<!--
* 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/xlockword/">
      
      
        <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>-Xlockword -  </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="#-xlockword" 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">
    <a href="../shrc/" title="Class data sharing" class="md-nav__link">
      Class data sharing
    </a>
  </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--active md-nav__item--nested">
    
      <input class="md-toggle md-nav__toggle" data-md-toggle="nav-9" type="checkbox" id="nav-9" checked>
    
    <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--active md-nav__item--nested">
    
      <input class="md-toggle md-nav__toggle" data-md-toggle="nav-9-5" type="checkbox" id="nav-9-5" checked>
    
    <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 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">
        -Xlockword
      </label>
    
    <a href="./" title="-Xlockword" class="md-nav__link md-nav__link--active">
      -Xlockword
    </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="#syntax" title="Syntax" class="md-nav__link">
    Syntax
  </a>
  
</li>
      
        <li class="md-nav__item">
  <a href="#parameters" title="Parameters" class="md-nav__link">
    Parameters
  </a>
  
    <nav class="md-nav">
      <ul class="md-nav__list">
        
          <li class="md-nav__item">
  <a href="#mode" title="mode" class="md-nav__link">
    mode
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#nolockword" title="nolockword" class="md-nav__link">
    nolockword
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#what" title="what" class="md-nav__link">
    what
  </a>
  
</li>
        
      </ul>
    </nav>
  
</li>
      
      
    </ul>
  
</nav>
    
  </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="#syntax" title="Syntax" class="md-nav__link">
    Syntax
  </a>
  
</li>
      
        <li class="md-nav__item">
  <a href="#parameters" title="Parameters" class="md-nav__link">
    Parameters
  </a>
  
    <nav class="md-nav">
      <ul class="md-nav__list">
        
          <li class="md-nav__item">
  <a href="#mode" title="mode" class="md-nav__link">
    mode
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#nolockword" title="nolockword" class="md-nav__link">
    nolockword
  </a>
  
</li>
        
          <li class="md-nav__item">
  <a href="#what" title="what" class="md-nav__link">
    what
  </a>
  
</li>
        
      </ul>
    </nav>
  
</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/xlockword.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="-xlockword">-Xlockword</h1>
<p>Test whether performance optimizations are negatively impacting an application.</p>
<h2 id="syntax">Syntax</h2>
<div class="codehilite"><pre><span></span>    -Xlockword:&lt;parameters&gt;
</pre></div>


<h2 id="parameters">Parameters</h2>
<h3 id="mode"><code>mode</code></h3>
<div class="codehilite"><pre><span></span>    -Xlockword:mode=all
    -Xlockword:mode=default
</pre></div>


<p>Locking optimizations typically reduce memory usage and improve performance. However, there might be some situations where a smaller heap size is achieved for an application, but overall application performance decreases.</p>
<p>For example, if your application synchronizes on objects that are not typically synchronized on, such as <code>Java.lang.String</code>, run the following test:<br />
Use the following command-line option to revert to behavior that is closer to earlier versions and monitor application performance:</p>
<div class="codehilite"><pre><span></span>-Xlockword:mode=all
</pre></div>


<p>If performance does not improve, remove the previous command-line options or use the following command-line option to reestablish the new behavior:</p>
<div class="codehilite"><pre><span></span>-Xlockword:mode=default
</pre></div>


<h3 id="nolockword"><code>nolockword</code></h3>
<div class="codehilite"><pre><span></span>    -Xlockword:nolockword=&lt;class_name&gt;
</pre></div>


<dl>
<dd>
<p>Removes the lockword from object instances of the class <code>&lt;class_name&gt;</code>, reducing the space required for these objects. However, this action might have an adverse effect on synchronization for those objects.</p>
<p>You should only use this option for troubleshooting.</p>
</dd>
</dl>
<h3 id="what"><code>what</code></h3>
<div class="codehilite"><pre><span></span>    -Xlockword:what
</pre></div>


<dl>
<dd>Shows the current lockword configuration.</dd>
</dl>
<!-- ==== END OF TOPIC ==== xlockword.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="../xlockreservation/" title="-XlockReservation" 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>
                            -XlockReservation
                          </span>
                        </div>
                      </a>
                    
                    
                      <a href="../xlog/" title="-Xlog" 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>
                            -Xlog
                          </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>