test/tck/SynchronousQueueTest.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.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.SynchronousQueue;

import junit.framework.Test;

public class SynchronousQueueTest extends JSR166TestCase {

    public static class Fair extends BlockingQueueTest {
        protected BlockingQueue emptyCollection() {
            return new SynchronousQueue(true);
        }
    }

    public static class NonFair extends BlockingQueueTest {
        protected BlockingQueue emptyCollection() {
            return new SynchronousQueue(false);
        }
    }

    public static void main(String[] args) {
        main(suite(), args);
    }

    public static Test suite() {
        return newTestSuite(SynchronousQueueTest.class,
                            new Fair().testSuite(),
                            new NonFair().testSuite());
    }

    /**
     * Any SynchronousQueue is both empty and full
     */
    public void testEmptyFull()      { testEmptyFull(false); }
    public void testEmptyFull_fair() { testEmptyFull(true); }
    public void testEmptyFull(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        assertTrue(q.isEmpty());
        mustEqual(0, q.size());
        mustEqual(0, q.remainingCapacity());
        assertFalse(q.offer(zero));
    }

    /**
     * offer fails if no active taker
     */
    public void testOffer()      { testOffer(false); }
    public void testOffer_fair() { testOffer(true); }
    public void testOffer(boolean fair) {
        SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        assertFalse(q.offer(one));
    }

    /**
     * add throws IllegalStateException if no active taker
     */
    public void testAdd()      { testAdd(false); }
    public void testAdd_fair() { testAdd(true); }
    public void testAdd(boolean fair) {
        SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        mustEqual(0, q.remainingCapacity());
        try {
            q.add(one);
            shouldThrow();
        } catch (IllegalStateException success) {}
    }

    /**
     * addAll(this) throws IllegalArgumentException
     */
    public void testAddAll_self()      { testAddAll_self(false); }
    public void testAddAll_self_fair() { testAddAll_self(true); }
    public void testAddAll_self(boolean fair) {
        SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        try {
            q.addAll(q);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**S
     * addAll throws IllegalStateException if no active taker
     */
    public void testAddAll_ISE()      { testAddAll_ISE(false); }
    public void testAddAll_ISE_fair() { testAddAll_ISE(true); }
    public void testAddAll_ISE(boolean fair) {
        SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Item[] items = seqItems(1);
        Collection<Item> coll = Arrays.asList(items);
        try {
            q.addAll(coll);
            shouldThrow();
        } catch (IllegalStateException success) {}
    }

    /**
     * put blocks interruptibly if no active taker
     */
    public void testBlockingPut()      { testBlockingPut(false); }
    public void testBlockingPut_fair() { testBlockingPut(true); }
    public void testBlockingPut(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                Thread.currentThread().interrupt();
                try {
                    q.put(ninetynine);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();
                try {
                    q.put(ninetynine);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());
            }});

        await(pleaseInterrupt);
        if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
        t.interrupt();
        awaitTermination(t);
        mustEqual(0, q.remainingCapacity());
    }

    /**
     * put blocks interruptibly waiting for take
     */
    public void testPutWithTake()      { testPutWithTake(false); }
    public void testPutWithTake_fair() { testPutWithTake(true); }
    public void testPutWithTake(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final CountDownLatch pleaseTake = new CountDownLatch(1);
        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                pleaseTake.countDown();
                q.put(one);

                Thread.currentThread().interrupt();
                try {
                    q.put(ninetynine);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();
                try {
                    q.put(ninetynine);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());
            }});

        await(pleaseTake);
        mustEqual(0, q.remainingCapacity());
        try { assertSame(one, q.take()); }
        catch (InterruptedException e) { threadUnexpectedException(e); }

        await(pleaseInterrupt);
        if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
        t.interrupt();
        awaitTermination(t);
        mustEqual(0, q.remainingCapacity());
    }

    /**
     * timed offer times out if elements not taken
     */
    public void testTimedOffer() {
        final boolean fair = randomBoolean();
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                long startTime = System.nanoTime();

                assertFalse(q.offer(zero, timeoutMillis(), MILLISECONDS));
                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());

                Thread.currentThread().interrupt();
                try {
                    q.offer(one, randomTimeout(), randomTimeUnit());
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();
                try {
                    q.offer(two, LONGER_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());
            }});

        await(pleaseInterrupt);
        if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
        t.interrupt();
        awaitTermination(t);
    }

