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 @SuppressWarnings("initialization")
71 private CopyOnWriteArrayList<?> oneItemInstance = new CopyOnWriteArrayList<>(oneItemArray);
72
73 private byte[] emptyInstanceBytes;
74 private byte[] oneInstanceBytes;
75
76 @SuppressWarnings("initialization")
77 public CopyOnWriteArrayListBenchmark() {
78 try {
79 emptyInstanceBytes = getSerializedBytes(emptyInstance);
80 oneInstanceBytes = getSerializedBytes(oneItemInstance);
81 } catch (IOException e) {
82 throw new RuntimeException(e);
83 }
84 }
85
86 @Benchmark
87 public void clear() {
88 // have to create a new instance on each execution
89 ((CopyOnWriteArrayList<?>) oneItemInstance.clone()).clear();
90 }
91
92 @Benchmark
93 public void clearEmpty() {
94 emptyInstance.clear();
95 }
96
97 @Benchmark
98 public CopyOnWriteArrayList<?> createInstanceArray() {
99 return new CopyOnWriteArrayList<>(oneItemArray);
100 }
101
102 @Benchmark
103 public CopyOnWriteArrayList<?> createInstanceArrayEmpty() {
104 return new CopyOnWriteArrayList<>(emptyArray);
105 }
106
107 @Benchmark
108 public CopyOnWriteArrayList<?> createInstanceCollection() {
109 return new CopyOnWriteArrayList<>(oneItemCollection);
110 }
111
112 @Benchmark
113 public CopyOnWriteArrayList<?> createInstanceCollectionEmpty() {
114 return new CopyOnWriteArrayList<>(emptyCollection);
115 }
116
117 @Benchmark
118 public CopyOnWriteArrayList<?> createInstanceDefault() {
119 return new CopyOnWriteArrayList<Object>();
120 }
121
122 @Benchmark
123 public CopyOnWriteArrayList<?> readInstance() throws IOException, ClassNotFoundException {
124 try (ObjectInputStream objIn = new ObjectInputStream(new ByteArrayInputStream(oneInstanceBytes))) {
125 return (CopyOnWriteArrayList<?>) objIn.readObject();
126 }
127 }
128
129 @Benchmark
130 public CopyOnWriteArrayList<?> readInstanceEmpty() throws IOException, ClassNotFoundException {
131 try (ObjectInputStream objIn = new ObjectInputStream(new ByteArrayInputStream(emptyInstanceBytes))) {
132 return (CopyOnWriteArrayList<?>) objIn.readObject();
133 }
134 }
135
136 @Benchmark
137 public CopyOnWriteArrayList<?> removeObjectLastRemaining() {
138 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
139 list.add("");
140 list.remove("");
141 return list;
142 }
143
144 @Benchmark
145 public CopyOnWriteArrayList<?> removeIndexLastRemaining() {
146 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
147 list.add("");
148 list.remove(0);
149 return list;
150 }
151 @Benchmark
152 public CopyOnWriteArrayList<?> removeObject() {
153 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
154 list.add("");
155 list.add("a");
156 list.remove("");
157 return list;
158 }
159
160 @Benchmark
161 public CopyOnWriteArrayList<?> remove() {
162 CopyOnWriteArrayList<String> list = new CopyOnWriteArrayList<>();
163 list.add("");
164 list.add("a");
165 list.remove(0);
166 return list;
167 }
168 }