blob: c03b2942f9d678a3669a4f308dba561c6a868f8f [file] [log] [blame]
<!--
* Copyright (c) 2017, 2018 IBM Corp. and others
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/legal/epl-2.0/ or the Apache
* License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the
* following Secondary Licenses when the conditions for such
* availability set forth in the Eclipse Public License, v. 2.0
* are satisfied: GNU General Public License, version 2 with
* the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH
* Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
-->
<!DOCTYPE html>
<html lang="en" class="no-js">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<meta name="description" content="Eclipse OpenJ9 documentation">
<link rel="canonical" href="https://www.eclipse.org/openj9/docs/shrc/">
<meta name="lang:clipboard.copy" content="">
<meta name="lang:clipboard.copied" content="">
<meta name="lang:search.language" content="">
<meta name="lang:search.pipeline.stopwords" content="">
<meta name="lang:search.pipeline.trimmer" content="">
<meta name="lang:search.result.none" content="">
<meta name="lang:search.result.one" content="">
<meta name="lang:search.result.other" content="">
<meta name="lang:search.tokenizer" content="">
<link rel="shortcut icon" href="../cr/oj9logo_img9.ico">
<meta name="generator" content="mkdocs-0.17.2, mkdocs-material-2.6.3">
<title>Class data sharing - </title>
<link rel="stylesheet" href="../assets/stylesheets/application.9b572555.css">
<link rel="stylesheet" href="../assets/stylesheets/application-palette.6079476c.css">
<script src="../assets/javascripts/modernizr.1aa3b519.js"></script>
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,400i,700|Roboto+Mono">
<style>body,input{font-family:"Roboto","Helvetica Neue",Helvetica,Arial,sans-serif}code,kbd,pre{font-family:"Roboto Mono","Courier New",Courier,monospace}</style>
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
<link rel="stylesheet" href="../stylesheets/oj9.css">
</head>
<body dir="" data-md-color-primary="cyan" data-md-color-accent="cyan">
<svg class="md-svg">
<defs>
<svg xmlns="http://www.w3.org/2000/svg" width="416" height="448"
viewBox="0 0 416 448" id="github">
<path fill="currentColor" d="M160 304q0 10-3.125 20.5t-10.75 19-18.125
8.5-18.125-8.5-10.75-19-3.125-20.5 3.125-20.5 10.75-19 18.125-8.5
18.125 8.5 10.75 19 3.125 20.5zM320 304q0 10-3.125 20.5t-10.75
19-18.125 8.5-18.125-8.5-10.75-19-3.125-20.5 3.125-20.5 10.75-19
18.125-8.5 18.125 8.5 10.75 19 3.125 20.5zM360
304q0-30-17.25-51t-46.75-21q-10.25 0-48.75 5.25-17.75 2.75-39.25
2.75t-39.25-2.75q-38-5.25-48.75-5.25-29.5 0-46.75 21t-17.25 51q0 22 8
38.375t20.25 25.75 30.5 15 35 7.375 37.25 1.75h42q20.5 0
37.25-1.75t35-7.375 30.5-15 20.25-25.75 8-38.375zM416 260q0 51.75-15.25
82.75-9.5 19.25-26.375 33.25t-35.25 21.5-42.5 11.875-42.875 5.5-41.75
1.125q-19.5 0-35.5-0.75t-36.875-3.125-38.125-7.5-34.25-12.875-30.25-20.25-21.5-28.75q-15.5-30.75-15.5-82.75
0-59.25 34-99-6.75-20.5-6.75-42.5 0-29 12.75-54.5 27 0 47.5 9.875t47.25
30.875q36.75-8.75 77.25-8.75 37 0 70 8 26.25-20.5
46.75-30.25t47.25-9.75q12.75 25.5 12.75 54.5 0 21.75-6.75 42 34 40 34
99.5z" />
</svg>
</defs>
</svg>
<input class="md-toggle" data-md-toggle="drawer" type="checkbox" id="drawer">
<input class="md-toggle" data-md-toggle="search" type="checkbox" id="search">
<label class="md-overlay" data-md-component="overlay" for="drawer"></label>
<a href="#class-data-sharing" tabindex="1" class="md-skip">
</a>
<!--
* Copyright (c) 2017, 2018 IBM Corp. and others
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/legal/epl-2.0/ or the Apache
* License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the
* following Secondary Licenses when the conditions for such
* availability set forth in the Eclipse Public License, v. 2.0
* are satisfied: GNU General Public License, version 2 with
* the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH
* Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
-->
<header class="md-header" data-md-component="header">
<nav class="md-header-nav md-grid">
<div class="md-flex">
<div class="md-flex__cell md-flex__cell--shrink">
<a href="https://www.eclipse.org/openj9/docs" title=" " class="md-header-nav__button md-logo">
<img src="../cr/openj9_6b.png">
</a>
</div>
<div class="md-flex__cell md-flex__cell--shrink">
<label class="md-icon md-icon--menu md-header-nav__button" for="drawer"></label>
</div>
<div class="md-flex__cell md-flex__cell--stretch">
<div class="md-flex__ellipsis md-header-nav__title" data-md-component="title">
</div>
</div>
<div class="md-flex__cell md-flex__cell--shrink">
<label class="md-icon md-icon--search md-header-nav__button" for="search"></label>
<div class="md-search" data-md-component="search" role="dialog">
<label class="md-search__overlay" for="search"></label>
<div class="md-search__inner" role="search">
<form class="md-search__form" name="search">
<input type="text" class="md-search__input" name="query" placeholder="Search" autocapitalize="off" autocorrect="off" autocomplete="off" spellcheck="false" data-md-component="query" data-md-state="active">
<label class="md-icon md-search__icon" for="search"></label>
<button type="reset" class="md-icon md-search__icon" data-md-component="reset" tabindex="-1">
&#xE5CD;
</button>
</form>
<div class="md-search__output">
<div class="md-search__scrollwrap" data-md-scrollfix>
<div class="md-search-result" data-md-component="result">
<div class="md-search-result__meta">
</div>
<ol class="md-search-result__list"></ol>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="md-flex__cell md-flex__cell--shrink">