    /**
     * poll return null if no active putter
     */
    public void testPoll()      { testPoll(false); }
    public void testPoll_fair() { testPoll(true); }
    public void testPoll(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        assertNull(q.poll());
    }

    /**
     * timed poll with zero timeout times out if no active putter
     */
    public void testTimedPoll0()      { testTimedPoll0(false); }
    public void testTimedPoll0_fair() { testTimedPoll0(true); }
    public void testTimedPoll0(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        try { assertNull(q.poll(0, MILLISECONDS)); }
        catch (InterruptedException e) { threadUnexpectedException(e); }
    }

    /**
     * timed poll with nonzero timeout times out if no active putter
     */
    public void testTimedPoll() {
        final boolean fair = randomBoolean();
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final long startTime = System.nanoTime();
        try { assertNull(q.poll(timeoutMillis(), MILLISECONDS)); }
        catch (InterruptedException e) { threadUnexpectedException(e); }
        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
    }

    /**
     * timed poll before a delayed offer times out, returning null;
     * after offer succeeds; on interruption throws
     */
    public void testTimedPollWithOffer() {
        final boolean fair = randomBoolean();
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final CountDownLatch pleaseOffer = new CountDownLatch(1);
        final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                long startTime = System.nanoTime();
                assertNull(q.poll(timeoutMillis(), MILLISECONDS));
                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());

                pleaseOffer.countDown();
                startTime = System.nanoTime();
                assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));

                Thread.currentThread().interrupt();
                try {
                    q.poll(randomTimeout(), randomTimeUnit());
                    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(pleaseOffer);
        long startTime = System.nanoTime();
        try { assertTrue(q.offer(zero, LONG_DELAY_MS, MILLISECONDS)); }
        catch (InterruptedException e) { threadUnexpectedException(e); }
        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);

        await(pleaseInterrupt);
        if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
        t.interrupt();
        awaitTermination(t);
    }

    /**
     * peek() returns null if no active putter
     */
    public void testPeek()      { testPeek(false); }
    public void testPeek_fair() { testPeek(true); }
    public void testPeek(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        assertNull(q.peek());
    }

    /**
     * element() throws NoSuchElementException if no active putter
     */
    public void testElement()      { testElement(false); }
    public void testElement_fair() { testElement(true); }
    public void testElement(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        try {
            q.element();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove() throws NoSuchElementException if no active putter
     */
    public void testRemove()      { testRemove(false); }
    public void testRemove_fair() { testRemove(true); }
    public void testRemove(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        try {
            q.remove();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * contains returns false
     */
    public void testContains()      { testContains(false); }
    public void testContains_fair() { testContains(true); }
    public void testContains(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        assertFalse(q.contains(zero));
    }

    /**
     * clear ensures isEmpty
     */
    public void testClear()      { testClear(false); }
    public void testClear_fair() { testClear(true); }
    public void testClear(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll returns false unless empty
     */
    public void testContainsAll()      { testContainsAll(false); }
    public void testContainsAll_fair() { testContainsAll(true); }
    public void testContainsAll(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Item[] empty = new Item[0];
        assertTrue(q.containsAll(Arrays.asList(empty)));
        Item[] items = new Item[1]; items[0] = zero;
        assertFalse(q.containsAll(Arrays.asList(items)));
    }

    /**
     * retainAll returns false
     */
    public void testRetainAll()      { testRetainAll(false); }
    public void testRetainAll_fair() { testRetainAll(true); }
    public void testRetainAll(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Item[] empty = new Item[0];
        assertFalse(q.retainAll(Arrays.asList(empty)));
        Item[] items = new Item[1]; items[0] = zero;
        assertFalse(q.retainAll(Arrays.asList(items)));
    }

    /**
     * removeAll returns false
     */
    public void testRemoveAll()      { testRemoveAll(false); }
    public void testRemoveAll_fair() { testRemoveAll(true); }
    public void testRemoveAll(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Item[] empty = new Item[0];
        assertFalse(q.removeAll(Arrays.asList(empty)));
        Item[] items = new Item[1]; items[0] = zero;
        assertFalse(q.containsAll(Arrays.asList(items)));
    }

    /**
     * toArray is empty
     */
    public void testToArray()      { testToArray(false); }
    public void testToArray_fair() { testToArray(true); }
    public void testToArray(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Object[] o = q.toArray();
        mustEqual(0, o.length);
    }

