test/tck/DelayQueueTest.java

/*
 * 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) {
        junit.textui.TestRunner.run(suite());
    }

    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 {
            PDelay[] ints = new PDelay[SIZE];
            new DelayQueue(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Initializing from Collection with some null elements throws NPE
     */
    public void testConstructor5() {
        try {
            PDelay[] ints = new PDelay[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new PDelay(i);
            new DelayQueue(Arrays.asList(ints));
            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() {
        try {
            DelayQueue q = populatedQueue(SIZE);
            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() {
        try {
            DelayQueue q = new DelayQueue();
            PDelay[] ints = new PDelay[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new PDelay(i);
            q.addAll(Arrays.asList(ints));
            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);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                DelayQueue q = populatedQueue(SIZE);
                for (int i = 0; i < SIZE; ++i) {
                    assertEquals(new PDelay(i), ((PDelay)q.poll(SHORT_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());
            }});

        await(pleaseInterrupt);
        assertThreadStaysAlive(t);
        t.interrupt();
        awaitTermination(t);
    }

    /**
     * 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)));
        }
    }

    /**
     * clear removes all elements
     */
    public void testClear() {
        DelayQueue q = populatedQueue(SIZE);
        q.clear();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
        PDelay x = new PDelay(1);
        q.add(x);
        assertFalse(q.isEmpty());
        assertTrue(q.contains(x));
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll(c) is true when c contains a subset of elements
     */
    public void testContainsAll() {
        DelayQueue q = populatedQueue(SIZE);
        DelayQueue p = new DelayQueue();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.containsAll(p));
            assertFalse(p.containsAll(q));
            p.add(new PDelay(i));
        }
        assertTrue(p.containsAll(q));
    }

    /**
     * retainAll(c) retains only those elements of c and reports true if changed
     */
    public void testRetainAll() {
        DelayQueue q = populatedQueue(SIZE);
        DelayQueue p = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            boolean changed = q.retainAll(p);
            if (i == 0)
                assertFalse(changed);
            else
                assertTrue(changed);

            assertTrue(q.containsAll(p));
            assertEquals(SIZE-i, q.size());
            p.remove();
        }
    }

    /**
     * removeAll(c) removes only those elements of c and reports true if changed
     */
    public void testRemoveAll() {
        for (int i = 1; i < SIZE; ++i) {
            DelayQueue q = populatedQueue(SIZE);
            DelayQueue p = populatedQueue(i);
            assertTrue(q.removeAll(p));
            assertEquals(SIZE-i, q.size());
            for (int j = 0; j < i; ++j) {
                PDelay x = (PDelay)(p.remove());
                assertFalse(q.contains(x));
            }
        }
    }

    /**
     * toArray contains all elements
     */
    public void testToArray() throws InterruptedException {
        DelayQueue q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        Arrays.sort(o);
        for (int i = 0; i < o.length; i++)
            assertSame(o[i], q.take());
    }

    /**
     * toArray(a) contains all elements
     */
    public void testToArray2() {
        DelayQueue<PDelay> q = populatedQueue(SIZE);
        PDelay[] ints = new PDelay[SIZE];
        PDelay[] array = q.toArray(ints);
        assertSame(ints, array);
        Arrays.sort(ints);
        for (int i = 0; i < ints.length; i++)
            assertSame(ints[i], q.remove());
    }

    /**
     * toArray(incompatible array type) throws ArrayStoreException
     */
    public void testToArray1_BadArg() {
        DelayQueue q = populatedQueue(SIZE);
        try {
            q.toArray(new String[10]);
            shouldThrow();
        } catch (ArrayStoreException success) {}
    }

    /**
     * iterator iterates through all elements
     */
    public void testIterator() {
        DelayQueue q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.iterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
        assertIteratorExhausted(it);
    }

    /**
     * iterator of empty collection has no elements
     */
    public void testEmptyIterator() {
        assertIteratorExhausted(new DelayQueue().iterator());
    }

    /**
     * iterator.remove removes current element
     */
    public void testIteratorRemove() {
        final DelayQueue q = new DelayQueue();
        q.add(new PDelay(2));
        q.add(new PDelay(1));
        q.add(new PDelay(3));
        Iterator it = q.iterator();
        it.next();
        it.remove();
        it = q.iterator();
        assertEquals(new PDelay(2), it.next());
        assertEquals(new PDelay(3), it.next());
        assertFalse(it.hasNext());
    }

