/*

 * 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.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Comparator;

import java.util.Iterator;

import java.util.NoSuchElementException;

import java.util.Queue;

import java.util.concurrent.BlockingQueue;

import java.util.concurrent.CountDownLatch;

import java.util.concurrent.Executors;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.PriorityBlockingQueue;

import junit.framework.Test;

public class PriorityBlockingQueueTest extends JSR166TestCase {

    public static class Generic extends BlockingQueueTest {

        protected BlockingQueue emptyCollection() {

            return new PriorityBlockingQueue();

        }

    }

    public static class InitialCapacity extends BlockingQueueTest {

        protected BlockingQueue emptyCollection() {

            return new PriorityBlockingQueue(SIZE);

        }

    }

    public static void main(String[] args) {

        main(suite(), args);

    }

    public static Test suite() {

        class Implementation implements CollectionImplementation {

            public Class<?> klazz() { return PriorityBlockingQueue.class; }

            public Collection emptyCollection() { return new PriorityBlockingQueue(); }

            public Object makeElement(int i) { return i; }

            public boolean isConcurrent() { return true; }

            public boolean permitsNulls() { return false; }

        }

        return newTestSuite(PriorityBlockingQueueTest.class,

                            new Generic().testSuite(),

                            new InitialCapacity().testSuite(),

                            CollectionTest.testSuite(new Implementation()));

    }

    /** Sample Comparator */

    static class MyReverseComparator implements Comparator {

        public int compare(Object x, Object y) {

            return ((Comparable)y).compareTo(x);

        }

    }

    /**

     * Returns a new queue of given size containing consecutive

     * Integers 0 ... n - 1.

     */

    private static PriorityBlockingQueue<Integer> populatedQueue(int n) {

        PriorityBlockingQueue<Integer> q =

            new PriorityBlockingQueue<Integer>(n);

        assertTrue(q.isEmpty());

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

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

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

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

        assertFalse(q.isEmpty());

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

        assertEquals(n, q.size());

        assertEquals((Integer) 0, q.peek());

        return q;

    }

    /**

     * A new queue has unbounded capacity

     */

    public void testConstructor1() {

        assertEquals(Integer.MAX_VALUE,

                     new PriorityBlockingQueue(SIZE).remainingCapacity());

    }

    /**

     * Constructor throws IllegalArgumentException if capacity argument nonpositive

     */

    public void testConstructor2() {

        try {

            new PriorityBlockingQueue(0);

            shouldThrow();

        } catch (IllegalArgumentException success) {}

    }

    /**

     * Initializing from null Collection throws NPE

     */

    public void testConstructor3() {

        try {

            new PriorityBlockingQueue(null);

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Initializing from Collection of null elements throws NPE

     */

    public void testConstructor4() {

        Collection<Integer> elements = Arrays.asList(new Integer[SIZE]);

        try {

            new PriorityBlockingQueue(elements);

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Initializing from Collection with some null elements throws NPE

     */

    public void testConstructor5() {

        Integer[] ints = new Integer[SIZE];

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

            ints[i] = i;

        Collection<Integer> elements = Arrays.asList(ints);

        try {

            new PriorityBlockingQueue(elements);

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Queue contains all elements of collection used to initialize

     */

    public void testConstructor6() {

        Integer[] ints = new Integer[SIZE];

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

            ints[i] = i;

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

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

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

    }

    /**

     * The comparator used in constructor is used

     */

    public void testConstructor7() {

        MyReverseComparator cmp = new MyReverseComparator();

        PriorityBlockingQueue q = new PriorityBlockingQueue(SIZE, cmp);

        assertEquals(cmp, q.comparator());

        Integer[] ints = new Integer[SIZE];

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

            ints[i] = new Integer(i);

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

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

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

    }

    /**

     * isEmpty is true before add, false after

     */

    public void testEmpty() {

        PriorityBlockingQueue q = new PriorityBlockingQueue(2);

        assertTrue(q.isEmpty());

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

        q.add(one);

        assertFalse(q.isEmpty());

        q.add(two);

        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());

            assertEquals(i, q.remove());

        }

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

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

            assertEquals(i, q.size());

            assertTrue(q.add(i));

        }

    }

    /**

     * Offer of comparable element succeeds

     */

    public void testOffer() {

        PriorityBlockingQueue q = new PriorityBlockingQueue(1);

        assertTrue(q.offer(zero));

        assertTrue(q.offer(one));

