attach002aAgent00.cpp

/*
 * Copyright (c) 2007, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <jni.h>
#include <jvmti.h>
#include <aod.h>
#include <jvmti_aod.h>

extern "C" {

/*
 * Expected agent work scenario:
 *  - during initialization agent enables events VMObjectAlloc
 *  - agent receives VMObjectAlloc event for instance of InterruptedException,
 *    redefines class InterruptedException and finishes work
 */

#define REDEFINED_CLASS_NAME "Ljava/lang/InterruptedException;"
#define REDEFINED_CLASS_FILE_NAME "java/lang/InterruptedException"

static Options* options = NULL;
static const char* agentName;

static jvmtiEvent testEvents[] = { JVMTI_EVENT_VM_OBJECT_ALLOC };

static const int testEventsNumber = 1;

void JNICALL vmObjectAllocHandler(jvmtiEnv * jvmti,
        JNIEnv * jni,
        jthread thread,
        jobject object,
        jclass object_class,
        jlong size) {
    char className[MAX_STRING_LENGTH];

    if (!nsk_jvmti_aod_getClassName(jvmti, object_class, className)) {
        nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, 0, jvmti, jni);
        return;
    }

    NSK_DISPLAY2("%s: ObjectAlloc event received (object class: %s)\n", agentName, className);

    if (!strcmp(className, REDEFINED_CLASS_NAME)) {
        int success = 1;

        if (!NSK_VERIFY(nsk_jvmti_aod_redefineClass(options, jvmti, object_class, REDEFINED_CLASS_FILE_NAME))) {
            NSK_COMPLAIN1("%s: failed to redefine class\n", agentName);
            success = 0;
        }

        nsk_jvmti_aod_disableEventsAndFinish(agentName, testEvents, testEventsNumber, success, jvmti, jni);
    }
}

#ifdef STATIC_BUILD
JNIEXPORT jint JNI_OnLoad_attach002aAgent00(JavaVM *jvm, char *options, void *reserved) {
    return JNI_VERSION_1_8;
}
#endif

JNIEXPORT jint JNICALL
#ifdef STATIC_BUILD
Agent_OnAttach_attach002aAgent00(JavaVM *vm, char *optionsString, void *reserved)
#else
Agent_OnAttach(JavaVM *vm, char *optionsString, void *reserved)
#endif
{
    jvmtiEventCallbacks eventCallbacks;
    jvmtiCapabilities caps;
    jvmtiEnv* jvmti = NULL;
    JNIEnv* jni = NULL;

    options = (Options*) nsk_aod_createOptions(optionsString);
    if (!NSK_VERIFY(options != NULL))
        return JNI_ERR;

    agentName = nsk_aod_getOptionValue(options, NSK_AOD_AGENT_NAME_OPTION);

    jni = (JNIEnv*) nsk_aod_createJNIEnv(vm);
    if (jni == NULL)
        return NSK_FALSE;

    jvmti = nsk_jvmti_createJVMTIEnv(vm, reserved);
    if (!NSK_VERIFY(jvmti != NULL))
        return JNI_ERR;

    memset(&caps, 0, sizeof(caps));
    caps.can_redefine_classes = 1;
    caps.can_generate_vm_object_alloc_events = 1;
    if (!NSK_JVMTI_VERIFY(jvmti->AddCapabilities(&caps))) {
        return JNI_ERR;
    }

    memset(&eventCallbacks,0, sizeof(eventCallbacks));
    eventCallbacks.VMObjectAlloc = vmObjectAllocHandler;
    if (!NSK_JVMTI_VERIFY(jvmti->SetEventCallbacks(&eventCallbacks, sizeof(eventCallbacks)))) {
        return JNI_ERR;
    }

    if (!(nsk_jvmti_aod_enableEvents(jvmti, testEvents, testEventsNumber))) {
        return JNI_ERR;
    }

    NSK_DISPLAY1("%s: initialization was done\n", agentName);

    if (!NSK_VERIFY(nsk_aod_agentLoaded(jni, agentName)))
        return JNI_ERR;

    return JNI_OK;
}

}