    /**
     * toString contains toStrings of elements
     */
    public void testToString() {
        DelayQueue q = populatedQueue(SIZE);
        String s = q.toString();
        for (Object e : q)
            assertTrue(s.contains(e.toString()));
    }

    /**
     * timed poll transfers elements across Executor tasks
     */
    public void testPollInExecutor() {
        final DelayQueue q = new DelayQueue();
        final CheckedBarrier threadsStarted = new CheckedBarrier(2);
        ExecutorService executor = Executors.newFixedThreadPool(2);
        executor.execute(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertNull(q.poll());
                threadsStarted.await();
                assertNotNull(q.poll(LONG_DELAY_MS, MILLISECONDS));
                checkEmpty(q);
            }});

        executor.execute(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                threadsStarted.await();
                q.put(new PDelay(1));
            }});

        joinPool(executor);
    }

    /**
     * Delayed actions do not occur until their delay elapses
     */
    public void testDelay() throws InterruptedException {
        DelayQueue<NanoDelay> q = new DelayQueue<NanoDelay>();
        for (int i = 0; i < SIZE; ++i)
            q.add(new NanoDelay(1000000L * (SIZE - i)));

        long last = 0;
        for (int i = 0; i < SIZE; ++i) {
            NanoDelay e = q.take();
            long tt = e.getTriggerTime();
            assertTrue(System.nanoTime() - tt >= 0);
            if (i != 0)
                assertTrue(tt >= last);
            last = tt;
        }
        assertTrue(q.isEmpty());
    }

    /**
     * peek of a non-empty queue returns non-null even if not expired
     */
    public void testPeekDelayed() {
        DelayQueue q = new DelayQueue();
        q.add(new NanoDelay(Long.MAX_VALUE));
        assertNotNull(q.peek());
    }

    /**
     * poll of a non-empty queue returns null if no expired elements.
     */
    public void testPollDelayed() {
        DelayQueue q = new DelayQueue();
        q.add(new NanoDelay(Long.MAX_VALUE));
        assertNull(q.poll());
    }

    /**
     * timed poll of a non-empty queue returns null if no expired elements.
     */
    public void testTimedPollDelayed() throws InterruptedException {
        DelayQueue q = new DelayQueue();
        q.add(new NanoDelay(LONG_DELAY_MS * 1000000L));
        assertNull(q.poll(timeoutMillis(), MILLISECONDS));
    }

    /**
     * drainTo(c) empties queue into another collection c
     */
    public void testDrainTo() {
        DelayQueue q = new DelayQueue();
        PDelay[] elems = new PDelay[SIZE];
        for (int i = 0; i < SIZE; ++i) {
            elems[i] = new PDelay(i);
            q.add(elems[i]);
        }
        ArrayList l = new ArrayList();
        q.drainTo(l);
        assertEquals(0, q.size());
        for (int i = 0; i < SIZE; ++i)
            assertEquals(elems[i], l.get(i));
        q.add(elems[0]);
        q.add(elems[1]);
        assertFalse(q.isEmpty());
        assertTrue(q.contains(elems[0]));
        assertTrue(q.contains(elems[1]));
        l.clear();
        q.drainTo(l);
        assertEquals(0, q.size());
        assertEquals(2, l.size());
        for (int i = 0; i < 2; ++i)
            assertEquals(elems[i], l.get(i));
    }

    /**
     * drainTo empties queue
     */
    public void testDrainToWithActivePut() throws InterruptedException {
        final DelayQueue q = populatedQueue(SIZE);
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() {
                q.put(new PDelay(SIZE+1));
            }});

        t.start();
        ArrayList l = new ArrayList();
        q.drainTo(l);
        assertTrue(l.size() >= SIZE);
        t.join();
        assertTrue(q.size() + l.size() >= SIZE);
    }

    /**
     * drainTo(c, n) empties first min(n, size) elements of queue into c
     */
    public void testDrainToN() {
        for (int i = 0; i < SIZE + 2; ++i) {
            DelayQueue q = populatedQueue(SIZE);
            ArrayList l = new ArrayList();
            q.drainTo(l, i);
            int k = (i < SIZE) ? i : SIZE;
            assertEquals(SIZE-k, q.size());
            assertEquals(k, l.size());
        }
    }