<div class="md-header-nav__source">
<a href="https://github.com/eclipse/openj9-docs/" title="Go to repository" class="md-source" data-md-source="github">
<div class="md-source__icon">
<svg viewBox="0 0 24 24" width="24" height="24">
<use xlink:href="#github" width="24" height="24"></use>
</svg>
</div>
<div class="md-source__repository">
GitHub
</div>
</a>
</div>
</div>
<!-- Eclipse Incubator link -->
<div class="md-flex__cell md-flex__cell--shrink">
<a href="http://wiki.eclipse.org/Development_Resources/Process_Guidelines/What_is_Incubation" target="_blank"><img class="egg" src="../cr/egg-incubation.png" alt="Eclipse Incubation"></a>
</div>
</div>
</nav>
</header>
<div class="md-container">
<main class="md-main">
<div class="md-main__inner md-grid" data-md-component="container">
<div class="md-sidebar md-sidebar--primary" data-md-component="navigation">
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--primary" data-md-level="0">
<label class="md-nav__title md-nav__title--site" for="drawer">
<span class="md-nav__button md-logo">
<img src="../cr/openj9_6b.png" width="24" height="24">
</span>
</label>
<div class="md-nav__source">
<a href="https://github.com/eclipse/openj9-docs/" title="Go to repository" class="md-source" data-md-source="github">
<div class="md-source__icon">
<svg viewBox="0 0 24 24" width="24" height="24">
<use xlink:href="#github" width="24" height="24"></use>
</svg>
</div>
<div class="md-source__repository">
GitHub
</div>
</a>
</div>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href=".." title="About" class="md-nav__link">
About
</a>
</li>
<li class="md-nav__item">
<a href="../introduction/" title="Introduction" class="md-nav__link">
Introduction
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-3" type="checkbox" id="nav-3">
<label class="md-nav__link" for="nav-3">
Release notes
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="1">
<label class="md-nav__title" for="nav-3">
Release notes
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../version0.10/" title="Version 0.10.0" class="md-nav__link">
Version 0.10.0
</a>
</li>
<li class="md-nav__item">
<a href="../version0.9/" title="Version 0.9.0" class="md-nav__link">
Version 0.9.0
</a>
</li>
<li class="md-nav__item">
<a href="../version0.8/" title="Version 0.8.0" class="md-nav__link">
Version 0.8.0
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../gc/" title="Garbage Collection" class="md-nav__link">
Garbage Collection
</a>
</li>
<li class="md-nav__item">
<a href="../jit/" title="JIT Compiler" class="md-nav__link">
JIT Compiler
</a>
</li>
<li class="md-nav__item">
<a href="../aot/" title="AOT Compiler" class="md-nav__link">
AOT Compiler
</a>
</li>
<li class="md-nav__item md-nav__item--active">
<input class="md-toggle md-nav__toggle" data-md-toggle="toc" type="checkbox" id="toc">
<label class="md-nav__link md-nav__link--active" for="toc">
Class data sharing
</label>
<a href="./" title="Class data sharing" class="md-nav__link md-nav__link--active">
Class data sharing
</a>
<nav class="md-nav md-nav--secondary">
<label class="md-nav__title" for="toc">On this page ...</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="#support-for-custom-class-loaders" title="Support for custom class loaders" class="md-nav__link">
Support for custom class loaders
</a>
</li>
<li class="md-nav__item">
<a href="#cache-utilities" title="Cache utilities" class="md-nav__link">
Cache utilities
</a>
</li>
<li class="md-nav__item">
<a href="#see-also" title="See also" class="md-nav__link">
See also
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-8" type="checkbox" id="nav-8">
<label class="md-nav__link" for="nav-8">
Diagnostics
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="1">
<label class="md-nav__title" for="nav-8">
Diagnostics
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../diag_overview/" title="Tools and data" class="md-nav__link">
Tools and data
</a>
</li>
<li class="md-nav__item">
<a href="../dump_javadump/" title="Java dump" class="md-nav__link">
Java dump
</a>
</li>
<li class="md-nav__item">
<a href="../dump_heapdump/" title="Heap dump" class="md-nav__link">
Heap dump
</a>
</li>
<li class="md-nav__item">
<a href="../dump_systemdump/" title="System dump" class="md-nav__link">
System dump
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-9" type="checkbox" id="nav-9">
<label class="md-nav__link" for="nav-9">
Command-line options
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="1">
<label class="md-nav__title" for="nav-9">
Command-line options
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../cmdline_specifying/" title="Specifying options" class="md-nav__link">
Specifying options
</a>
</li>
<li class="md-nav__item">
<a href="../cmdline_general/" title="Standard options" class="md-nav__link">
Standard options
</a>
</li>
<li class="md-nav__item">
<a href="../cmdline_migration/" title="Migrating to OpenJ9" class="md-nav__link">
Migrating to OpenJ9
</a>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-9-4" type="checkbox" id="nav-9-4">
<label class="md-nav__link" for="nav-9-4">
System property options
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="2">
<label class="md-nav__title" for="nav-9-4">
System property options
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../d_jvm_commands/" title="Using System properties" class="md-nav__link">
Using System properties
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmenableclasscaching/" title="-Dcom.ibm.enableClassCaching" class="md-nav__link">
