1 /*
2 * Copyright (c) 2005, 2006, 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 6303187
27 * @summary Test that no locks are held when a monitor attribute is sampled
28 * or notif delivered.
29 * @author Eamonn McManus
30 * @run clean GaugeMonitorDeadlockTest
31 * @run build GaugeMonitorDeadlockTest
32 * @run main GaugeMonitorDeadlockTest 1
33 * @run main GaugeMonitorDeadlockTest 2
34 * @run main GaugeMonitorDeadlockTest 3
35 * @run main GaugeMonitorDeadlockTest 4
36 */
37
38 import java.lang.management.ManagementFactory;
39 import java.lang.management.ThreadInfo;
40 import java.lang.management.ThreadMXBean;
41 import java.util.concurrent.atomic.AtomicInteger;
42 import javax.management.JMX;
43 import javax.management.MBeanServer;
44 import javax.management.Notification;
45 import javax.management.NotificationListener;
46 import javax.management.ObjectName;
47 import javax.management.monitor.GaugeMonitor;
48 import javax.management.monitor.GaugeMonitorMBean;
49
50 public class GaugeMonitorDeadlockTest {
51 private static enum When {IN_GET_ATTRIBUTE, IN_NOTIFY};
52 private static long checkingTime;
53
54 public static void main(String[] args) throws Exception {
55 if (args.length != 1)
56 throw new Exception("Arg should be test number");
57 double factor = Double.parseDouble(System.getProperty("test.timeout.factor", "1.0"));
58 checkingTime = (long)factor*1000;
59 System.out.println("=== checkingTime = " + checkingTime + "ms");
60
61 int testNo = Integer.parseInt(args[0]) - 1;
62 TestCase test = testCases[testNo];
63 System.out.println("Test: " + test.getDescription());
64 test.run();
65 System.out.println("Test passed");
66 }
67
68 private static abstract class TestCase {
69 TestCase(String description, When when) {
70 this.description = description;
71 this.when = when;
72 }
73
74 void run() throws Exception {
75 final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
76 final ObjectName observedName = new ObjectName("a:b=c");
77 final ObjectName monitorName = new ObjectName("a:type=Monitor");
78 mbs.registerMBean(new GaugeMonitor(), monitorName);
79 final GaugeMonitorMBean monitorProxy =
80 JMX.newMBeanProxy(mbs, monitorName, GaugeMonitorMBean.class);
81 final TestMBean observedProxy =
82 JMX.newMBeanProxy(mbs, observedName, TestMBean.class);
83
84 final Runnable sensitiveThing = new Runnable() {
85 public void run() {
86 doSensitiveThing(monitorProxy, observedName);
87 }
88 };
89
90 final Runnable nothing = new Runnable() {
91 public void run() {}
92 };
93
94 final Runnable withinGetAttribute =
95 (when == When.IN_GET_ATTRIBUTE) ? sensitiveThing : nothing;
96
97 mbs.registerMBean(new Test(withinGetAttribute), observedName);
98 monitorProxy.addObservedObject(observedName);
99 monitorProxy.setObservedAttribute("Thing");
100 monitorProxy.setThresholds(105, 100);
101 monitorProxy.setGranularityPeriod(10L); // 10 ms
102 monitorProxy.setNotifyHigh(true);
103 monitorProxy.setNotifyLow(true);
104 monitorProxy.start();
105
106 System.out.println("=== Waiting observedProxy.getGetCount() to be "
107 + "changed, presumable deadlock if timeout?");
108 final int initGetCount = observedProxy.getGetCount();
109 long checkedTime = System.currentTimeMillis();
110 long nowTime;
111 ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();
112 while (observedProxy.getGetCount() == initGetCount) {
113 Thread.sleep(100);
114
115 nowTime = System.currentTimeMillis();
116 if (nowTime - checkedTime >= checkingTime) {
117 System.out.println("=== Checking deadlocked ...");
118 if (threadMXBean.findDeadlockedThreads() != null) {
119 for (ThreadInfo info : threadMXBean.dumpAllThreads(true, true)) {
120 System.out.println(info);
121 }
122 throw new Error("Found deadlocked threads: "
123 + threadMXBean.findDeadlockedThreads().length);
124 }
125 checkedTime = System.currentTimeMillis();
126 }
127 }
128
129 // This won't show up as a deadlock in CTRL-\ or in
130 // ThreadMXBean.findDeadlockedThreads(), because they don't
131 // see that thread A is waiting for thread B (B.join()), and
132 // thread B is waiting for a lock held by thread A
133
134 // Now we know the monitor has observed the initial value,
135 // so if we want to test notify behaviour we can trigger by
136 // exceeding the threshold.
