1 /*
2 * Copyright (c) 2010, 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 6957378
27 * @summary Test that a listener can be removed remotely from an MBean that no longer exists.
28 * @modules java.management/com.sun.jmx.remote.internal
29 * @author Eamonn McManus
30 */
31
32 import com.sun.jmx.remote.internal.ServerNotifForwarder;
33 import java.io.IOException;
34 import java.lang.management.ManagementFactory;
35 import java.lang.ref.WeakReference;
36 import java.lang.reflect.Field;
37 import java.lang.reflect.Method;
38 import java.util.ArrayList;
39 import java.util.HashMap;
40 import java.util.List;
41 import java.util.Map;
42 import java.util.Set;
43 import java.util.concurrent.atomic.AtomicInteger;
44 import javax.management.ListenerNotFoundException;
45 import javax.management.MBeanServer;
46 import javax.management.MBeanServerConnection;
47 import javax.management.MBeanServerDelegate;
48 import javax.management.Notification;
49 import javax.management.NotificationBroadcasterSupport;
50 import javax.management.NotificationFilterSupport;
51 import javax.management.NotificationListener;
52 import javax.management.ObjectName;
53 import javax.management.remote.JMXConnector;
54 import javax.management.remote.JMXConnectorFactory;
55 import javax.management.remote.JMXServiceURL;
56 import javax.management.remote.rmi.RMIConnection;
57 import javax.management.remote.rmi.RMIConnectionImpl;
58 import javax.management.remote.rmi.RMIConnectorServer;
59 import javax.management.remote.rmi.RMIJRMPServerImpl;
60 import javax.security.auth.Subject;
61
62 public class DeadListenerTest {
63 public static void main(String[] args) throws Exception {
64 final ObjectName delegateName = MBeanServerDelegate.DELEGATE_NAME;
65
66 MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
67 Noddy mbean = new Noddy();
68 ObjectName name = new ObjectName("d:k=v");
69 mbs.registerMBean(mbean, name);
70
71 JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///");
72 SnoopRMIServerImpl rmiServer = new SnoopRMIServerImpl();
73 RMIConnectorServer cs = new RMIConnectorServer(url, null, rmiServer, mbs);
74 cs.start();
75 JMXServiceURL addr = cs.getAddress();
76 assertTrue("No connections in new connector server", rmiServer.connections.isEmpty());
77
78 JMXConnector cc = JMXConnectorFactory.connect(addr);
79 MBeanServerConnection mbsc = cc.getMBeanServerConnection();
80 assertTrue("One connection on server after client connect", rmiServer.connections.size() == 1);
81 RMIConnectionImpl connection = rmiServer.connections.get(0);
82 Method getServerNotifFwdM = RMIConnectionImpl.class.getDeclaredMethod("getServerNotifFwd");
83 getServerNotifFwdM.setAccessible(true);
84 ServerNotifForwarder serverNotifForwarder = (ServerNotifForwarder) getServerNotifFwdM.invoke(connection);
85 Field listenerMapF = ServerNotifForwarder.class.getDeclaredField("listenerMap");
86 listenerMapF.setAccessible(true);
87 @SuppressWarnings("unchecked")
88 Map<ObjectName, Set<?>> listenerMap = (Map<ObjectName, Set<?>>) listenerMapF.get(serverNotifForwarder);
89 assertTrue("Server listenerMap initially empty", mapWithoutKey(listenerMap, delegateName).isEmpty());
90
91 final AtomicInteger count1Val = new AtomicInteger();
92 CountListener count1 = new CountListener(count1Val);
93 mbsc.addNotificationListener(name, count1, null, null);
94 WeakReference<CountListener> count1Ref = new WeakReference<>(count1);
95 count1 = null;
96
97 final AtomicInteger count2Val = new AtomicInteger();
98 CountListener count2 = new CountListener(count2Val);
99 NotificationFilterSupport dummyFilter = new NotificationFilterSupport();
100 dummyFilter.enableType("");
101 mbsc.addNotificationListener(name, count2, dummyFilter, "noddy");
102 WeakReference<CountListener> count2Ref = new WeakReference<>(count2);
103 count2 = null;
104
105 assertTrue("One entry in listenerMap for two listeners on same MBean", mapWithoutKey(listenerMap, delegateName).size() == 1);
106 Set<?> set = listenerMap.get(name);
107 assertTrue("Set in listenerMap for MBean has two elements", set != null && set.size() == 2);
108
109 assertTrue("Initial value of count1 == 0", count1Val.get() == 0);
110 assertTrue("Initial value of count2 == 0", count2Val.get() == 0);
111
112 Notification notif = new Notification("type", name, 0);
113
114 mbean.sendNotification(notif);
115
116 // Make sure notifs are working normally.
