesOfClass functions;
14161
disallow NULL for this parameter.
14162
Clarify, correct and make consistent: wording about current thread,
14163
opaque frames and insufficient number of frames in PopFrame.
14164
Consistently use "current frame" rather than "topmost".
14165
Clarify the JVMTI_ERROR_TYPE_MISMATCH errors in GetLocal* and SetLocal*
14166
by making them compatible with those in ForceEarlyReturn*.
14167
Many other clarifications and wording clean ups.
14168
</change>
14169
<change date="25 April 2005" version="1.1.48">
14170
Add GetConstantPool.
14171
Switch references to the first edition of the VM Spec, to the seconds edition.
14172
</change>
14173
<change date="26 April 2005" version="1.1.49">
14174
Clarify minor/major version order in GetConstantPool.
14175
</change>
14176
<change date="26 April 2005" version="1.1.50">
14177
Add SetNativeMethodPrefix and SetNativeMethodPrefixes.
14178
Reassign GetOwnedMonitorStackDepthInfo to position 153.
14179
Break out Class Loader Search in its own documentation category.
14180
Deal with overly long lines in XML source.
14181
</change>
14182
<change date="29 April 2005" version="1.1.51">
14183
Allow agents be started in the live phase.
14184
Added paragraph about deploying agents.
14185
</change>
14186
<change date="30 April 2005" version="1.1.52">
14187
Add specification description to SetNativeMethodPrefix(es).
14188
Better define the conditions on GetConstantPool.
14189
</change>
14190
<change date="30 April 2005" version="1.1.53">
14191
Break out the GetClassVersionNumber function from GetConstantPool.
14192
Clean-up the references to the VM Spec.
14193
</change>
14194
<change date="1 May 2005" version="1.1.54">
14195
Allow SetNativeMethodPrefix(es) in any phase.
14196
Add clarifications about the impact of redefinition on GetConstantPool.
14197
</change>
14198
<change date="2 May 2005" version="1.1.56">
14199
Various clarifications to SetNativeMethodPrefix(es).
14200
</change>
14201
<change date="2 May 2005" version="1.1.57">
14202
Add missing performance warning to the method entry event.
14203
</change>
14204
<change date="5 May 2005" version="1.1.58">
14205
Remove internal JVMDI support.
14206
</change>
14207
<change date="8 May 2005" version="1.1.59">
14208
Add <functionlink id="RetransformClasses"/>.
14209
Revamp the bytecode instrumentation documentation.
14210
Change <functionlink id="IsMethodObsolete"/> to no longer
14211
require the can_redefine_classes capability.
14212
</change>
14213
<change date="11 May 2005" version="1.1.63">
14214
Clarifications for retransformation.
14215
</change>
14216
<change date="11 May 2005" version="1.1.64">
14217
Clarifications for retransformation, per review.
14218
Lock "retransformation (in)capable" at class load enable time.
14219
</change>
14220
<change date="4 June 2005" version="1.1.67">
14221
Add new heap functionity which supports reporting primitive values,
14222
allows setting the referrer tag, and has more powerful filtering:
14223
FollowReferences, IterateThroughHeap, and their associated
14224
callbacks, structs, enums, and constants.
14225
</change>
14226
<change date="4 June 2005" version="1.1.68">
14227
Clarification.
14228
</change>
14229
<change date="6 June 2005" version="1.1.69">
14230
FollowReferences, IterateThroughHeap: Put callbacks in a struct;
14231
Add missing error codes; reduce bits in the visit control flags.
14232
</change>
14233
<change date="14 June 2005" version="1.1.70">
14234
More on new heap functionity: spec clean-up per review.
14235
</change>
14236
<change date="15 June 2005" version="1.1.71">
14237
More on new heap functionity: Rename old heap section to Heap (1.0).
14238
</change>
14239
<change date="21 June 2005" version="1.1.72">
14240
Fix typos.
14241
</change>
14242
<change date="27 June 2005" version="1.1.73">
14243
Make referrer info structure a union.
14244
</change>
14245
<change date="9 September 2005" version="1.1.74">
14246
In new heap functions:
14247
Add missing superclass reference kind.
14248
Use a single scheme for computing field indexes.
14249
Remove outdated references to struct based referrer info.
14250
</change>
14251
<change date="12 September 2005" version="1.1.75">
14252
Don't callback during FollowReferences on frivolous java.lang.Object superclass.
14253
</change>
14254
<change date="13 September 2005" version="1.1.76">
14255
In string primitive callback, length now Unicode length.
14256
In array and string primitive callbacks, value now "const".
14257
Note possible compiler impacts on setting JNI function table.
