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.vm.lang; 24 25 import org.openjdk.jmh.annotations.Benchmark; 26 import org.openjdk.jmh.annotations.BenchmarkMode; 27 import org.openjdk.jmh.annotations.Mode; 28 import org.openjdk.jmh.annotations.OutputTimeUnit; 29 import org.openjdk.jmh.annotations.Param; 30 import org.openjdk.jmh.annotations.Scope; 31 import org.openjdk.jmh.annotations.Setup; 32 import org.openjdk.jmh.annotations.State; 33 34 import java.util.concurrent.TimeUnit; 35 36 37 /** 38 * Benchmark class for simple lock unlock tests. Nothing big should ever go into this class. 39 */ 40 @BenchmarkMode(Mode.AverageTime) 41 @OutputTimeUnit(TimeUnit.NANOSECONDS) 42 @State(Scope.Benchmark) 43 public class LockUnlock { 44 45 @Param("100") 46 private int innerCount; 47 48 public Object lockObject1; 49 public Object lockObject2; 50 public int factorial; 51 public int dummyInt1; 52 public int dummyInt2; 53 54 @Setup 55 public void setup() { 56 lockObject1 = new Object(); 57 lockObject2 = new Object(); 58 dummyInt1 = 47; 59 dummyInt2 = 11; // anything 60 } 61 62 /** Perform a synchronized on a local object within a loop. */ 63 @Benchmark 64 public void testSimpleLockUnlock() { 65 Object localObject = lockObject1; 66 for (int i = 0; i < innerCount; i++) { 67 synchronized (localObject) { 68 dummyInt1++; 69 dummyInt2++; 70 } 71 } 72 } 73 74 /** Perform a recursive synchronized on a local object within a loop. */ 75 @Benchmark 76 public void testRecursiveLockUnlock() { 77 Object localObject = lockObject1; 78 for (int i = 0; i < innerCount; i++) { 79 synchronized (localObject) { 80 synchronized (localObject) { 81 dummyInt1++; 82 dummyInt2++; 83 } 84 } 85 } 86 } 87 88 /** Perform two synchronized after each other on the same local object. */ 89 @Benchmark 90 public void testSerialLockUnlock() { 91 Object localObject = lockObject1; 92 for (int i = 0; i < innerCount; i++) { 93 synchronized (localObject) { 94 dummyInt1++; 95 } 96 synchronized (localObject) { 97 dummyInt2++; 98 } 99 } 100 } 101 102 /** 103 * Performs recursive synchronizations on the same local object. 104 * <p/> 105 * Result is 3628800 106 */ 107 @Benchmark 108 public void testRecursiveSynchronization() { 109 factorial = fact(10); 110 } 111 112 private synchronized int fact(int n) { 113 if (n == 0) { 114 return 1; 115 } else { 116 return fact(n - 1) * n; 117 } 118 } 119 }