-Dcom.ibm.enableClassCaching
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmenablelegacydumpsecurity/" title="-Dcom.ibm.enableLegacyDumpSecurity" class="md-nav__link">
-Dcom.ibm.enableLegacyDumpSecurity
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmenablelegacylogsecurity/" title="-Dcom.ibm.enableLegacyLogSecurity" class="md-nav__link">
-Dcom.ibm.enableLegacyLogSecurity
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmenablelegacytracesecurity/" title="-Dcom.ibm.enableLegacyTraceSecurity" class="md-nav__link">
-Dcom.ibm.enableLegacyTraceSecurity
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmlangmanagementosmxbeaniscputime100ns/" title="-Dcom.ibm.lang.management.OperatingSystemMXBean.isCpuTime100ns" class="md-nav__link">
-Dcom.ibm.lang.management.OperatingSystemMXBean.isCpuTime100ns
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmlangmanagementverbose/" title="-Dcom.ibm.lang.management.verbose" class="md-nav__link">
-Dcom.ibm.lang.management.verbose
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmtoolsattachdirectory/" title="-Dcom.ibm.tools.attach.directory" class="md-nav__link">
-Dcom.ibm.tools.attach.directory
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmtoolsattachdisplayname/" title="-Dcom.ibm.tools.attach.displayName" class="md-nav__link">
-Dcom.ibm.tools.attach.displayName
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmtoolsattachenable/" title="-Dcom.ibm.tools.attach.enable" class="md-nav__link">
-Dcom.ibm.tools.attach.enable
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmtoolsattachid/" title="-Dcom.ibm.tools.attach.id" class="md-nav__link">
-Dcom.ibm.tools.attach.id
</a>
</li>
<li class="md-nav__item">
<a href="../dcomibmtoolsattachtimeout/" title="-Dcom.ibm.tools.attach.timeout" class="md-nav__link">
-Dcom.ibm.tools.attach.timeout
</a>
</li>
<li class="md-nav__item">
<a href="../dfileencoding/" title="-Dfile.encoding" class="md-nav__link">
-Dfile.encoding
</a>
</li>
<li class="md-nav__item">
<a href="../djavacompiler/" title="-Djava.compiler" class="md-nav__link">
-Djava.compiler
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-9-5" type="checkbox" id="nav-9-5">
<label class="md-nav__link" for="nav-9-5">
JVM -X options
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="2">
<label class="md-nav__title" for="nav-9-5">
JVM -X options
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../x_jvm_commands/" title="Using -X options" class="md-nav__link">
Using -X options
</a>
</li>
<li class="md-nav__item">
<a href="../x/" title="-X" class="md-nav__link">
-X
</a>
</li>
<li class="md-nav__item">
<a href="../xaggressive/" title="-Xaggressive" class="md-nav__link">
-Xaggressive
</a>
</li>
<li class="md-nav__item">
<a href="../xalwaysclassgc/" title="-Xalwaysclassgc" class="md-nav__link">
-Xalwaysclassgc
</a>
</li>
<li class="md-nav__item">
<a href="../xaot/" title="-Xaot" class="md-nav__link">
-Xaot
</a>
</li>
<li class="md-nav__item">
<a href="../xargencoding/" title="-Xargencoding" class="md-nav__link">
-Xargencoding
</a>
</li>
<li class="md-nav__item">
<a href="../xbootclasspath/" title="-Xbootclasspath" class="md-nav__link">
-Xbootclasspath
</a>
</li>
<li class="md-nav__item">
<a href="../xceehdlr/" title="-XCEEHDLR" class="md-nav__link">
-XCEEHDLR
</a>
</li>
<li class="md-nav__item">
<a href="../xcheck/" title="-Xcheck" class="md-nav__link">
-Xcheck
</a>
</li>
<li class="md-nav__item">
<a href="../xclassgc/" title="-Xclassgc" class="md-nav__link">
-Xclassgc
</a>
</li>
<li class="md-nav__item">
<a href="../xcodecache/" title="-Xcodecache" class="md-nav__link">
-Xcodecache
</a>
</li>
<li class="md-nav__item">
<a href="../xcodecachetotal/" title="-Xcodecachetotal" class="md-nav__link">
-Xcodecachetotal
</a>
</li>
<li class="md-nav__item">
<a href="../xcomp/" title="-Xcomp" class="md-nav__link">
-Xcomp
</a>
</li>
<li class="md-nav__item">
<a href="../xcompactexplicitgc/" title="-Xcompactexplicitgc" class="md-nav__link">
-Xcompactexplicitgc
</a>
</li>
<li class="md-nav__item">
<a href="../xcompactgc/" title="-Xcompactgc" class="md-nav__link">
-Xcompactgc
</a>
</li>
<li class="md-nav__item">
<a href="../xcompilationthreads/" title="-XcompilationThreads" class="md-nav__link">
-XcompilationThreads
</a>
</li>
<li class="md-nav__item">
<a href="../xcompressedrefs/" title="-Xcompressedrefs" class="md-nav__link">
-Xcompressedrefs
</a>
</li>
<li class="md-nav__item">
<a href="../xconcurrentbackground/" title="-Xconcurrentbackground" class="md-nav__link">
-Xconcurrentbackground
</a>
</li>
<li class="md-nav__item">
<a href="../xconcurrentlevel/" title="-Xconcurrentlevel" class="md-nav__link">
-Xconcurrentlevel
</a>
</li>
<li class="md-nav__item">
<a href="../xconcurrentslack/" title="-Xconcurrentslack" class="md-nav__link">
-Xconcurrentslack
</a>
</li>
<li class="md-nav__item">
<a href="../xconmeter/" title="-Xconmeter" class="md-nav__link">
-Xconmeter
</a>
</li>
<li class="md-nav__item">
<a href="../xdiagnosticscollector/" title="-Xdiagnosticscollector" class="md-nav__link">
-Xdiagnosticscollector
</a>
</li>
<li class="md-nav__item">
<a href="../xenableexcessivegc/" title="-Xdisableexcessivegc" class="md-nav__link">
-Xdisableexcessivegc
</a>
</li>
<li class="md-nav__item">
<a href="../xenableexplicitgc/" title="-Xdisableexplicitgc" class="md-nav__link">
-Xdisableexplicitgc
</a>
</li>
<li class="md-nav__item">
<a href="../xdisablejavadump/" title="-Xdisablejavadump" class="md-nav__link">
-Xdisablejavadump
</a>
</li>
<li class="md-nav__item">
