1 /*
   2  * Copyright (c) 2011, 2016, 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     7036199
  27  * @summary Check that GarbageCollection notification are thrown by every GarbageCollectorMXBean
  28  * @author  Frederic Parain
  29  *
  30  * @requires vm.opt.ExplicitGCInvokesConcurrent == null | vm.opt.ExplicitGCInvokesConcurrent == false
  31  * @modules java.management/sun.management
  32  *          jdk.management
  33  *
  34  * @run     main/othervm GarbageCollectionNotificationTest
  35  */
  36 
  37 import java.util.*;
  38 import java.lang.management.*;
  39 import java.lang.reflect.*;
  40 import javax.management.*;
  41 import javax.management.openmbean.*;
  42 import com.sun.management.GarbageCollectionNotificationInfo;
  43 import com.sun.management.GcInfo;
  44 import java.security.AccessController;
  45 import java.security.PrivilegedAction;
  46 import java.lang.reflect.Field;
  47 
  48 public class GarbageCollectionNotificationTest {
  49     private static HashMap<String,Boolean> listenerInvoked = new HashMap<String,Boolean>();
  50     static volatile long count = 0;
  51     static volatile long number = 0;
  52     static Object synchronizer = new Object();
  53 
  54     static class GcListener implements NotificationListener {
  55         public void handleNotification(Notification notif, Object handback) {
  56             String type = notif.getType();
  57             if (type.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
  58                 GarbageCollectionNotificationInfo gcNotif =
  59                     GarbageCollectionNotificationInfo.from((CompositeData) notif.getUserData());
  60                 String source = ((ObjectName)notif.getSource()).getCanonicalName();
  61                 synchronized(synchronizer) {
  62                     if(!listenerInvoked.get(source)) {
  63                             listenerInvoked.put(((ObjectName)notif.getSource()).getCanonicalName(),true);
  64                             count++;
  65                             if(count >= number) {
  66                                 synchronizer.notify();
  67                             }
  68                     }
  69                 }
  70             }
  71         }
  72     }
  73 
  74     public static void main(String[] args) throws Exception {
  75         MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
  76         final boolean isNotificationSupported =
  77                  sun.management.ManagementFactoryHelper.getVMManagement().isGcNotificationSupported();
  78 
  79         if(!isNotificationSupported) {
  80             System.out.println("GC Notification not supported by the JVM, test skipped");
  81             return;
  82         }
  83         final ObjectName gcMXBeanPattern =
  84                 new ObjectName("java.lang:type=GarbageCollector,*");
  85         Set<ObjectName> names =
  86                 mbs.queryNames(gcMXBeanPattern, null);
  87         if (names.isEmpty())
  88             throw new Exception("Test incorrect: no GC MXBeans");
  89         number = names.size();
  90         for (ObjectName n : names) {
  91             if(mbs.isInstanceOf(n,"javax.management.NotificationEmitter")) {
  92                 listenerInvoked.put(n.getCanonicalName(),false);
  93                 GcListener listener = new GcListener();
  94                 mbs.addNotificationListener(n, listener, null, null);
  95             }
  96         }
  97         // Invocation of System.gc() to trigger major GC
  98         System.gc();
  99         // Allocation of many short living and small objects to trigger minor GC
 100         Object data[] = new Object[32];
 101         for(int i = 0; i<100000000; i++) {
 102             data[i%32] = new int[8];
 103         }
 104         int wakeup = 0;
 105         synchronized(synchronizer) {
 106             while(count != number) {
 107                 synchronizer.wait(10000);
 108                 wakeup++;
 109                 if(wakeup > 10)
 110                     break;
 111             }
 112         }
 113         for (String source : listenerInvoked.keySet()) {
 114             if(!listenerInvoked.get(source))
 115                 throw new Exception("Test incorrect: notifications have not been sent for "
 116                                     + source);
 117         }
 118         System.out.println("Test passed");
 119     }
 120 }