1 /*
   2  * Copyright (c) 2015, 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  * @bug 8143157
  27  * @summary vmoperation=debug should have logging output
  28  * @library /testlibrary
  29  * @modules java.base/sun.misc
  30  *          java.management
  31  * @build jdk.test.lib.OutputAnalyzer jdk.test.lib.ProcessTools
  32  * @run driver VMOperationTest
  33  */
  34 
  35 import java.lang.ref.WeakReference;
  36 import jdk.test.lib.OutputAnalyzer;
  37 import jdk.test.lib.ProcessTools;
  38 
  39 public class VMOperationTest {
  40     public static void main(String[] args) throws Exception {
  41         ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(
  42             "-Xlog:vmoperation=debug", "-Xmx64m", "-Xms64m",
  43             InternalClass.class.getName());
  44         OutputAnalyzer output = new OutputAnalyzer(pb.start());
  45         output.shouldContain("VM_Operation (");
  46         output.shouldHaveExitValue(0);
  47     }
  48 
  49     public static class InternalClass {
  50         public static byte[] garbage;
  51         public static volatile WeakReference<Object> weakref;
  52 
  53         public static void createweakref() {
  54             Object o = new Object();
  55             weakref = new WeakReference<>(o);
  56         }
  57 
  58         // Loop until a GC runs.
  59         public static void main(String[] args) throws Exception {
  60             createweakref();
  61             while (weakref.get() != null) {
  62                 garbage = new byte[8192];
  63                 System.gc();
  64             }
  65         }
  66     }
  67 }
  68