<a href="../xenablestringconstantgc/" title="-Xdisablestringconstantgc" class="md-nav__link">
-Xdisablestringconstantgc
</a>
</li>
<li class="md-nav__item">
<a href="../xdump/" title="-Xdump" class="md-nav__link">
-Xdump
</a>
</li>
<li class="md-nav__item">
<a href="../xenableexcessivegc/" title="-Xenableexcessivegc" class="md-nav__link">
-Xenableexcessivegc
</a>
</li>
<li class="md-nav__item">
<a href="../xenableexplicitgc/" title="-Xenableexplicitgc" class="md-nav__link">
-Xenableexplicitgc
</a>
</li>
<li class="md-nav__item">
<a href="../xenablestringconstantgc/" title="-Xenablestringconstantgc" class="md-nav__link">
-Xenablestringconstantgc
</a>
</li>
<li class="md-nav__item">
<a href="../xfastresolve/" title="-Xfastresolve" class="md-nav__link">
-Xfastresolve
</a>
</li>
<li class="md-nav__item">
<a href="../xfuture/" title="-Xfuture" class="md-nav__link">
-Xfuture
</a>
</li>
<li class="md-nav__item">
<a href="../xgc/" title="-Xgc" class="md-nav__link">
-Xgc
</a>
</li>
<li class="md-nav__item">
<a href="../xgcsplitheap/" title="-Xgc:splitheap" class="md-nav__link">
-Xgc:splitheap
</a>
</li>
<li class="md-nav__item">
<a href="../xgcpolicy/" title="-Xgcpolicy" class="md-nav__link">
-Xgcpolicy
</a>
</li>
<li class="md-nav__item">
<a href="../xgcthreads/" title="-Xgcthreads" class="md-nav__link">
-Xgcthreads
</a>
</li>
<li class="md-nav__item">
<a href="../xgcworkpackets/" title="-Xgcworkpackets" class="md-nav__link">
-Xgcworkpackets
</a>
</li>
<li class="md-nav__item">
<a href="../xifa/" title="-Xifa" class="md-nav__link">
-Xifa
</a>
</li>
<li class="md-nav__item">
<a href="../xint/" title="-Xint" class="md-nav__link">
-Xint
</a>
</li>
<li class="md-nav__item">
<a href="../xss/" title="-Xiss" class="md-nav__link">
-Xiss
</a>
</li>
<li class="md-nav__item">
<a href="../xjit/" title="-Xjit" class="md-nav__link">
-Xjit
</a>
</li>
<li class="md-nav__item">
<a href="../xjni/" title="-Xjni" class="md-nav__link">
-Xjni
</a>
</li>
<li class="md-nav__item">
<a href="../xlinenumbers/" title="-Xlinenumbers" class="md-nav__link">
-Xlinenumbers
</a>
</li>
<li class="md-nav__item">
<a href="../xloa/" title="-Xloa" class="md-nav__link">
-Xloa
</a>
</li>
<li class="md-nav__item">
<a href="../xloaminimum/" title="-Xloainitial" class="md-nav__link">
-Xloainitial
</a>
</li>
<li class="md-nav__item">
<a href="../xloaminimum/" title="-Xloamaximum" class="md-nav__link">
-Xloamaximum
</a>
</li>
<li class="md-nav__item">
<a href="../xloaminimum/" title="-Xloaminimum" class="md-nav__link">
-Xloaminimum
</a>
</li>
<li class="md-nav__item">
<a href="../xlockreservation/" title="-XlockReservation" class="md-nav__link">
-XlockReservation
</a>
</li>
<li class="md-nav__item">
<a href="../xlockword/" title="-Xlockword" class="md-nav__link">
-Xlockword
</a>
</li>
<li class="md-nav__item">
<a href="../xlog/" title="-Xlog" class="md-nav__link">
-Xlog
</a>
</li>
<li class="md-nav__item">
<a href="../xlp/" title="-Xlp" class="md-nav__link">
-Xlp
</a>
</li>
<li class="md-nav__item">
<a href="../xlpcodecache/" title="-Xlp:codecache" class="md-nav__link">
-Xlp:codecache
</a>
</li>
<li class="md-nav__item">
<a href="../xlpobjectheap/" title="-Xlp:objectheap" class="md-nav__link">
-Xlp:objectheap
</a>
</li>
<li class="md-nav__item">
<a href="../xmine/" title="-Xmaxe" class="md-nav__link">
-Xmaxe
</a>
</li>
<li class="md-nav__item">
<a href="../xminf/" title="-Xmaxf" class="md-nav__link">
-Xmaxf
</a>
</li>
<li class="md-nav__item">
<a href="../xmint/" title="-Xmaxt" class="md-nav__link">
-Xmaxt
</a>
</li>
<li class="md-nav__item">
<a href="../xmca/" title="-Xmca" class="md-nav__link">
-Xmca
</a>
</li>
<li class="md-nav__item">
<a href="../xmca/" title="-Xmco" class="md-nav__link">
-Xmco
</a>
</li>
<li class="md-nav__item">
<a href="../xmcrs/" title="-Xmcrs" class="md-nav__link">
-Xmcrs
</a>
</li>
<li class="md-nav__item">
<a href="../xmine/" title="-Xmine" class="md-nav__link">
-Xmine
</a>
</li>
<li class="md-nav__item">
<a href="../xminf/" title="-Xminf" class="md-nav__link">
-Xminf
</a>
</li>
<li class="md-nav__item">
<a href="../xmint/" title="-Xmint" class="md-nav__link">
-Xmint
</a>
</li>
<li class="md-nav__item">
<a href="../xmn/" title="-Xmn" class="md-nav__link">
-Xmn
</a>
</li>
<li class="md-nav__item">
<a href="../xmn/" title="-Xmns" class="md-nav__link">
-Xmns
</a>
</li>
<li class="md-nav__item">
<a href="../xmn/" title="-Xmnx" class="md-nav__link">
-Xmnx
</a>
</li>
<li class="md-nav__item">
<a href="../xmo/" title="-Xmo" class="md-nav__link">
-Xmo
</a>
</li>
<li class="md-nav__item">
<a href="../xmo/" title="-Xmoi" class="md-nav__link">
-Xmoi
</a>
</li>
<li class="md-nav__item">
<a href="../xmo/" title="-Xmos" class="md-nav__link">
-Xmos
</a>
</li>
<li class="md-nav__item">
<a href="../xmo/" title="-Xmox" class="md-nav__link">
-Xmox
</a>
</li>
<li class="md-nav__item">
<a href="../xmr/" title="-Xmr" class="md-nav__link">
-Xmr
</a>
</li>
<li class="md-nav__item">
<a href="../xmr/" title="-Xmrx" class="md-nav__link">
-Xmrx
</a>
</li>
<li class="md-nav__item">
<a href="../xms/" title="-Xms" class="md-nav__link">
-Xms
</a>
</li>
<li class="md-nav__item">
<a href="../xmso/" title="-Xmso" class="md-nav__link">
-Xmso
</a>
</li>
<li class="md-nav__item">
<a href="../xms/" title="-Xmx" class="md-nav__link">
-Xmx
</a>
</li>
<li class="md-nav__item">
<a href="../xaot/" title="-Xnoaot" class="md-nav__link">
-Xnoaot
</a>
</li>
<li class="md-nav__item">
<a href="../xclassgc/" title="-Xnoclassgc" class="md-nav__link">
-Xnoclassgc
</a>
</li>
<li class="md-nav__item">
<a href="../xcompactexplicitgc/" title="-Xnocompactexplicitgc" class="md-nav__link">
