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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * 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/publicdomain/zero/1.0/
  32  */
  33 
  34 /*
  35  * @test
  36  * @bug 4486658 8031651
  37  * @compile CancelledLockLoops.java
  38  * @run main/timeout=2800 CancelledLockLoops
  39  * @summary tests lockInterruptibly.
  40  * Checks for responsiveness of locks to interrupts. Runs under that
  41  * assumption that ITERS_VALUE computations require more than TIMEOUT
  42  * msecs to complete.
  43  */
  44 
  45 import java.util.concurrent.*;
  46 import java.util.concurrent.locks.*;
  47 import java.util.*;
  48 
  49 public final class CancelledLockLoops {
  50     static final Random rng = new Random();
  51     static boolean print = false;
  52     static final int ITERS = 5000000;
  53     static final long TIMEOUT = 100;
  54 
  55     public static void main(String[] args) throws Exception {
  56         int maxThreads = (args.length > 0) ? Integer.parseInt(args[0]) : 5;
  57         print = true;
  58 
  59         for (int i = 2; i <= maxThreads; i += (i+1) >>> 1) {
  60             System.out.print("Threads: " + i);
  61             try {
  62                 new ReentrantLockLoop(i).test();
  63             }
  64             catch (BrokenBarrierException bb) {
  65                 // OK, ignore
  66             }
  67             Thread.sleep(TIMEOUT);
  68         }
  69     }
  70 
  71     static final class ReentrantLockLoop implements Runnable {
  72         private int v = rng.nextInt();
  73         private int completed;
  74         private volatile int result = 17;
  75         private final ReentrantLock lock = new ReentrantLock();
  76         private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
  77         private final CyclicBarrier barrier;
  78         private final int nthreads;
  79         ReentrantLockLoop(int nthreads) {
  80             this.nthreads = nthreads;
  81             barrier = new CyclicBarrier(nthreads+1, timer);
  82         }
  83 
  84         final void test() throws Exception {
  85             Thread[] threads = new Thread[nthreads];
  86             for (int i = 0; i < threads.length; ++i)
  87                 threads[i] = new Thread(this);
  88             for (int i = 0; i < threads.length; ++i)
  89                 threads[i].start();
  90             Thread[] cancels = threads.clone();
  91             Collections.shuffle(Arrays.asList(cancels), rng);
  92             barrier.await();
  93             Thread.sleep(TIMEOUT);
  94             for (int i = 0; i < cancels.length-2; ++i) {
  95                 cancels[i].interrupt();
  96                 // make sure all OK even when cancellations spaced out
  97                 if ( (i & 3) == 0)
  98                     Thread.sleep(1 + rng.nextInt(10));
  99             }
 100             barrier.await();
 101             if (print) {
 102                 long time = timer.getTime();
 103                 double secs = (double)(time) / 1000000000.0;
 104                 System.out.println("\t " + secs + "s run time");
 105             }
 106 
 107             int c;
 108             lock.lock();
 109             try {
 110                 c = completed;
 111             }
 112             finally {
 113                 lock.unlock();
 114             }
 115             if (c != 2)
 116                 throw new Error("Completed != 2");
 117             int r = result;
 118             if (r == 0) // avoid overoptimization
 119                 System.out.println("useless result: " + r);
 120         }
 121 
 122         public final void run() {
 123             try {
 124                 barrier.await();
 125                 int sum = v;
 126                 int x = 0;
 127                 int n = ITERS;
 128                 boolean done = false;
 129                 do {
 130                     try {
 131                         lock.lockInterruptibly();
 132                     }
 133                     catch (InterruptedException ie) {
 134                         break;
 135                     }
 136                     try {
 137                         v = x = LoopHelpers.compute1(v);
 138                     }
 139                     finally {
 140                         lock.unlock();
 141                     }
 142                     sum += LoopHelpers.compute2(x);
 143                 } while (n-- > 0);
 144                 if (n <= 0) {
 145                     lock.lock();
 146                     try {
 147                         ++completed;
 148                     }
 149                     finally {
 150                         lock.unlock();
 151                     }
 152                 }
 153                 barrier.await();
 154                 result += sum;
 155             }
 156             catch (Exception ex) {
 157                 ex.printStackTrace();
 158                 return;
 159             }
 160         }
 161     }
 162 
 163 }