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