1 /*
   2  * Copyright (c) 2013, 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  */
  29 
  30 import java.lang.annotation.Retention;
  31 import java.util.concurrent.atomic.AtomicInteger;
  32 
  33 import static java.lang.annotation.RetentionPolicy.RUNTIME;
  34 
  35 public class AnnotationTypeDeadlockTest {
  36 
  37     @Retention(RUNTIME)
  38     @AnnB
  39     public @interface AnnA {
  40     }
  41 
  42     @Retention(RUNTIME)
  43     @AnnA
  44     public @interface AnnB {
  45     }
  46 
  47     static class Task extends Thread {
  48         final AtomicInteger latch;
  49         final Class<?> clazz;
  50 
  51         Task(AtomicInteger latch, Class<?> clazz) {
  52             super(clazz.getSimpleName());
  53             setDaemon(true); // in case it deadlocks
  54             this.latch = latch;
  55             this.clazz = clazz;
  56         }
  57 
  58         @Override
  59         public void run() {
  60             latch.incrementAndGet();
  61             while (latch.get() > 0) ; // spin-wait
  62             clazz.getDeclaredAnnotations();
  63         }
  64     }
  65 
  66     static void dumpState(Task task) {
  67         System.err.println(
  68             "Task[" + task.getName() + "].state: " +
  69             task.getState() + " ..."
  70         );
  71         for (StackTraceElement ste : task.getStackTrace()) {
  72             System.err.println("\tat " + ste);
  73         }
  74         System.err.println();
  75     }
  76 
  77     public static void main(String[] args) throws Exception {
  78         AtomicInteger latch = new AtomicInteger();
  79         Task taskA = new Task(latch, AnnA.class);
  80         Task taskB = new Task(latch, AnnB.class);
  81         taskA.start();
  82         taskB.start();
  83         // spin-wait for both threads to start-up
  84         while (latch.get() < 2) ;
  85         // trigger coherent start
  86         latch.set(0);
  87         // join them
  88         taskA.join(500L);
  89         taskB.join(500L);
  90 
  91         if (taskA.isAlive() || taskB.isAlive()) {
  92             dumpState(taskA);
  93             dumpState(taskB);
  94             throw new IllegalStateException(
  95                 taskA.getState() == Thread.State.BLOCKED &&
  96                 taskB.getState() == Thread.State.BLOCKED
  97                 ? "deadlock detected"
  98                 : "unexpected condition");
  99         }
 100     }
 101 }