/*

 * 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.

 *

 */

/*

 * 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/licenses/publicdomain

 */

/*

 * @test

 * @bug 4486658

 * @compile CancelledLockLoops.java

 * @run main/timeout=2800 CancelledLockLoops

 * @summary tests lockInterruptibly.

 * Checks for responsiveness of locks to interrupts. Runs under that

 * assumption that ITERS_VALUE computations require more than TIMEOUT

 * msecs to complete.

 */

import java.util.concurrent.*;

import java.util.concurrent.locks.*;

import java.util.*;

public final class CancelledLockLoops {

    static final Random rng = new Random();

    static boolean print = false;

    static final int ITERS = 1000000;

    static final long TIMEOUT = 100;

    public static void main(String[] args) throws Exception {

        int maxThreads = 5;

        if (args.length > 0)

            maxThreads = Integer.parseInt(args[0]);

        print = true;

        for (int i = 2; i <= maxThreads; i += (i+1) >>> 1) {

            System.out.print("Threads: " + i);

            try {

                new ReentrantLockLoop(i).test();

            }

            catch(BrokenBarrierException bb) {

                // OK, ignore

            }

            Thread.sleep(TIMEOUT);

        }

    }

    static final class ReentrantLockLoop implements Runnable {

        private int v = rng.nextInt();

        private int completed;

        private volatile int result = 17;

        private final ReentrantLock lock = new ReentrantLock();

        private final LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();

        private final CyclicBarrier barrier;

        private final int nthreads;

        ReentrantLockLoop(int nthreads) {

            this.nthreads = nthreads;

            barrier = new CyclicBarrier(nthreads+1, timer);

        }

        final void test() throws Exception {

            Thread[] threads = new Thread[nthreads];

            for (int i = 0; i < threads.length; ++i)

                threads[i] = new Thread(this);

            for (int i = 0; i < threads.length; ++i)

                threads[i].start();

            Thread[] cancels = (Thread[]) (threads.clone());

            Collections.shuffle(Arrays.asList(cancels), rng);

            barrier.await();

            Thread.sleep(TIMEOUT);

            for (int i = 0; i < cancels.length-2; ++i) {

                cancels[i].interrupt();

                // make sure all OK even when cancellations spaced out

                if ( (i & 3) == 0)

                    Thread.sleep(1 + rng.nextInt(10));

            }

            barrier.await();

            if (print) {

                long time = timer.getTime();

                double secs = (double)(time) / 1000000000.0;

                System.out.println("\t " + secs + "s run time");

            }

            int c;

            lock.lock();

            try {

                c = completed;

            }

            finally {

                lock.unlock();

            }

            if (c != 2)

                throw new Error("Completed != 2");

            int r = result;

            if (r == 0) // avoid overoptimization

                System.out.println("useless result: " + r);

        }

        public final void run() {

            try {

                barrier.await();

                int sum = v;

                int x = 0;

                int n = ITERS;

                boolean done = false;

                do {

                    try {

                        lock.lockInterruptibly();

                    }

                    catch (InterruptedException ie) {

                        break;

                    }

                    try {

                        v = x = LoopHelpers.compute1(v);

                    }

                    finally {

                        lock.unlock();

                    }

                    sum += LoopHelpers.compute2(x);

                } while (n-- > 0);

                if (n <= 0) {

                    lock.lock();

                    try {

                        ++completed;

                    }

                    finally {

                        lock.unlock();

                    }

                }

                barrier.await();

                result += sum;

            }

            catch (Exception ex) {

                ex.printStackTrace();

                return;

            }

        }

    }

}