1 /*
   2  * Copyright (c) 2011, 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  * @requires vm.opt.ExplicitGCInvokesConcurrent == null | vm.opt.ExplicitGCInvokesConcurrent == false
  30  * @run     main/othervm GarbageCollectionNotificationTest
  31  */
  32 
  33 import java.util.*;
  34 import java.lang.management.*;
  35 import java.lang.reflect.*;
  36 import javax.management.*;
  37 import javax.management.openmbean.*;
  38 import com.sun.management.GarbageCollectionNotificationInfo;
  39 import com.sun.management.GcInfo;
  40 import java.security.AccessController;
  41 import java.security.PrivilegedAction;
  42 import java.lang.reflect.Field;
  43 
  44 public class GarbageCollectionNotificationTest {
  45     private static HashMap<String,Boolean> listenerInvoked = new HashMap<String,Boolean>();
  46     static volatile long count = 0;
  47     static volatile long number = 0;
  48     static Object synchronizer = new Object();
  49 
  50     static class GcListener implements NotificationListener {
  51         public void handleNotification(Notification notif, Object handback) {
  52             String type = notif.getType();
  53             if (type.equals(GarbageCollectionNotificationInfo.GARBAGE_COLLECTION_NOTIFICATION)) {
  54                 GarbageCollectionNotificationInfo gcNotif =
  55                     GarbageCollectionNotificationInfo.from((CompositeData) notif.getUserData());
  56                 String source = ((ObjectName)notif.getSource()).getCanonicalName();
  57                 synchronized(synchronizer) {
  58                     if(!listenerInvoked.get(source)) {
  59                             listenerInvoked.put(((ObjectName)notif.getSource()).getCanonicalName(),true);
  60                             count++;
  61                             if(count >= number) {
  62                                 synchronizer.notify();
  63                             }
  64                     }
  65                 }
  66             }
  67         }
  68     }
  69 
  70     public static void main(String[] args) throws Exception {
  71         MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
  72         final Boolean isNotificationSupported = AccessController.doPrivileged (new PrivilegedAction<Boolean>() {
  73                 public Boolean run() {
  74                     try {
  75                         Class cl = Class.forName("sun.management.VMManagementImpl");
  76                         Field f = cl.getDeclaredField("gcNotificationSupport");
  77                         f.setAccessible(true);
  78                         return f.getBoolean(null);
  79                     } catch(ClassNotFoundException e) {
  80                         return false;
  81                     } catch(NoSuchFieldException e) {
  82                         return false;
  83                     } catch(IllegalAccessException e) {
  84                         return false;
  85                     }
  86                 }
  87             });
  88         if(!isNotificationSupported) {
  89             System.out.println("GC Notification not supported by the JVM, test skipped");
  90             return;
  91         }
  92         final ObjectName gcMXBeanPattern =
  93                 new ObjectName("java.lang:type=GarbageCollector,*");
  94         Set<ObjectName> names =
  95                 mbs.queryNames(gcMXBeanPattern, null);
  96         if (names.isEmpty())
  97             throw new Exception("Test incorrect: no GC MXBeans");
  98         number = names.size();
  99         for (ObjectName n : names) {
 100             if(mbs.isInstanceOf(n,"javax.management.NotificationEmitter")) {
 101                 listenerInvoked.put(n.getCanonicalName(),false);
 102                 GcListener listener = new GcListener();
 103                 mbs.addNotificationListener(n, listener, null, null);
 104             }
 105         }
 106         // Invocation of System.gc() to trigger major GC
 107         System.gc();
 108         // Allocation of many short living and small objects to trigger minor GC
 109         Object data[] = new Object[32];
 110         for(int i = 0; i<100000000; i++) {
 111             data[i%32] = new int[8];
 112         }
 113         int wakeup = 0;
 114         synchronized(synchronizer) {
 115             while(count != number) {
 116                 synchronizer.wait(10000);
 117                 wakeup++;
 118                 if(wakeup > 10)
 119                     break;
 120             }
 121         }
 122         for (String source : listenerInvoked.keySet()) {
 123             if(!listenerInvoked.get(source))
 124                 throw new Exception("Test incorrect: notifications have not been sent for "
 125                                     + source);
 126         }
 127         System.out.println("Test passed");
 128     }
 129 }