    /**
     * toArray(Item array) returns its argument with the first
     * element (if present) nulled out
     */
    public void testToArray2()      { testToArray2(false); }
    public void testToArray2_fair() { testToArray2(true); }
    public void testToArray2(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Item[] a;

        a = new Item[0];
        assertSame(a, q.toArray(a));

        a = new Item[3];
        Arrays.fill(a, fortytwo);
        assertSame(a, q.toArray(a));
        assertNull(a[0]);
        for (int i = 1; i < a.length; i++)
            mustEqual(42, a[i]);
    }

    /**
     * toArray(null) throws NPE
     */
    public void testToArray_null()      { testToArray_null(false); }
    public void testToArray_null_fair() { testToArray_null(true); }
    public void testToArray_null(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        try {
            Object[] unused = q.toArray((Object[])null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * iterator does not traverse any elements
     */
    public void testIterator()      { testIterator(false); }
    public void testIterator_fair() { testIterator(true); }
    public void testIterator(boolean fair) {
        assertIteratorExhausted(new SynchronousQueue<Item>(fair).iterator());
    }

    /**
     * iterator remove throws IllegalStateException
     */
    public void testIteratorRemove()      { testIteratorRemove(false); }
    public void testIteratorRemove_fair() { testIteratorRemove(true); }
    public void testIteratorRemove(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Iterator<? extends Item> it = q.iterator();
        try {
            it.remove();
            shouldThrow();
        } catch (IllegalStateException success) {}
    }

    /**
     * toString returns a non-null string
     */
    public void testToString()      { testToString(false); }
    public void testToString_fair() { testToString(true); }
    public void testToString(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        String s = q.toString();
        assertNotNull(s);
    }

    /**
     * offer transfers elements across Executor tasks
     */
    public void testOfferInExecutor()      { testOfferInExecutor(false); }
    public void testOfferInExecutor_fair() { testOfferInExecutor(true); }
    public void testOfferInExecutor(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final CheckedBarrier threadsStarted = new CheckedBarrier(2);
        final ExecutorService executor = Executors.newFixedThreadPool(2);
        try (PoolCleaner cleaner = cleaner(executor)) {

            executor.execute(new CheckedRunnable() {
                public void realRun() throws InterruptedException {
                    assertFalse(q.offer(one));
                    threadsStarted.await();
                    assertTrue(q.offer(one, LONG_DELAY_MS, MILLISECONDS));
                    mustEqual(0, q.remainingCapacity());
                }});

            executor.execute(new CheckedRunnable() {
                public void realRun() throws InterruptedException {
                    threadsStarted.await();
                    assertSame(one, q.take());
                }});
        }
    }

    /**
     * timed poll retrieves elements across Executor threads
     */
    public void testPollInExecutor()      { testPollInExecutor(false); }
    public void testPollInExecutor_fair() { testPollInExecutor(true); }
    public void testPollInExecutor(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        final CheckedBarrier threadsStarted = new CheckedBarrier(2);
        final ExecutorService executor = Executors.newFixedThreadPool(2);
        try (PoolCleaner cleaner = cleaner(executor)) {
            executor.execute(new CheckedRunnable() {
                public void realRun() throws InterruptedException {
                    assertNull(q.poll());
                    threadsStarted.await();
                    assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
                    assertTrue(q.isEmpty());
                }});

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

    /**
     * a deserialized/reserialized queue is usable
     */
    public void testSerialization() {
        final SynchronousQueue<Item> x = new SynchronousQueue<>();
        final SynchronousQueue<Item> y = new SynchronousQueue<>(false);
        final SynchronousQueue<Item> z = new SynchronousQueue<>(true);
        assertSerialEquals(x, y);
        assertNotSerialEquals(x, z);
        SynchronousQueue[] rqs = { x, y, z };
        @SuppressWarnings("unchecked")
        SynchronousQueue<Item>[] qs = (SynchronousQueue<Item>[])rqs;
        for (SynchronousQueue<Item> q : qs) {
            SynchronousQueue<Item> clone = serialClone(q);
            assertNotSame(q, clone);
            assertSerialEquals(q, clone);
            assertTrue(clone.isEmpty());
            mustEqual(0, clone.size());
            mustEqual(0, clone.remainingCapacity());
            assertFalse(clone.offer(zero));
        }
    }

