Path: blob/aarch64-shenandoah-jdk8u272-b10/jdk/src/share/demo/jvmti/heapViewer/README.txt
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#1# Copyright (c) 2004, 2007, Oracle and/or its affiliates. All rights reserved.2#3# Redistribution and use in source and binary forms, with or without4# modification, are permitted provided that the following conditions5# are met:6#7# - Redistributions of source code must retain the above copyright8# notice, this list of conditions and the following disclaimer.9#10# - Redistributions in binary form must reproduce the above copyright11# notice, this list of conditions and the following disclaimer in the12# documentation and/or other materials provided with the distribution.13#14# - Neither the name of Oracle nor the names of its15# contributors may be used to endorse or promote products derived16# from this software without specific prior written permission.17#18# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS19# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,20# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR21# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR22# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,23# EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,24# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR25# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF26# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING27# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS28# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.29#3031heapViewer3233This agent library demonstrates how to get an easy view of the34heap in terms of total object count and space used.35It uses GetLoadedClasses(), SetTag(), and IterateThroughHeap()36to count up all the objects of all the current loaded classes.37The heap dump will happen at the event JVMTI_EVENT_VM_DEATH, or the38event JVMTI_EVENT_DATA_DUMP_REQUEST.3940It also demonstrates some more robust agent error handling using41GetErrorName(),4243Using the heap iterate functions, lots of statistics can be generated44without resorting to using Byte Code Instrumentation (BCI).4546You can use this agent library as follows:4748java -agentlib:heapViewer ...4950To get help on the available options try:5152java -agentlib:heapViewer=help5354See ${JAVA_HOME}/demo/jvmti/index.html for help running and building agents.55565758