1 /*
2 * Copyright (c) 2010, 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 6957378
27 * @summary Test that a listener can be removed remotely from an MBean that no longer exists.
28 * @modules java.management/javax.management.remote.rmi:open
29 * java.management/com.sun.jmx.remote.internal:+open
30 * @author Eamonn McManus
31 * @run main/othervm -XX:+UsePerfData DeadListenerTest
32 */
33
34 import com.sun.jmx.remote.internal.ServerNotifForwarder;
35 import java.io.IOException;
36 import java.lang.management.ManagementFactory;
37 import java.lang.ref.WeakReference;
38 import java.lang.reflect.Field;
39 import java.lang.reflect.Method;
40 import java.util.ArrayList;
41 import java.util.HashMap;
42 import java.util.List;
43 import java.util.Map;
44 import java.util.Set;
45 import java.util.concurrent.atomic.AtomicInteger;
46 import javax.management.ListenerNotFoundException;
47 import javax.management.MBeanServer;
48 import javax.management.MBeanServerConnection;
49 import javax.management.MBeanServerDelegate;
50 import javax.management.Notification;
51 import javax.management.NotificationBroadcasterSupport;
52 import javax.management.NotificationFilterSupport;
53 import javax.management.NotificationListener;
54 import javax.management.ObjectName;
55 import javax.management.remote.JMXConnector;
56 import javax.management.remote.JMXConnectorFactory;
57 import javax.management.remote.JMXServiceURL;
58 import javax.management.remote.rmi.RMIConnection;
59 import javax.management.remote.rmi.RMIConnectionImpl;
60 import javax.management.remote.rmi.RMIConnectorServer;
61 import javax.management.remote.rmi.RMIJRMPServerImpl;
62 import javax.security.auth.Subject;
63
64 public class DeadListenerTest {
65 public static void main(String[] args) throws Exception {
66 final ObjectName delegateName = MBeanServerDelegate.DELEGATE_NAME;
67
68 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
69 Noddy mbean = new Noddy();
70 ObjectName name = new ObjectName("d:k=v");
71 mbs.registerMBean(mbean, name);
72
73 JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///");
74 SnoopRMIServerImpl rmiServer = new SnoopRMIServerImpl();
75 RMIConnectorServer cs = new RMIConnectorServer(url, null, rmiServer, mbs);
76 cs.start();
77 JMXServiceURL addr = cs.getAddress();
78 assertTrue("No connections in new connector server", rmiServer.connections.isEmpty());
79
80 JMXConnector cc = JMXConnectorFactory.connect(addr);
81 MBeanServerConnection mbsc = cc.getMBeanServerConnection();
82 assertTrue("One connection on server after client connect", rmiServer.connections.size() == 1);
83 RMIConnectionImpl connection = rmiServer.connections.get(0);
84 Method getServerNotifFwdM = RMIConnectionImpl.class.getDeclaredMethod("getServerNotifFwd");
85 getServerNotifFwdM.setAccessible(true);
86 ServerNotifForwarder serverNotifForwarder = (ServerNotifForwarder) getServerNotifFwdM.invoke(connection);
87 Field listenerMapF = ServerNotifForwarder.class.getDeclaredField("listenerMap");
88 listenerMapF.setAccessible(true);
89 @SuppressWarnings("unchecked")
90 Map<ObjectName, Set<?>> listenerMap = (Map<ObjectName, Set<?>>) listenerMapF.get(serverNotifForwarder);
91 assertTrue("Server listenerMap initially empty", mapWithoutKey(listenerMap, delegateName).isEmpty());
92
93 final AtomicInteger count1Val = new AtomicInteger();
94 CountListener count1 = new CountListener(count1Val);
95 mbsc.addNotificationListener(name, count1, null, null);
96 WeakReference<CountListener> count1Ref = new WeakReference<>(count1);
97 count1 = null;
98
99 final AtomicInteger count2Val = new AtomicInteger();
100 CountListener count2 = new CountListener(count2Val);
101 NotificationFilterSupport dummyFilter = new NotificationFilterSupport();
102 dummyFilter.enableType("");
103 mbsc.addNotificationListener(name, count2, dummyFilter, "noddy");
104 WeakReference<CountListener> count2Ref = new WeakReference<>(count2);
105 count2 = null;
106
107 assertTrue("One entry in listenerMap for two listeners on same MBean", mapWithoutKey(listenerMap, delegateName).size() == 1);
108 Set<?> set = listenerMap.get(name);
109 assertTrue("Set in listenerMap for MBean has two elements", set != null && set.size() == 2);
110
111 assertTrue("Initial value of count1 == 0", count1Val.get() == 0);
112 assertTrue("Initial value of count2 == 0", count2Val.get() == 0);
113
114 Notification notif = new Notification("type", name, 0);
115
116 mbean.sendNotification(notif);
117
118 // Make sure notifs are working normally.