    /**
     * drainTo(c) of empty queue doesn't transfer elements
     */
    public void testDrainTo()      { testDrainTo(false); }
    public void testDrainTo_fair() { testDrainTo(true); }
    public void testDrainTo(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        ArrayList<Item> l = new ArrayList<>();
        q.drainTo(l);
        mustEqual(0, q.size());
        mustEqual(0, l.size());
    }

    /**
     * drainTo empties queue, unblocking a waiting put.
     */
    public void testDrainToWithActivePut()      { testDrainToWithActivePut(false); }
    public void testDrainToWithActivePut_fair() { testDrainToWithActivePut(true); }
    public void testDrainToWithActivePut(boolean fair) {
        final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                q.put(one);
            }});

        ArrayList<Item> l = new ArrayList<>();
        long startTime = System.nanoTime();
        while (l.isEmpty()) {
            q.drainTo(l);
            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
                fail("timed out");
            Thread.yield();
        }
        mustEqual(1, l.size());
        assertSame(one, l.get(0));
        awaitTermination(t);
    }

    /**
     * drainTo(c, n) empties up to n elements of queue into c
     */
    public void testDrainToN() throws InterruptedException {
        final SynchronousQueue<Item> q = new SynchronousQueue<>();
        Thread t1 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                q.put(one);
            }});

        Thread t2 = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                q.put(two);
            }});

        ArrayList<Item> l = new ArrayList<>();
        int drained;
        while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
        mustEqual(1, drained);
        mustEqual(1, l.size());
        while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
        mustEqual(1, drained);
        mustEqual(2, l.size());
        assertTrue(l.contains(one));
        assertTrue(l.contains(two));
        awaitTermination(t1);
        awaitTermination(t2);
    }

    /**
     * remove(null), contains(null) always return false
     */
    public void testNeverContainsNull() {
        Collection<?> q = new SynchronousQueue<>();
        assertFalse(q.contains(null));
        assertFalse(q.remove(null));
    }

