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  */
  23 package micro.benchmarks;
  24 
  25 import org.openjdk.jmh.annotations.Benchmark;
  26 import org.openjdk.jmh.annotations.Scope;
  27 import org.openjdk.jmh.annotations.State;
  28 import org.openjdk.jmh.annotations.Warmup;
  29 
  30 /**
  31  * Benchmarks cost of non-contended synchronization.
  32  */
  33 public 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 }