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 
 24 package org.openjdk.bench.vm.compiler.pea;
 25 
 26 import org.openjdk.jmh.annotations.Benchmark;
 27 import org.openjdk.jmh.annotations.BenchmarkMode;
 28 import org.openjdk.jmh.annotations.Fork;
 29 import org.openjdk.jmh.annotations.Measurement;
 30 import org.openjdk.jmh.annotations.Mode;
 31 import org.openjdk.jmh.annotations.Param;
 32 import org.openjdk.jmh.annotations.Setup;
 33 import org.openjdk.jmh.annotations.Scope;
 34 import org.openjdk.jmh.annotations.State;
 35 import org.openjdk.jmh.annotations.OutputTimeUnit;
 36 import org.openjdk.jmh.annotations.Warmup;
 37 
 38 import java.util.concurrent.TimeUnit;
 39 import java.util.ArrayList;
 40 import java.util.HashMap;
 41 
 42 @BenchmarkMode(Mode.AverageTime)
 43 @OutputTimeUnit(TimeUnit.NANOSECONDS)
 44 @Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
 45 @Measurement(iterations = 10, time = 1, timeUnit = TimeUnit.SECONDS)
 46 @State(Scope.Benchmark)
 47 @Fork(value = 3)
 48 public class HashMapBench {
 49     class Key {
 50         int x;
 51         Key(int x) { this.x = x; }
 52         public int hashCode() { return x; }
 53         public boolean equals(Object other) { return this.hashCode() == other.hashCode(); }
 54     }
 55 
 56     static void blackhole(Object o) {}
 57 
 58     @Param("1024")
 59     private int size;
 60 
 61     @Param({"1", "2", "4"})
 62     private int fillInterval;
 63 
 64     ArrayList<Key> keys;
 65     HashMap<Key, Object> map;
 66 
 67     @Setup
 68     public void setUp() {
 69         keys = new ArrayList<>();
 70         map = new HashMap<>();
 71         for (int i = 0; i < size; ++i) {
 72             keys.add(new Key(i));
 73             if (i % fillInterval == 0) {
 74                 map.put(new Key(i), new Object());
 75             }
 76         }
 77     }
 78 
 79     @Benchmark
 80     public void replace() {
 81         for (int i = 0; i < size; ++i) {
 82             map.replace(keys.get(i), new Object());
 83         }
 84     }
 85 
 86     @Benchmark
 87     public void computeIfAbsent() {
 88         for (int i = 0; i < size; ++i) {
 89             map.computeIfAbsent(new Key(i), key -> new Object());
 90         }
 91     }
 92 
 93     @Benchmark
 94     public void cacheUpdate() {
 95         for (int i = 0; i < size; ++i) {
 96             Key key = new Key(i);
 97             if (!map.containsKey(key)) {
 98                 map.put(key, new Object());
 99             }
100         }
101     }
102 }
103