TestLockEliminatedAtDeopt.java revision 11707:ad7af1afda7a 
1/*
2 * Copyright (c) 2014, 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 8032011
27 * @summary biased locking's revoke_bias locks monitor in compiled frame with eliminated lock
28 *
29 * @run main/othervm -XX:-UseOnStackReplacement
30 *      -XX:CompileCommand=dontinline,compiler.uncommontrap.TestLockEliminatedAtDeopt$A::m2
31 *      -XX:-BackgroundCompilation -XX:BiasedLockingStartupDelay=0
32 *      compiler.uncommontrap.TestLockEliminatedAtDeopt
33 */
34
35package compiler.uncommontrap;
36
37public class TestLockEliminatedAtDeopt {
38
39    static class A {
40        void m() {
41        }
42
43        // This lock is not eliminated but biased to main thread on
44        // first call
45        synchronized void m2(boolean trap) {
46            if (trap) {
47                new B();
48            }
49        }
50    }
51
52    static class B extends A {
53        void m() {
54        }
55    }
56
57    static void m1(boolean trap) {
58        A a = new A();
59        // This lock is eliminated by c2
60        synchronized(a) {
61            a.m2(trap);
62            a.m();
63        }
64    }
65
66     public static void main(String[] args) {
67        for (int i = 0; i < 20000; i++) {
68            m1(false);
69        }
70        // Trigger uncommon trap in A.m2() (class unloaded) and
71        // deoptimization of m1() (CHA invalidated). Uncommon trap
72        // code locks monitor in m1's frame where's it's eliminated.
73        m1(true);
74    }
75}
76