-Xnocompactexplicitgc
</a>
</li>
<li class="md-nav__item">
<a href="../xcompactgc/" title="-Xnocompactgc" class="md-nav__link">
-Xnocompactgc
</a>
</li>
<li class="md-nav__item">
<a href="../xcompressedrefs/" title="-Xnocompressedrefs" class="md-nav__link">
-Xnocompressedrefs
</a>
</li>
<li class="md-nav__item">
<a href="../xjit/" title="-Xnojit" class="md-nav__link">
-Xnojit
</a>
</li>
<li class="md-nav__item">
<a href="../xlinenumbers/" title="-Xnolinenumbers" class="md-nav__link">
-Xnolinenumbers
</a>
</li>
<li class="md-nav__item">
<a href="../xloa/" title="-Xnoloa" class="md-nav__link">
-Xnoloa
</a>
</li>
<li class="md-nav__item">
<a href="../xsigcatch/" title="-Xnosigcatch" class="md-nav__link">
-Xnosigcatch
</a>
</li>
<li class="md-nav__item">
<a href="../xsigchain/" title="-Xnosigchain" class="md-nav__link">
-Xnosigchain
</a>
</li>
<li class="md-nav__item">
<a href="../xnumanone/" title="-Xnuma:none" class="md-nav__link">
-Xnuma:none
</a>
</li>
<li class="md-nav__item">
<a href="../xoptionsfile/" title="-Xoptionsfile" class="md-nav__link">
-Xoptionsfile
</a>
</li>
<li class="md-nav__item">
<a href="../xquickstart/" title="-Xquickstart" class="md-nav__link">
-Xquickstart
</a>
</li>
<li class="md-nav__item">
<a href="../xrdbginfo/" title="-Xrdbginfo" class="md-nav__link">
-Xrdbginfo
</a>
</li>
<li class="md-nav__item">
<a href="../xrs/" title="-Xrs" class="md-nav__link">
-Xrs
</a>
</li>
<li class="md-nav__item">
<a href="../xsamplingexpirationtime/" title="-XsamplingExpirationTime" class="md-nav__link">
-XsamplingExpirationTime
</a>
</li>
<li class="md-nav__item">
<a href="../xscdmx/" title="-Xscdmx" class="md-nav__link">
-Xscdmx
</a>
</li>
<li class="md-nav__item">
<a href="../xscminaot/" title="-Xscmaxaot" class="md-nav__link">
-Xscmaxaot
</a>
</li>
<li class="md-nav__item">
<a href="../xscminjitdata/" title="-Xscmaxjitdata" class="md-nav__link">
-Xscmaxjitdata
</a>
</li>
<li class="md-nav__item">
<a href="../xscminaot/" title="-Xscminaot" class="md-nav__link">
-Xscminaot
</a>
</li>
<li class="md-nav__item">
<a href="../xscminjitdata/" title="-Xscminjitdata" class="md-nav__link">
-Xscminjitdata
</a>
</li>
<li class="md-nav__item">
<a href="../xscmx/" title="-Xscmx" class="md-nav__link">
-Xscmx
</a>
</li>
<li class="md-nav__item">
<a href="../xshareclasses/" title="-Xshareclasses" class="md-nav__link">
-Xshareclasses
</a>
</li>
<li class="md-nav__item">
<a href="../xsigcatch/" title="-Xsigcatch" class="md-nav__link">
-Xsigcatch
</a>
</li>
<li class="md-nav__item">
<a href="../xsigchain/" title="-Xsigchain" class="md-nav__link">
-Xsigchain
</a>
</li>
<li class="md-nav__item">
<a href="../xsignal/" title="-Xsignal" class="md-nav__link">
-Xsignal
</a>
</li>
<li class="md-nav__item">
<a href="../xsoftmx/" title="-Xsoftmx" class="md-nav__link">
-Xsoftmx
</a>
</li>
<li class="md-nav__item">
<a href="../xsoftrefthreshold/" title="-Xsoftrefthreshold" class="md-nav__link">
-Xsoftrefthreshold
</a>
</li>
<li class="md-nav__item">
<a href="../xss/" title="-Xss" class="md-nav__link">
-Xss
</a>
</li>
<li class="md-nav__item">
<a href="../xss/" title="-Xssi" class="md-nav__link">
-Xssi
</a>
</li>
<li class="md-nav__item">
<a href="../xtgc/" title="-Xtgc" class="md-nav__link">
-Xtgc
</a>
</li>
<li class="md-nav__item">
<a href="../xthr/" title="-Xthr" class="md-nav__link">
-Xthr
</a>
</li>
<li class="md-nav__item">
<a href="../xtlhprefetch/" title="-XtlhPrefetch" class="md-nav__link">
-XtlhPrefetch
</a>
</li>
<li class="md-nav__item">
<a href="../xtrace/" title="-Xtrace" class="md-nav__link">
-Xtrace
</a>
</li>
<li class="md-nav__item">
<a href="../xtunevirtualized/" title="-Xtune:virtualized" class="md-nav__link">
-Xtune:virtualized
</a>
</li>
<li class="md-nav__item">
<a href="../xverbosegclog/" title="-Xverbosegclog" class="md-nav__link">
-Xverbosegclog
</a>
</li>
<li class="md-nav__item">
<a href="../xverify/" title="-Xverify" class="md-nav__link">
-Xverify
</a>
</li>
<li class="md-nav__item">
<a href="../xzero/" title="-Xzero" class="md-nav__link">
-Xzero
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-9-6" type="checkbox" id="nav-9-6">
<label class="md-nav__link" for="nav-9-6">
JVM -XX: options
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="2">
<label class="md-nav__title" for="nav-9-6">
JVM -XX: options
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../xx_jvm_commands/" title="Using -XX options" class="md-nav__link">
Using -XX options
</a>
</li>
<li class="md-nav__item">
<a href="../xxactiveprocessorcount/" title="-XXActiveProcessorCount" class="md-nav__link">
-XXActiveProcessorCount
</a>
</li>
<li class="md-nav__item">
<a href="../xxallowvmshutdown/" title="-XXallowvmshutdown" class="md-nav__link">
-XXallowvmshutdown
</a>
</li>
<li class="md-nav__item">
<a href="../xxcodecachetotal/" title="-XX:codecachetotal" class="md-nav__link">
-XX:codecachetotal
</a>
</li>
<li class="md-nav__item">
<a href="../xxdisableexplicitgc/" title="-XX:[+|-]DisableExplicitGC" class="md-nav__link">
-XX:[+|-]DisableExplicitGC
</a>
</li>
<li class="md-nav__item">
<a href="../xxdisclaimjitscratch/" title="-XX:[+|-]DisclaimJitScratch" class="md-nav__link">
-XX:[+|-]DisclaimJitScratch
</a>
</li>
<li class="md-nav__item">
<a href="../xxenablecpumonitor/" title="-XX:[+|-]EnableCPUMonitor" class="md-nav__link">
-XX:[+|-]EnableCPUMonitor
</a>
</li>
<li class="md-nav__item">
<a href="../xxhandlesigxfsz/" title="-XX:[+|-]handleSIGXFSZ" class="md-nav__link">
-XX:[+|-]handleSIGXFSZ
</a>
</li>
<li class="md-nav__item">
