1 /*
   2  * Copyright (c) 2014 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 org.openjdk.bench.java.util.concurrent;
  24 
  25 import org.openjdk.jmh.annotations.Benchmark;
  26 import org.openjdk.jmh.annotations.BenchmarkMode;
  27 import org.openjdk.jmh.annotations.Level;
  28 import org.openjdk.jmh.annotations.Mode;
  29 import org.openjdk.jmh.annotations.OperationsPerInvocation;
  30 import org.openjdk.jmh.annotations.OutputTimeUnit;
  31 import org.openjdk.jmh.annotations.Scope;
  32 import org.openjdk.jmh.annotations.Setup;
  33 import org.openjdk.jmh.annotations.State;
  34 import org.openjdk.jmh.infra.Blackhole;
  35 
  36 import java.util.concurrent.TimeUnit;
  37 import java.util.concurrent.atomic.AtomicBoolean;
  38 import java.util.concurrent.atomic.AtomicInteger;
  39 import java.util.concurrent.atomic.AtomicLong;
  40 import java.util.concurrent.atomic.AtomicReference;
  41 
  42 @BenchmarkMode(Mode.AverageTime)
  43 @OutputTimeUnit(TimeUnit.NANOSECONDS)
  44 @State(Scope.Benchmark)
  45 public class Atomic {
  46 
  47     public AtomicInteger aInteger;
  48     public AtomicLong aLong;
  49     public AtomicBoolean aBool;
  50 
  51     public Object testObject1;
  52     public Object testObject2;
  53     public AtomicReference<Object> aReference;
  54 
  55     /**
  56      * The test variables are allocated every iteration so you can assume they are initialized to get similar behaviour
  57      * across iterations
  58      */
  59     @Setup(Level.Iteration)
  60     public void setupIteration() {
  61         testObject1 = new Object();
  62         testObject2 = new Object();
  63         aInteger = new AtomicInteger(0);
  64         aBool = new AtomicBoolean(false);
  65         aReference = new AtomicReference<>(testObject1);
  66         aLong = new AtomicLong(0);
  67     }
  68 
  69 
  70     /** Always swap in value. This test should be compiled into a CAS */
  71     @Benchmark
  72     @OperationsPerInvocation(2)
  73     public void testAtomicIntegerAlways(Blackhole bh) {
  74         bh.consume(aInteger.compareAndSet(0, 2));
  75         bh.consume(aInteger.compareAndSet(2, 0));
  76     }
  77 
  78     /** Never write a value just return the old one. This test should be compiled into a CAS */
  79     @Benchmark
  80     public void testAtomicIntegerNever(Blackhole bh) {
  81         bh.consume(aInteger.compareAndSet(1, 3));
  82     }
  83 
  84     /** Flips an atomic boolean on and off */
  85     @Benchmark
  86     @OperationsPerInvocation(2)
  87     public void testAtomicBooleanFlip(Blackhole bh) {
  88         bh.consume(aBool.getAndSet(true));
  89         bh.consume(aBool.getAndSet(false));
  90     }
  91 
  92     /** Writes same value over and over */
  93     @Benchmark
  94     public void testAtomicBooleanSame(Blackhole bh) {
  95         bh.consume(aBool.getAndSet(true));
  96     }
  97 
  98     /** Increment and get over multiple threads */
  99     @Benchmark
 100     public void testAtomicIntegerGetAndIncrement(Blackhole bh) {
 101         bh.consume(aInteger.getAndIncrement());
 102     }
 103 
 104     /** Increment and get over multiple threads */
 105     @Benchmark
 106     public void testAtomicLongGetAndIncrement(Blackhole bh) {
 107         bh.consume(aLong.getAndIncrement());
 108     }
 109 
 110     /** Swap a few references */
 111     @Benchmark
 112     @OperationsPerInvocation(2)
 113     public void testAtomicReference(Blackhole bh) {
 114         bh.consume(aReference.compareAndSet(testObject1, testObject2));
 115         bh.consume(aReference.compareAndSet(testObject2, testObject1));
 116     }
 117 }