1 /*
2 * Copyright (c) 2006, 2012, 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 6338874
27 * @summary Check that notification dispatch is not linear in number of MBeans.
28 * @author Eamonn McManus
29 */
30
31 /*
32 * The notification dispatch logic in the connector server used to be
33 * linear in the number of listeners there were on any MBean. For
34 * example, if there were 1000 MBeans, each with one listener, then
35 * every time a notification was sent it would be compared against
36 * every one of the 1000 MBeans, even though its source ObjectName was
37 * known and could not possibly match the name of 999 of the MBeans.
38 * This test checks that we no longer have linear behaviour. We do
39 * this by registering just one MBean and measuring the time it takes
40 * to send and receive a certain number of notifications from that
41 * MBean. Then we register many other MBeans, each with a listener,
42 * and we make the same measurement as before. The presence of the
43 * extra MBeans with their listeners should not impact the dispatch
44 * time significantly. If it does, the test fails.
45 *
46 * As usual with timing-sensitive tests, we could potentially get
47 * sporadic failures. We fail if the ratio of the time with many
48 * MBeans to the time with just one MBean is more than 500. With the
49 * fix in place, it is usually less than 1, presumably because some
50 * code was being interpreted during the first measurement but had
51 * been compiled by the second.
52 */
53
54 import java.util.concurrent.Semaphore;
55 import javax.management.MBeanServer;
56 import javax.management.MBeanServerConnection;
57 import javax.management.MBeanServerFactory;
58 import javax.management.MalformedObjectNameException;
59 import javax.management.Notification;
60 import javax.management.NotificationBroadcasterSupport;
61 import javax.management.NotificationListener;
62 import javax.management.ObjectName;
63 import javax.management.remote.JMXConnector;
64 import javax.management.remote.JMXConnectorFactory;
65 import javax.management.remote.JMXConnectorServer;
66 import javax.management.remote.JMXConnectorServerFactory;
67 import javax.management.remote.JMXServiceURL;
68
69 public class ListenerScaleTest {
70 private static final int WARMUP_WITH_ONE_MBEAN = 1000;
71 private static final int NOTIFS_TO_TIME = 100;
72 private static final int EXTRA_MBEANS = 20000;
73
74 private static final ObjectName testObjectName;
75 static {
76 try {
77 testObjectName = new ObjectName("test:type=Sender,number=-1");
78 } catch (MalformedObjectNameException e) {
79 throw new RuntimeException(e);
80 }
81 }
82
83 private static volatile int nnotifs;
84 private static volatile long startTime;
85 private static volatile long elapsed;
86 private static final Semaphore sema = new Semaphore(0);
87
88 private static final NotificationListener timingListener =
89 new NotificationListener() {
90 public void handleNotification(Notification n, Object h) {
91 if (++nnotifs == NOTIFS_TO_TIME) {
92 elapsed = System.nanoTime() - startTime;
93 sema.release();
94 }
95 }
96 };
97
98 private static final long timeNotif(MBeanServer mbs) {
99 try {
100 startTime = System.nanoTime();
101 nnotifs = 0;
102 mbs.invoke(testObjectName, "send", null, null);
103 sema.acquire();
104 return elapsed;
105 } catch (Exception e) {
106 throw new RuntimeException(e);
107 }
108 }
109
110 public static interface SenderMBean {
111 public void send();
112 }
113
114 public static class Sender extends NotificationBroadcasterSupport
115 implements SenderMBean {
116 public void send() {
117 for (int i = 0; i < NOTIFS_TO_TIME; i++)
118 sendNotification(new Notification("type", this, 1L));
119 }
120 }
121
122 private static final NotificationListener nullListener =
123 new NotificationListener() {
124 public void handleNotification(Notification n, Object h) {}
125 };
126
127 public static void main(String[] args) throws Exception {
128 MBeanServer mbs = MBeanServerFactory.newMBeanServer();
129 Sender sender = new Sender();
130 mbs.registerMBean(sender, testObjectName);
131 JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://");
132 JMXConnectorServer cs =
133 JMXConnectorServerFactory.newJMXConnectorServer(url, null, mbs);
134 cs.start();
135 JMXServiceURL addr = cs.getAddress();
136 JMXConnector cc = JMXConnectorFactory.connect(addr);
137 try {
138 test(mbs, cs, cc);
139 } finally {
140 cc.close();
141 cs.stop();
142 }
143 }
144
145 private static void test(MBeanServer mbs, JMXConnectorServer cs,
146 JMXConnector cc) throws Exception {
147 MBeanServerConnection mbsc = cc.getMBeanServerConnection();
148 mbsc.addNotificationListener(testObjectName, timingListener, null, null);
149 long singleMBeanTime = 0;
150 for (int i = 0; i < WARMUP_WITH_ONE_MBEAN; i++)
151 singleMBeanTime = timeNotif(mbs);
152 if (singleMBeanTime == 0)
153 singleMBeanTime = 1;
154 System.out.println("Time with a single MBean: " + singleMBeanTime + "ns");
155 System.out.println("Now registering " + EXTRA_MBEANS + " MBeans");
156 for (int i = 0; i < EXTRA_MBEANS; i++) {
157 ObjectName on = new ObjectName("test:type=Sender,number=" + i);
158 mbs.registerMBean(new Sender(), on);
159 if (i % 1000 == 999) {
160 System.out.print("..." + (i+1));
161 System.out.flush();
162 }
163 }
164 System.out.println();
165 System.out.println("Now registering " + EXTRA_MBEANS + " listeners");
166 for (int i = 0; i < EXTRA_MBEANS; i++) {
167 ObjectName on = new ObjectName("test:type=Sender,number=" + i);
168 mbsc.addNotificationListener(on, nullListener, null, null);
169 if (i % 1000 == 999) {
170 System.out.print("..." + (i+1));
171 System.out.flush();
172 }
173 }
174 System.out.println();
175 System.out.println("Timing a notification send now");
176 long manyMBeansTime = timeNotif(mbs);
177 System.out.println("Time with many MBeans: " + manyMBeansTime + "ns");
178 double ratio = (double) manyMBeansTime / singleMBeanTime;
179 if (ratio > 500.0)
180 throw new Exception("Failed: ratio=" + ratio);
181 System.out.println("Test passed: ratio=" + ratio);
182 }
183 }