<a href="../xxheapdumponoutofmemory/" title="-XX:[+|-]HeapDumpOnOutOfMemory" class="md-nav__link">
-XX:[+|-]HeapDumpOnOutOfMemory
</a>
</li>
<li class="md-nav__item">
<a href="../xxheapdumppath/" title="-XX:HeapDumpPath" class="md-nav__link">
-XX:HeapDumpPath
</a>
</li>
<li class="md-nav__item">
<a href="../xxheapmanagementmxbeancompatibility/" title="-XX:[+|-]HeapManagementMXBeanCompatibility" class="md-nav__link">
-XX:[+|-]HeapManagementMXBeanCompatibility
</a>
</li>
<li class="md-nav__item">
<a href="../xxidletuningcompactonidle/" title="-XX:[+|-]IdleTuningCompactOnIdle" class="md-nav__link">
-XX:[+|-]IdleTuningCompactOnIdle
</a>
</li>
<li class="md-nav__item">
<a href="../xxidletuninggconidle/" title="-XX:[+|-]IdleTuningGcOnIdle" class="md-nav__link">
-XX:[+|-]IdleTuningGcOnIdle
</a>
</li>
<li class="md-nav__item">
<a href="../xxidletuningminfreeheaponidle/" title="-XX:IdleTuningMinFreeHeapOnIdle" class="md-nav__link">
-XX:IdleTuningMinFreeHeapOnIdle
</a>
</li>
<li class="md-nav__item">
<a href="../xxidletuningminidlewaittime/" title="-XX:IdleTuningMinIdleWaitTime" class="md-nav__link">
-XX:IdleTuningMinIdleWaitTime
</a>
</li>
<li class="md-nav__item">
<a href="../xxignoreunrecognizedvmoptions/" title="-XX:[+|-]IgnoreUnrecognizedVMOptions" class="md-nav__link">
-XX:[+|-]IgnoreUnrecognizedVMOptions
</a>
</li>
<li class="md-nav__item">
<a href="../xxinitialrampercentage/" title="-XX:InitialRAMPercentage" class="md-nav__link">
-XX:InitialRAMPercentage
</a>
</li>
<li class="md-nav__item">
<a href="../xxinitialheapsize/" title="-XX:InitialHeapSize" class="md-nav__link">
-XX:InitialHeapSize
</a>
</li>
<li class="md-nav__item">
<a href="../xxinterleavememory/" title="-XX:[+|-]InterleaveMemory" class="md-nav__link">
-XX:[+|-]InterleaveMemory
</a>
</li>
<li class="md-nav__item">
<a href="../xxlazysymbolresolution/" title="-XX:[+|-]LazySymbolResolution" class="md-nav__link">
-XX:[+|-]LazySymbolResolution
</a>
</li>
<li class="md-nav__item">
<a href="../xxmaxdirectmemorysize/" title="-XX:MaxDirectMemorySize" class="md-nav__link">
-XX:MaxDirectMemorySize
</a>
</li>
<li class="md-nav__item">
<a href="../xxinitialheapsize/" title="-XX:MaxHeapSize" class="md-nav__link">
-XX:MaxHeapSize
</a>
</li>
<li class="md-nav__item">
<a href="../xxmaxrampercentage/" title="-XX:MaxRAMPercentage" class="md-nav__link">
-XX:MaxRAMPercentage
</a>
</li>
<li class="md-nav__item">
<a href="../xxnosuballoc32bitmem/" title="-XXnosuballoc32bitmem" class="md-nav__link">
-XXnosuballoc32bitmem
</a>
</li>
<li class="md-nav__item">
<a href="../xxpagealigndirectmemory/" title="-XX:[+|-]PageAlignDirectMemory" class="md-nav__link">
-XX:[+|-]PageAlignDirectMemory
</a>
</li>
<li class="md-nav__item">
<a href="../xxreducecpumonitoroverhead/" title="-XX:[+|-]ReduceCPUMonitorOverhead" class="md-nav__link">
-XX:[+|-]ReduceCPUMonitorOverhead
</a>
</li>
<li class="md-nav__item">
<a href="../xxruntimeinstrumentation/" title="-XX:[+|-]RuntimeInstrumentation" class="md-nav__link">
-XX:[+|-]RuntimeInstrumentation
</a>
</li>
<li class="md-nav__item">
<a href="../xxsethwprefetch/" title="-XXsetHWPrefetch" class="md-nav__link">
-XXsetHWPrefetch
</a>
</li>
<li class="md-nav__item">
<a href="../xxshareclassesenablebci/" title="-XX:ShareClassesDisableBCI" class="md-nav__link">
-XX:ShareClassesDisableBCI
</a>
</li>
<li class="md-nav__item">
<a href="../xxshareclassesenablebci/" title="-XX:ShareClassesEnableBCI" class="md-nav__link">
-XX:ShareClassesEnableBCI
</a>
</li>
<li class="md-nav__item">
<a href="../xxsharedcachehardlimit/" title="-XX:SharedCacheHardLimit" class="md-nav__link">
-XX:SharedCacheHardLimit
</a>
</li>
<li class="md-nav__item">
<a href="../xxstacktraceinthrowable/" title="-XX:-StackTraceInThrowable" class="md-nav__link">
-XX:-StackTraceInThrowable
</a>
</li>
<li class="md-nav__item">
<a href="../xxthreadstacksize/" title="-XX:ThreadStackSize" class="md-nav__link">
-XX:ThreadStackSize
</a>
</li>
<li class="md-nav__item">
<a href="../xxusecompressedoops/" title="-XX:[+|-]UseCompressedOops" class="md-nav__link">
-XX:[+|-]UseCompressedOops
</a>
</li>
<li class="md-nav__item">
<a href="../xxusecontainersupport/" title="-XX:[+|-]UseContainerSupport" class="md-nav__link">
-XX:[+|-]UseContainerSupport
</a>
</li>
<li class="md-nav__item">
<a href="../xxusenogc/" title="-XX:[+|-]UseNoGC" class="md-nav__link">
-XX:[+|-]UseNoGC
</a>
</li>
<li class="md-nav__item">
<a href="../xxverboseverification/" title="-XX:[+|-]VerboseVerification" class="md-nav__link">
-XX:[+|-]VerboseVerification
</a>
</li>
<li class="md-nav__item">
<a href="../xxvmlockclassloader/" title="-XX:[+|-]VMLockClassLoader" class="md-nav__link">
-XX:[+|-]VMLockClassLoader
</a>
</li>
</ul>
</nav>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-10" type="checkbox" id="nav-10">
<label class="md-nav__link" for="nav-10">
Tools
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="1">
<label class="md-nav__title" for="nav-10">
Tools
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../tool_jdmpview/" title="Dump viewer" class="md-nav__link">
Dump viewer
</a>
</li>
<li class="md-nav__item">
<a href="../tool_traceformat/" title="Trace formatter" class="md-nav__link">
Trace formatter
</a>
</li>
<li class="md-nav__item">
<a href="../tool_builder/" title="Option builder" class="md-nav__link">
Option builder
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item md-nav__item--nested">
<input class="md-toggle md-nav__toggle" data-md-toggle="nav-11" type="checkbox" id="nav-11">
<label class="md-nav__link" for="nav-11">
Reference
</label>
<nav class="md-nav" data-md-component="collapsible" data-md-level="1">