}
Revision:	1.69
Committed:	Wed Jan 27 01:57:24 2021 UTC (3 years, 2 months ago) by jsr166
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.68:	+37 -37 lines
Log Message:	use diamond <> pervasively
#	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.Executors;
19	import java.util.concurrent.ExecutorService;
20	import java.util.concurrent.SynchronousQueue;
21
22	import junit.framework.Test;
23
24	public class SynchronousQueueTest extends JSR166TestCase {
25
26	public static class Fair extends BlockingQueueTest {
27	protected BlockingQueue emptyCollection() {
28	return new SynchronousQueue(true);
29	}
30	}
31
32	public static class NonFair extends BlockingQueueTest {
33	protected BlockingQueue emptyCollection() {
34	return new SynchronousQueue(false);
35	}
36	}
37
38	public static void main(String[] args) {
39	main(suite(), args);
40	}
41
42	public static Test suite() {
43	return newTestSuite(SynchronousQueueTest.class,
44	new Fair().testSuite(),
45	new NonFair().testSuite());
46	}
47
48	/**
49	* Any SynchronousQueue is both empty and full
50	*/
51	public void testEmptyFull() { testEmptyFull(false); }
52	public void testEmptyFull_fair() { testEmptyFull(true); }
53	public void testEmptyFull(boolean fair) {
54	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
55	assertTrue(q.isEmpty());
56	mustEqual(0, q.size());
57	mustEqual(0, q.remainingCapacity());
58	assertFalse(q.offer(zero));
59	}
60
61	/**
62	* offer fails if no active taker
63	*/
64	public void testOffer() { testOffer(false); }
65	public void testOffer_fair() { testOffer(true); }
66	public void testOffer(boolean fair) {
67	SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
68	assertFalse(q.offer(one));
69	}
70
71	/**
72	* add throws IllegalStateException if no active taker
73	*/
74	public void testAdd() { testAdd(false); }
75	public void testAdd_fair() { testAdd(true); }
76	public void testAdd(boolean fair) {
77	SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
78	mustEqual(0, q.remainingCapacity());
79	try {
80	q.add(one);
81	shouldThrow();
82	} catch (IllegalStateException success) {}
83	}
84
85	/**
86	* addAll(this) throws IllegalArgumentException
87	*/
88	public void testAddAll_self() { testAddAll_self(false); }
89	public void testAddAll_self_fair() { testAddAll_self(true); }
90	public void testAddAll_self(boolean fair) {
91	SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
92	try {
93	q.addAll(q);
94	shouldThrow();
95	} catch (IllegalArgumentException success) {}
96	}
97
98	/**S
99	* addAll throws IllegalStateException if no active taker
100	*/
101	public void testAddAll_ISE() { testAddAll_ISE(false); }
102	public void testAddAll_ISE_fair() { testAddAll_ISE(true); }
103	public void testAddAll_ISE(boolean fair) {
104	SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
105	Item[] items = seqItems(1);
106	Collection<Item> coll = Arrays.asList(items);
107	try {
108	q.addAll(coll);
109	shouldThrow();
110	} catch (IllegalStateException success) {}
111	}
112
113	/**
114	* put blocks interruptibly if no active taker
115	*/
116	public void testBlockingPut() { testBlockingPut(false); }
117	public void testBlockingPut_fair() { testBlockingPut(true); }
118	public void testBlockingPut(boolean fair) {
119	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
120	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
121	Thread t = newStartedThread(new CheckedRunnable() {
122	public void realRun() throws InterruptedException {
123	Thread.currentThread().interrupt();
124	try {
125	q.put(ninetynine);
126	shouldThrow();
127	} catch (InterruptedException success) {}
128	assertFalse(Thread.interrupted());
129
130	pleaseInterrupt.countDown();
131	try {
132	q.put(ninetynine);
133	shouldThrow();
134	} catch (InterruptedException success) {}
135	assertFalse(Thread.interrupted());
136	}});
137
138	await(pleaseInterrupt);
139	if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
140	t.interrupt();
141	awaitTermination(t);
142	mustEqual(0, q.remainingCapacity());
143	}
144
145	/**
146	* put blocks interruptibly waiting for take
147	*/
148	public void testPutWithTake() { testPutWithTake(false); }
149	public void testPutWithTake_fair() { testPutWithTake(true); }
150	public void testPutWithTake(boolean fair) {
151	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
152	final CountDownLatch pleaseTake = new CountDownLatch(1);
153	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
154	Thread t = newStartedThread(new CheckedRunnable() {
155	public void realRun() throws InterruptedException {
156	pleaseTake.countDown();
157	q.put(one);
158
159	Thread.currentThread().interrupt();
160	try {
161	q.put(ninetynine);
162	shouldThrow();
163	} catch (InterruptedException success) {}
164	assertFalse(Thread.interrupted());
165
166	pleaseInterrupt.countDown();
167	try {
168	q.put(ninetynine);
169	shouldThrow();
170	} catch (InterruptedException success) {}
171	assertFalse(Thread.interrupted());
172	}});
173
174	await(pleaseTake);
