/*

 * Copyright (c) 2007, Oracle and/or its affiliates. All rights reserved.

 * 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.

 */

/*

 * @test

 * @bug 6458662

 * @summary poolSize might shrink below corePoolSize after timeout

 * @author Martin Buchholz

 */

import java.util.concurrent.CyclicBarrier;

import java.util.concurrent.SynchronousQueue;

import java.util.concurrent.ThreadPoolExecutor;

import java.util.concurrent.TimeUnit;

public class TimeOutShrink {

    static void checkPoolSizes(ThreadPoolExecutor pool,

                               int size, int core, int max) {

        equal(pool.getPoolSize(), size);

        equal(pool.getCorePoolSize(), core);

        equal(pool.getMaximumPoolSize(), max);

    }

    private static void realMain(String[] args) throws Throwable {

        final int n = 4;

        final CyclicBarrier barrier = new CyclicBarrier(2*n+1);

        final ThreadPoolExecutor pool

                                     new SynchronousQueue<Runnable>());

        final Runnable r = new Runnable() { public void run() {

            try {

                barrier.await();

                barrier.await();

            } catch (Throwable t) { unexpected(t); }}};

        for (int i = 0; i < 2*n; i++)

            pool.execute(r);

        barrier.await();

        checkPoolSizes(pool, 2*n, n, 2*n);

        barrier.await();

        checkPoolSizes(pool, n, n, 2*n);

        pool.shutdown();

    }

    //--------------------- Infrastructure ---------------------------

    static volatile int passed = 0, failed = 0;

    static void pass() {passed++;}

    static void fail() {failed++; Thread.dumpStack();}

    static void fail(String msg) {System.out.println(msg); fail();}

    static void unexpected(Throwable t) {failed++; t.printStackTrace();}

    static void check(boolean cond) {if (cond) pass(); else fail();}

    static void equal(Object x, Object y) {

        if (x == null ? y == null : x.equals(y)) pass();

        else fail(x + " not equal to " + y);}

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

        try {realMain(args);} catch (Throwable t) {unexpected(t);}

        System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);

        if (failed > 0) throw new AssertionError("Some tests failed");}

}