1 /*
2 * Copyright (c) 2006, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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7 * published by the Free Software Foundation.
8 *
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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
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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
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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 * @library /test/lib
31 *
32 * @run build jdk.test.lib.Platform ListenerScaleTest
33 * @run main ListenerScaleTest
34 */
35
36 /*
37 * The notification dispatch logic in the connector server used to be
38 * linear in the number of listeners there were on any MBean. For
39 * example, if there were 1000 MBeans, each with one listener, then
40 * every time a notification was sent it would be compared against
41 * every one of the 1000 MBeans, even though its source ObjectName was
42 * known and could not possibly match the name of 999 of the MBeans.
43 * This test checks that we no longer have linear behaviour. We do
44 * this by registering just one MBean and measuring the time it takes
45 * to send and receive a certain number of notifications from that
46 * MBean. Then we register many other MBeans, each with a listener,
47 * and we make the same measurement as before. The presence of the
48 * extra MBeans with their listeners should not impact the dispatch
49 * time significantly. If it does, the test fails.
50 *
51 * As usual with timing-sensitive tests, we could potentially get
52 * sporadic failures. We fail if the ratio of the time with many
53 * MBeans to the time with just one MBean is more than 500. With the
54 * fix in place, it is usually less than 1, presumably because some
55 * code was being interpreted during the first measurement but had
56 * been compiled by the second.
57 */
58
59 import java.util.concurrent.Semaphore;
60 import javax.management.MBeanServer;
61 import javax.management.MBeanServerConnection;
62 import javax.management.MBeanServerFactory;
63 import javax.management.MalformedObjectNameException;
64 import javax.management.Notification;
65 import javax.management.NotificationBroadcasterSupport;
66 import javax.management.NotificationListener;
67 import javax.management.ObjectName;
68 import javax.management.remote.JMXConnector;
69 import javax.management.remote.JMXConnectorFactory;
70 import javax.management.remote.JMXConnectorServer;
71 import javax.management.remote.JMXConnectorServerFactory;
72 import javax.management.remote.JMXServiceURL;
73
74 import jdk.test.lib.Platform;
75
76 public class ListenerScaleTest {
77 private static final int WARMUP_WITH_ONE_MBEAN = 1000;
78 private static final int NOTIFS_TO_TIME = 100;
79 private static final int EXTRA_MBEANS = 20000;
80
81 private static final ObjectName testObjectName;
82 static {
83 try {
84 testObjectName = new ObjectName("test:type=Sender,number=-1");
85 } catch (MalformedObjectNameException e) {
86 throw new RuntimeException(e);
87 }
88 }
89
90 private static volatile int nnotifs;
91 private static volatile long startTime;
92 private static volatile long elapsed;
93 private static final Semaphore sema = new Semaphore(0);
94
95 private static final NotificationListener timingListener =
96 new NotificationListener() {
97 public void handleNotification(Notification n, Object h) {
98 if (++nnotifs == NOTIFS_TO_TIME) {
99 elapsed = System.nanoTime() - startTime;
100 sema.release();
101 }
102 }
103 };
104
105 private static final long timeNotif(MBeanServer mbs) {
106 try {
107 startTime = System.nanoTime();
108 nnotifs = 0;
109 mbs.invoke(testObjectName, "send", null, null);
110 sema.acquire();
111 return elapsed;
112 } catch (Exception e) {
113 throw new RuntimeException(e);
114 }
115 }
116
117 public static interface SenderMBean {
118 public void send();
119 }
120
121 public static class Sender extends NotificationBroadcasterSupport
122 implements SenderMBean {
123 public void send() {
124 for (int i = 0; i < NOTIFS_TO_TIME; i++)
125 sendNotification(new Notification("type", this, 1L));
126 }
127 }
128
129 private static final NotificationListener nullListener =
130 new NotificationListener() {
131 public void handleNotification(Notification n, Object h) {}
132 };
133
134 public static void main(String[] args) throws Exception {
135 if (Platform.isDebugBuild()) {
136 System.out.println("Running on a debug build. Performance test not applicable. Skipping.");
137 return;
138 }
139 MBeanServer mbs = MBeanServerFactory.newMBeanServer();
140 Sender sender = new Sender();
141 mbs.registerMBean(sender, testObjectName);
142 JMXServiceURL url = new JMXServiceURL("service:jmx:rmi://");
143 JMXConnectorServer cs =
144 JMXConnectorServerFactory.newJMXConnectorServer(url, null, mbs);
145 cs.start();
146 JMXServiceURL addr = cs.getAddress();
147 JMXConnector cc = JMXConnectorFactory.connect(addr);
148 try {
149 test(mbs, cs, cc);
150 } finally {
151 cc.close();
152 cs.stop();
153 }
154 }
155
156 private static void test(MBeanServer mbs, JMXConnectorServer cs,
157 JMXConnector cc) throws Exception {
158 MBeanServerConnection mbsc = cc.getMBeanServerConnection();
159 mbsc.addNotificationListener(testObjectName, timingListener, null, null);
160 long singleMBeanTime = 0;
161 for (int i = 0; i < WARMUP_WITH_ONE_MBEAN; i++)
162 singleMBeanTime = timeNotif(mbs);
163 if (singleMBeanTime == 0)
164 singleMBeanTime = 1;
165 System.out.println("Time with a single MBean: " + singleMBeanTime + "ns");
166 System.out.println("Now registering " + EXTRA_MBEANS + " MBeans");
167 for (int i = 0; i < EXTRA_MBEANS; i++) {
168 ObjectName on = new ObjectName("test:type=Sender,number=" + i);
169 mbs.registerMBean(new Sender(), on);
170 if (i % 1000 == 999) {
171 System.out.print("..." + (i+1));
172 System.out.flush();
173 }
174 }
175 System.out.println();
176 System.out.println("Now registering " + EXTRA_MBEANS + " listeners");
177 for (int i = 0; i < EXTRA_MBEANS; i++) {
178 ObjectName on = new ObjectName("test:type=Sender,number=" + i);
179 mbsc.addNotificationListener(on, nullListener, null, null);
180 if (i % 1000 == 999) {
181 System.out.print("..." + (i+1));
182 System.out.flush();
183 }
184 }
185 System.out.println();
186 System.out.println("Timing a notification send now");
187 long manyMBeansTime = timeNotif(mbs);
188 System.out.println("Time with many MBeans: " + manyMBeansTime + "ns");
189 double ratio = (double) manyMBeansTime / singleMBeanTime;
190 if (ratio > 500.0)
191 throw new Exception("Failed: ratio=" + ratio);
192 System.out.println("Test passed: ratio=" + ratio);
193 }
194 }