    /**
     * remove(null), contains(null) always return false
     */
    public void testNeverContainsNull() {
        Collection<?> q = populatedQueue(SIZE);
        assertFalse(q.contains(null));
        assertFalse(q.remove(null));
    }
}
Revision:	1.70
Committed:	Sat Feb 28 19:59:23 2015 UTC (9 years, 2 months ago) by jsr166
Branch:	MAIN
Changes since 1.69:	+10 -13 lines
Log Message:	improve testRemainingCapacity
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	* Pat Fisher, Mike Judd.
7	*/
8
9	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10
11	import java.util.ArrayList;
12	import java.util.Arrays;
13	import java.util.Collection;
14	import java.util.Iterator;
15	import java.util.NoSuchElementException;
16	import java.util.concurrent.BlockingQueue;
17	import java.util.concurrent.CountDownLatch;
18	import java.util.concurrent.Delayed;
19	import java.util.concurrent.DelayQueue;
20	import java.util.concurrent.Executors;
21	import java.util.concurrent.ExecutorService;
22	import java.util.concurrent.TimeUnit;
23
24	import junit.framework.Test;
25
26	public class DelayQueueTest extends JSR166TestCase {
27
28	public static class Generic extends BlockingQueueTest {
29	protected BlockingQueue emptyCollection() {
30	return new DelayQueue();
31	}
32	protected PDelay makeElement(int i) {
33	return new PDelay(i);
34	}
35	}
36
37	public static void main(String[] args) {
38	junit.textui.TestRunner.run(suite());
39	}
40
41	public static Test suite() {
42	return newTestSuite(DelayQueueTest.class,
43	new Generic().testSuite());
44	}
45
46	/**
47	* A delayed implementation for testing.
48	* Most tests use Pseudodelays, where delays are all elapsed
49	* (so, no blocking solely for delays) but are still ordered
50	*/
51	static class PDelay implements Delayed {
52	int pseudodelay;
53	PDelay(int i) { pseudodelay = i; }
54	public int compareTo(PDelay other) {
55	int a = this.pseudodelay;
56	int b = other.pseudodelay;
57	return (a < b) ? -1 : (a > b) ? 1 : 0;
58	}
59	public int compareTo(Delayed y) {
60	return compareTo((PDelay)y);
61	}
62	public boolean equals(Object other) {
63	return (other instanceof PDelay) &&
64	this.pseudodelay == ((PDelay)other).pseudodelay;
65	}
66	// suppress [overrides] javac warning
67	public int hashCode() { return pseudodelay; }
68	public long getDelay(TimeUnit ignore) {
69	return Integer.MIN_VALUE + pseudodelay;
70	}
71	public String toString() {
72	return String.valueOf(pseudodelay);
73	}
74	}
75
76	/**
77	* Delayed implementation that actually delays
78	*/
79	static class NanoDelay implements Delayed {
80	long trigger;
81	NanoDelay(long i) {
82	trigger = System.nanoTime() + i;
83	}
84	public int compareTo(NanoDelay y) {
85	long i = trigger;
86	long j = y.trigger;
87	if (i < j) return -1;
88	if (i > j) return 1;
89	return 0;
90	}
91
92	public int compareTo(Delayed y) {
93	return compareTo((NanoDelay)y);
94	}
95
96	public boolean equals(Object other) {
97	return equals((NanoDelay)other);
98	}
99	public boolean equals(NanoDelay other) {
100	return other.trigger == trigger;
101	}
102
103	// suppress [overrides] javac warning
104	public int hashCode() { return (int) trigger; }
105
106	public long getDelay(TimeUnit unit) {
107	long n = trigger - System.nanoTime();
108	return unit.convert(n, TimeUnit.NANOSECONDS);
109	}
110
111	public long getTriggerTime() {
112	return trigger;
113	}
114
115	public String toString() {
116	return String.valueOf(trigger);
117	}
118	}
119
120	/**
121	* Returns a new queue of given size containing consecutive
122	* PDelays 0 ... n.
123	*/
124	private DelayQueue<PDelay> populatedQueue(int n) {
