/*

 * 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

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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.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Iterator;

import java.util.NoSuchElementException;

import java.util.concurrent.BlockingQueue;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.Delayed;

import java.util.concurrent.DelayQueue;

import java.util.concurrent.Executors;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.TimeUnit;

import junit.framework.Test;

public class DelayQueueTest extends JSR166TestCase {

    public static class Generic extends BlockingQueueTest {

        protected BlockingQueue emptyCollection() {

            return new DelayQueue();

        }

        protected PDelay makeElement(int i) {

            return new PDelay(i);

        }

    }

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        return newTestSuite(DelayQueueTest.class,

                            new Generic().testSuite());

    }

    /**

     * A delayed implementation for testing.

     * Most tests use Pseudodelays, where delays are all elapsed

     * (so, no blocking solely for delays) but are still ordered

     */

    static class PDelay implements Delayed {

        int pseudodelay;

        PDelay(int i) { pseudodelay = i; }

        public int compareTo(PDelay other) {

            int a = this.pseudodelay;

            int b = other.pseudodelay;

            return (a < b) ? -1 : (a > b) ? 1 : 0;

        }

        public int compareTo(Delayed y) {

            return compareTo((PDelay)y);

        }

        public boolean equals(Object other) {

            return (other instanceof PDelay) &&

                this.pseudodelay == ((PDelay)other).pseudodelay;

        }

        // suppress [overrides] javac warning

        public int hashCode() { return pseudodelay; }

        public long getDelay(TimeUnit ignore) {

            return Integer.MIN_VALUE + pseudodelay;

        }

        public String toString() {

            return String.valueOf(pseudodelay);

        }

    }

    /**

     * Delayed implementation that actually delays

     */

    static class NanoDelay implements Delayed {

        long trigger;

        NanoDelay(long i) {

            trigger = System.nanoTime() + i;

        }

        public int compareTo(NanoDelay y) {

            long i = trigger;

            long j = y.trigger;

            if (i < j) return -1;

            if (i > j) return 1;

            return 0;

        }

        public int compareTo(Delayed y) {

            return compareTo((NanoDelay)y);

        }

        public boolean equals(Object other) {

            return equals((NanoDelay)other);

        }

        public boolean equals(NanoDelay other) {

            return other.trigger == trigger;

        }

        // suppress [overrides] javac warning

        public int hashCode() { return (int) trigger; }

        public long getDelay(TimeUnit unit) {

            long n = trigger - System.nanoTime();

            return unit.convert(n, TimeUnit.NANOSECONDS);

        }

        public long getTriggerTime() {

            return trigger;

        }

        public String toString() {

            return String.valueOf(trigger);

        }

    }

    /**

     * Returns a new queue of given size containing consecutive

     * PDelays 0 ... n.

     */

    private DelayQueue<PDelay> populatedQueue(int n) {

        DelayQueue<PDelay> q = new DelayQueue<PDelay>();

        assertTrue(q.isEmpty());

        for (int i = n - 1; i >= 0; i -= 2)

            assertTrue(q.offer(new PDelay(i)));

        for (int i = (n & 1); i < n; i += 2)

            assertTrue(q.offer(new PDelay(i)));

        assertFalse(q.isEmpty());

        assertEquals(Integer.MAX_VALUE, q.remainingCapacity());

        assertEquals(n, q.size());

        return q;

    }

    /**

     * A new queue has unbounded capacity

     */

    public void testConstructor1() {

        assertEquals(Integer.MAX_VALUE, new DelayQueue().remainingCapacity());

    }

    /**

     * Initializing from null Collection throws NPE

     */

    public void testConstructor3() {

        try {

            new DelayQueue(null);

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Initializing from Collection of null elements throws NPE

     */

    public void testConstructor4() {

        try {

            new DelayQueue(Arrays.asList(new PDelay[SIZE]));

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Initializing from Collection with some null elements throws NPE

     */

    public void testConstructor5() {

        PDelay[] a = new PDelay[SIZE];

        for (int i = 0; i < SIZE - 1; ++i)

            a[i] = new PDelay(i);

        try {

            new DelayQueue(Arrays.asList(a));

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Queue contains all elements of collection used to initialize

