001/*
002 * Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.jtt.jdk;
024
025import jdk.internal.jvmci.meta.*;
026
027import org.junit.*;
028
029import sun.misc.*;
030
031import com.oracle.graal.jtt.*;
032
033public class Unsafe_compareAndSwap extends JTTTest {
034
035    static final Unsafe unsafe = UnsafeAccess01.getUnsafe();
036    static final long valueOffset;
037    static {
038        try {
039            valueOffset = unsafe.objectFieldOffset(Unsafe_compareAndSwap.class.getDeclaredField("value"));
040        } catch (Exception ex) {
041            throw new Error(ex);
042        }
043    }
044
045    public static String test(Unsafe_compareAndSwap u, Object o, String expected, String newValue) {
046        // First arg is not an array - can use a field write barrier
047        unsafe.compareAndSwapObject(u, valueOffset, expected, newValue);
048        // Not known if first arg is an array - different write barrier may be used
049        unsafe.compareAndSwapObject(o, valueOffset, expected, newValue);
050
051        return instance.value;
052    }
053
054    private String value;
055
056    private static final Unsafe_compareAndSwap instance = new Unsafe_compareAndSwap();
057
058    @Override
059    protected void before(ResolvedJavaMethod m) {
060        instance.value = "a";
061    }
062
063    @Test
064    public void run0() throws Throwable {
065        runTest("test", instance, instance, "a", "b");
066    }
067}