/*

 * 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.

 *

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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 java.util.concurrent.atomic.AtomicMarkableReference;

import junit.framework.Test;

import junit.framework.TestSuite;

public class AtomicMarkableReferenceTest extends JSR166TestCase {

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        return new TestSuite(AtomicMarkableReferenceTest.class);

    }

    /**

     * constructor initializes to given reference and mark

     */

    public void testConstructor() {

        AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        assertSame(one, ai.getReference());

        assertFalse(ai.isMarked());

        AtomicMarkableReference a2 = new AtomicMarkableReference(null, true);

        assertNull(a2.getReference());

        assertTrue(a2.isMarked());

    }

    /**

     * get returns the last values of reference and mark set

     */

    public void testGetSet() {

        boolean[] mark = new boolean[1];

        AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        assertSame(one, ai.getReference());

        assertFalse(ai.isMarked());

        assertSame(one, ai.get(mark));

        assertFalse(mark[0]);

        ai.set(two, false);

        assertSame(two, ai.getReference());

        assertFalse(ai.isMarked());

        assertSame(two, ai.get(mark));

        assertFalse(mark[0]);

        ai.set(one, true);

        assertSame(one, ai.getReference());

        assertTrue(ai.isMarked());

        assertSame(one, ai.get(mark));

        assertTrue(mark[0]);

    }

    /**

     * attemptMark succeeds in single thread

     */

    public void testAttemptMark() {

        boolean[] mark = new boolean[1];

        AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        assertFalse(ai.isMarked());

        assertTrue(ai.attemptMark(one, true));

        assertTrue(ai.isMarked());

        assertSame(one, ai.get(mark));

        assertTrue(mark[0]);

    }

    /**

     * compareAndSet succeeds in changing values if equal to expected reference

     * and mark else fails

     */

    public void testCompareAndSet() {

        boolean[] mark = new boolean[1];

        AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        assertSame(one, ai.get(mark));

        assertFalse(ai.isMarked());

        assertFalse(mark[0]);

        assertTrue(ai.compareAndSet(one, two, false, false));

        assertSame(two, ai.get(mark));

        assertFalse(mark[0]);

        assertTrue(ai.compareAndSet(two, m3, false, true));

        assertSame(m3, ai.get(mark));

        assertTrue(mark[0]);

        assertFalse(ai.compareAndSet(two, m3, true, true));

        assertSame(m3, ai.get(mark));

        assertTrue(mark[0]);

    }

    /**

     * compareAndSet in one thread enables another waiting for reference value

     * to succeed

     */

    public void testCompareAndSetInMultipleThreads() throws Exception {

        final AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        Thread t = new Thread(new CheckedRunnable() {

            public void realRun() {

                while (!ai.compareAndSet(two, three, false, false))

                    Thread.yield();

            }});

        t.start();

        assertTrue(ai.compareAndSet(one, two, false, false));

        t.join(LONG_DELAY_MS);

        assertFalse(t.isAlive());

        assertSame(three, ai.getReference());

        assertFalse(ai.isMarked());

    }

    /**

     * compareAndSet in one thread enables another waiting for mark value

     * to succeed

     */

    public void testCompareAndSetInMultipleThreads2() throws Exception {

        final AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        Thread t = new Thread(new CheckedRunnable() {

            public void realRun() {

                while (!ai.compareAndSet(one, one, true, false))

                    Thread.yield();

            }});

        t.start();

        assertTrue(ai.compareAndSet(one, one, false, true));

        t.join(LONG_DELAY_MS);

        assertFalse(t.isAlive());

        assertSame(one, ai.getReference());

        assertFalse(ai.isMarked());

    }

    /**

     * repeated weakCompareAndSet succeeds in changing values when equal

     * to expected

     */

    public void testWeakCompareAndSet() {

        boolean[] mark = new boolean[1];

        AtomicMarkableReference ai = new AtomicMarkableReference(one, false);

        assertSame(one, ai.get(mark));

        assertFalse(ai.isMarked());

        assertFalse(mark[0]);

        do {} while (!ai.weakCompareAndSet(one, two, false, false));

        assertSame(two, ai.get(mark));

        assertFalse(mark[0]);

        do {} while (!ai.weakCompareAndSet(two, m3, false, true));

        assertSame(m3, ai.get(mark));

        assertTrue(mark[0]);

    }

}