1 /* 2 * Copyright (C) 2011 The Guava Authors 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.google.common.util.concurrent; 18 19 import com.google.caliper.BeforeExperiment; 20 import com.google.caliper.Benchmark; 21 import com.google.caliper.Param; 22 23 import java.util.concurrent.locks.Lock; 24 import java.util.concurrent.locks.ReentrantLock; 25 26 /** 27 * Benchmarks for {@link CycleDetectingLockFactory}. 28 * 29 * @author Darick Tong 30 */ 31 public class CycleDetectingLockFactoryBenchmark { 32 33 @Param({"2","3","4","5","10"}) int lockNestingDepth; 34 35 CycleDetectingLockFactory factory; 36 private Lock[] plainLocks; 37 private Lock[] detectingLocks; 38 39 @BeforeExperiment 40 void setUp() throws Exception { 41 this.factory = CycleDetectingLockFactory.newInstance( 42 CycleDetectingLockFactory.Policies.WARN); 43 this.plainLocks = new Lock[lockNestingDepth]; 44 for (int i = 0; i < lockNestingDepth; i++) { 45 plainLocks[i] = new ReentrantLock(); 46 } 47 this.detectingLocks = new Lock[lockNestingDepth]; 48 for (int i = 0; i < lockNestingDepth; i++) { 49 detectingLocks[i] = factory.newReentrantLock("Lock" + i); 50 } 51 } 52 53 @Benchmark void unorderedPlainLocks(int reps) { 54 lockAndUnlock(new ReentrantLock(), reps); 55 } 56 57 @Benchmark void unorderedCycleDetectingLocks(int reps) { 58 lockAndUnlock(factory.newReentrantLock("foo"), reps); 59 } 60 61 private void lockAndUnlock(Lock lock, int reps) { 62 for (int i = 0; i < reps; i++) { 63 lock.lock(); 64 lock.unlock(); 65 } 66 } 67 68 @Benchmark void orderedPlainLocks(int reps) { 69 lockAndUnlockNested(plainLocks, reps); 70 } 71 72 @Benchmark void orderedCycleDetectingLocks(int reps) { 73 lockAndUnlockNested(detectingLocks, reps); 74 } 75 76 private void lockAndUnlockNested(Lock[] locks, int reps) { 77 for (int i = 0; i < reps; i++) { 78 for (int j = 0; j < locks.length; j++) { 79 locks[j].lock(); 80 } 81 for (int j = locks.length - 1; j >= 0; j--) { 82 locks[j].unlock(); 83 } 84 } 85 } 86 } 87
