1 /*
2 * Copyright (c) 2005, 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 6303187
27 * @summary Test that no locks are held when a monitor attribute is sampled
28 * or notif delivered.
29 * @author Eamonn McManus
30 * @library /lib/testlibrary
31 * @modules java.management
32 * @run clean GaugeMonitorDeadlockTest
33 * @run build GaugeMonitorDeadlockTest
34 * @run main GaugeMonitorDeadlockTest 1
35 * @run main GaugeMonitorDeadlockTest 2
36 * @run main GaugeMonitorDeadlockTest 3
37 * @run main GaugeMonitorDeadlockTest 4
38 */
39
40 import java.lang.management.ManagementFactory;
41 import java.lang.management.ThreadInfo;
42 import java.lang.management.ThreadMXBean;
43 import java.util.concurrent.atomic.AtomicInteger;
44 import javax.management.JMX;
45 import javax.management.MBeanServer;
46 import javax.management.Notification;
47 import javax.management.NotificationListener;
48 import javax.management.ObjectName;
49 import javax.management.monitor.GaugeMonitor;
50 import javax.management.monitor.GaugeMonitorMBean;
51
52 import jdk.testlibrary.Utils;
53
54 public class GaugeMonitorDeadlockTest {
55 private static enum When {IN_GET_ATTRIBUTE, IN_NOTIFY};
56 private static long checkingTime;
57
58 public static void main(String[] args) throws Exception {
59 if (args.length != 1)
60 throw new Exception("Arg should be test number");
61 checkingTime = Utils.adjustTimeout(1000); // default 1s timeout
62 System.out.println("=== checkingTime = " + checkingTime + "ms");
63
64 int testNo = Integer.parseInt(args[0]) - 1;
65 TestCase test = testCases[testNo];
66 System.out.println("Test: " + test.getDescription());
67 test.run();
68 System.out.println("Test passed");
69 }
70
71 private static abstract class TestCase {
72 TestCase(String description, When when) {
73 this.description = description;
74 this.when = when;
75 }
76
77 void run() throws Exception {
78 final MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
79 final ObjectName observedName = new ObjectName("a:b=c");
80 final ObjectName monitorName = new ObjectName("a:type=Monitor");
81 mbs.registerMBean(new GaugeMonitor(), monitorName);
82 final GaugeMonitorMBean monitorProxy =
83 JMX.newMBeanProxy(mbs, monitorName, GaugeMonitorMBean.class);
84 final TestMBean observedProxy =
85 JMX.newMBeanProxy(mbs, observedName, TestMBean.class);
86
87 final Runnable sensitiveThing = new Runnable() {
88 public void run() {
89 doSensitiveThing(monitorProxy, observedName);
90 }
91 };
92
93 final Runnable nothing = new Runnable() {
94 public void run() {}
95 };
96
97 final Runnable withinGetAttribute =
98 (when == When.IN_GET_ATTRIBUTE) ? sensitiveThing : nothing;
99
100 mbs.registerMBean(new Test(withinGetAttribute), observedName);
101 monitorProxy.addObservedObject(observedName);
102 monitorProxy.setObservedAttribute("Thing");
103 monitorProxy.setThresholds(105, 100);
104 monitorProxy.setGranularityPeriod(10L); // 10 ms
105 monitorProxy.setNotifyHigh(true);
106 monitorProxy.setNotifyLow(true);
107
108 System.out.println("=== Waiting observedProxy.getGetCount() to be "
109 + "changed, presumable deadlock if timeout?");
110 final int initGetCount = observedProxy.getGetCount();
111 monitorProxy.start();
112
113 long checkedTime = System.currentTimeMillis();
114 long nowTime;
115 ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();
116 while (observedProxy.getGetCount() == initGetCount) {
117 Thread.sleep(100);
118
119 nowTime = System.currentTimeMillis();
120 if (nowTime - checkedTime >= checkingTime) {
121 System.out.println("=== Checking deadlocked ...");
122 if (threadMXBean.findDeadlockedThreads() != null) {
123 for (ThreadInfo info : threadMXBean.dumpAllThreads(true, true)) {
124 System.out.println(info);
125 }
126 throw new Error("Found deadlocked threads: "
127 + threadMXBean.findDeadlockedThreads().length);
128 }
129 checkedTime = System.currentTimeMillis();
130 }
131 }
132
133 // This won't show up as a deadlock in CTRL-\ or in
134 // ThreadMXBean.findDeadlockedThreads(), because they don't
135 // see that thread A is waiting for thread B (B.join()), and
136 // thread B is waiting for a lock held by thread A
137
138 // Now we know the monitor has observed the initial value,
139 // so if we want to test notify behaviour we can trigger by
140 // exceeding the threshold.
