1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.rng.examples.jmh.core;
19
20 import org.apache.commons.rng.UniformRandomProvider;
21 import org.openjdk.jmh.annotations.Benchmark;
22 import org.openjdk.jmh.annotations.Scope;
23 import org.openjdk.jmh.annotations.State;
24
25 /**
26 * Executes benchmark to compare the speed of generation of random numbers from the
27 * various source providers for {@link UniformRandomProvider#nextBytes(byte[])}.
28 */
29 public class NextBytesGenerationPerformance extends AbstractBenchmark {
30 /**
31 * The value. This is a pre-allocated array. Must NOT be final to prevent JVM
32 * optimisation!
33 */
34 private byte[] value = new byte[BaselineGenerationPerformance.NEXT_BYTES_SIZE];
35
36 /**
37 * The benchmark state (retrieve the various "RandomSource"s).
38 */
39 @State(Scope.Benchmark)
40 public static class Sources extends BaselineSources {
41 /** {@inheritDoc} */
42 @Override
43 protected UniformRandomProvider createBaseline() {
44 return BaselineUtils.getNextBytes();
45 }
46 }
47
48 /**
49 * Baseline for a JMH method call with no return value.
50 */
51 @Benchmark
52 public void baselineVoid() {
53 // Do nothing, this is a baseline
54 }
55
56 /**
57 * Baseline for a JMH method call returning a {@code byte[]}.
58 *
59 * @return the value
60 */
61 @Benchmark
62 public byte[] baselineBytes() {
63 return value;
64 }
65
66 /**
67 * Exercise the {@link UniformRandomProvider#nextBytes(byte[])} method.
68 *
69 * @param sources Source of randomness.
70 * @return the boolean
71 */
72 @Benchmark
73 public byte[] nextBytes(Sources sources) {
74 // The array allocation is not part of the benchmark.
75 sources.getGenerator().nextBytes(value);
76 return value;
77 }
78 }