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 8019623 27 * @summary Tests that AppContext.getAppContext() works correctly in multi-threads scenario. 28 * @author Leonid Romanov 29 */ 30 31 import sun.awt.AppContext; 32 33 public class MultiThreadTest { 34 private static final int NUM_THREADS = 2; 35 36 private static AppContextGetter[] getters = new AppContextGetter[NUM_THREADS]; 37 38 public static void main(String[] args) { 39 createAndStartThreads(); 40 compareAppContexts(); 41 } 42 43 private static void createAndStartThreads() { 44 ThreadGroup systemGroup = getSystemThreadGroup(); 45 for (int i = 0; i < NUM_THREADS; ++i) { 46 ThreadGroup tg = new ThreadGroup(systemGroup, "AppContextGetter" + i); 47 getters[i] = new AppContextGetter(tg); 48 } 49 50 for (int i = 0; i < NUM_THREADS; ++i) { 51 getters[i].start(); 52 } 53 54 for (int i = 0; i < NUM_THREADS; ++i) { 55 try { 56 getters[i].join(); 57 } catch (InterruptedException e) { 58 // ignore 59 } 60 } 61 } 62 63 private static ThreadGroup getSystemThreadGroup() { 64 ThreadGroup currentThreadGroup = 65 Thread.currentThread().getThreadGroup(); 66 ThreadGroup parentThreadGroup = currentThreadGroup.getParent(); 67 while (parentThreadGroup != null) { 68 currentThreadGroup = parentThreadGroup; 69 parentThreadGroup = currentThreadGroup.getParent(); 70 } 71 72 return currentThreadGroup; 73 } 74 75 private static void compareAppContexts() { 76 AppContext ctx = getters[0].getAppContext(); 77 for (int i = 1; i < NUM_THREADS; ++i) { 78 if (!ctx.equals(getters[i].getAppContext())) { 79 throw new RuntimeException("Unexpected AppContexts difference, could be a race condition"); 80 } 81 } 82 } 83 84 private static class AppContextGetter extends Thread { 85 private AppContext appContext; 86 87 public AppContextGetter(ThreadGroup tg) { 88 super(tg, tg.getName()); 89 } 90 91 AppContext getAppContext() { 92 return appContext; 93 } 94 95 @Override 96 public void run() { 97 appContext = AppContext.getAppContext(); 98 } 99 } 100 }