1 /* 2 * Copyright (c) 2011, 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 /* @test 25 * @bug 4268317 8132306 26 * @summary Test if Reference.enqueue() works properly with GC 27 */ 28 29 import java.lang.ref.*; 30 31 public class ReferenceEnqueue { 32 33 public static void main(String args[]) throws Exception { 34 for (int i=0; i < 5; i++) 35 new WeakRef().run(); 36 System.out.println("Test passed."); 37 } 38 39 static class WeakRef { 40 final ReferenceQueue<Object> queue = new ReferenceQueue<Object>(); 41 final Reference<Object> ref; 42 final int iterations = 1000; 43 44 WeakRef() { 45 this.ref = new WeakReference<Object>(new Object(), queue); 46 } 47 48 void run() throws InterruptedException { 49 System.gc(); 50 for (int i = 0; i < iterations; i++) { 51 System.gc(); 52 if (ref.isEnqueued()) { 53 break; 54 } 55 56 Thread.sleep(100); 57 } 58 59 if (ref.isEnqueued() == false) { 60 // GC have not enqueued refWeak for the timeout period 61 System.out.println("Reference not enqueued yet"); 62 return; 63 } 64 65 if (ref.enqueue() == true) { 66 // enqueue() should return false since 67 // ref is already enqueued by the GC 68 throw new RuntimeException("Error: enqueue() returned true;" 69 + " expected false"); 70 } 71 72 if (queue.poll() == null) { 73 // poll() should return ref enqueued by the GC 74 throw new RuntimeException("Error: poll() returned null;" 75 + " expected ref object"); 76 } 77 } 78 } 79 }