1 /*
   2  * Copyright (c) 2014, 2020, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 package gc.class_unloading;
  25 
  26 /*
  27  * @test
  28  * @bug 8049831
  29  * @requires vm.gc.G1
  30  * @library /test/lib
  31  * @modules java.base/jdk.internal.misc
  32  *          java.management
  33  * @build sun.hotspot.WhiteBox
  34  * @run driver ClassFileInstaller sun.hotspot.WhiteBox
  35  * @run driver gc.class_unloading.TestG1ClassUnloadingHWM
  36  * @summary Test that -XX:-ClassUnloadingWithConcurrentMark will trigger a Full GC when more than MetaspaceSize metadata is allocated.
  37  */
  38 
  39 import jdk.test.lib.process.OutputAnalyzer;
  40 import jdk.test.lib.process.ProcessTools;
  41 import sun.hotspot.WhiteBox;
  42 
  43 public class TestG1ClassUnloadingHWM {
  44   private static long MetaspaceSize = 32 * 1024 * 1024;
  45   private static long YoungGenSize  = 32 * 1024 * 1024;
  46 
  47   private static OutputAnalyzer run(boolean enableUnloading) throws Exception {
  48     ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
  49       "-Xbootclasspath/a:.",
  50       "-XX:+UnlockDiagnosticVMOptions",
  51       "-XX:+WhiteBoxAPI",
  52       "-XX:MetaspaceSize=" + MetaspaceSize,
  53       "-Xmn" + YoungGenSize,
  54       "-XX:+UseG1GC",
  55       "-XX:" + (enableUnloading ? "+" : "-") + "ClassUnloadingWithConcurrentMark",
  56       "-Xlog:gc",
  57       TestG1ClassUnloadingHWM.AllocateBeyondMetaspaceSize.class.getName(),
  58       "" + MetaspaceSize,
  59       "" + YoungGenSize);
  60     return new OutputAnalyzer(pb.start());
  61   }
  62 
  63   public static OutputAnalyzer runWithG1ClassUnloading() throws Exception {
  64     return run(true);
  65   }
  66 
  67   public static OutputAnalyzer runWithoutG1ClassUnloading() throws Exception {
  68     return run(false);
  69   }
  70 
  71   public static void testWithoutG1ClassUnloading() throws Exception {
  72     // -XX:-ClassUnloadingWithConcurrentMark is used, so we expect a full GC instead of a concurrent cycle.
  73     OutputAnalyzer out = runWithoutG1ClassUnloading();
  74 
  75     out.shouldMatch(".*Pause Full.*");
  76     out.shouldNotMatch(".*Pause Young \\(Concurrent Start\\).*");
  77   }
  78 
  79   public static void testWithG1ClassUnloading() throws Exception {
  80     // -XX:+ClassUnloadingWithConcurrentMark is used, so we expect a concurrent cycle instead of a full GC.
  81     OutputAnalyzer out = runWithG1ClassUnloading();
  82 
  83     out.shouldMatch(".*Pause Young \\(Concurrent Start\\).*");
  84     out.shouldNotMatch(".*Pause Full.*");
  85   }
  86 
  87   public static void main(String args[]) throws Exception {
  88     testWithG1ClassUnloading();
  89     testWithoutG1ClassUnloading();
  90   }
  91 
  92   public static class AllocateBeyondMetaspaceSize {
  93     public static Object dummy;
  94 
  95     public static void main(String [] args) throws Exception {
  96       if (args.length != 2) {
  97         throw new IllegalArgumentException("Usage: <MetaspaceSize> <YoungGenSize>");
  98       }
  99 
 100       WhiteBox wb = WhiteBox.getWhiteBox();
 101 
 102       // Allocate past the MetaspaceSize limit
 103       long metaspaceSize = Long.parseLong(args[0]);
 104       long allocationBeyondMetaspaceSize  = metaspaceSize * 2;
 105       long metaspace = wb.allocateMetaspace(null, allocationBeyondMetaspaceSize);
 106 
 107       long youngGenSize = Long.parseLong(args[1]);
 108       triggerYoungGCs(youngGenSize);
 109 
 110       wb.freeMetaspace(null, metaspace, metaspace);
 111     }
 112 
 113     public static void triggerYoungGCs(long youngGenSize) {
 114       long approxAllocSize = 32 * 1024;
 115       long numAllocations  = 2 * youngGenSize / approxAllocSize;
 116 
 117       for (long i = 0; i < numAllocations; i++) {
 118         dummy = new byte[(int)approxAllocSize];
 119       }
 120     }
 121   }
 122 }
 123