| /* |
| * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. |
| * Copyright (c) 2016, Red Hat, Inc. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /** |
| * @test |
| * @bug 8167298 |
| * @summary Unsafe.compareAndExchangeObject should keep track of returned type after matching |
| * @modules java.base/jdk.internal.misc |
| * @run main/othervm -XX:+IgnoreUnrecognizedVMOptions -XX:-BackgroundCompilation -XX:-UseOnStackReplacement -XX:-UseCompressedOops TestCAEAntiDep |
| * |
| */ |
| |
| import java.lang.reflect.Field; |
| import jdk.internal.misc.Unsafe; |
| |
| public class TestCAEAntiDep { |
| static final jdk.internal.misc.Unsafe UNSAFE = Unsafe.getUnsafe(); |
| static final long O_OFFSET; |
| |
| static class C { |
| int f1; |
| } |
| |
| C o = new C(); |
| |
| static { |
| try { |
| Field oField = TestCAEAntiDep.class.getDeclaredField("o"); |
| O_OFFSET = UNSAFE.objectFieldOffset(oField); |
| } catch (Exception e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| static int m(TestCAEAntiDep test, Object expected, Object x) { |
| C old = (C)UNSAFE.compareAndExchangeObject(test, O_OFFSET, expected, x); |
| int res = old.f1; |
| old.f1 = 0x42; |
| return res; |
| } |
| |
| static public void main(String[] args) { |
| TestCAEAntiDep test = new TestCAEAntiDep(); |
| for (int i = 0; i < 20000; i++) { |
| m(test, test.o, test.o); |
| } |
| } |
| } |