125	DelayQueue<PDelay> q = new DelayQueue<PDelay>();
126	assertTrue(q.isEmpty());
127	for (int i = n-1; i >= 0; i -= 2)
128	assertTrue(q.offer(new PDelay(i)));
129	for (int i = (n & 1); i < n; i += 2)
130	assertTrue(q.offer(new PDelay(i)));
131	assertFalse(q.isEmpty());
132	assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
133	assertEquals(n, q.size());
134	return q;
135	}
136
137	/**
138	* A new queue has unbounded capacity
139	*/
140	public void testConstructor1() {
141	assertEquals(Integer.MAX_VALUE, new DelayQueue().remainingCapacity());
142	}
143
144	/**
145	* Initializing from null Collection throws NPE
146	*/
147	public void testConstructor3() {
148	try {
149	new DelayQueue(null);
150	shouldThrow();
151	} catch (NullPointerException success) {}
152	}
153
154	/**
155	* Initializing from Collection of null elements throws NPE
156	*/
157	public void testConstructor4() {
158	try {
159	PDelay[] ints = new PDelay[SIZE];
160	new DelayQueue(Arrays.asList(ints));
161	shouldThrow();
162	} catch (NullPointerException success) {}
163	}
164
165	/**
166	* Initializing from Collection with some null elements throws NPE
167	*/
168	public void testConstructor5() {
169	try {
170	PDelay[] ints = new PDelay[SIZE];
171	for (int i = 0; i < SIZE-1; ++i)
172	ints[i] = new PDelay(i);
173	new DelayQueue(Arrays.asList(ints));
174	shouldThrow();
175	} catch (NullPointerException success) {}
176	}
177
178	/**
179	* Queue contains all elements of collection used to initialize
180	*/
181	public void testConstructor6() {
182	PDelay[] ints = new PDelay[SIZE];
183	for (int i = 0; i < SIZE; ++i)
184	ints[i] = new PDelay(i);
185	DelayQueue q = new DelayQueue(Arrays.asList(ints));
186	for (int i = 0; i < SIZE; ++i)
187	assertEquals(ints[i], q.poll());
188	}
189
190	/**
191	* isEmpty is true before add, false after
192	*/
193	public void testEmpty() {
194	DelayQueue q = new DelayQueue();
195	assertTrue(q.isEmpty());
196	assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
197	q.add(new PDelay(1));
198	assertFalse(q.isEmpty());
199	q.add(new PDelay(2));
200	q.remove();
201	q.remove();
202	assertTrue(q.isEmpty());
203	}
204
205	/**
206	* remainingCapacity() always returns Integer.MAX_VALUE
207	*/
208	public void testRemainingCapacity() {
209	BlockingQueue q = populatedQueue(SIZE);
210	for (int i = 0; i < SIZE; ++i) {
211	assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
212	assertEquals(SIZE-i, q.size());
213	assertTrue(q.remove() instanceof PDelay);
214	}
215	for (int i = 0; i < SIZE; ++i) {
216	assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
217	assertEquals(i, q.size());
218	assertTrue(q.add(new PDelay(i)));
219	}
220	}
221
222	/**
223	* offer non-null succeeds
224	*/
225	public void testOffer() {
226	DelayQueue q = new DelayQueue();
227	assertTrue(q.offer(new PDelay(0)));
228	assertTrue(q.offer(new PDelay(1)));
229	}
230
231	/**
232	* add succeeds
233	*/
234	public void testAdd() {
235	DelayQueue q = new DelayQueue();
236	for (int i = 0; i < SIZE; ++i) {
237	assertEquals(i, q.size());
238	assertTrue(q.add(new PDelay(i)));
239	}
240	}
241
242	/**
243	* addAll(this) throws IAE
244	*/
245	public void testAddAllSelf() {
246	try {
247	DelayQueue q = populatedQueue(SIZE);
248	q.addAll(q);
249	shouldThrow();
250	} catch (IllegalArgumentException success) {}
251	}
252
253	/**
254	* addAll of a collection with any null elements throws NPE after
255	* possibly adding some elements
256	*/
257	public void testAddAll3() {
258	try {
259	DelayQueue q = new DelayQueue();
260	PDelay[] ints = new PDelay[SIZE];
