1 /*
   2  * Copyright (c) 1999, 2016, 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 4176355
  27  * @library /test/lib/share/classes
  28  * @modules java.base/jdk.internal.misc
  29  * @summary Stopping a ThreadGroup that contains the current thread has
  30  *          unpredictable results.
  31  */
  32 
  33 import java.util.concurrent.CountDownLatch;
  34 
  35 import jdk.test.lib.Utils;
  36 
  37 public class Stop {
  38 
  39     private static final long LONG_DELAY_MS = Utils.adjustTimeout(5000L);
  40     private static final CountDownLatch ready = new CountDownLatch(1);
  41     private static final CountDownLatch done = new CountDownLatch(2);
  42     private static final ThreadGroup group = new ThreadGroup("");
  43 
  44     private static final Thread second = new Thread(group, () -> {
  45         ready.countDown();
  46         try {
  47             while (true) {
  48                 // keep it alive
  49             }
  50         } catch (final ThreadDeath td) {
  51             done.countDown();
  52             throw td;
  53         }
  54     });
  55 
  56     private static final Thread first = new Thread(group, () -> {
  57         // Wait until "second" is started
  58         await(ready);
  59         try {
  60             // Now stop the group
  61             // ThreadDeath then is thrown in the victim threads                
  62             group.stop();
  63         } catch (final ThreadDeath td) {
  64             // Inform the main thead that the test thread has completed
  65             done.countDown();
  66             // Rethrow the object so that the thread actually dies
  67             throw td;
  68         }
  69     });
  70 
  71     private static void await(CountDownLatch latch) {
  72         try {
  73             latch.await();
  74         } catch (InterruptedException e) {
  75             throw new RuntimeException(e);
  76         }
  77     }
  78 
  79     public static void main(String[] args) throws Exception {
  80         // Launch two threads as part of the same thread group
  81         first.start();
  82         second.start();
  83 
  84         try {
  85             // Wait for the thread group stop to be issued
  86             await(done);
  87 
  88             // Check that the second thread is terminated when the
  89             // first thread terminates the thread group.
  90             second.join(LONG_DELAY_MS);
  91             boolean failed = second.isAlive();
  92             if (failed) {
  93                 throw new RuntimeException("Failure.");
  94             }
  95         } finally {
  96             // Clean up any threads that may have not been terminated
  97             first.stop();
  98             second.stop();
  99         }
 100     }
 101 }