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 }