261	for (int i = 0; i < SIZE-1; ++i)
262	ints[i] = new PDelay(i);
263	q.addAll(Arrays.asList(ints));
264	shouldThrow();
265	} catch (NullPointerException success) {}
266	}
267
268	/**
269	* Queue contains all elements of successful addAll
270	*/
271	public void testAddAll5() {
272	PDelay[] empty = new PDelay[0];
273	PDelay[] ints = new PDelay[SIZE];
274	for (int i = SIZE-1; i >= 0; --i)
275	ints[i] = new PDelay(i);
276	DelayQueue q = new DelayQueue();
277	assertFalse(q.addAll(Arrays.asList(empty)));
278	assertTrue(q.addAll(Arrays.asList(ints)));
279	for (int i = 0; i < SIZE; ++i)
280	assertEquals(ints[i], q.poll());
281	}
282
283	/**
284	* all elements successfully put are contained
285	*/
286	public void testPut() {
287	DelayQueue q = new DelayQueue();
288	for (int i = 0; i < SIZE; ++i) {
289	PDelay x = new PDelay(i);
290	q.put(x);
291	assertTrue(q.contains(x));
292	}
293	assertEquals(SIZE, q.size());
294	}
295
296	/**
297	* put doesn't block waiting for take
298	*/
299	public void testPutWithTake() throws InterruptedException {
300	final DelayQueue q = new DelayQueue();
301	Thread t = newStartedThread(new CheckedRunnable() {
302	public void realRun() {
303	q.put(new PDelay(0));
304	q.put(new PDelay(0));
305	q.put(new PDelay(0));
306	q.put(new PDelay(0));
307	}});
308
309	awaitTermination(t);
310	assertEquals(4, q.size());
311	}
312
313	/**
314	* timed offer does not time out
315	*/
316	public void testTimedOffer() throws InterruptedException {
317	final DelayQueue q = new DelayQueue();
318	Thread t = newStartedThread(new CheckedRunnable() {
319	public void realRun() throws InterruptedException {
320	q.put(new PDelay(0));
321	q.put(new PDelay(0));
322	assertTrue(q.offer(new PDelay(0), SHORT_DELAY_MS, MILLISECONDS));
323	assertTrue(q.offer(new PDelay(0), LONG_DELAY_MS, MILLISECONDS));
324	}});
325
326	awaitTermination(t);
327	}
328
329	/**
330	* take retrieves elements in priority order
331	*/
332	public void testTake() throws InterruptedException {
333	DelayQueue q = populatedQueue(SIZE);
334	for (int i = 0; i < SIZE; ++i) {
335	assertEquals(new PDelay(i), q.take());
336	}
337	}
338
339	/**
340	* Take removes existing elements until empty, then blocks interruptibly
341	*/
342	public void testBlockingTake() throws InterruptedException {
343	final DelayQueue q = populatedQueue(SIZE);
344	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
345	Thread t = newStartedThread(new CheckedRunnable() {
346	public void realRun() throws InterruptedException {
347	for (int i = 0; i < SIZE; ++i) {
348	assertEquals(new PDelay(i), ((PDelay)q.take()));
349	}
350
351	Thread.currentThread().interrupt();
352	try {
353	q.take();
354	shouldThrow();
355	} catch (InterruptedException success) {}
356	assertFalse(Thread.interrupted());
357
358	pleaseInterrupt.countDown();
359	try {
360	q.take();
361	shouldThrow();
362	} catch (InterruptedException success) {}
363	assertFalse(Thread.interrupted());
364	}});
365
366	await(pleaseInterrupt);
367	assertThreadStaysAlive(t);
368	t.interrupt();
369	awaitTermination(t);
370	}
371
372	/**
373	* poll succeeds unless empty
374	*/
375	public void testPoll() {
376	DelayQueue q = populatedQueue(SIZE);
377	for (int i = 0; i < SIZE; ++i) {
378	assertEquals(new PDelay(i), q.poll());
379	}
380	assertNull(q.poll());
381	}
382
383	/**
384	* timed poll with zero timeout succeeds when non-empty, else times out
385	*/
386	public void testTimedPoll0() throws InterruptedException {
387	DelayQueue q = populatedQueue(SIZE);
388	for (int i = 0; i < SIZE; ++i) {
389	assertEquals(new PDelay(i), q.poll(0, MILLISECONDS));
390	}
