| /* |
| * 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 |
| * @run main/othervm -Djdk.lang.ref.disableClearBeforeEnqueue=true 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; |
| final boolean disableClearBeforeEnqueue = |
| Boolean.getBoolean("jdk.lang.ref.disableClearBeforeEnqueue"); |
| |
| 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 (disableClearBeforeEnqueue && ref.get() == null) { |
| throw new RuntimeException("Error: clearing should be disabled"); |
| } |
| if (!disableClearBeforeEnqueue && 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"); |
| } |
| } |
| } |
| } |