/* * Copyright (c) 2014 Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package org.openjdk.bench.java.util.concurrent; import org.openjdk.jmh.annotations.Benchmark; import org.openjdk.jmh.annotations.OutputTimeUnit; import org.openjdk.jmh.annotations.Param; import org.openjdk.jmh.annotations.Scope; import org.openjdk.jmh.annotations.Setup; import org.openjdk.jmh.annotations.State; import org.openjdk.jmh.annotations.TearDown; import java.util.concurrent.ExecutionException; import java.util.concurrent.ForkJoinPool; import java.util.concurrent.ForkJoinTask; import java.util.concurrent.RecursiveTask; import java.util.concurrent.TimeUnit; /** * Benchmark assesses ForkJoinPool forking infrastructure. * * @author Aleksey Shipilev (aleksey.shipilev@oracle.com) */ @OutputTimeUnit(TimeUnit.MINUTES) @State(Scope.Benchmark) public class ForkJoinPoolForking { /** * Implementation notes: * * This test harnesses forking infrastructure within FJP. * As such, no slack is given for allocating any humble number of tasks: the goal is to fork a lot. * The approximate number of tasks is (SIZE / THRESHOLD). * * Raw baseline gives the idea for compute bound for this benchmark. * FJP could be faster than baseline, because the baseline is single-threaded. */ @Param("0") private int workers; @Param("10000000") private int size; @Param("10") private int threshold; private Problem problem; private ForkJoinPool fjpSync; private ForkJoinPool fjpAsync; @Setup public void setup() { problem = new Problem(size); if (workers == 0) { workers = Runtime.getRuntime().availableProcessors(); } fjpSync = new ForkJoinPool(workers, ForkJoinPool.defaultForkJoinWorkerThreadFactory, null, false); fjpAsync = new ForkJoinPool(workers, ForkJoinPool.defaultForkJoinWorkerThreadFactory, null, true); } @TearDown public void teardown() { fjpSync.shutdownNow(); fjpAsync.shutdownNow(); } @Benchmark public long baselineRaw() { return problem.solve(); } @Benchmark public Long testExplicit_Sync() throws ExecutionException, InterruptedException { return fjpSync.invoke(new ExplicitTask(problem, 0, problem.size(), threshold)); } @Benchmark public Long testExplicit_Async() throws ExecutionException, InterruptedException { return fjpAsync.invoke(new ExplicitTask(problem, 0, problem.size(), threshold)); } @Benchmark public Long testStandard_Sync() throws ExecutionException, InterruptedException { return fjpSync.invoke(new StandardTask(problem, 0, problem.size(), threshold)); } @Benchmark public Long testStandard_Async() throws ExecutionException, InterruptedException { return fjpAsync.invoke(new StandardTask(problem, 0, problem.size(), threshold)); } private static class ExplicitTask extends RecursiveTask { private final Problem problem; private final int l; private final int r; private final int thresh; public ExplicitTask(Problem p, int l, int r, int thresh) { this.problem = p; this.l = l; this.r = r; this.thresh = thresh; } @Override protected Long compute() { if (r - l <= thresh) { return problem.solve(l, r); } int mid = (l + r) >>> 1; ForkJoinTask t1 = new ExplicitTask(problem, l, mid, thresh); ForkJoinTask t2 = new ExplicitTask(problem, mid, r, thresh); t1.fork(); t2.fork(); long res = 0; res += t2.join(); res += t1.join(); return res; } } private static class StandardTask extends RecursiveTask { private final Problem problem; private final int l; private final int r; private final int thresh; public StandardTask(Problem p, int l, int r, int thresh) { this.problem = p; this.l = l; this.r = r; this.thresh = thresh; } @Override protected Long compute() { if (r - l <= thresh) { return problem.solve(l, r); } int mid = (l + r) >>> 1; ForkJoinTask t1 = new StandardTask(problem, l, mid, thresh); ForkJoinTask t2 = new StandardTask(problem, mid, r, thresh); ForkJoinTask.invokeAll(t1, t2); long res = 0; res += t1.join(); res += t2.join(); return res; } } }