1 /* 2 * Copyright (c) 1999, 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 * @summary Suspending a ThreadGroup that contains the current thread has 28 * unpredictable results. 29 */ 30 31 public class Suspend implements Runnable { 32 private static Thread first=null; 33 private static Thread second=null; 34 private static ThreadGroup group = new ThreadGroup(""); 35 private static int count = 0; 36 37 Suspend() { 38 Thread thread = new Thread(group, this); 39 if (first == null) 40 first = thread; 41 else 42 second = thread; 43 44 thread.start(); 45 } 46 47 public void run() { 48 while (true) { 49 try { 50 Thread.sleep(1000); // Give other thread a chance to start 51 if (Thread.currentThread() == first) 52 group.suspend(); 53 else 54 count++; 55 } catch(InterruptedException e){ 56 } 57 } 58 } 59 60 public static void main(String[] args) throws Exception { 61 for (int i=0; i<2; i++) 62 new Suspend(); 63 Thread.sleep(3000); 64 boolean failed = (count > 1); 65 first.stop(); second.stop(); 66 if (failed) 67 throw new RuntimeException("Failure."); 68 } 69 }