| /* |
| * 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. |
| * |
| * 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. |
| */ |
| |
| /* |
| * This file is available under and governed by the GNU General Public |
| * License version 2 only, as published by the Free Software Foundation. |
| * However, the following notice accompanied the original version of this |
| * file: |
| * |
| * Written by Doug Lea with assistance from members of JCP JSR-166 |
| * Expert Group and released to the public domain, as explained at |
| * http://creativecommons.org/publicdomain/zero/1.0/ |
| */ |
| |
| /* |
| * @test |
| * @bug 8008378 |
| * @summary Basic checks for parallelism 0, and null returning factory |
| * @run main/othervm -Djava.util.concurrent.ForkJoinPool.common.parallelism=0 ThreadLessCommon |
| * @run main/othervm -Djava.util.concurrent.ForkJoinPool.common.threadFactory=ThreadLessCommon$NullForkJoinWorkerThreadFactory ThreadLessCommon |
| * @author Chris Hegarty |
| */ |
| |
| import java.util.concurrent.ForkJoinPool; |
| import java.util.concurrent.ForkJoinPool.ForkJoinWorkerThreadFactory; |
| import java.util.concurrent.ForkJoinWorkerThread; |
| import java.util.concurrent.RecursiveTask; |
| |
| public class ThreadLessCommon { |
| |
| static final int THRESHOLD = 1000; |
| static final boolean debug = true; |
| |
| private static void realMain(String[] args) throws Throwable { |
| if (debug) { |
| String pp = System.getProperty( |
| "java.util.concurrent.ForkJoinPool.common.parallelism"); |
| System.out.println( |
| "java.util.concurrent.ForkJoinPool.common.parallelism:" + pp); |
| String tf = System.getProperty( |
| "java.util.concurrent.ForkJoinPool.common.threadFactory"); |
| System.out.println( |
| "java.util.concurrent.ForkJoinPool.common.threadFactory:" + tf); |
| } |
| |
| long from = 0, to = 50000; |
| RecursiveTask<Long> task = new SumTask(from, to, Thread.currentThread()); |
| long sum = task.invoke(); |
| System.out.printf("%nSum: from [%d] to [%d] = [%d]%n", from, to, sum); |
| |
| task.fork(); |
| sum = task.join(); |
| System.out.printf("%nSum: from [%d] to [%d] = [%d]%n", from, to, sum); |
| |
| sum = ForkJoinPool.commonPool().invoke(task.fork()); |
| System.out.printf("%nSum: from [%d] to [%d] = [%d]%n", from, to, sum); |
| } |
| |
| static class SumTask extends RecursiveTask<Long> { |
| final Thread expectedThread; |
| final long from; |
| final long to; |
| SumTask(long from, long to, Thread thread) { |
| this.from = from; this.to = to; expectedThread = thread; |
| } |
| |
| @Override |
| public Long compute() { |
| check(Thread.currentThread() == expectedThread, |
| "Expected " + expectedThread + ", got " + Thread.currentThread()); |
| long range = to - from; |
| if (range < THRESHOLD) { |
| long acc = 0; |
| for (long i = from; i <= to; i++) |
| acc = acc + i; |
| return acc; |
| } else { |
| long half = from + range / 2; |
| SumTask t1 = new SumTask(from, half ,expectedThread); |
| SumTask t2 = new SumTask(half+1, to ,expectedThread); |
| if (half % 2 == 0) { |
| t1.fork(); |
| return t2.compute() + t1.join(); |
| } else { |
| invokeAll(t1, t2); |
| try { return t1.get() + t2.get(); } |
| catch (Exception x) { unexpected(x); return 0L;} |
| } |
| } |
| } |
| } |
| |
| public static class NullForkJoinWorkerThreadFactory |
| implements ForkJoinWorkerThreadFactory |
| { |
| @Override |
| public ForkJoinWorkerThread newThread(ForkJoinPool pool) { |
| return null; |
| } |
| } |
| |
| //--------------------- Infrastructure --------------------------- |
| static volatile int passed = 0, failed = 0; |
| static void pass() {passed++;} |
| static void fail() {failed++; /*Thread.dumpStack();*/} |
| static void fail(String msg) {System.out.println(msg); fail();} |
| static void unexpected(Throwable t) {failed++; t.printStackTrace();} |
| static void check(boolean cond, String msg) {if (cond) pass(); else fail(msg);} |
| static void equal(Object x, Object y) { |
| if (x == null ? y == null : x.equals(y)) pass(); |
| else fail(x + " not equal to " + y);} |
| public static void main(String[] args) throws Throwable { |
| try {realMain(args);} catch (Throwable t) {unexpected(t);} |
| System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed); |
| if (failed > 0) throw new AssertionError("Some tests failed");} |
| } |