     */

    public void testConstructor6() {

        PDelay[] ints = new PDelay[SIZE];

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

            ints[i] = new PDelay(i);

        DelayQueue q = new DelayQueue(Arrays.asList(ints));

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

            assertEquals(ints[i], q.poll());

    }

    /**

     * isEmpty is true before add, false after

     */

    public void testEmpty() {

        DelayQueue q = new DelayQueue();

        assertTrue(q.isEmpty());

        assertEquals(Integer.MAX_VALUE, q.remainingCapacity());

        q.add(new PDelay(1));

        assertFalse(q.isEmpty());

        q.add(new PDelay(2));

        q.remove();

        q.remove();

        assertTrue(q.isEmpty());

    }

    /**

     * remainingCapacity() always returns Integer.MAX_VALUE

     */

    public void testRemainingCapacity() {

        BlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(Integer.MAX_VALUE, q.remainingCapacity());

            assertEquals(SIZE - i, q.size());

            assertTrue(q.remove() instanceof PDelay);

        }

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

            assertEquals(Integer.MAX_VALUE, q.remainingCapacity());

            assertEquals(i, q.size());

            assertTrue(q.add(new PDelay(i)));

        }

    }

    /**

     * offer non-null succeeds

     */

    public void testOffer() {

        DelayQueue q = new DelayQueue();

        assertTrue(q.offer(new PDelay(0)));

        assertTrue(q.offer(new PDelay(1)));

    }

    /**

     * add succeeds

     */

    public void testAdd() {

        DelayQueue q = new DelayQueue();

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

            assertEquals(i, q.size());

            assertTrue(q.add(new PDelay(i)));

        }

    }

    /**

     * addAll(this) throws IAE

     */

    public void testAddAllSelf() {

        DelayQueue q = populatedQueue(SIZE);

        try {

            q.addAll(q);

            shouldThrow();

        } catch (IllegalArgumentException success) {}

    }

    /**

     * addAll of a collection with any null elements throws NPE after

     * possibly adding some elements

     */

    public void testAddAll3() {

        DelayQueue q = new DelayQueue();

        PDelay[] a = new PDelay[SIZE];

        for (int i = 0; i < SIZE - 1; ++i)

            a[i] = new PDelay(i);

        try {

            q.addAll(Arrays.asList(a));

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Queue contains all elements of successful addAll

     */

    public void testAddAll5() {

        PDelay[] empty = new PDelay[0];

        PDelay[] ints = new PDelay[SIZE];

        for (int i = SIZE - 1; i >= 0; --i)

            ints[i] = new PDelay(i);

        DelayQueue q = new DelayQueue();

        assertFalse(q.addAll(Arrays.asList(empty)));

        assertTrue(q.addAll(Arrays.asList(ints)));

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

            assertEquals(ints[i], q.poll());

    }

    /**

     * all elements successfully put are contained

     */

    public void testPut() {

        DelayQueue q = new DelayQueue();

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

            PDelay x = new PDelay(i);

            q.put(x);

            assertTrue(q.contains(x));

        }

        assertEquals(SIZE, q.size());

    }

    /**

     * put doesn't block waiting for take

     */

    public void testPutWithTake() throws InterruptedException {

        final DelayQueue q = new DelayQueue();

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() {

                q.put(new PDelay(0));

                q.put(new PDelay(0));

                q.put(new PDelay(0));

                q.put(new PDelay(0));

            }});

        awaitTermination(t);

        assertEquals(4, q.size());

    }

    /**

     * timed offer does not time out

     */

    public void testTimedOffer() throws InterruptedException {

        final DelayQueue q = new DelayQueue();

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                q.put(new PDelay(0));

                q.put(new PDelay(0));

                assertTrue(q.offer(new PDelay(0), SHORT_DELAY_MS, MILLISECONDS));

                assertTrue(q.offer(new PDelay(0), LONG_DELAY_MS, MILLISECONDS));

            }});

        awaitTermination(t);

    }

    /**

     * take retrieves elements in priority order

     */

    public void testTake() throws InterruptedException {

        DelayQueue q = populatedQueue(SIZE);

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

            assertEquals(new PDelay(i), q.take());