175	mustEqual(0, q.remainingCapacity());
176	try { assertSame(one, q.take()); }
177	catch (InterruptedException e) { threadUnexpectedException(e); }
178
179	await(pleaseInterrupt);
180	if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
181	t.interrupt();
182	awaitTermination(t);
183	mustEqual(0, q.remainingCapacity());
184	}
185
186	/**
187	* timed offer times out if elements not taken
188	*/
189	public void testTimedOffer() {
190	final boolean fair = randomBoolean();
191	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
192	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
193	Thread t = newStartedThread(new CheckedRunnable() {
194	public void realRun() throws InterruptedException {
195	long startTime = System.nanoTime();
196
197	assertFalse(q.offer(zero, timeoutMillis(), MILLISECONDS));
198	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
199
200	Thread.currentThread().interrupt();
201	try {
202	q.offer(one, randomTimeout(), randomTimeUnit());
203	shouldThrow();
204	} catch (InterruptedException success) {}
205	assertFalse(Thread.interrupted());
206
207	pleaseInterrupt.countDown();
208	try {
209	q.offer(two, LONGER_DELAY_MS, MILLISECONDS);
210	shouldThrow();
211	} catch (InterruptedException success) {}
212	assertFalse(Thread.interrupted());
213	}});
214
215	await(pleaseInterrupt);
216	if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
217	t.interrupt();
218	awaitTermination(t);
219	}
220
221	/**
222	* poll return null if no active putter
223	*/
224	public void testPoll() { testPoll(false); }
225	public void testPoll_fair() { testPoll(true); }
226	public void testPoll(boolean fair) {
227	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
228	assertNull(q.poll());
229	}
230
231	/**
232	* timed poll with zero timeout times out if no active putter
233	*/
234	public void testTimedPoll0() { testTimedPoll0(false); }
235	public void testTimedPoll0_fair() { testTimedPoll0(true); }
236	public void testTimedPoll0(boolean fair) {
237	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
238	try { assertNull(q.poll(0, MILLISECONDS)); }
239	catch (InterruptedException e) { threadUnexpectedException(e); }
240	}
241
242	/**
243	* timed poll with nonzero timeout times out if no active putter
244	*/
245	public void testTimedPoll() {
246	final boolean fair = randomBoolean();
247	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
248	final long startTime = System.nanoTime();
249	try { assertNull(q.poll(timeoutMillis(), MILLISECONDS)); }
250	catch (InterruptedException e) { threadUnexpectedException(e); }
251	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
252	}
253
254	/**
255	* timed poll before a delayed offer times out, returning null;
256	* after offer succeeds; on interruption throws
257	*/
258	public void testTimedPollWithOffer() {
259	final boolean fair = randomBoolean();
260	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
261	final CountDownLatch pleaseOffer = new CountDownLatch(1);
262	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
263	Thread t = newStartedThread(new CheckedRunnable() {
264	public void realRun() throws InterruptedException {
265	long startTime = System.nanoTime();
266	assertNull(q.poll(timeoutMillis(), MILLISECONDS));
267	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
268
269	pleaseOffer.countDown();
270	startTime = System.nanoTime();
271	assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
272
273	Thread.currentThread().interrupt();
274	try {
275	q.poll(randomTimeout(), randomTimeUnit());
276	shouldThrow();
277	} catch (InterruptedException success) {}
278	assertFalse(Thread.interrupted());
279
280	pleaseInterrupt.countDown();
281	try {
282	q.poll(LONG_DELAY_MS, MILLISECONDS);
283	shouldThrow();
284	} catch (InterruptedException success) {}
285	assertFalse(Thread.interrupted());
286
287	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
288	}});
289
290	await(pleaseOffer);
291	long startTime = System.nanoTime();
292	try { assertTrue(q.offer(zero, LONG_DELAY_MS, MILLISECONDS)); }
293	catch (InterruptedException e) { threadUnexpectedException(e); }
294	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
295
296	await(pleaseInterrupt);
297	if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
298	t.interrupt();
299	awaitTermination(t);
300	}
301
302	/**
303	* peek() returns null if no active putter
304	*/
305	public void testPeek() { testPeek(false); }
306	public void testPeek_fair() { testPeek(true); }
307	public void testPeek(boolean fair) {
308	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
309	assertNull(q.peek());
310	}
311
312	/**
313	* element() throws NoSuchElementException if no active putter
314	*/
315	public void testElement() { testElement(false); }
316	public void testElement_fair() { testElement(true); }
317	public void testElement(boolean fair) {
318	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
319	try {
320	q.element();
321	shouldThrow();
322	} catch (NoSuchElementException success) {}
323	}
