/*

 * 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

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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

 * http://creativecommons.org/publicdomain/zero/1.0/

 * Other contributors include Andrew Wright, Jeffrey Hayes,

 * Pat Fisher, Mike Judd.

 */

import static java.util.concurrent.TimeUnit.MILLISECONDS;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.Exchanger;

import java.util.concurrent.TimeoutException;

import junit.framework.Test;

import junit.framework.TestSuite;

public class ExchangerTest extends JSR166TestCase {

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        return new TestSuite(ExchangerTest.class);

    }

    /**

     * exchange exchanges objects across two threads

     */

    public void testExchange() {

        final Exchanger e = new Exchanger();

        Thread t1 = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                assertSame(one, e.exchange(two));

                assertSame(two, e.exchange(one));

            }});

        Thread t2 = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                assertSame(two, e.exchange(one));

                assertSame(one, e.exchange(two));

            }});

        awaitTermination(t1);

        awaitTermination(t2);

    }

    /**

     * timed exchange exchanges objects across two threads

     */

    public void testTimedExchange() {

        final Exchanger e = new Exchanger();

        Thread t1 = newStartedThread(new CheckedRunnable() {

            public void realRun() throws Exception {

                assertSame(one, e.exchange(two, LONG_DELAY_MS, MILLISECONDS));

                assertSame(two, e.exchange(one, LONG_DELAY_MS, MILLISECONDS));

            }});

        Thread t2 = newStartedThread(new CheckedRunnable() {

            public void realRun() throws Exception {

                assertSame(two, e.exchange(one, LONG_DELAY_MS, MILLISECONDS));

                assertSame(one, e.exchange(two, LONG_DELAY_MS, MILLISECONDS));

            }});

        awaitTermination(t1);

        awaitTermination(t2);

    }

    /**

     * interrupt during wait for exchange throws InterruptedException

     */

    public void testExchange_InterruptedException() {

        final Exchanger e = new Exchanger();

        final CountDownLatch threadStarted = new CountDownLatch(1);

        Thread t = newStartedThread(new CheckedInterruptedRunnable() {

            public void realRun() throws InterruptedException {

                threadStarted.countDown();

                e.exchange(one);

            }});

        await(threadStarted);

        t.interrupt();

        awaitTermination(t);

    }

    /**

     * interrupt during wait for timed exchange throws InterruptedException

     */

    public void testTimedExchange_InterruptedException() {

        final Exchanger e = new Exchanger();

        final CountDownLatch threadStarted = new CountDownLatch(1);

        Thread t = newStartedThread(new CheckedInterruptedRunnable() {

            public void realRun() throws Exception {

                threadStarted.countDown();

                e.exchange(null, LONG_DELAY_MS, MILLISECONDS);

            }});

        await(threadStarted);

        t.interrupt();

        awaitTermination(t);

    }

    /**

     * timeout during wait for timed exchange throws TimeoutException

     */

    public void testExchange_TimeoutException() {

        final Exchanger e = new Exchanger();

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() throws Exception {

                long startTime = System.nanoTime();

                try {

                    e.exchange(null, timeoutMillis(), MILLISECONDS);

                    shouldThrow();

                } catch (TimeoutException success) {}

                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());

            }});

        awaitTermination(t);

    }

    /**

     * If one exchanging thread is interrupted, another succeeds.

     */

    public void testReplacementAfterExchange() {

        final Exchanger e = new Exchanger();

        final CountDownLatch exchanged = new CountDownLatch(2);

        final CountDownLatch interrupted = new CountDownLatch(1);

        Thread t1 = newStartedThread(new CheckedInterruptedRunnable() {

            public void realRun() throws InterruptedException {

                assertSame(two, e.exchange(one));

                exchanged.countDown();

                e.exchange(two);

            }});

        Thread t2 = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                assertSame(one, e.exchange(two));

                exchanged.countDown();

                await(interrupted);

                assertSame(three, e.exchange(one));

            }});

        Thread t3 = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                await(interrupted);

                assertSame(one, e.exchange(three));

            }});

        await(exchanged);

        t1.interrupt();

        awaitTermination(t1);

        interrupted.countDown();

        awaitTermination(t2);

        awaitTermination(t3);

    }

}