1 /* 2 * Copyright Amazon.com Inc. 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 java.io.ByteArrayInputStream; 26 import java.io.ByteArrayOutputStream; 27 import java.io.IOException; 28 import java.io.ObjectInputStream; 29 import java.io.ObjectOutputStream; 30 import java.util.ArrayList; 31 import java.util.Arrays; 32 import java.util.Collection; 33 import java.util.concurrent.CopyOnWriteArrayList; 34 import java.util.concurrent.TimeUnit; 35 36 import org.openjdk.jmh.annotations.Benchmark; 37 import org.openjdk.jmh.annotations.BenchmarkMode; 38 import org.openjdk.jmh.annotations.Fork; 39 import org.openjdk.jmh.annotations.Measurement; 40 import org.openjdk.jmh.annotations.Mode; 41 import org.openjdk.jmh.annotations.OutputTimeUnit; 42 import org.openjdk.jmh.annotations.Scope; 43 import org.openjdk.jmh.annotations.State; 44 import org.openjdk.jmh.annotations.Warmup; 45 46 @BenchmarkMode(Mode.AverageTime) 47 @State(Scope.Benchmark) 48 @OutputTimeUnit(TimeUnit.NANOSECONDS) 49 @Fork(1) 50 @Warmup(iterations = 3, time = 1, timeUnit = TimeUnit.SECONDS) 51 @Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS) 52 public class CopyOnWriteArrayListBenchmark { 53 54 private static byte[] getSerializedBytes(CopyOnWriteArrayList<?> list) throws IOException { 55 ByteArrayOutputStream bytesOut = new ByteArrayOutputStream(); 56 ObjectOutputStream objectOut = new ObjectOutputStream(bytesOut); 57 objectOut.writeObject(list); 58 59 objectOut.close(); 60 return bytesOut.toByteArray(); 61 } 62 63 private Collection<Object> emptyCollection = new ArrayList<>(); 64 private Object[] emptyArray = new Object[0]; 65 66 private Collection<Object> oneItemCollection = Arrays.asList(""); 67 private Object[] oneItemArray = new Object[] { "" }; 68 69 private CopyOnWriteArrayList<?> emptyInstance = new CopyOnWriteArrayList<>(); 70 private CopyOnWriteArrayList<?> oneItemInstance = new CopyOnWriteArrayList<>(oneItemArray); 71 72 private byte[] emptyInstanceBytes; 73 private byte[] oneInstanceBytes; 74 75 public CopyOnWriteArrayListBenchmark() { 76 try { 77 emptyInstanceBytes = getSerializedBytes(emptyInstance); 78 oneInstanceBytes = getSerializedBytes(oneItemInstance); 79 } catch (IOException e) { 80 throw new RuntimeException(e); 81 } 82 } 83 84 @Benchmark 85 public void clear() { 86 // have to create a new instance on each execution 87 ((CopyOnWriteArrayList<?>) oneItemInstance.clone()).clear(); 88 } 89 90 @Benchmark 91 public void clearEmpty() { 92 emptyInstance.clear(); 93 } 94 95 @Benchmark 96 public CopyOnWriteArrayList<?> createInstanceArray() { 97 return new CopyOnWriteArrayList<>(oneItemArray); 98 } 99 100 @Benchmark 101 public CopyOnWriteArrayList<?> createInstanceArrayEmpty() { 102 return new CopyOnWriteArrayList<>(emptyArray); 103 } 104 105 @Benchmark 106 public CopyOnWriteArrayList<?> createInstanceCollection() { 107 return new CopyOnWriteArrayList<>(oneItemCollection); 108 } 109 110 @Benchmark 111 public CopyOnWriteArrayList<?> createInstanceCollectionEmpty() { 112 return new CopyOnWriteArrayList<>(emptyCollection); 113 } 114 115 @Benchmark 116 public CopyOnWriteArrayList<?> createInstanceDefault() { 117 return new CopyOnWriteArrayList<Object>(); 118 } 119 120 @Benchmark 121 public CopyOnWriteArrayList<?> readInstance() throws IOException, ClassNotFoundException { 122 try (ObjectInputStream objIn = new ObjectInputStream(new ByteArrayInputStream(oneInstanceBytes))) { 123 return (CopyOnWriteArrayList<?>) objIn.readObject(); 124 } 125 } 126 127 @Benchmark 128 public CopyOnWriteArrayList<?> readInstanceEmpty() throws IOException, ClassNotFoundException { 129 try (ObjectInputStream objIn = new ObjectInputStream(new ByteArrayInputStream(emptyInstanceBytes))) { 130 return (CopyOnWriteArrayList<?>) objIn.readObject(); 131 } 132 } 133 134 @Benchmark 135 public CopyOnWriteArrayList<?> removeObjectLastRemaining() { 136 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>(); 137 list.add(""); 138 list.remove(""); 139 return list; 140 } 141 142 @Benchmark 143 public CopyOnWriteArrayList<?> removeIndexLastRemaining() { 144 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>(); 145 list.add(""); 146 list.remove(0); 147 return list; 148 } 149 @Benchmark 150 public CopyOnWriteArrayList<?> removeObject() { 151 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>(); 152 list.add(""); 153 list.add("a"); 154 list.remove(""); 155 return list; 156 } 157 158 @Benchmark 159 public CopyOnWriteArrayList<?> remove() { 160 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>(); 161 list.add(""); 162 list.add("a"); 163 list.remove(0); 164 return list; 165 } 166 }