137 if (when == When.IN_NOTIFY) {
138 final Thread testedThread = new Thread(sensitiveThing);
139 final AtomicInteger notifCount = new AtomicInteger();
140 final NotificationListener listener = new NotificationListener() {
141 public void handleNotification(Notification n, Object h) {
142 testedThread.start();
143 try {
144 testedThread.join();
145 } catch (InterruptedException e) {
146 throw new RuntimeException(e);
147 }
148 notifCount.incrementAndGet();
149 }
150 };
151 mbs.addNotificationListener(monitorName, listener, null, null);
152 observedProxy.setThing(1000);
153 System.out.println("=== Waiting notifications, presumable "
154 + "deadlock if timeout?");
155 long startTime = System.currentTimeMillis();
156 checkedTime = startTime;
157 while (notifCount.get() == 0) {
158 Thread.sleep(100);
159
160 nowTime = System.currentTimeMillis();
161 if (nowTime - checkedTime >= checkingTime) {
162 System.out.println("=== Checking the thread state ...");
163 if (testedThread.isAlive()) {
164 System.out.println("=== Waiting testedThread to die "
165 + "after " + (nowTime - startTime) + "ms");
166
167 ThreadInfo tinfo = threadMXBean.getThreadInfo(testedThread.getId());
168 if (Thread.State.BLOCKED.equals(tinfo.getThreadState())) {
169 for (ThreadInfo info : threadMXBean.dumpAllThreads(true, true)) {
170 System.out.println(info);
171 }
172 } else {
173 System.out.println(tinfo);
174 }
175 } else {
176 System.out.println("=== The testedThread is dead as wished, "
177 + "the test must be passed soon.");
178 }
179 checkedTime = System.currentTimeMillis();
180 }
181 }
182 }
183 }
184
185 abstract void doSensitiveThing(GaugeMonitorMBean monitorProxy,
186 ObjectName observedName);
187
188 String getDescription() {
189 return description;
190 }
191
192 private final String description;
193 private final When when;
194 }
195
196 private static final TestCase[] testCases = {
197 new TestCase("Remove monitored MBean within monitored getAttribute",
198 When.IN_GET_ATTRIBUTE) {
199 @Override
200 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
201 ObjectName observedName) {
202 monitorProxy.removeObservedObject(observedName);
203 }
204 },
205 new TestCase("Stop monitor within monitored getAttribute",
206 When.IN_GET_ATTRIBUTE) {
207 @Override
208 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
209 ObjectName observedName) {
210 monitorProxy.stop();
211 }
212 },
213 new TestCase("Remove monitored MBean within threshold listener",
214 When.IN_NOTIFY) {
215 @Override
216 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
217 ObjectName observedName) {
218 monitorProxy.removeObservedObject(observedName);
219 }
220 },
221 new TestCase("Stop monitor within threshold listener",
222 When.IN_NOTIFY) {
223 @Override
224 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
225 ObjectName observedName) {
226 monitorProxy.stop();
227 }
228 },
229 };
230
231 public static interface TestMBean {
232 public int getThing();
233 public void setThing(int thing);
234 public int getGetCount();
235 }
236
237 public static class Test implements TestMBean {
238 public Test(Runnable runWithinGetAttribute) {
239 this.runWithinGetAttribute = runWithinGetAttribute;
240 }
241
242 public int getThing() {
243 Thread t = new Thread(runWithinGetAttribute);
244 t.start();
245 try {
246 t.join();
247 } catch (InterruptedException e) {
248 throw new RuntimeException(e);
249 }
250 getCount++;
251 return thing;
252 }
253
254 public void setThing(int thing) {
255 this.thing = thing;
256 }
257
258 public int getGetCount() {
259 return getCount;
260 }
261
262 private final Runnable runWithinGetAttribute;
263 private volatile int getCount;
264 private volatile int thing;
265 }
266 }