Test7190310.java revision 11707:ad7af1afda7a 
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/*
26 * @test
27 * @bug 7190310
28 * @summary Inlining WeakReference.get(), and hoisting $referent may lead to non-terminating loops
29 *
30 * @run main/othervm/timeout=600 -Xbatch compiler.c2.Test7190310
31 */
32
33/*
34 * Note bug exhibits as infinite loop, timeout is helpful.
35 * It should normally finish pretty quickly, but on some especially slow machines
36 * it may not.  The companion _unsafe test lacks a timeout, but that is okay.
37 */
38package compiler.c2;
39
40import java.lang.ref.Reference;
41import java.lang.ref.ReferenceQueue;
42import java.lang.ref.WeakReference;
43
44public class Test7190310 {
45    private static Object str = new Object() {
46        public String toString() {
47            return "The Object";
48        }
49
50        protected void finalize() throws Throwable {
51            System.out.println("The Object is being finalized");
52            super.finalize();
53        }
54    };
55    private final static ReferenceQueue<Object> rq =
56            new ReferenceQueue<Object>();
57    private final static WeakReference<Object> wr =
58            new WeakReference<Object>(str, rq);
59
60    public static void main(String[] args)
61            throws InterruptedException {
62        Thread reader = new Thread() {
63            public void run() {
64                while (wr.get() != null) {
65                }
66                System.out.println("wr.get() returned null");
67            }
68        };
69
70        Thread queueReader = new Thread() {
71            public void run() {
72                try {
73                    Reference<? extends Object> ref = rq.remove();
74                    System.out.println(ref);
75                    System.out.println("queueReader returned, ref==wr is "
76                            + (ref == wr));
77                } catch (InterruptedException e) {
78                    System.err.println("Sleep interrupted - exiting");
79                }
80            }
81        };
82
83        reader.start();
84        queueReader.start();
85
86        Thread.sleep(1000);
87        str = null;
88        System.gc();
89    }
90}
91
92