391	assertNull(q.poll(0, MILLISECONDS));
392	}
393
394	/**
395	* timed poll with nonzero timeout succeeds when non-empty, else times out
396	*/
397	public void testTimedPoll() throws InterruptedException {
398	DelayQueue q = populatedQueue(SIZE);
399	for (int i = 0; i < SIZE; ++i) {
400	long startTime = System.nanoTime();
401	assertEquals(new PDelay(i), q.poll(LONG_DELAY_MS, MILLISECONDS));
402	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
403	}
404	long startTime = System.nanoTime();
405	assertNull(q.poll(timeoutMillis(), MILLISECONDS));
406	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
407	checkEmpty(q);
408	}
409
410	/**
411	* Interrupted timed poll throws InterruptedException instead of
412	* returning timeout status
413	*/
414	public void testInterruptedTimedPoll() throws InterruptedException {
415	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
416	Thread t = newStartedThread(new CheckedRunnable() {
417	public void realRun() throws InterruptedException {
418	DelayQueue q = populatedQueue(SIZE);
419	for (int i = 0; i < SIZE; ++i) {
420	assertEquals(new PDelay(i), ((PDelay)q.poll(SHORT_DELAY_MS, MILLISECONDS)));
421	}
422
423	Thread.currentThread().interrupt();
424	try {
425	q.poll(LONG_DELAY_MS, MILLISECONDS);
426	shouldThrow();
427	} catch (InterruptedException success) {}
428	assertFalse(Thread.interrupted());
429
430	pleaseInterrupt.countDown();
431	try {
432	q.poll(LONG_DELAY_MS, MILLISECONDS);
433	shouldThrow();
434	} catch (InterruptedException success) {}
435	assertFalse(Thread.interrupted());
436	}});
437
438	await(pleaseInterrupt);
439	assertThreadStaysAlive(t);
440	t.interrupt();
441	awaitTermination(t);
442	}
443
444	/**
445	* peek returns next element, or null if empty
446	*/
447	public void testPeek() {
448	DelayQueue q = populatedQueue(SIZE);
449	for (int i = 0; i < SIZE; ++i) {
450	assertEquals(new PDelay(i), q.peek());
451	assertEquals(new PDelay(i), q.poll());
452	if (q.isEmpty())
453	assertNull(q.peek());
454	else
455	assertFalse(new PDelay(i).equals(q.peek()));
456	}
457	assertNull(q.peek());
458	}
459
460	/**
461	* element returns next element, or throws NSEE if empty
462	*/
463	public void testElement() {
464	DelayQueue q = populatedQueue(SIZE);
465	for (int i = 0; i < SIZE; ++i) {
466	assertEquals(new PDelay(i), q.element());
467	q.poll();
468	}
469	try {
470	q.element();
471	shouldThrow();
472	} catch (NoSuchElementException success) {}
473	}
474
475	/**
476	* remove removes next element, or throws NSEE if empty
477	*/
478	public void testRemove() {
479	DelayQueue q = populatedQueue(SIZE);
480	for (int i = 0; i < SIZE; ++i) {
481	assertEquals(new PDelay(i), q.remove());
482	}
483	try {
484	q.remove();
485	shouldThrow();
486	} catch (NoSuchElementException success) {}
487	}
488
489	/**
490	* contains(x) reports true when elements added but not yet removed
491	*/
492	public void testContains() {
493	DelayQueue q = populatedQueue(SIZE);
494	for (int i = 0; i < SIZE; ++i) {
495	assertTrue(q.contains(new PDelay(i)));
496	q.poll();
497	assertFalse(q.contains(new PDelay(i)));
498	}
499	}
500
501	/**
502	* clear removes all elements
503	*/
504	public void testClear() {
505	DelayQueue q = populatedQueue(SIZE);
506	q.clear();
507	assertTrue(q.isEmpty());
508	assertEquals(0, q.size());
509	assertEquals(Integer.MAX_VALUE, q.remainingCapacity());
510	PDelay x = new PDelay(1);
511	q.add(x);
512	assertFalse(q.isEmpty());
513	assertTrue(q.contains(x));
514	q.clear();
515	assertTrue(q.isEmpty());
516	}
517
518	/**
519	* containsAll(c) is true when c contains a subset of elements
520	*/
