1/*
2 * Copyright (c) 2015, 2015, 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 */
23package micro.benchmarks;
24
25import org.openjdk.jmh.annotations.Benchmark;
26import org.openjdk.jmh.annotations.Scope;
27import org.openjdk.jmh.annotations.State;
28import org.openjdk.jmh.annotations.Warmup;
29
30/**
31 * Benchmarks cost of non-contended synchronization.
32 */
33public class SimpleSyncBenchmark extends BenchmarkBase {
34
35    public static class Person {
36        public int age;
37
38        public Person(int age) {
39            this.age = age;
40        }
41
42        public synchronized int getAge() {
43            return age;
44        }
45
46        public synchronized void setAge(int age) {
47            this.age = age;
48        }
49
50        public synchronized void setAgeIfNonZero(int age) {
51            if (age != 0) {
52                this.age = age;
53            }
54        }
55    }
56
57    @State(Scope.Benchmark)
58    public static class ThreadState {
59        Person person = new Person(22);
60        int newAge = 45;
61    }
62
63    @Benchmark
64    @Warmup(iterations = 20)
65    public void setAgeCond(ThreadState state) {
66        Person person = state.person;
67        person.setAgeIfNonZero(state.newAge);
68    }
69
70    @Benchmark
71    @Warmup(iterations = 20)
72    public int getAge(ThreadState state) {
73        Person person = state.person;
74        return person.getAge();
75    }
76
77    @Benchmark
78    @Warmup(iterations = 20)
79    public int getAndIncAge(ThreadState state) {
80        Person person = state.person;
81        int oldAge = person.getAge();
82        person.setAge(oldAge + 1);
83        return oldAge;
84    }
85}
86