| /* |
| * Copyright (c) 2013, 2014, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* @test |
| * @bug 8014890 |
| * @summary Verify that a race between ReferenceQueue.enqueue() and poll() does not occur. |
| * @author thomas.schatzl@oracle.com |
| * @run main/othervm -Xmx10M EnqueuePollRace |
| */ |
| |
| import java.lang.ref.*; |
| |
| public class EnqueuePollRace { |
| |
| public static void main(String args[]) throws Exception { |
| new WeakRef().run(); |
| System.out.println("Test passed."); |
| } |
| |
| static class WeakRef { |
| ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); |
| final int numReferences = 100; |
| final Reference refs[] = new Reference[numReferences]; |
| final int iterations = 1000; |
| |
| void run() throws InterruptedException { |
| for (int i = 0; i < iterations; i++) { |
| queue = new ReferenceQueue<Object>(); |
| |
| for (int j = 0; j < refs.length; j++) { |
| refs[j] = new WeakReference(new Object(), queue); |
| } |
| |
| System.gc(); // enqueues references into the list of discovered references |
| |
| // now manually enqueue all of them |
| for (int j = 0; j < refs.length; j++) { |
| refs[j].enqueue(); |
| } |
| // and get them back. There should be exactly numReferences |
| // entries in the queue now. |
| int foundReferences = 0; |
| while (queue.poll() != null) { |
| foundReferences++; |
| } |
| |
| if (foundReferences != refs.length) { |
| throw new RuntimeException("Got " + foundReferences + " references in the queue, but expected " + refs.length); |
| } |
| } |
| } |
| } |
| } |