521	public void testContainsAll() {
522	DelayQueue q = populatedQueue(SIZE);
523	DelayQueue p = new DelayQueue();
524	for (int i = 0; i < SIZE; ++i) {
525	assertTrue(q.containsAll(p));
526	assertFalse(p.containsAll(q));
527	p.add(new PDelay(i));
528	}
529	assertTrue(p.containsAll(q));
530	}
531
532	/**
533	* retainAll(c) retains only those elements of c and reports true if changed
534	*/
535	public void testRetainAll() {
536	DelayQueue q = populatedQueue(SIZE);
537	DelayQueue p = populatedQueue(SIZE);
538	for (int i = 0; i < SIZE; ++i) {
539	boolean changed = q.retainAll(p);
540	if (i == 0)
541	assertFalse(changed);
542	else
543	assertTrue(changed);
544
545	assertTrue(q.containsAll(p));
546	assertEquals(SIZE-i, q.size());
547	p.remove();
548	}
549	}
550
551	/**
552	* removeAll(c) removes only those elements of c and reports true if changed
553	*/
554	public void testRemoveAll() {
555	for (int i = 1; i < SIZE; ++i) {
556	DelayQueue q = populatedQueue(SIZE);
557	DelayQueue p = populatedQueue(i);
558	assertTrue(q.removeAll(p));
559	assertEquals(SIZE-i, q.size());
560	for (int j = 0; j < i; ++j) {
561	PDelay x = (PDelay)(p.remove());
562	assertFalse(q.contains(x));
563	}
564	}
565	}
566
567	/**
568	* toArray contains all elements
569	*/
570	public void testToArray() throws InterruptedException {
571	DelayQueue q = populatedQueue(SIZE);
572	Object[] o = q.toArray();
573	Arrays.sort(o);
574	for (int i = 0; i < o.length; i++)
575	assertSame(o[i], q.take());
576	}
577
578	/**
579	* toArray(a) contains all elements
580	*/
581	public void testToArray2() {
582	DelayQueue<PDelay> q = populatedQueue(SIZE);
583	PDelay[] ints = new PDelay[SIZE];
584	PDelay[] array = q.toArray(ints);
585	assertSame(ints, array);
586	Arrays.sort(ints);
587	for (int i = 0; i < ints.length; i++)
588	assertSame(ints[i], q.remove());
589	}
590
591	/**
592	* toArray(incompatible array type) throws ArrayStoreException
593	*/
594	public void testToArray1_BadArg() {
595	DelayQueue q = populatedQueue(SIZE);
596	try {
597	q.toArray(new String[10]);
598	shouldThrow();
599	} catch (ArrayStoreException success) {}
600	}
601
602	/**
603	* iterator iterates through all elements
604	*/
605	public void testIterator() {
606	DelayQueue q = populatedQueue(SIZE);
607	int i = 0;
608	Iterator it = q.iterator();
609	while (it.hasNext()) {
610	assertTrue(q.contains(it.next()));
611	++i;
612	}
613	assertEquals(i, SIZE);
614	assertIteratorExhausted(it);
615	}
616
617	/**
618	* iterator of empty collection has no elements
619	*/
620	public void testEmptyIterator() {
621	assertIteratorExhausted(new DelayQueue().iterator());
622	}
623
624	/**
625	* iterator.remove removes current element
626	*/
627	public void testIteratorRemove() {
628	final DelayQueue q = new DelayQueue();
629	q.add(new PDelay(2));
630	q.add(new PDelay(1));
631	q.add(new PDelay(3));
632	Iterator it = q.iterator();
633	it.next();
634	it.remove();
635	it = q.iterator();
636	assertEquals(new PDelay(2), it.next());
637	assertEquals(new PDelay(3), it.next());
638	assertFalse(it.hasNext());
639	}
640
641	/**
642	* toString contains toStrings of elements
643	*/
644	public void testToString() {
645	DelayQueue q = populatedQueue(SIZE);
646	String s = q.toString();
647	for (Object e : q)
648	assertTrue(s.contains(e.toString()));
649	}
650
651	/**
652	* timed poll transfers elements across Executor tasks
653	*/
654	public void testPollInExecutor() {
655	final DelayQueue q = new DelayQueue();
656	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
657	ExecutorService executor = Executors.newFixedThreadPool(2);