324
325	/**
326	* remove() throws NoSuchElementException if no active putter
327	*/
328	public void testRemove() { testRemove(false); }
329	public void testRemove_fair() { testRemove(true); }
330	public void testRemove(boolean fair) {
331	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
332	try {
333	q.remove();
334	shouldThrow();
335	} catch (NoSuchElementException success) {}
336	}
337
338	/**
339	* contains returns false
340	*/
341	public void testContains() { testContains(false); }
342	public void testContains_fair() { testContains(true); }
343	public void testContains(boolean fair) {
344	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
345	assertFalse(q.contains(zero));
346	}
347
348	/**
349	* clear ensures isEmpty
350	*/
351	public void testClear() { testClear(false); }
352	public void testClear_fair() { testClear(true); }
353	public void testClear(boolean fair) {
354	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
355	q.clear();
356	assertTrue(q.isEmpty());
357	}
358
359	/**
360	* containsAll returns false unless empty
361	*/
362	public void testContainsAll() { testContainsAll(false); }
363	public void testContainsAll_fair() { testContainsAll(true); }
364	public void testContainsAll(boolean fair) {
365	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
366	Item[] empty = new Item[0];
367	assertTrue(q.containsAll(Arrays.asList(empty)));
368	Item[] items = new Item[1]; items[0] = zero;
369	assertFalse(q.containsAll(Arrays.asList(items)));
370	}
371
372	/**
373	* retainAll returns false
374	*/
375	public void testRetainAll() { testRetainAll(false); }
376	public void testRetainAll_fair() { testRetainAll(true); }
377	public void testRetainAll(boolean fair) {
378	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
379	Item[] empty = new Item[0];
380	assertFalse(q.retainAll(Arrays.asList(empty)));
381	Item[] items = new Item[1]; items[0] = zero;
382	assertFalse(q.retainAll(Arrays.asList(items)));
383	}
384
385	/**
386	* removeAll returns false
387	*/
388	public void testRemoveAll() { testRemoveAll(false); }
389	public void testRemoveAll_fair() { testRemoveAll(true); }
390	public void testRemoveAll(boolean fair) {
391	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
392	Item[] empty = new Item[0];
393	assertFalse(q.removeAll(Arrays.asList(empty)));
394	Item[] items = new Item[1]; items[0] = zero;
395	assertFalse(q.containsAll(Arrays.asList(items)));
396	}
397
398	/**
399	* toArray is empty
400	*/
401	public void testToArray() { testToArray(false); }
402	public void testToArray_fair() { testToArray(true); }
403	public void testToArray(boolean fair) {
404	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
405	Object[] o = q.toArray();
406	mustEqual(0, o.length);
407	}
408
409	/**
410	* toArray(Item array) returns its argument with the first
411	* element (if present) nulled out
412	*/
413	public void testToArray2() { testToArray2(false); }
414	public void testToArray2_fair() { testToArray2(true); }
415	public void testToArray2(boolean fair) {
416	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
417	Item[] a;
418
419	a = new Item[0];
420	assertSame(a, q.toArray(a));
421
422	a = new Item[3];
423	Arrays.fill(a, fortytwo);
424	assertSame(a, q.toArray(a));
425	assertNull(a[0]);
426	for (int i = 1; i < a.length; i++)
427	mustEqual(42, a[i]);
428	}
429
430	/**
431	* toArray(null) throws NPE
432	*/
433	public void testToArray_null() { testToArray_null(false); }
434	public void testToArray_null_fair() { testToArray_null(true); }
435	public void testToArray_null(boolean fair) {
436	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
437	try {
438	Object[] unused = q.toArray((Object[])null);
439	shouldThrow();
440	} catch (NullPointerException success) {}
441	}
442
443	/**
444	* iterator does not traverse any elements
445	*/
446	public void testIterator() { testIterator(false); }
447	public void testIterator_fair() { testIterator(true); }
448	public void testIterator(boolean fair) {
449	assertIteratorExhausted(new SynchronousQueue<Item>(fair).iterator());
450	}
451
452	/**
453	* iterator remove throws IllegalStateException
454	*/
455	public void testIteratorRemove() { testIteratorRemove(false); }
456	public void testIteratorRemove_fair() { testIteratorRemove(true); }
457	public void testIteratorRemove(boolean fair) {
458	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
459	Iterator<? extends Item> it = q.iterator();
460	try {
461	it.remove();
462	shouldThrow();
463	} catch (IllegalStateException success) {}
464	}
465
466	/**
467	* toString returns a non-null string
468	*/
469	public void testToString() { testToString(false); }
470	public void testToString_fair() { testToString(true); }
471	public void testToString(boolean fair) {
472	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
473	String s = q.toString();
474	assertNotNull(s);
475	}
476
477	/**
478	* offer transfers elements across Executor tasks
479	*/
480	public void testOfferInExecutor() { testOfferInExecutor(false); }
