/*

 * 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 4486658

 * @summary Checks for responsiveness of blocking queues to cancellation.

 */

import java.util.ArrayList;

import java.util.List;

import java.util.SplittableRandom;

import java.util.concurrent.ArrayBlockingQueue;

import java.util.concurrent.BlockingQueue;

import java.util.concurrent.Callable;

import java.util.concurrent.CancellationException;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.CyclicBarrier;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.Future;

import java.util.concurrent.LinkedBlockingDeque;

import java.util.concurrent.LinkedBlockingQueue;

import java.util.concurrent.SynchronousQueue;

import java.util.concurrent.TimeUnit;

public class CancelledProducerConsumerLoops {

    static ExecutorService pool;

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

        final int maxPairs = (args.length > 0) ? Integer.parseInt(args[0]) : 5;

        pool = Executors.newCachedThreadPool();

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

            final List<BlockingQueue<Integer>> queues = new ArrayList<>();

            queues.add(new ArrayBlockingQueue<Integer>(100));

            queues.add(new LinkedBlockingQueue<Integer>(100));

            queues.add(new LinkedBlockingDeque<Integer>(100));

            queues.add(new SynchronousQueue<Integer>());

            // unbounded queue implementations are prone to OOME:

            // PriorityBlockingQueue, LinkedTransferQueue

            for (BlockingQueue<Integer> queue : queues)

                new CancelledProducerConsumerLoops(i, queue).run();

        }

        pool.shutdown();

            throw new AssertionError("timed out");

        pool = null;

    }

    final int npairs;

    final BlockingQueue<Integer> queue;

    final CountDownLatch producersInterrupted;

    final CountDownLatch consumersInterrupted;

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

    final CyclicBarrier barrier;

    final SplittableRandom rnd = new SplittableRandom();

    volatile boolean done = false;

    CancelledProducerConsumerLoops(int npairs, BlockingQueue<Integer> queue) {

        this.npairs = npairs;

        this.queue = queue;

        this.producersInterrupted = new CountDownLatch(npairs - 1);

        this.consumersInterrupted = new CountDownLatch(npairs - 1);

        this.barrier = new CyclicBarrier(npairs * 2 + 1, timer);

    }

    void run() throws Exception {

        Future<?>[] prods = new Future<?>[npairs];

        Future<?>[] cons  = new Future<?>[npairs];

        for (int i = 0; i < npairs; i++) {

            prods[i] = pool.submit(new Producer());

            cons[i] = pool.submit(new Consumer());

        }

        barrier.await();

        Thread.sleep(rnd.nextInt(5));

        for (int i = 1; i < npairs; i++) {

            if (!prods[i].cancel(true) ||

                !cons[i].cancel(true))

                throw new AssertionError("completed before done");

        }

        for (int i = 1; i < npairs; i++) {

            assertCancelled(prods[i]);

            assertCancelled(cons[i]);

        }

            throw new AssertionError("timed out");

            throw new AssertionError("timed out");

        if (prods[0].isDone() || prods[0].isCancelled())

            throw new AssertionError("completed too early");

        done = true;

            throw new AssertionError("expected Integer");

            throw new AssertionError("expected Integer");

    }

    void assertCancelled(Future<?> future) throws Exception {

        if (!future.isDone())

            throw new AssertionError("not done");

        if (!future.isCancelled())

            throw new AssertionError("not cancelled");

        try {

            throw new AssertionError("should throw CancellationException");

        } catch (CancellationException success) {}

    }

    class Producer implements Callable<Integer> {

        public Integer call() throws Exception {

            barrier.await();

            int sum = 0;

            try {

                int x = 4321;

                while (!done) {

                    if (Thread.interrupted()) throw new InterruptedException();

                    x = LoopHelpers.compute1(x);

                    sum += LoopHelpers.compute2(x);

                    queue.offer(new Integer(x), 1, TimeUnit.MILLISECONDS);

                }

            } catch (InterruptedException cancelled) {

                producersInterrupted.countDown();

            }

            return sum;

        }

    }

    class Consumer implements Callable<Integer> {

        public Integer call() throws Exception {

            barrier.await();

            int sum = 0;

            try {

                while (!done) {

                    Integer x = queue.poll(1, TimeUnit.MILLISECONDS);

                    if (x != null)

                        sum += LoopHelpers.compute1(x.intValue());

                }

            } catch (InterruptedException cancelled) {

                consumersInterrupted.countDown();

            }

            return sum;

        }

    }

}