/*

 * 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 4965960

 * @compile ExecutorCompletionServiceLoops.java

 * @run main/timeout=3600 ExecutorCompletionServiceLoops

 * @summary  Exercise ExecutorCompletionServiceLoops

 */

import java.util.concurrent.*;

public class ExecutorCompletionServiceLoops {

    static final int POOLSIZE =      100;

    static final ExecutorService pool =

        Executors.newFixedThreadPool(POOLSIZE);

    static final ExecutorCompletionService<Integer> ecs =

        new ExecutorCompletionService<Integer>(pool);

    static boolean print = false;

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

        int max = 8;

        int base = 10000;

        if (args.length > 0)

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

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

        oneTest( base );

        Thread.sleep(100);

        print = true;

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

            System.out.print("n: " + i * base);

            oneTest(i * base );

            Thread.sleep(100);

        }

        pool.shutdown();

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

            throw new Error();

   }

    static class Task implements Callable<Integer> {

        public Integer call() {

            int s = 0;

            int l = System.identityHashCode(this);

            for (int i = 0; i < 5; ++i) {

                l = LoopHelpers.compute2(l);

                s += LoopHelpers.compute1(l);

            }

            return new Integer(s);

        }

    }

    static class Producer implements Runnable {

        final ExecutorCompletionService cs;

        final int iters;

        Producer(ExecutorCompletionService ecs, int i) {

            cs = ecs;

            iters = i;

        }

        public void run() {

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

                ecs.submit(new Task());

        }

    }

    static void oneTest(int iters) throws Exception {

        long startTime = System.nanoTime();

        new Thread(new Producer(ecs, iters)).start();

        int r = 0;

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

            r += ecs.take().get().intValue();

        long elapsed = System.nanoTime() - startTime;

        long tpi = elapsed/ iters;

        if (print)

            System.out.println("\t: " + LoopHelpers.rightJustify(tpi) + " ns per task");

        if (r == 0) // avoid overoptimization

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

    }

}