481	public void testOfferInExecutor_fair() { testOfferInExecutor(true); }
482	public void testOfferInExecutor(boolean fair) {
483	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
484	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
485	final ExecutorService executor = Executors.newFixedThreadPool(2);
486	try (PoolCleaner cleaner = cleaner(executor)) {
487
488	executor.execute(new CheckedRunnable() {
489	public void realRun() throws InterruptedException {
490	assertFalse(q.offer(one));
491	threadsStarted.await();
492	assertTrue(q.offer(one, LONG_DELAY_MS, MILLISECONDS));
493	mustEqual(0, q.remainingCapacity());
494	}});
495
496	executor.execute(new CheckedRunnable() {
497	public void realRun() throws InterruptedException {
498	threadsStarted.await();
499	assertSame(one, q.take());
500	}});
501	}
502	}
503
504	/**
505	* timed poll retrieves elements across Executor threads
506	*/
507	public void testPollInExecutor() { testPollInExecutor(false); }
508	public void testPollInExecutor_fair() { testPollInExecutor(true); }
509	public void testPollInExecutor(boolean fair) {
510	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
511	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
512	final ExecutorService executor = Executors.newFixedThreadPool(2);
513	try (PoolCleaner cleaner = cleaner(executor)) {
514	executor.execute(new CheckedRunnable() {
515	public void realRun() throws InterruptedException {
516	assertNull(q.poll());
517	threadsStarted.await();
518	assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
519	assertTrue(q.isEmpty());
520	}});
521
522	executor.execute(new CheckedRunnable() {
523	public void realRun() throws InterruptedException {
524	threadsStarted.await();
525	q.put(one);
526	}});
527	}
528	}
529
530	/**
531	* a deserialized/reserialized queue is usable
532	*/
533	public void testSerialization() {
534	final SynchronousQueue<Item> x = new SynchronousQueue<>();
535	final SynchronousQueue<Item> y = new SynchronousQueue<>(false);
536	final SynchronousQueue<Item> z = new SynchronousQueue<>(true);
537	assertSerialEquals(x, y);
538	assertNotSerialEquals(x, z);
539	SynchronousQueue[] rqs = { x, y, z };
540	@SuppressWarnings("unchecked")
541	SynchronousQueue<Item>[] qs = (SynchronousQueue<Item>[])rqs;
542	for (SynchronousQueue<Item> q : qs) {
543	SynchronousQueue<Item> clone = serialClone(q);
544	assertNotSame(q, clone);
545	assertSerialEquals(q, clone);
546	assertTrue(clone.isEmpty());
547	mustEqual(0, clone.size());
548	mustEqual(0, clone.remainingCapacity());
549	assertFalse(clone.offer(zero));
550	}
551	}
552
553	/**
554	* drainTo(c) of empty queue doesn't transfer elements
555	*/
556	public void testDrainTo() { testDrainTo(false); }
557	public void testDrainTo_fair() { testDrainTo(true); }
558	public void testDrainTo(boolean fair) {
559	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
560	ArrayList<Item> l = new ArrayList<>();
561	q.drainTo(l);
562	mustEqual(0, q.size());
563	mustEqual(0, l.size());
564	}
565
566	/**
567	* drainTo empties queue, unblocking a waiting put.
568	*/
569	public void testDrainToWithActivePut() { testDrainToWithActivePut(false); }
570	public void testDrainToWithActivePut_fair() { testDrainToWithActivePut(true); }
571	public void testDrainToWithActivePut(boolean fair) {
572	final SynchronousQueue<Item> q = new SynchronousQueue<>(fair);
573	Thread t = newStartedThread(new CheckedRunnable() {
574	public void realRun() throws InterruptedException {
575	q.put(one);
576	}});
577
578	ArrayList<Item> l = new ArrayList<>();
579	long startTime = System.nanoTime();
580	while (l.isEmpty()) {
581	q.drainTo(l);
582	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
583	fail("timed out");
584	Thread.yield();
585	}
586	mustEqual(1, l.size());
587	assertSame(one, l.get(0));
588	awaitTermination(t);
589	}
590
591	/**
592	* drainTo(c, n) empties up to n elements of queue into c
593	*/
594	public void testDrainToN() throws InterruptedException {
595	final SynchronousQueue<Item> q = new SynchronousQueue<>();
596	Thread t1 = newStartedThread(new CheckedRunnable() {
597	public void realRun() throws InterruptedException {
598	q.put(one);
599	}});
600
601	Thread t2 = newStartedThread(new CheckedRunnable() {
602	public void realRun() throws InterruptedException {
603	q.put(two);
604	}});
605
606	ArrayList<Item> l = new ArrayList<>();
607	int drained;
608	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
609	mustEqual(1, drained);
610	mustEqual(1, l.size());
611	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
612	mustEqual(1, drained);
613	mustEqual(2, l.size());
614	assertTrue(l.contains(one));
615	assertTrue(l.contains(two));
616	awaitTermination(t1);
617	awaitTermination(t2);
618	}
619
620	/**
621	* remove(null), contains(null) always return false
622	*/
623	public void testNeverContainsNull() {
624	Collection<?> q = new SynchronousQueue<>();
625	assertFalse(q.contains(null));
626	assertFalse(q.remove(null));
627	}
628
629	}