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/*
* Copyright (c) 2011, 2017, 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 4268317 8132306 8175797
* @summary Test if Reference.enqueue() works properly with GC
* @run main ReferenceEnqueue
*/
import java.lang.ref.*;
import java.util.ArrayList;
import java.util.List;
public class ReferenceEnqueue {
public static void main(String args[]) throws Exception {
for (int i=0; i < 5; i++) {
new WeakRef().run();
new ExplicitEnqueue().run();
}
System.out.println("Test passed.");
}
static class WeakRef {
final ReferenceQueue<Object> queue = new ReferenceQueue<Object>();
final Reference<Object> ref;
final int iterations = 1000;
WeakRef() {
this.ref = new WeakReference<Object>(new Object(), queue);
}
void run() throws InterruptedException {
System.gc();
for (int i = 0; i < iterations; i++) {
System.gc();
if (ref.isEnqueued()) {
break;
}
Thread.sleep(100);
}
if (ref.isEnqueued() == false) {
// GC have not enqueued refWeak for the timeout period
System.out.println("Reference not enqueued yet");
return;
}
if (ref.enqueue() == true) {
// enqueue() should return false since
// ref is already enqueued by the GC
throw new RuntimeException("Error: enqueue() returned true;"
+ " expected false");
}
if (queue.poll() == null) {
// poll() should return ref enqueued by the GC
throw new RuntimeException("Error: poll() returned null;"
+ " expected ref object");
}
}
}
static class ExplicitEnqueue {
final ReferenceQueue<Object> queue = new ReferenceQueue<>();
final List<Reference<Object>> refs = new ArrayList<>();
final int iterations = 1000;
ExplicitEnqueue() {
this.refs.add(new SoftReference<>(new Object(), queue));
this.refs.add(new WeakReference<>(new Object(), queue));
// Can't test PhantomReference because get() always returns null.
}
void run() throws InterruptedException {
for (Reference<Object> ref : refs) {
if (ref.enqueue() == false) {
throw new RuntimeException("Error: enqueue failed");
}
if (ref.get() != null) {
throw new RuntimeException("Error: referent must be cleared");
}
}
System.gc();
for (int i = 0; refs.size() > 0 && i < iterations; i++) {
Reference<Object> ref = (Reference<Object>)queue.poll();
if (ref == null) {
System.gc();
Thread.sleep(100);
continue;
}
if (refs.remove(ref) == false) {
throw new RuntimeException("Error: unknown reference " + ref);
}
}
if (!refs.isEmpty()) {
throw new RuntimeException("Error: not all references are removed");
}
}
}
}
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