/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

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 * 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.

 *

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/*

 * 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

 */

/*

 * @test

 * @bug 4486658

 * @compile -source 1.5 SingleProducerMultipleConsumerLoops.java

 * @run main/timeout=600 SingleProducerMultipleConsumerLoops

 * @summary  check ordering for blocking queues with 1 producer and multiple consumers

 */

import java.util.concurrent.*;

public class SingleProducerMultipleConsumerLoops {

    static final int CAPACITY =      100;

    static final ExecutorService pool = Executors.newCachedThreadPool();

    static boolean print = false;

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

        int maxConsumers = 5;

        int iters = 10000;

        if (args.length > 0)

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

        print = false;

        System.out.println("Warmup...");

        oneTest(1, 10000);

        Thread.sleep(100);

        oneTest(2, 10000);

        Thread.sleep(100);

        print = true;

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

            System.out.println("----------------------------------------");

            System.out.println("Consumers: " + i);

            oneTest(i, iters);

            Thread.sleep(100);

        }

        pool.shutdown();

        if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS))

            throw new Error();

   }

    static void oneTest(int consumers, int iters) throws Exception {

        oneRun(new ArrayBlockingQueue<Integer>(CAPACITY), consumers, iters);

        oneRun(new LinkedBlockingQueue<Integer>(CAPACITY), consumers, iters);

        oneRun(new LinkedBlockingDeque<Integer>(CAPACITY), consumers, iters);

        oneRun(new LinkedTransferQueue<Integer>(), consumers, iters);

        oneRun(new PriorityBlockingQueue<Integer>(), consumers, iters);

        oneRun(new SynchronousQueue<Integer>(), consumers, iters);

        if (print)

            System.out.println("fair implementations:");

        oneRun(new SynchronousQueue<Integer>(true), consumers, iters);

        oneRun(new ArrayBlockingQueue<Integer>(CAPACITY, true), consumers, iters);

    }

    abstract static class Stage implements Runnable {

        final int iters;

        final BlockingQueue<Integer> queue;

        final CyclicBarrier barrier;

        volatile int result;

        Stage(BlockingQueue<Integer> q, CyclicBarrier b, int iters) {

            queue = q;

            barrier = b;

            this.iters = iters;

        }

    }

    static class Producer extends Stage {

        Producer(BlockingQueue<Integer> q, CyclicBarrier b, int iters) {

            super(q, b, iters);

        }

        public void run() {

            try {

                barrier.await();

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

                    queue.put(new Integer(i));

                }

                barrier.await();

                result = 432;

            }

            catch (Exception ie) {

                ie.printStackTrace();

                return;

            }

        }

    }

    static class Consumer extends Stage {

        Consumer(BlockingQueue<Integer> q, CyclicBarrier b, int iters) {

            super(q, b, iters);

        }

        public void run() {

            try {

                barrier.await();

                int l = 0;

                int s = 0;

                int last = -1;

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

                    Integer item = queue.take();

                    int v = item.intValue();

                    if (v < last)

                        throw new Error("Out-of-Order transfer");

                    last = v;

                    l = LoopHelpers.compute1(v);

                    s += l;

                }

                barrier.await();

                result = s;

            }

            catch (Exception ie) {

                ie.printStackTrace();

                return;

            }

        }

    }

    static void oneRun(BlockingQueue<Integer> q, int nconsumers, int iters) throws Exception {

        if (print)

            System.out.printf("%-18s", q.getClass().getSimpleName());

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

        CyclicBarrier barrier = new CyclicBarrier(nconsumers + 2, timer);

        pool.execute(new Producer(q, barrier, iters * nconsumers));

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

            pool.execute(new Consumer(q, barrier, iters));

        }

        barrier.await();

        barrier.await();

        long time = timer.getTime();

        if (print)

            System.out.println("\t: " + LoopHelpers.rightJustify(time / (iters * nconsumers)) + " ns per transfer");

    }

}