119 while ((count1Val.get() != 1 || count2Val.get() != 1) ) {
120 Thread.sleep(20);
121 }
122 assertTrue("New value of count1 == 1", count1Val.get() == 1);
123 assertTrue("Initial value of count2 == 1", count2Val.get() == 1);
124
125 // Make sure that removing a nonexistent listener from an existent MBean produces ListenerNotFoundException
126 CountListener count3 = new CountListener();
127 try {
128 mbsc.removeNotificationListener(name, count3);
129 assertTrue("Remove of nonexistent listener succeeded but should not have", false);
130 } catch (ListenerNotFoundException e) {
131 // OK: expected
132 }
133
134 // Make sure that removing a nonexistent listener from a nonexistent MBean produces ListenerNotFoundException
135 ObjectName nonexistent = new ObjectName("foo:bar=baz");
136 assertTrue("Nonexistent is nonexistent", !mbs.isRegistered(nonexistent));
137 try {
138 mbsc.removeNotificationListener(nonexistent, count3);
139 assertTrue("Remove of listener from nonexistent MBean succeeded but should not have", false);
140 } catch (ListenerNotFoundException e) {
141 // OK: expected
142 }
143
144 // Now unregister our MBean, and check that notifs it sends no longer go anywhere.
145 mbs.unregisterMBean(name);
146 mbean.sendNotification(notif);
147 Thread.sleep(200);
148
149 assertTrue("New value of count1 == 1", count1Val.get() == 1);
150 assertTrue("Initial value of count2 == 1", count2Val.get() == 1);
151
152 // wait for the listener cleanup to take place upon processing notifications
153 int countdown = 50; // waiting max. 5 secs
154 while (countdown-- > 0 &&
155 (count1Ref.get() != null ||
156 count2Ref.get() != null)) {
157 System.gc();
158 Thread.sleep(100);
159 System.gc();
160 }
161 // listener has been removed or the wait has timed out
162
163 assertTrue("count1 notification listener has not been cleaned up", count1Ref.get() == null);
164 assertTrue("count2 notification listener has not been cleaned up", count2Ref.get() == null);
165
166 // Check that there is no trace of the listeners any more in ServerNotifForwarder.listenerMap.
167 // THIS DEPENDS ON JMX IMPLEMENTATION DETAILS.
168 // If the JMX implementation changes, the code here may have to change too.
169 Set<?> setForUnreg = listenerMap.get(name);
170 assertTrue("No trace of unregistered MBean: " + setForUnreg, setForUnreg == null);
171 }
172
173 private static <K, V> Map<K, V> mapWithoutKey(Map<K, V> map, K key) {
174 Map<K, V> copy = new HashMap<K, V>(map);
175 copy.remove(key);
176 return copy;
177 }
178
179 public static interface NoddyMBean {}
180
181 public static class Noddy extends NotificationBroadcasterSupport implements NoddyMBean {}
182
183 public static class CountListener implements NotificationListener {
184 final AtomicInteger count;
185
186 public CountListener(AtomicInteger i) {
187 count = i;
188 }
189
190 public CountListener() {
191 this.count = new AtomicInteger();
192 }
193
194 int count() {
195 return count.get();
196 }
197
198 public void handleNotification(Notification notification, Object handback) {
199 count.incrementAndGet();
200 }
201 }
202
203 private static void assertTrue(String what, boolean cond) {
204 if (!cond) {
205 throw new AssertionError("Assertion failed: " + what);
206 }
207 }
208
209 private static class SnoopRMIServerImpl extends RMIJRMPServerImpl {
210 final List<RMIConnectionImpl> connections = new ArrayList<RMIConnectionImpl>();
211 SnoopRMIServerImpl() throws IOException {
212 super(0, null, null, null);
213 }
214
215 @Override
216 protected RMIConnection makeClient(String id, Subject subject) throws IOException {
217 RMIConnectionImpl conn = (RMIConnectionImpl) super.makeClient(id, subject);
218 connections.add(conn);
219 return conn;
220 }
221 }
222 }