1 /* 2 * Copyright (c) 2014, Oracle and/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.stream; 24 25 import org.openjdk.jmh.annotations.Benchmark; 26 import org.openjdk.jmh.annotations.BenchmarkMode; 27 import org.openjdk.jmh.annotations.Level; 28 import org.openjdk.jmh.annotations.Mode; 29 import org.openjdk.jmh.annotations.OutputTimeUnit; 30 import org.openjdk.jmh.annotations.Param; 31 import org.openjdk.jmh.annotations.Scope; 32 import org.openjdk.jmh.annotations.Setup; 33 import org.openjdk.jmh.annotations.State; 34 35 import java.util.concurrent.TimeUnit; 36 import java.util.stream.LongStream; 37 38 /** 39 * This benchmark is the golden benchmark for decompositions. 40 * There are at least four parameters to juggle: 41 * - pool parallelism (P), controlled via -Djava.util.concurrent.ForkJoinUtils.pool.parallelism 42 * - problem size (N), controlled as benchmark param 43 * - operation cost (Q), controlled as benchmark param 44 * - number of clients (C), controlled via -t option in harness 45 * 46 * @author Aleksey Shipilev (aleksey.shipilev@oracle.com) 47 */ 48 @BenchmarkMode(Mode.SampleTime) 49 @OutputTimeUnit(TimeUnit.MICROSECONDS) 50 @State(Scope.Thread) 51 public class Decomposition { 52 53 @Param("1000") 54 private int N; 55 56 @Param("1000") 57 private int Q; 58 59 @State(Scope.Thread) 60 public static class Thinktime { 61 @Param("10") 62 private int S; 63 64 @Setup(Level.Invocation) sleep()65 public void sleep() throws InterruptedException { 66 TimeUnit.MILLISECONDS.sleep(S); 67 } 68 } 69 70 @Benchmark saturated_sequential()71 public long saturated_sequential() throws InterruptedException { 72 return LongStream.range(1, N).filter(k -> doWork(k, Q)).sum(); 73 } 74 75 @Benchmark thinktime_sequential(Thinktime t)76 public long thinktime_sequential(Thinktime t) throws InterruptedException { 77 return LongStream.range(1, N).filter(k -> doWork(k, Q)).sum(); 78 } 79 80 @Benchmark saturated_parallel()81 public long saturated_parallel() throws InterruptedException { 82 return LongStream.range(1, N).parallel().filter(k -> doWork(k, Q)).sum(); 83 } 84 85 @Benchmark thinktime_parallel(Thinktime t)86 public long thinktime_parallel(Thinktime t) throws InterruptedException { 87 return LongStream.range(1, N).parallel().filter(k -> doWork(k, Q)).sum(); 88 } 89 90 /** 91 * Make some work. 92 * This method have a couple of distinguishable properties: 93 * - the run time is linear with Q 94 * - the computation is dependent on input, preventing common reductions 95 * - the returned result is dependent on loop result, preventing dead code elimination 96 * - the returned result is almost always false 97 * 98 * This code uses inlined version of ThreadLocalRandom.next() to mitigate the edge effects 99 * of acquiring TLR every single call. 100 * 101 * @param input input 102 * @return result 103 */ doWork(long input, long count)104 public static boolean doWork(long input, long count) { 105 long t = input; 106 for (int i = 0; i < count; i++) { 107 t += (t * 0x5DEECE66DL + 0xBL) & (0xFFFFFFFFFFFFL); 108 } 109 return (t == 0); 110 } 111 112 } 113