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 5031862 8140471
  37  * @summary Checks for responsiveness of locks to timeouts.
  38  * @library /test/lib
  39  */
  40 
  41 import static java.util.concurrent.TimeUnit.MILLISECONDS;
  42 
  43 import java.util.concurrent.CyclicBarrier;
  44 import java.util.concurrent.ExecutorService;
  45 import java.util.concurrent.Executors;
  46 import java.util.concurrent.ThreadLocalRandom;
  47 import java.util.concurrent.TimeUnit;
  48 import java.util.concurrent.locks.ReentrantLock;
  49 import jdk.test.lib.Utils;
  50 
  51 public final class TimeoutLockLoops {
  52     static final long LONG_DELAY_MS = Utils.adjustTimeout(10_000);
  53     static final ExecutorService pool = Executors.newCachedThreadPool();
  54     static boolean print = false;
  55     static final long TIMEOUT = 10;
  56 
  57     public static void main(String[] args) throws Exception {
  58         int maxThreads = 8;
  59         if (args.length > 0)
  60             maxThreads = Integer.parseInt(args[0]);
  61 
  62         print = true;
  63 
  64         for (int i = 1; i <= maxThreads; i += (i+1) >>> 1) {
  65             System.out.print("Threads: " + i);
  66             new ReentrantLockLoop(i).test();
  67         }
  68         pool.shutdown();
  69         if (! pool.awaitTermination(LONG_DELAY_MS, MILLISECONDS))
  70             throw new Error();
  71     }
  72 
  73     static final class ReentrantLockLoop implements Runnable {
  74         private int v = ThreadLocalRandom.current().nextInt();
  75         private volatile int result = 17;
  76         private final ReentrantLock lock = new ReentrantLock();
  77         private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
  78         private final CyclicBarrier barrier;
  79         private final int nthreads;
  80         private volatile Throwable fail = null;
  81         ReentrantLockLoop(int nthreads) {
  82             this.nthreads = nthreads;
  83             barrier = new CyclicBarrier(nthreads+1, timer);
  84         }
  85 
  86         final void test() throws Exception {
  87             for (int i = 0; i < nthreads; ++i) {
  88                 lock.lock();
  89                 pool.execute(this);
  90                 lock.unlock();
  91             }
  92             barrier.await();
  93             Thread.sleep(ThreadLocalRandom.current().nextInt(5));
  94             while (!lock.tryLock()); // Jam lock
  95             //            lock.lock();
  96             barrier.await();
  97             if (print) {
  98                 long time = timer.getTime();
  99                 double secs = (double)(time) / 1000000000.0;
 100                 System.out.println("\t " + secs + "s run time");
 101             }
 102 
 103             int r = result;
 104             if (r == 0) // avoid overoptimization
 105                 System.out.println("useless result: " + r);
 106             if (fail != null) throw new RuntimeException(fail);
 107         }
 108 
 109         public final void run() {
 110             try {
 111                 barrier.await();
 112                 int sum = v;
 113                 int x = 17;
 114                 final ReentrantLock lock = this.lock;
 115                 while (lock.tryLock(TIMEOUT, TimeUnit.MILLISECONDS)) {
 116                     try {
 117                         v = x = LoopHelpers.compute1(v);
 118                     }
 119                     finally {
 120                         lock.unlock();
 121                     }
 122                     sum += LoopHelpers.compute2(x);
 123                 }
 124                 barrier.await();
 125                 result += sum;
 126             }
 127             catch (Throwable ex) {
 128                 fail = ex;
 129                 throw new RuntimeException(ex);
 130             }
 131         }
 132     }
 133 }