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/*
* 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);
}
}
}
}
}
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