<label class="md-nav__title" for="nav-11">
Reference
</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="../openj9_support/" title="Supported environments" class="md-nav__link">
Supported environments
</a>
</li>
<li class="md-nav__item">
<a href="../openj9_defaults/" title="Default settings" class="md-nav__link">
Default settings
</a>
</li>
<li class="md-nav__item">
<a href="../openj9_directories/" title="Directory conventions" class="md-nav__link">
Directory conventions
</a>
</li>
<li class="md-nav__item">
<a href="../messages_intro/" title="OpenJ9 messages" class="md-nav__link">
OpenJ9 messages
</a>
</li>
<li class="md-nav__item">
<a href="../env_var/" title="Environment variables" class="md-nav__link">
Environment variables
</a>
</li>
</ul>
</nav>
</li>
<li class="md-nav__item">
<a href="../legal/" title="Legal" class="md-nav__link">
Legal
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-sidebar md-sidebar--secondary" data-md-component="toc">
<div class="md-sidebar__scrollwrap">
<div class="md-sidebar__inner">
<nav class="md-nav md-nav--secondary">
<label class="md-nav__title" for="toc">On this page ...</label>
<ul class="md-nav__list" data-md-scrollfix>
<li class="md-nav__item">
<a href="#support-for-custom-class-loaders" title="Support for custom class loaders" class="md-nav__link">
Support for custom class loaders
</a>
</li>
<li class="md-nav__item">
<a href="#cache-utilities" title="Cache utilities" class="md-nav__link">
Cache utilities
</a>
</li>
<li class="md-nav__item">
<a href="#see-also" title="See also" class="md-nav__link">
See also
</a>
</li>
</ul>
</nav>
</div>
</div>
</div>
<div class="md-content">
<article class="md-content__inner md-typeset">
<!-- this adds 'pencil' icon to H1 so that you can edit the page directly in GitHub
<a href="https://github.com/eclipse/openj9-docs/edit/master/docs/shrc.md" title="Edit this page" class="md-icon md-content__icon">&#xE3C9;</a>
-->
<!--
* Copyright (c) 2017, 2018 IBM Corp. and others
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/legal/epl-2.0/ or the Apache
* License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the
* following Secondary Licenses when the conditions for such
* availability set forth in the Eclipse Public License, v. 2.0
* are satisfied: GNU General Public License, version 2 with
* the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH
* Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
-->
<h1 id="class-data-sharing">Class Data Sharing</h1>
<p>Sharing class data between JVMs improves start up performance and reduces memory footprint.</p>
<p>Start up performance is improved by placing classes that an application needs when initializing into a shared classes cache. The next time the
application runs, it takes much less time to start because the classes are already available. When you enable class data sharing, AOT compilation is also enabled by default, which dynamically compiles certain methods into AOT code at runtime. By using these features in combination, startup performance can be improved even further because the cached AOT code can be used to quickly enable native code performance for subsequent runs of your application.</p>
<p>Class data sharing is enabled by setting the <code>-Xshareclasses</code> option on the command line when you start your application. When specified, OpenJ9 automatically creates a memory mapped file that stores and shares the classes in memory. By default, OpenJ9 always shares both the bootstrap and application classes that are loaded by the default system class loader.</p>
<p>The shared classes cache is updated dynamically; When an application loads new classes, the JVM automatically stores them in the cache without any user intervention.</p>
<p>Memory footprint is reduced by sharing common classes between applications that run in separate Java VMs.</p>
<p>The <a href="../xshareclasses/">-Xshareclasses</a> option is highly configurable, allowing you to specify where to create the cache, how much space to allocate for AOT code and more. You can also set the cache size by using the <a href="../xscmx/">-Xscmx</a> option. </p>
<h2 id="support-for-custom-class-loaders">Support for custom class loaders</h2>
<p>Classes are shared by the bootstrap class loader internally in the OpenJ9 VM. If you are using a custom class loader, you can use the Java Helper API to find and store classes in the shared class cache.</p>
<p>For more information, see <a href="https://www.ibm.com/support/knowledgecenter/SSYKE2_8.0.0/com.ibm.java.vm.80.doc/docs/shrc_pd_helper.html">Using the Java Helper API</a>.</p>
<h2 id="cache-utilities">Cache utilities</h2>
<p>Several utilities are provided for managing active caches, which are invoked by specifying <code>-Xshareclasses</code> suboptions. These utilities control the following types of operations:</p>
<ul>
<li>Adjust the minimum and maximum amount of cache space reserved for AOT or JIT data.</li>
<li>Adjust the soft maximum size of the cache.</li>
<li>Create snapshots of a cache.</li>
<li>Create a cache from a snapshot.</li>
<li>Remove caches and cache snapshots.</li>
<li>List all the compatible and incompatible caches and snapshots.</li>
<li>For problem determination, invalidate and revalidate AOT methods that cause a failure in an application.</li>
<li>For problem determination, provide information to analyze the contents of a shared classes cache.</li>
</ul>
<p>For more information, see <a href="../xshareclasses/">-Xshareclasses</a>.</p>
<h2 id="see-also">See also</h2>
<ul>