        }

    }

    /**

     * Take removes existing elements until empty, then blocks interruptibly

     */

    public void testBlockingTake() throws InterruptedException {

        final DelayQueue q = populatedQueue(SIZE);

        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

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

                    assertEquals(new PDelay(i), ((PDelay)q.take()));

                }

                Thread.currentThread().interrupt();

                try {

                    q.take();

                    shouldThrow();

                } catch (InterruptedException success) {}

                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();

                try {

                    q.take();

                    shouldThrow();

                } catch (InterruptedException success) {}

                assertFalse(Thread.interrupted());

            }});

        await(pleaseInterrupt);

        assertThreadStaysAlive(t);

        t.interrupt();

        awaitTermination(t);

    }

    /**

     * poll succeeds unless empty

     */

    public void testPoll() {

        DelayQueue q = populatedQueue(SIZE);

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

            assertEquals(new PDelay(i), q.poll());

        }

        assertNull(q.poll());

    }

    /**

     * timed poll with zero timeout succeeds when non-empty, else times out

     */

    public void testTimedPoll0() throws InterruptedException {

        DelayQueue q = populatedQueue(SIZE);

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

            assertEquals(new PDelay(i), q.poll(0, MILLISECONDS));

        }

        assertNull(q.poll(0, MILLISECONDS));

    }

    /**

     * timed poll with nonzero timeout succeeds when non-empty, else times out

     */

    public void testTimedPoll() throws InterruptedException {

        DelayQueue q = populatedQueue(SIZE);

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

            long startTime = System.nanoTime();

            assertEquals(new PDelay(i), q.poll(LONG_DELAY_MS, MILLISECONDS));

            assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);

        }

        long startTime = System.nanoTime();

        assertNull(q.poll(timeoutMillis(), MILLISECONDS));

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

        checkEmpty(q);

    }

    /**

     * Interrupted timed poll throws InterruptedException instead of

     * returning timeout status

     */

    public void testInterruptedTimedPoll() throws InterruptedException {

        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);

        final DelayQueue q = populatedQueue(SIZE);

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                long startTime = System.nanoTime();

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

                    assertEquals(new PDelay(i),

                                 ((PDelay)q.poll(LONG_DELAY_MS, MILLISECONDS)));

                }

                Thread.currentThread().interrupt();

                try {

                    q.poll(LONG_DELAY_MS, MILLISECONDS);

                    shouldThrow();

                } catch (InterruptedException success) {}

                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();

                try {

                    q.poll(LONG_DELAY_MS, MILLISECONDS);

                    shouldThrow();

                } catch (InterruptedException success) {}

                assertFalse(Thread.interrupted());

                assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);

            }});

        await(pleaseInterrupt);

        assertThreadStaysAlive(t);

        t.interrupt();

        awaitTermination(t);

        checkEmpty(q);

    }

    /**

     * peek returns next element, or null if empty

     */

    public void testPeek() {

        DelayQueue q = populatedQueue(SIZE);

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

            assertEquals(new PDelay(i), q.peek());

            assertEquals(new PDelay(i), q.poll());

            if (q.isEmpty())

                assertNull(q.peek());

            else

                assertFalse(new PDelay(i).equals(q.peek()));

        }

        assertNull(q.peek());

    }

    /**

     * element returns next element, or throws NSEE if empty

     */

    public void testElement() {

        DelayQueue q = populatedQueue(SIZE);

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

            assertEquals(new PDelay(i), q.element());

            q.poll();

        }

        try {

            q.element();

            shouldThrow();

        } catch (NoSuchElementException success) {}

    }

    /**

     * remove removes next element, or throws NSEE if empty

     */

    public void testRemove() {

        DelayQueue q = populatedQueue(SIZE);

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

            assertEquals(new PDelay(i), q.remove());

        }

        try {

            q.remove();

            shouldThrow();

        } catch (NoSuchElementException success) {}

    }

    /**

     * contains(x) reports true when elements added but not yet removed

     */

    public void testContains() {

        DelayQueue q = populatedQueue(SIZE);

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

            assertTrue(q.contains(new PDelay(i)));

            q.poll();

            assertFalse(q.contains(new PDelay(i)));

        }