14258
</change>
14259
<change date="13 September 2005" version="1.1.77">
14260
GetClassVersionNumbers() and GetConstantPool() should return
14261
error on array or primitive class.
14262
</change>
14263
<change date="14 September 2005" version="1.1.78">
14264
Grammar fixes.
14265
</change>
14266
<change date="26 September 2005" version="1.1.79">
14267
Add IsModifiableClass query.
14268
</change>
14269
<change date="9 February 2006" version="1.1.81">
14270
Add referrer_class_tag parameter to jvmtiHeapReferenceCallback.
14271
</change>
14272
<change date="13 February 2006" version="1.1.82">
14273
Doc fixes: update can_redefine_any_class to include retransform.
14274
Clarify that exception events cover all Throwables.
14275
In GetStackTrace, no test is done for start_depth too big if start_depth is zero,
14276
Clarify fields reported in Primitive Field Callback -- static vs instance.
14277
Repair confusing names of heap types, including callback names.
14278
Require consistent usage of stack depth in the face of thread launch methods.
14279
Note incompatibility of <jvmti/> memory management with other systems.
14280
</change>
14281
<change date="14 February 2006" version="1.1.85">
14282
Fix typos and missing renames.
14283
</change>
14284
<change date="13 March 2006" version="1.1.86">
14285
Clarify that jmethodIDs and jfieldIDs can be saved.
14286
Clarify that Iterate Over Instances Of Class includes subclasses.
14287
</change>
14288
<change date="14 March 2006" version="1.1.87">
14289
Better phrasing.
14290
</change>
14291
<change date="16 March 2006" version="1.1.88">
14292
Match the referrer_index for static fields in Object Reference Callback
14293
with the Reference Implementation (and all other known implementations);
14294
that is, make it match the definition for instance fields.
14295
In GetThreadListStackTraces, add JVMTI_ERROR_INVALID_THREAD to cover
14296
an invalid thread in the list; and specify that not started threads
14297
return empty stacks.
14298
</change>
14299
<change date="17 March 2006" version="1.1.89">
14300
Typo.
14301
</change>
14302
<change date="25 March 2006" version="1.1.90">
14303
Typo.
14304
</change>
14305
<change date="6 April 2006" version="1.1.91">
14306
Remove restrictions on AddToBootstrapClassLoaderSearch and
14307
AddToSystemClassLoaderSearch.
14308
</change>
14309
<change date="1 May 2006" version="1.1.93">
14310
Changed spec to return -1 for monitor stack depth for the
14311
implementation which can not determine stack depth.
14312
</change>
14313
<change date="3 May 2006" version="1.1.94">
14314
Corrections for readability and accuracy courtesy of Alan Pratt of IBM.
14315
List the object relationships reported in FollowReferences.
14316
</change>
14317
<change date="5 May 2006" version="1.1.95">
14318
Clarify the object relationships reported in FollowReferences.
14319
</change>
14320
<change date="28 June 2006" version="1.1.98">
14321
Clarify DisposeEnvironment; add warning.
14322
Fix typos in SetLocalXXX "retrieve" => "set".
14323
Clarify that native method prefixes must remain set while used.
14324
Clarify that exactly one Agent_OnXXX is called per agent.
14325
Clarify that library loading is independent from start-up.
14326
Remove ambiguous reference to Agent_OnLoad in the Agent_OnUnload spec.
14327
</change>
14328
<change date="31 July 2006" version="1.1.99">
14329
Clarify the interaction between functions and exceptions.
14330
Clarify and give examples of field indices.
14331
Remove confusing "That is" sentence from MonitorWait and MonitorWaited events.
14332
Update links to point to Java 6.
14333
</change>
14334
<change date="6 August 2006" version="1.1.102">
14335
Add ResourceExhaustedEvent.
14336
</change>
14337
<change date="11 October 2012" version="1.2.2">
14338
Fixed the "HTTP" and "Missing Anchor" errors reported by the LinkCheck tool.
14339
</change>
14340
<change date="19 June 2013" version="1.2.3">
14341
Added support for statically linked agents.
14342
</change>
14343
</changehistory>
14344
14345
</specification>
14346
<!-- Keep this comment at the end of the file
14347
Local variables:
14348
mode: sgml
14349
sgml-omittag:t
14350
sgml-shorttag:t
14351
sgml-namecase-general:t
14352
sgml-general-insert-case:lower
14353
sgml-minimize-attributes:nil
14354
sgml-always-quote-attributes:t
14355
sgml-indent-step:2
14356
sgml-indent-data:t
14357
sgml-parent-document:nil
14358
sgml-exposed-tags:nil
14359
sgml-local-catalogs:nil
14360
sgml-local-ecat-files:nil
14361
End:
14362
-->
14363
14364