    }

    /**

     * Offer of non-Comparable throws CCE

     */

    public void testOfferNonComparable() {

        PriorityBlockingQueue q = new PriorityBlockingQueue(1);

        try {

            q.offer(new Object());

            shouldThrow();

        } catch (ClassCastException success) {

            assertTrue(q.isEmpty());

            assertEquals(0, q.size());

            assertNull(q.poll());

        }

    }

    /**

     * add of comparable succeeds

     */

    public void testAdd() {

        PriorityBlockingQueue q = new PriorityBlockingQueue(SIZE);

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

            assertEquals(i, q.size());

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

        }

    }

    /**

     * addAll(this) throws IllegalArgumentException

     */

    public void testAddAllSelf() {

        PriorityBlockingQueue 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() {

        PriorityBlockingQueue q = new PriorityBlockingQueue(SIZE);

        Integer[] ints = new Integer[SIZE];

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

            ints[i] = new Integer(i);

        try {

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

            shouldThrow();

        } catch (NullPointerException success) {}

    }

    /**

     * Queue contains all elements of successful addAll

     */

    public void testAddAll5() {

        Integer[] empty = new Integer[0];

        Integer[] ints = new Integer[SIZE];

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

            ints[i] = new Integer(i);

        PriorityBlockingQueue q = new PriorityBlockingQueue(SIZE);

        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() {

        PriorityBlockingQueue q = new PriorityBlockingQueue(SIZE);

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

            Integer x = new Integer(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 PriorityBlockingQueue q = new PriorityBlockingQueue(2);

        final int size = 4;

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() {

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

                    q.put(new Integer(0));

            }});

        awaitTermination(t);

        assertEquals(size, q.size());

        q.take();

    }

    /**

     * timed offer does not time out

     */

    public void testTimedOffer() {

        final PriorityBlockingQueue q = new PriorityBlockingQueue(2);

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() {

                q.put(new Integer(0));

                q.put(new Integer(0));

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

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

            }});

        awaitTermination(t);

    }

    /**

     * take retrieves elements in priority order

     */

    public void testTake() throws InterruptedException {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(i, q.take());

        }

    }

    /**

     * Take removes existing elements until empty, then blocks interruptibly

     */

    public void testBlockingTake() throws InterruptedException {

        final PriorityBlockingQueue 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(i, 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);

        assertThreadBlocks(t, Thread.State.WAITING);

        t.interrupt();

        awaitTermination(t);

    }

    /**

     * poll succeeds unless empty

     */

    public void testPoll() {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(i, q.poll());

        }

        assertNull(q.poll());

    }

    /**

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

     */

    public void testTimedPoll0() throws InterruptedException {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(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 {

        PriorityBlockingQueue<Integer> q = populatedQueue(SIZE);

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

            long startTime = System.nanoTime();

            assertEquals(i, (int) 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 BlockingQueue<Integer> q = populatedQueue(SIZE);

        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);

        Thread t = newStartedThread(new CheckedRunnable() {

            public void realRun() throws InterruptedException {

                long startTime = System.nanoTime();

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

                    assertEquals(i, (int) 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);

        assertThreadBlocks(t, Thread.State.TIMED_WAITING);

        t.interrupt();

        awaitTermination(t);

    }

    /**

     * peek returns next element, or null if empty

     */

    public void testPeek() {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(i, q.peek());

            assertEquals(i, q.poll());

            assertTrue(q.peek() == null ||

                       !q.peek().equals(i));

        }

        assertNull(q.peek());

    }

    /**

     * element returns next element, or throws NSEE if empty

     */

    public void testElement() {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(i, q.element());

            assertEquals(i, q.poll());

        }

        try {

            q.element();

            shouldThrow();

        } catch (NoSuchElementException success) {}

    }

    /**

     * remove removes next element, or throws NSEE if empty

     */

    public void testRemove() {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

            assertEquals(i, q.remove());

        }

        try {

            q.remove();

            shouldThrow();

        } catch (NoSuchElementException success) {}

    }

    /**

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

     */

    public void testContains() {

        PriorityBlockingQueue q = populatedQueue(SIZE);

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

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

            q.poll();

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

        }

    }

    /**

     * clear removes all elements

     */

    public void testClear() {

        PriorityBlockingQueue q = populatedQueue(SIZE);

        q.clear();

        assertTrue(q.isEmpty());

        assertEquals(0, q.size());

        q.add(one);

        assertFalse(q.isEmpty());