<li><a href="../aot/">AOT compiler</a></li>
<li><a href="https://www.ibm.com/developerworks/java/library/j-ibmjava4/index.html">Class Sharing</a></li>
<li><a href="https://www.ibm.com/support/knowledgecenter/SSYKE2_8.0.0/com.ibm.java.vm.80.doc/docs/shrc_pd_intro.html">Diagnosing class data sharing problems</a></li>
</ul>
<!-- ==== END OF TOPIC ==== shrc.md ==== -->
<!--
-->
<!-- This block was originally in the theme's 'footer.html' partial file. It has been moved here in part to resolve issues with the footer being too large. -->
<!--
* Copyright (c) 2017, 2018 IBM Corp. and others
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/legal/epl-2.0/ or the Apache
* License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the
* following Secondary Licenses when the conditions for such
* availability set forth in the Eclipse Public License, v. 2.0
* are satisfied: GNU General Public License, version 2 with
* the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH
* Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
-->
<div class="md-footer-nav">
<nav class="md-footer-nav__inner md-grid">
<!-- Separator -->
<img alt="" src="../cr/rule.png">
<a href="../aot/" title="AOT Compiler" class="md-flex md-footer-nav__link md-footer-nav__link--prev" rel="prev">
<div class="md-flex__cell md-flex__cell--shrink">
<i class="md-icon md-icon--arrow-back md-footer-nav__button"></i>
</div>
<div class="md-flex__cell md-flex__cell--stretch md-footer-nav__title">
<span class="md-flex__ellipsis">
<span class="md-footer-nav__direction">
Previous
</span>
AOT Compiler
</span>
</div>
</a>
<a href="../diag_overview/" title="Tools and data" class="md-flex md-footer-nav__link md-footer-nav__link--next" rel="next">
<div class="md-flex__cell md-flex__cell--stretch md-footer-nav__title">
<span class="md-flex__ellipsis">
<span class="md-footer-nav__direction">
Next
</span>
Tools and data
</span>
</div>
<div class="md-flex__cell md-flex__cell--shrink">
<i class="md-icon md-icon--arrow-forward md-footer-nav__button"></i>
</div>
</a>
</nav>
</div>
</article>
</div>
</div>
</main>
<!--
* Copyright (c) 2017, 2018 IBM Corp. and others
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/legal/epl-2.0/ or the Apache
* License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the
* following Secondary Licenses when the conditions for such
* availability set forth in the Eclipse Public License, v. 2.0
* are satisfied: GNU General Public License, version 2 with
* the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH
* Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
-->
<cite></cite>
<footer class="md-footer">
<div class="md-footer-meta md-typeset">
<!--
* Copyright (c) 2017, 2018 IBM Corp. and others
*
* This program and the accompanying materials are made
* available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution and is available at
* https://www.eclipse.org/legal/epl-2.0/ or the Apache
* License, Version 2.0 which accompanies this distribution and
* is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* This Source Code may also be made available under the
* following Secondary Licenses when the conditions for such
* availability set forth in the Eclipse Public License, v. 2.0
* are satisfied: GNU General Public License, version 2 with
* the GNU Classpath Exception [1] and GNU General Public
* License, version 2 with the OpenJDK Assembly Exception [2].
*
* [1] https://www.gnu.org/software/classpath/license.html
* [2] http://openjdk.java.net/legal/assembly-exception.html
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH
* Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
-->
<div class="md-footer-social1">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<a href="https://github.com/eclipse/openj9" class="md-footer-social__link fa fa-github"></a>
<a href="https://openj9.slack.com" class="md-footer-social__link fa fa-slack"></a>
<a href="https://twitter.com/openj9" class="md-footer-social__link fa fa-twitter"></a>
<a href="https://stackoverflow.com/search?q=OpenJ9" class="md-footer-social__link fa fa-stack-overflow"></a>
</div>
<div class="md-footer-eclipse1">OpenJ9 is an Eclipse Incubator project.</div>
<div class="md-footer-links1">
<span class="no-wrap"><i class="fa fa-chevron-circle-right f_mini" aria-hidden="true"></i><a class="dark-link" href="http://www.eclipse.org">Eclipse Foundation website</a></span>
&nbsp; <span class="no-wrap"><i class="fa fa-chevron-circle-right f_mini" aria-hidden="true"></i><a class="dark-link" href="http://www.eclipse.org/legal/privacy.php">Privacy policy</a></span>
&nbsp; <span class="no-wrap"><i class="fa fa-chevron-circle-right f_mini" aria-hidden="true"></i><a class="dark-link" href="http://www.eclipse.org/legal/termsofuse.php">Website terms of use</a></span>
&nbsp; <span class="no-wrap"><i class="fa fa-chevron-circle-right f_mini" aria-hidden="true"></i><a class="dark-link" href="http://www.eclipse.org/legal/copyright.php">Copyright agent</a></span>
&nbsp; <span class="no-wrap"><i class="fa fa-chevron-circle-right f_mini" aria-hidden="true"></i><a class="dark-link" href="http://www.eclipse.org/legal">Legal</a></span>
</div>
<div class="md-footer-power1">
powered by
<a href="http://www.mkdocs.org" title="MkDocs">MkDocs</a>
and
<a href="http://squidfunk.github.io/mkdocs-material/" title="Material for MkDocs">
Material for MkDocs</a><br/><br/>
</div>
</div>
</footer>
</div>
<script src="../assets/javascripts/application.abd7b172.js"></script>
<script>app.initialize({version:"0.17.2",url:{base:".."}})</script>
</body>
</html>