1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/*
* Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* @test
* @run testng AsyncShutdownNowInvokeAnyRace
* @summary A variant of AsyncShutdownNow useful for race bug hunting
*/
// TODO: reorganize all of the AsyncShutdown tests
import java.util.Collections;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.CancellationException;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;
import static java.util.concurrent.TimeUnit.SECONDS;
import java.lang.management.ManagementFactory;
import java.lang.management.LockInfo;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
import org.testng.annotations.Test;
import static org.testng.Assert.*;
public class AsyncShutdownNowInvokeAnyRace {
// TODO: even more jitter-inducing parallelism?
// int nThreads = ThreadLocalRandom.current().nextInt(1, 50);
// ExecutorService pool = Executors.newCachedThreadPool();
// Callable<Void> task = () -> { testInvokeAny_1(); return null; };
// List<Callable<Void>> tasks = Collections.nCopies(nThreads, task);
// try {
// for (Future<Void> future : pool.invokeAll(tasks)) {
// future.get();
// }
// } finally {
// pool.shutdown();
// }
// }
// public void testInvokeAny_1() throws Exception {
/**
* Test shutdownNow with thread blocked in invokeAny.
*/
@Test
public void testInvokeAny() throws Exception {
final int reps = 30_000;
ThreadLocalRandom rnd = ThreadLocalRandom.current();
int falseAlarms = 0;
for (int rep = 1; rep < reps; rep++) {
ForkJoinPool pool = new ForkJoinPool(1);
CountDownLatch pleaseShutdownNow = new CountDownLatch(1);
int nTasks = rnd.nextInt(2, 5);
AtomicInteger threadsStarted = new AtomicInteger(0);
AtomicReference<String> poolAtShutdownNow = new AtomicReference<>();
Callable<Void> blockPool = () -> {
threadsStarted.getAndIncrement();
// await submission quiescence; may false-alarm
// TODO: consider re-checking to reduce false alarms
while (threadsStarted.get() + pool.getQueuedSubmissionCount() < nTasks)
Thread.yield();
pleaseShutdownNow.countDown();
Thread.sleep(86400_000);
return null;
};
List<Callable<Void>> tasks = Collections.nCopies(nTasks, blockPool);
Runnable shutdown = () -> {
try {
pleaseShutdownNow.await();
poolAtShutdownNow.set(pool.toString());
pool.shutdownNow();
} catch (Throwable t) { throw new AssertionError(t); }
};
Future<Void> shutdownResult = CompletableFuture.runAsync(shutdown);
try {
try {
if (rnd.nextBoolean())
pool.invokeAny(tasks, 10L, SECONDS);
else
pool.invokeAny(tasks);
throw new AssertionError("should throw");
} catch (RejectedExecutionException re) {
falseAlarms++;
} catch (CancellationException re) {
} catch (ExecutionException ex) {
Throwable cause = ex.getCause();
if (!(cause instanceof InterruptedException) &&
!(cause instanceof CancellationException))
throw ex;
} catch (TimeoutException ex) {
dumpTestThreads();
int i = rep;
String detail = String.format(
"invokeAny timed out, "
+ "nTasks=%d rep=%d threadsStarted=%d%n"
+ "poolAtShutdownNow=%s%n"
+ "poolAtTimeout=%s%n"
+ "queuedTaskCount=%d queuedSubmissionCount=%d",
nTasks, i, threadsStarted.get(),
poolAtShutdownNow,
pool,
pool.getQueuedTaskCount(),
pool.getQueuedSubmissionCount());
throw new AssertionError(detail, ex);
}
} finally {
pool.shutdown();
}
if (falseAlarms != 0)
System.out.println("Premature shutdowns = " + falseAlarms);
shutdownResult.get();
}
}
//--- thread stack dumping (from JSR166TestCase.java) ---
private static final ThreadMXBean THREAD_MXBEAN
= ManagementFactory.getThreadMXBean();
/** Returns true if thread info might be useful in a thread dump. */
static boolean threadOfInterest(ThreadInfo info) {
final String name = info.getThreadName();
String lockName;
if (name == null)
return true;
if (name.equals("Signal Dispatcher")
|| name.equals("WedgedTestDetector"))
return false;
if (name.equals("Reference Handler")) {
// Reference Handler stacktrace changed in JDK-8156500
StackTraceElement[] stackTrace; String methodName;
if ((stackTrace = info.getStackTrace()) != null
&& stackTrace.length > 0
&& (methodName = stackTrace[0].getMethodName()) != null
&& methodName.equals("waitForReferencePendingList"))
return false;
// jdk8 Reference Handler stacktrace
if ((lockName = info.getLockName()) != null
&& lockName.startsWith("java.lang.ref"))
return false;
}
if ((name.equals("Finalizer") || name.equals("Common-Cleaner"))
&& (lockName = info.getLockName()) != null
&& lockName.startsWith("java.lang.ref"))
return false;
if (name.startsWith("ForkJoinPool.commonPool-worker")
&& (lockName = info.getLockName()) != null
&& lockName.startsWith("java.util.concurrent.ForkJoinPool"))
return false;
return true;
}
/**
* A debugging tool to print stack traces of most threads, as jstack does.
* Uninteresting threads are filtered out.
*/
static void dumpTestThreads() {
System.err.println("------ stacktrace dump start ------");
for (ThreadInfo info : THREAD_MXBEAN.dumpAllThreads(true, true))
if (threadOfInterest(info))
System.err.print(info);
System.err.println("------ stacktrace dump end ------");
}
}
|
