/*

 * 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 java.util.concurrent.atomic.AtomicInteger;

import junit.framework.Test;

import junit.framework.TestSuite;

public class AtomicIntegerTest extends JSR166TestCase {

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        return new TestSuite(AtomicIntegerTest.class);

    }

    final int[] VALUES = {

        Integer.MIN_VALUE, -1, 0, 1, 42, Integer.MAX_VALUE,

    };

    /**

     * constructor initializes to given value

     */

    public void testConstructor() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.get());

    }

    /**

     * default constructed initializes to zero

     */

    public void testConstructor2() {

        AtomicInteger ai = new AtomicInteger();

        assertEquals(0, ai.get());

    }

    /**

     * get returns the last value set

     */

    public void testGetSet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.get());

        ai.set(2);

        assertEquals(2, ai.get());

        ai.set(-3);

        assertEquals(-3, ai.get());

    }

    /**

     * get returns the last value lazySet in same thread

     */

    public void testGetLazySet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.get());

        ai.lazySet(2);

        assertEquals(2, ai.get());

        ai.lazySet(-3);

        assertEquals(-3, ai.get());

    }

    /**

     * compareAndSet succeeds in changing value if equal to expected else fails

     */

    public void testCompareAndSet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertTrue(ai.compareAndSet(1, 2));

        assertTrue(ai.compareAndSet(2, -4));

        assertEquals(-4, ai.get());

        assertFalse(ai.compareAndSet(-5, 7));

        assertEquals(-4, ai.get());

        assertTrue(ai.compareAndSet(-4, 7));

        assertEquals(7, ai.get());

    }

    /**

     * compareAndSet in one thread enables another waiting for value

     * to succeed

     */

    public void testCompareAndSetInMultipleThreads() throws Exception {

        final AtomicInteger ai = new AtomicInteger(1);

        Thread t = new Thread(new CheckedRunnable() {

            public void realRun() {

                while (!ai.compareAndSet(2, 3))

                    Thread.yield();

            }});

        t.start();

        assertTrue(ai.compareAndSet(1, 2));

        t.join(LONG_DELAY_MS);

        assertFalse(t.isAlive());

        assertEquals(3, ai.get());

    }

    /**

     * repeated weakCompareAndSet succeeds in changing value when equal

     * to expected

     */

    public void testWeakCompareAndSet() {

        AtomicInteger ai = new AtomicInteger(1);

        do {} while (!ai.weakCompareAndSet(1, 2));

        do {} while (!ai.weakCompareAndSet(2, -4));

        assertEquals(-4, ai.get());

        do {} while (!ai.weakCompareAndSet(-4, 7));

        assertEquals(7, ai.get());

    }

    /**

     * getAndSet returns previous value and sets to given value

     */

    public void testGetAndSet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.getAndSet(0));

        assertEquals(0, ai.getAndSet(-10));

        assertEquals(-10, ai.getAndSet(1));

    }

    /**

     * getAndAdd returns previous value and adds given value

     */

    public void testGetAndAdd() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.getAndAdd(2));

        assertEquals(3, ai.get());

        assertEquals(3, ai.getAndAdd(-4));

        assertEquals(-1, ai.get());

    }

    /**

     * getAndDecrement returns previous value and decrements

     */

    public void testGetAndDecrement() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.getAndDecrement());

        assertEquals(0, ai.getAndDecrement());

        assertEquals(-1, ai.getAndDecrement());

    }

    /**

     * getAndIncrement returns previous value and increments

     */

    public void testGetAndIncrement() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(1, ai.getAndIncrement());

        assertEquals(2, ai.get());

        ai.set(-2);

        assertEquals(-2, ai.getAndIncrement());

        assertEquals(-1, ai.getAndIncrement());

        assertEquals(0, ai.getAndIncrement());

        assertEquals(1, ai.get());

    }

    /**

     * addAndGet adds given value to current, and returns current value

     */

    public void testAddAndGet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(3, ai.addAndGet(2));

        assertEquals(3, ai.get());

        assertEquals(-1, ai.addAndGet(-4));

        assertEquals(-1, ai.get());

    }

    /**

     * decrementAndGet decrements and returns current value

     */

    public void testDecrementAndGet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(0, ai.decrementAndGet());

        assertEquals(-1, ai.decrementAndGet());

        assertEquals(-2, ai.decrementAndGet());

        assertEquals(-2, ai.get());

    }

    /**

     * incrementAndGet increments and returns current value

     */

    public void testIncrementAndGet() {

        AtomicInteger ai = new AtomicInteger(1);

        assertEquals(2, ai.incrementAndGet());

        assertEquals(2, ai.get());

        ai.set(-2);

        assertEquals(-1, ai.incrementAndGet());

        assertEquals(0, ai.incrementAndGet());

        assertEquals(1, ai.incrementAndGet());

        assertEquals(1, ai.get());

    }

    /**

     * a deserialized serialized atomic holds same value

     */

    public void testSerialization() throws Exception {

        AtomicInteger x = new AtomicInteger();

        AtomicInteger y = serialClone(x);

        assertNotSame(x, y);

        x.set(22);

        AtomicInteger z = serialClone(x);

        assertEquals(22, x.get());

        assertEquals(0, y.get());

        assertEquals(22, z.get());

    }

    /**

     * toString returns current value.

     */

    public void testToString() {

        AtomicInteger ai = new AtomicInteger();

        assertEquals("0", ai.toString());

        for (int x : VALUES) {

            ai.set(x);

            assertEquals(Integer.toString(x), ai.toString());

        }

    }

    /**

     * intValue returns current value.

     */

    public void testIntValue() {

        AtomicInteger ai = new AtomicInteger();

        assertEquals(0, ai.intValue());

        for (int x : VALUES) {

            ai.set(x);

            assertEquals(x, ai.intValue());

        }

    }

    /**

     * longValue returns current value.

     */

    public void testLongValue() {

        AtomicInteger ai = new AtomicInteger();

        assertEquals(0L, ai.longValue());

        for (int x : VALUES) {

            ai.set(x);

            assertEquals((long)x, ai.longValue());

        }

    }

    /**

     * floatValue returns current value.

     */

    public void testFloatValue() {

        AtomicInteger ai = new AtomicInteger();

        assertEquals(0.0f, ai.floatValue());

        for (int x : VALUES) {

            ai.set(x);

            assertEquals((float)x, ai.floatValue());

        }

    }

    /**

     * doubleValue returns current value.

     */

    public void testDoubleValue() {

        AtomicInteger ai = new AtomicInteger();

        assertEquals(0.0d, ai.doubleValue());

        for (int x : VALUES) {

            ai.set(x);

            assertEquals((double)x, ai.doubleValue());

        }

    }

}