1 /* 2 * Copyright (c) 2012, 2013, 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 /* 25 * @test 26 * @bug 7190310 27 * @summary Inlining WeakReference.get(), and hoisting $referent may lead to non-terminating loops 28 * 29 * @run main/othervm/timeout=600 -Xbatch compiler.c2.Test7190310 30 */ 31 32 /* 33 * Note bug exhibits as infinite loop, timeout is helpful. 34 * It should normally finish pretty quickly, but on some especially slow machines 35 * it may not. The companion _unsafe test lacks a timeout, but that is okay. 36 */ 37 package compiler.c2; 38 39 import java.lang.ref.Reference; 40 import java.lang.ref.ReferenceQueue; 41 import java.lang.ref.WeakReference; 42 43 public class Test7190310 { 44 private static Object str = new Object() { 45 public String toString() { 46 return "The Object"; 47 } 48 49 protected void finalize() throws Throwable { 50 System.out.println("The Object is being finalized"); 51 super.finalize(); 52 } 53 }; 54 private final static ReferenceQueue<Object> rq = 55 new ReferenceQueue<Object>(); 56 private final static WeakReference<Object> wr = 57 new WeakReference<Object>(str, rq); 58 main(String[] args)59 public static void main(String[] args) 60 throws InterruptedException { 61 Thread reader = new Thread() { 62 public void run() { 63 while (wr.get() != null) { 64 } 65 System.out.println("wr.get() returned null"); 66 } 67 }; 68 69 Thread queueReader = new Thread() { 70 public void run() { 71 try { 72 Reference<? extends Object> ref = rq.remove(); 73 System.out.println(ref); 74 System.out.println("queueReader returned, ref==wr is " 75 + (ref == wr)); 76 } catch (InterruptedException e) { 77 System.err.println("Sleep interrupted - exiting"); 78 } 79 } 80 }; 81 82 reader.start(); 83 queueReader.start(); 84 85 Thread.sleep(1000); 86 str = null; 87 System.gc(); 88 } 89 } 90 91