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 8019623 27 * @summary Tests that AppContext.getAppContext() works correctly in multi-threads scenario. 28 * @author Leonid Romanov 29 * @modules java.desktop/sun.awt 30 */ 31 32 import sun.awt.AppContext; 33 34 public class MultiThreadTest { 35 private static final int NUM_THREADS = 2; 36 37 private static AppContextGetter[] getters = new AppContextGetter[NUM_THREADS]; 38 39 public static void main(String[] args) { 40 createAndStartThreads(); 41 compareAppContexts(); 42 } 43 44 private static void createAndStartThreads() { 45 ThreadGroup systemGroup = getSystemThreadGroup(); 46 for (int i = 0; i < NUM_THREADS; ++i) { 47 ThreadGroup tg = new ThreadGroup(systemGroup, "AppContextGetter" + i); 48 getters[i] = new AppContextGetter(tg); 49 } 50 51 for (int i = 0; i < NUM_THREADS; ++i) { 52 getters[i].start(); 53 } 54 55 for (int i = 0; i < NUM_THREADS; ++i) { 56 try { 57 getters[i].join(); 58 } catch (InterruptedException e) { 59 // ignore 60 } 61 } 62 } 63 64 private static ThreadGroup getSystemThreadGroup() { 65 ThreadGroup currentThreadGroup = 66 Thread.currentThread().getThreadGroup(); 67 ThreadGroup parentThreadGroup = currentThreadGroup.getParent(); 68 while (parentThreadGroup != null) { 69 currentThreadGroup = parentThreadGroup; 70 parentThreadGroup = currentThreadGroup.getParent(); 71 } 72 73 return currentThreadGroup; 74 } 75 76 private static void compareAppContexts() { 77 AppContext ctx = getters[0].getAppContext(); 78 for (int i = 1; i < NUM_THREADS; ++i) { 79 if (!ctx.equals(getters[i].getAppContext())) { 80 throw new RuntimeException("Unexpected AppContexts difference, could be a race condition"); 81 } 82 } 83 } 84 85 private static class AppContextGetter extends Thread { 86 private AppContext appContext; 87 88 public AppContextGetter(ThreadGroup tg) { 89 super(tg, tg.getName()); 90 } 91 92 AppContext getAppContext() { 93 return appContext; 94 } 95 96 @Override 97 public void run() { 98 appContext = AppContext.getAppContext(); 99 } 100 } 101 }