|
1 /* |
|
2 * Copyright (c) 2016, 2018, Red Hat, Inc. 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 TestWriteBarrierClearControl |
|
26 * @summary Clearing control during final graph reshape causes memory barrier to loose dependency on null check |
|
27 * @key gc |
|
28 * @requires vm.gc.Shenandoah |
|
29 * @run main/othervm -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:-TieredCompilation |
|
30 * -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC |
|
31 * -XX:+UnlockDiagnosticVMOptions -XX:+StressLCM -XX:+StressGCM |
|
32 * TestWriteBarrierClearControl |
|
33 * |
|
34 */ |
|
35 public class TestWriteBarrierClearControl { |
|
36 |
|
37 int f; |
|
38 |
|
39 static void test1(TestWriteBarrierClearControl o) { |
|
40 o.f = 0x42; |
|
41 } |
|
42 |
|
43 static TestWriteBarrierClearControl fo = new TestWriteBarrierClearControl(); |
|
44 |
|
45 static void test2() { |
|
46 TestWriteBarrierClearControl o = fo; |
|
47 o.f = 0x42; |
|
48 } |
|
49 |
|
50 static public void main(String[] args) { |
|
51 TestWriteBarrierClearControl o = new TestWriteBarrierClearControl(); |
|
52 for (int i = 0; i < 20000; i++) { |
|
53 test1(o); |
|
54 test2(); |
|
55 } |
|
56 try { |
|
57 test1(null); |
|
58 } catch (NullPointerException npe) {} |
|
59 fo = null; |
|
60 try { |
|
61 test2(); |
|
62 } catch (NullPointerException npe) {} |
|
63 } |
|
64 } |