1 /*
   2  * Copyright (c) 2016, 2017, 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 /*
  25  * @test
  26  * @summary Ensure module information is cleaned when owning class loader unloads
  27  * @modules java.base/jdk.internal.misc
  28  * @library /test/lib ..
  29  * @build sun.hotspot.WhiteBox
  30  * @compile/module=java.base java/lang/reflect/ModuleHelper.java
  31  * @run main ClassFileInstaller sun.hotspot.WhiteBox
  32  *                              sun.hotspot.WhiteBox$WhiteBoxPermission
  33  * @run main/othervm -Xbootclasspath/a:. -XX:+UnlockDiagnosticVMOptions -XX:+WhiteBoxAPI -Xmx64m -Xmx64m LoadUnloadModuleStress 15000
  34  */
  35 
  36 import java.lang.ref.WeakReference;
  37 
  38 import static jdk.test.lib.Asserts.*;
  39 
  40 public class LoadUnloadModuleStress {
  41     private static long timeout;
  42     private static long timeStamp;
  43 
  44     public static byte[] garbage;
  45     public static volatile WeakReference<MyClassLoader> clweak;
  46 
  47     public static Object createModule() throws Throwable {
  48         MyClassLoader cl = new MyClassLoader();
  49         Object module = ModuleHelper.ModuleObject("mymodule", cl, new String [] {"PackageA"});
  50         assertNotNull(module);
  51         ModuleHelper.DefineModule(module, false, "9.0", "mymodule", new String[] { "PackageA" });
  52         clweak = new WeakReference<>(cl);
  53         return module;
  54     }
  55 
  56     public static void main(String args[]) throws Throwable {
  57         timeout = Long.valueOf(args[0]);
  58         timeStamp = System.currentTimeMillis();
  59 
  60         while(System.currentTimeMillis() - timeStamp < timeout) {
  61             WeakReference<Object> modweak = new WeakReference<>(createModule());
  62 
  63             while(clweak.get() != null) {
  64                 garbage = new byte[8192];
  65                 System.gc();
  66             }
  67             assertNull(modweak.get());
  68         }
  69     }
  70     static class MyClassLoader extends ClassLoader { }
  71 }