141 if (when == When.IN_NOTIFY) {
142 final Thread testedThread = new Thread(sensitiveThing);
143 final AtomicInteger notifCount = new AtomicInteger();
144 final NotificationListener listener = new NotificationListener() {
145 public void handleNotification(Notification n, Object h) {
146 testedThread.start();
147 try {
148 testedThread.join();
149 } catch (InterruptedException e) {
150 throw new RuntimeException(e);
151 }
152 notifCount.incrementAndGet();
153 }
154 };
155 mbs.addNotificationListener(monitorName, listener, null, null);
156 observedProxy.setThing(1000);
157 System.out.println("=== Waiting notifications, presumable "
158 + "deadlock if timeout?");
159 long startTime = System.currentTimeMillis();
160 checkedTime = startTime;
161 while (notifCount.get() == 0) {
162 Thread.sleep(100);
163
164 nowTime = System.currentTimeMillis();
165 if (nowTime - checkedTime >= checkingTime) {
166 System.out.println("=== Checking the thread state ...");
167 if (testedThread.isAlive()) {
168 System.out.println("=== Waiting testedThread to die "
169 + "after " + (nowTime - startTime) + "ms");
170
171 ThreadInfo tinfo = threadMXBean.getThreadInfo(testedThread.getId());
172 if (Thread.State.BLOCKED.equals(tinfo.getThreadState())) {
173 for (ThreadInfo info : threadMXBean.dumpAllThreads(true, true)) {
174 System.out.println(info);
175 }
176 } else {
177 System.out.println(tinfo);
178 }
179 } else {
180 System.out.println("=== The testedThread is dead as wished, "
181 + "the test must be passed soon.");
182 }
183 checkedTime = System.currentTimeMillis();
184 }
185 }
186 }
187 }
188
189 abstract void doSensitiveThing(GaugeMonitorMBean monitorProxy,
190 ObjectName observedName);
191
192 String getDescription() {
193 return description;
194 }
195
196 private final String description;
197 private final When when;
198 }
199
200 private static final TestCase[] testCases = {
201 new TestCase("Remove monitored MBean within monitored getAttribute",
202 When.IN_GET_ATTRIBUTE) {
203 @Override
204 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
205 ObjectName observedName) {
206 monitorProxy.removeObservedObject(observedName);
207 }
208 },
209 new TestCase("Stop monitor within monitored getAttribute",
210 When.IN_GET_ATTRIBUTE) {
211 @Override
212 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
213 ObjectName observedName) {
214 monitorProxy.stop();
215 }
216 },
217 new TestCase("Remove monitored MBean within threshold listener",
218 When.IN_NOTIFY) {
219 @Override
220 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
221 ObjectName observedName) {
222 monitorProxy.removeObservedObject(observedName);
223 }
224 },
225 new TestCase("Stop monitor within threshold listener",
226 When.IN_NOTIFY) {
227 @Override
228 void doSensitiveThing(GaugeMonitorMBean monitorProxy,
229 ObjectName observedName) {
230 monitorProxy.stop();
231 }
232 },
233 };
234
235 public static interface TestMBean {
236 public int getThing();
237 public void setThing(int thing);
238 public int getGetCount();
239 }
240
241 public static class Test implements TestMBean {
242 public Test(Runnable runWithinGetAttribute) {
243 this.runWithinGetAttribute = runWithinGetAttribute;
244 }
245
246 public int getThing() {
247 Thread t = new Thread(runWithinGetAttribute);
248 t.start();
249 try {
250 t.join();
251 } catch (InterruptedException e) {
252 throw new RuntimeException(e);
253 }
254 getCount++;
255 return thing;
256 }
257
258 public void setThing(int thing) {
259 this.thing = thing;
260 }
261
262 public int getGetCount() {
263 return getCount;
264 }
265
266 private final Runnable runWithinGetAttribute;
267 private volatile int getCount;
268 private volatile int thing;
269 }
270 }