658	executor.execute(new CheckedRunnable() {
659	public void realRun() throws InterruptedException {
660	assertNull(q.poll());
661	threadsStarted.await();
662	assertNotNull(q.poll(LONG_DELAY_MS, MILLISECONDS));
663	checkEmpty(q);
664	}});
665
666	executor.execute(new CheckedRunnable() {
667	public void realRun() throws InterruptedException {
668	threadsStarted.await();
669	q.put(new PDelay(1));
670	}});
671
672	joinPool(executor);
673	}
674
675	/**
676	* Delayed actions do not occur until their delay elapses
677	*/
678	public void testDelay() throws InterruptedException {
679	DelayQueue<NanoDelay> q = new DelayQueue<NanoDelay>();
680	for (int i = 0; i < SIZE; ++i)
681	q.add(new NanoDelay(1000000L * (SIZE - i)));
682
683	long last = 0;
684	for (int i = 0; i < SIZE; ++i) {
685	NanoDelay e = q.take();
686	long tt = e.getTriggerTime();
687	assertTrue(System.nanoTime() - tt >= 0);
688	if (i != 0)
689	assertTrue(tt >= last);
690	last = tt;
691	}
692	assertTrue(q.isEmpty());
693	}
694
695	/**
696	* peek of a non-empty queue returns non-null even if not expired
697	*/
698	public void testPeekDelayed() {
699	DelayQueue q = new DelayQueue();
700	q.add(new NanoDelay(Long.MAX_VALUE));
701	assertNotNull(q.peek());
702	}
703
704	/**
705	* poll of a non-empty queue returns null if no expired elements.
706	*/
707	public void testPollDelayed() {
708	DelayQueue q = new DelayQueue();
709	q.add(new NanoDelay(Long.MAX_VALUE));
710	assertNull(q.poll());
711	}
712
713	/**
714	* timed poll of a non-empty queue returns null if no expired elements.
715	*/
716	public void testTimedPollDelayed() throws InterruptedException {
717	DelayQueue q = new DelayQueue();
718	q.add(new NanoDelay(LONG_DELAY_MS * 1000000L));
719	assertNull(q.poll(timeoutMillis(), MILLISECONDS));
720	}
721
722	/**
723	* drainTo(c) empties queue into another collection c
724	*/
725	public void testDrainTo() {
726	DelayQueue q = new DelayQueue();
727	PDelay[] elems = new PDelay[SIZE];
728	for (int i = 0; i < SIZE; ++i) {
729	elems[i] = new PDelay(i);
730	q.add(elems[i]);
731	}
732	ArrayList l = new ArrayList();
733	q.drainTo(l);
734	assertEquals(0, q.size());
735	for (int i = 0; i < SIZE; ++i)
736	assertEquals(elems[i], l.get(i));
737	q.add(elems[0]);
738	q.add(elems[1]);
739	assertFalse(q.isEmpty());
740	assertTrue(q.contains(elems[0]));
741	assertTrue(q.contains(elems[1]));
742	l.clear();
743	q.drainTo(l);
744	assertEquals(0, q.size());
745	assertEquals(2, l.size());
746	for (int i = 0; i < 2; ++i)
747	assertEquals(elems[i], l.get(i));
748	}
749
750	/**
751	* drainTo empties queue
752	*/
753	public void testDrainToWithActivePut() throws InterruptedException {
754	final DelayQueue q = populatedQueue(SIZE);
755	Thread t = new Thread(new CheckedRunnable() {
756	public void realRun() {
757	q.put(new PDelay(SIZE+1));
758	}});
759
760	t.start();
761	ArrayList l = new ArrayList();
762	q.drainTo(l);
763	assertTrue(l.size() >= SIZE);
764	t.join();
765	assertTrue(q.size() + l.size() >= SIZE);
766	}
767
768	/**
769	* drainTo(c, n) empties first min(n, size) elements of queue into c
770	*/
771	public void testDrainToN() {
772	for (int i = 0; i < SIZE + 2; ++i) {
773	DelayQueue q = populatedQueue(SIZE);
774	ArrayList l = new ArrayList();
775	q.drainTo(l, i);
776	int k = (i < SIZE) ? i : SIZE;
777	assertEquals(SIZE-k, q.size());
778	assertEquals(k, l.size());
779	}
780	}
781
782	/**
783	* remove(null), contains(null) always return false
784	*/
785	public void testNeverContainsNull() {
786	Collection<?> q = populatedQueue(SIZE);
787	assertFalse(q.contains(null));
788	assertFalse(q.remove(null));
789	}
790	}