117 long deadline = System.currentTimeMillis() + 2000;
118 while ((count1Val.get() != 1 || count2Val.get() != 1) && System.currentTimeMillis() < deadline) {
119 Thread.sleep(10);
120 }
121 assertTrue("New value of count1 == 1", count1Val.get() == 1);
122 assertTrue("Initial value of count2 == 1", count2Val.get() == 1);
123
124 // Make sure that removing a nonexistent listener from an existent MBean produces ListenerNotFoundException
125 CountListener count3 = new CountListener();
126 try {
127 mbsc.removeNotificationListener(name, count3);
128 assertTrue("Remove of nonexistent listener succeeded but should not have", false);
129 } catch (ListenerNotFoundException e) {
130 // OK: expected
131 }
132
133 // Make sure that removing a nonexistent listener from a nonexistent MBean produces ListenerNotFoundException
134 ObjectName nonexistent = new ObjectName("foo:bar=baz");
135 assertTrue("Nonexistent is nonexistent", !mbs.isRegistered(nonexistent));
136 try {
137 mbsc.removeNotificationListener(nonexistent, count3);
138 assertTrue("Remove of listener from nonexistent MBean succeeded but should not have", false);
139 } catch (ListenerNotFoundException e) {
140 // OK: expected
141 }
142
143 // Now unregister our MBean, and check that notifs it sends no longer go anywhere.
144 mbs.unregisterMBean(name);
145 mbean.sendNotification(notif);
146 Thread.sleep(200);
147
148 assertTrue("New value of count1 == 1", count1Val.get() == 1);
149 assertTrue("Initial value of count2 == 1", count2Val.get() == 1);
150
151 // wait for the listener cleanup to take place upon processing notifications
152 int countdown = 50; // waiting max. 5 secs
153 while (countdown-- > 0 &&
154 (count1Ref.get() != null ||
155 count2Ref.get() != null)) {
156 System.gc();
157 Thread.sleep(100);
158 System.gc();
159 }
160 // listener has been removed or the wait has timed out
161
162 assertTrue("count1 notification listener has not been cleaned up", count1Ref.get() == null);
163 assertTrue("count2 notification listener has not been cleaned up", count2Ref.get() == null);
164
165 // Check that there is no trace of the listeners any more in ServerNotifForwarder.listenerMap.
166 // THIS DEPENDS ON JMX IMPLEMENTATION DETAILS.
167 // If the JMX implementation changes, the code here may have to change too.
168 Set<?> setForUnreg = listenerMap.get(name);
169 assertTrue("No trace of unregistered MBean: " + setForUnreg, setForUnreg == null);
170 }
171
172 private static <K, V> Map<K, V> mapWithoutKey(Map<K, V> map, K key) {
173 Map<K, V> copy = new HashMap<K, V>(map);
174 copy.remove(key);
175 return copy;
176 }
177
178 public static interface NoddyMBean {}
179
180 public static class Noddy extends NotificationBroadcasterSupport implements NoddyMBean {}
181
182 public static class CountListener implements NotificationListener {
183 final AtomicInteger count;
184
185 public CountListener(AtomicInteger i) {
186 count = i;
187 }
188
189 public CountListener() {
190 this.count = new AtomicInteger();
191 }
192
193 int count() {
194 return count.get();
195 }
196
197 public void handleNotification(Notification notification, Object handback) {
198 count.incrementAndGet();
199 }
200 }
201
202 private static void assertTrue(String what, boolean cond) {
203 if (!cond) {
204 throw new AssertionError("Assertion failed: " + what);
205 }
206 }
207
208 private static class SnoopRMIServerImpl extends RMIJRMPServerImpl {
209 final List<RMIConnectionImpl> connections = new ArrayList<RMIConnectionImpl>();
210 SnoopRMIServerImpl() throws IOException {
211 super(0, null, null, null);
212 }
213
214 @Override
215 protected RMIConnection makeClient(String id, Subject subject) throws IOException {
216 RMIConnectionImpl conn = (RMIConnectionImpl) super.makeClient(id, subject);
217 connections.add(conn);
218 return conn;
219 }
220 }
221 }