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) setupIteration()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) testAtomicIntegerAlways(Blackhole bh)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 testAtomicIntegerNever(Blackhole bh)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) testAtomicBooleanFlip(Blackhole bh)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 testAtomicBooleanSame(Blackhole bh)94 public void testAtomicBooleanSame(Blackhole bh) { 95 bh.consume(aBool.getAndSet(true)); 96 } 97 98 /** Increment and get over multiple threads */ 99 @Benchmark testAtomicIntegerGetAndIncrement(Blackhole bh)100 public void testAtomicIntegerGetAndIncrement(Blackhole bh) { 101 bh.consume(aInteger.getAndIncrement()); 102 } 103 104 /** Increment and get over multiple threads */ 105 @Benchmark testAtomicLongGetAndIncrement(Blackhole bh)106 public void testAtomicLongGetAndIncrement(Blackhole bh) { 107 bh.consume(aLong.getAndIncrement()); 108 } 109 110 /** Swap a few references */ 111 @Benchmark 112 @OperationsPerInvocation(2) testAtomicReference(Blackhole bh)113 public void testAtomicReference(Blackhole bh) { 114 bh.consume(aReference.compareAndSet(testObject1, testObject2)); 115 bh.consume(aReference.compareAndSet(testObject2, testObject1)); 116 } 117 } 118