1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 19 * CA 95054 USA or visit www.sun.com if you need additional information or 20 * have any questions. 21 */ 22 23 /* 24 * This file is available under and governed by the GNU General Public 25 * License version 2 only, as published by the Free Software Foundation. 26 * However, the following notice accompanied the original version of this 27 * file: 28 * 29 * Written by Doug Lea with assistance from members of JCP JSR-166 30 * Expert Group and released to the public domain, as explained at 31 * http://creativecommons.org/licenses/publicdomain 32 */ 33 34 /* 35 * @test 36 * @bug 4486658 37 * @compile -source 1.5 CancelledFutureLoops.java 38 * @run main/timeout=2000 CancelledFutureLoops 39 * @summary Checks for responsiveness of futures to cancellation. 40 * Runs under the assumption that ITERS computations require more than 41 * TIMEOUT msecs to complete. 42 */ 43 44 import java.util.concurrent.*; 45 import java.util.concurrent.locks.*; 46 import java.util.*; 47 48 public final class CancelledFutureLoops { 49 static final ExecutorService pool = Executors.newCachedThreadPool(); 50 static final LoopHelpers.SimpleRandom rng = new LoopHelpers.SimpleRandom(); 51 static boolean print = false; 52 static final int ITERS = 1000000; 53 static final long TIMEOUT = 100; 54 55 public static void main(String[] args) throws Exception { 56 int maxThreads = 5; 57 if (args.length > 0) 58 maxThreads = Integer.parseInt(args[0]); 59 60 print = true; 61 62 for (int i = 2; i <= maxThreads; i += (i+1) >>> 1) { 63 System.out.print("Threads: " + i); 64 try { 65 new FutureLoop(i).test(); 66 } 67 catch(BrokenBarrierException bb) { 68 // OK; ignore 69 } 70 catch(ExecutionException ee) { 71 // OK; ignore 72 } 73 Thread.sleep(TIMEOUT); 74 } 75 pool.shutdown(); 76 if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS)) 77 throw new Error(); 78 } 79 80 static final class FutureLoop implements Callable { 81 private int v = rng.next(); 82 private final ReentrantLock lock = new ReentrantLock(); 83 private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer(); 84 private final CyclicBarrier barrier; 85 private final int nthreads; 86 FutureLoop(int nthreads) { 87 this.nthreads = nthreads; 88 barrier = new CyclicBarrier(nthreads+1, timer); 89 } 90 91 final void test() throws Exception { 92 Future[] futures = new Future[nthreads]; 93 for (int i = 0; i < nthreads; ++i) 94 futures[i] = pool.submit(this); 95 96 barrier.await(); 97 Thread.sleep(TIMEOUT); 98 boolean tooLate = false; 99 for (int i = 1; i < nthreads; ++i) { 100 if (!futures[i].cancel(true)) 101 tooLate = true; 102 // Unbunch some of the cancels 103 if ( (i & 3) == 0) 104 Thread.sleep(1 + rng.next() % 10); 105 } 106 107 Object f0 = futures[0].get(); 108 if (!tooLate) { 109 for (int i = 1; i < nthreads; ++i) { 110 if (!futures[i].isDone() || !futures[i].isCancelled()) 111 throw new Error("Only one thread should complete"); 112 } 113 } 114 else 115 System.out.print("(cancelled too late) "); 116 117 long endTime = System.nanoTime(); 118 long time = endTime - timer.startTime; 119 if (print) { 120 double secs = (double)(time) / 1000000000.0; 121 System.out.println("\t " + secs + "s run time"); 122 } 123 124 } 125 126 public final Object call() throws Exception { 127 barrier.await(); 128 int sum = v; 129 int x = 0; 130 int n = ITERS; 131 while (n-- > 0) { 132 lock.lockInterruptibly(); 133 try { 134 v = x = LoopHelpers.compute1(v); 135 } 136 finally { 137 lock.unlock(); 138 } 139 sum += LoopHelpers.compute2(LoopHelpers.compute2(x)); 140 } 141 return new Integer(sum); 142 } 143 } 144 145 }