1 /*
 2  * Copyright Amazon.com Inc. 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 package org.openjdk.bench.vm.gc.barriers.cas;
26 
27 import org.openjdk.jmh.annotations.*;
28 
29 import java.util.concurrent.TimeUnit;
30 import java.util.concurrent.atomic.AtomicReference;
31 
32 @Warmup(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS)
33 @Measurement(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS)
34 @Fork(3)
35 @BenchmarkMode(Mode.AverageTime)
36 @OutputTimeUnit(TimeUnit.NANOSECONDS)
37 @State(Scope.Thread)
38 public class RefSuccess {
39 
40     AtomicReference<Object> ref;
41 
42     Object o1 = new Object();
43     Object o2 = o1;
44 
45     @Setup
46     public void setup() {
47         ref = new AtomicReference<>();
48         ref.set(o1);
49     }
50 
51     @Benchmark
52     @CompilerControl(CompilerControl.Mode.DONT_INLINE)
53     public void test() {
54         ref.compareAndSet(o1, o2);
55     }
56 
57 }