1/*
2 * Copyright (c) 2013, 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 7122142
27 * @summary Test deadlock situation when recursive annotations are parsed
28 * @modules java.management
29 */
30
31import java.lang.annotation.Retention;
32import java.lang.management.ManagementFactory;
33import java.lang.management.ThreadInfo;
34import java.lang.management.ThreadMXBean;
35import java.util.concurrent.CountDownLatch;
36import java.util.concurrent.atomic.AtomicInteger;
37
38import static java.lang.annotation.RetentionPolicy.RUNTIME;
39
40public class AnnotationTypeDeadlockTest {
41
42    @Retention(RUNTIME)
43    @AnnB
44    public @interface AnnA {
45    }
46
47    @Retention(RUNTIME)
48    @AnnA
49    public @interface AnnB {
50    }
51
52    static class Task extends Thread {
53        final CountDownLatch prepareLatch;
54        final AtomicInteger goLatch;
55        final Class<?> clazz;
56
57        Task(CountDownLatch prepareLatch, AtomicInteger goLatch, Class<?> clazz) {
58            super(clazz.getSimpleName());
59            setDaemon(true); // in case it deadlocks
60            this.prepareLatch = prepareLatch;
61            this.goLatch = goLatch;
62            this.clazz = clazz;
63        }
64
65        @Override
66        public void run() {
67            prepareLatch.countDown();  // notify we are prepared
68            while (goLatch.get() > 0); // spin-wait before go
69            clazz.getDeclaredAnnotations();
70        }
71    }
72
73    public static void main(String[] args) throws Exception {
74        CountDownLatch prepareLatch = new CountDownLatch(2);
75        AtomicInteger goLatch = new AtomicInteger(1);
76        Task taskA = new Task(prepareLatch, goLatch, AnnA.class);
77        Task taskB = new Task(prepareLatch, goLatch, AnnB.class);
78        taskA.start();
79        taskB.start();
80        // wait until both threads start-up
81        prepareLatch.await();
82        // let them go
83        goLatch.set(0);
84        // obtain ThreadMXBean
85        ThreadMXBean threadBean = ManagementFactory.getThreadMXBean();
86        // wait for threads to finish or dead-lock
87        while (taskA.isAlive() || taskB.isAlive()) {
88            // attempt to join threads
89            taskA.join(500L);
90            taskB.join(500L);
91            // detect dead-lock
92            long[] deadlockedIds = threadBean.findMonitorDeadlockedThreads();
93            if (deadlockedIds != null && deadlockedIds.length > 0) {
94                StringBuilder sb = new StringBuilder("deadlock detected:\n\n");
95                for (ThreadInfo ti : threadBean.getThreadInfo(deadlockedIds, Integer.MAX_VALUE)) {
96                    sb.append(ti);
97                }
98                throw new IllegalStateException(sb.toString());
99            }
100        }
101    }
102}
103