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 q = new SynchronousQueue(fair);
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        assertEquals(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 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 q = new SynchronousQueue(fair);
        assertEquals(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 q = new SynchronousQueue(fair);
        try {
            q.addAll(q);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * 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 q = new SynchronousQueue(fair);
        Integer[] ints = new Integer[1];
        for (int i = 0; i < ints.length; i++)
            ints[i] = i;
        Collection<Integer> coll = Arrays.asList(ints);
        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 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(99);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();
                try {
                    q.put(99);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());
            }});

        await(pleaseInterrupt);
        if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
        t.interrupt();
        awaitTermination(t);
        assertEquals(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 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(99);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();
                try {
                    q.put(99);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());
            }});

        await(pleaseTake);
        assertEquals(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);
        assertEquals(0, q.remainingCapacity());
    }

    /**
     * timed offer times out if elements not taken
     */
    public void testTimedOffer() {
        final boolean fair = randomBoolean();
        final SynchronousQueue 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(new Object(), timeoutMillis(), MILLISECONDS));
                assertTrue(millisElapsedSince(startTime) >= timeoutMillis());

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

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

                assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
            }});

        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 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 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 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 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 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 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 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 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 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 q = new SynchronousQueue(fair);
        Integer[] empty = new Integer[0];
        assertTrue(q.containsAll(Arrays.asList(empty)));
        Integer[] ints = new Integer[1]; ints[0] = zero;
        assertFalse(q.containsAll(Arrays.asList(ints)));
    }

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

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

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

    /**
     * toArray(Integer 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<Integer> q = new SynchronousQueue<>(fair);
        Integer[] a;

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

        a = new Integer[3];
        Arrays.fill(a, 42);
        assertSame(a, q.toArray(a));
        assertNull(a[0]);
        for (int i = 1; i < a.length; i++)
            assertEquals(42, (int) 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 q = new SynchronousQueue(fair);
        try {
            Object[] o = 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(fair).iterator());
    }

    /**
     * iterator remove throws IllegalStateException
     */
    public void testIteratorRemove()      { testIteratorRemove(false); }
    public void testIteratorRemove_fair() { testIteratorRemove(true); }
    public void testIteratorRemove(boolean fair) {
        final SynchronousQueue q = new SynchronousQueue(fair);
        Iterator 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 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 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));
                    assertEquals(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 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 x = new SynchronousQueue();
        final SynchronousQueue y = new SynchronousQueue(false);
        final SynchronousQueue z = new SynchronousQueue(true);
        assertSerialEquals(x, y);
        assertNotSerialEquals(x, z);
        SynchronousQueue[] qs = { x, y, z };
        for (SynchronousQueue q : qs) {
            SynchronousQueue clone = serialClone(q);
            assertNotSame(q, clone);
            assertSerialEquals(q, clone);
            assertTrue(clone.isEmpty());
            assertEquals(0, clone.size());
            assertEquals(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 q = new SynchronousQueue(fair);
        ArrayList l = new ArrayList();
        q.drainTo(l);
        assertEquals(0, q.size());
        assertEquals(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 q = new SynchronousQueue(fair);
        Thread t = newStartedThread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                q.put(one);
            }});

        ArrayList l = new ArrayList();
        long startTime = System.nanoTime();
        while (l.isEmpty()) {
            q.drainTo(l);
            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
                fail("timed out");
            Thread.yield();
        }
        assertEquals(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 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 l = new ArrayList();
        int drained;
        while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
        assertEquals(1, drained);
        assertEquals(1, l.size());
        while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
        assertEquals(1, drained);
        assertEquals(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:	1.65
Committed:	Tue Aug 13 23:06:39 2019 UTC (4 years, 9 months ago) by jsr166
Branch:	MAIN
Changes since 1.64:	+0 -1 lines
Log Message:	fix imports
#	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 q = new SynchronousQueue(fair);
55	assertTrue(q.isEmpty());
56	assertEquals(0, q.size());
57	assertEquals(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 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 q = new SynchronousQueue(fair);
78	assertEquals(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 q = new SynchronousQueue(fair);
92	try {
93	q.addAll(q);
94	shouldThrow();
95	} catch (IllegalArgumentException success) {}
96	}
97
98	/**
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 q = new SynchronousQueue(fair);
105	Integer[] ints = new Integer[1];
106	for (int i = 0; i < ints.length; i++)
107	ints[i] = i;
108	Collection<Integer> coll = Arrays.asList(ints);
109	try {
110	q.addAll(coll);
111	shouldThrow();
112	} catch (IllegalStateException success) {}
113	}
114
115	/**
116	* put blocks interruptibly if no active taker
117	*/
118	public void testBlockingPut() { testBlockingPut(false); }
119	public void testBlockingPut_fair() { testBlockingPut(true); }
120	public void testBlockingPut(boolean fair) {
121	final SynchronousQueue q = new SynchronousQueue(fair);
122	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
123	Thread t = newStartedThread(new CheckedRunnable() {
124	public void realRun() throws InterruptedException {
125	Thread.currentThread().interrupt();
126	try {
127	q.put(99);
128	shouldThrow();
129	} catch (InterruptedException success) {}
130	assertFalse(Thread.interrupted());
131
132	pleaseInterrupt.countDown();
133	try {
134	q.put(99);
135	shouldThrow();
136	} catch (InterruptedException success) {}
137	assertFalse(Thread.interrupted());
138	}});
139
140	await(pleaseInterrupt);
141	if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
142	t.interrupt();
143	awaitTermination(t);
144	assertEquals(0, q.remainingCapacity());
145	}
146
147	/**
148	* put blocks interruptibly waiting for take
149	*/
150	public void testPutWithTake() { testPutWithTake(false); }
151	public void testPutWithTake_fair() { testPutWithTake(true); }
152	public void testPutWithTake(boolean fair) {
153	final SynchronousQueue q = new SynchronousQueue(fair);
154	final CountDownLatch pleaseTake = new CountDownLatch(1);
155	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
156	Thread t = newStartedThread(new CheckedRunnable() {
157	public void realRun() throws InterruptedException {
158	pleaseTake.countDown();
159	q.put(one);
160
161	Thread.currentThread().interrupt();
162	try {
163	q.put(99);
164	shouldThrow();
165	} catch (InterruptedException success) {}
166	assertFalse(Thread.interrupted());
167
168	pleaseInterrupt.countDown();
169	try {
170	q.put(99);
171	shouldThrow();
172	} catch (InterruptedException success) {}
173	assertFalse(Thread.interrupted());
174	}});
175
176	await(pleaseTake);
177	assertEquals(0, q.remainingCapacity());
178	try { assertSame(one, q.take()); }
179	catch (InterruptedException e) { threadUnexpectedException(e); }
180
181	await(pleaseInterrupt);
182	if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING);
183	t.interrupt();
184	awaitTermination(t);
185	assertEquals(0, q.remainingCapacity());
186	}
187
188	/**
189	* timed offer times out if elements not taken
190	*/
191	public void testTimedOffer() {
192	final boolean fair = randomBoolean();
193	final SynchronousQueue q = new SynchronousQueue(fair);
194	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
195	Thread t = newStartedThread(new CheckedRunnable() {
196	public void realRun() throws InterruptedException {
197	long startTime = System.nanoTime();
198
199	assertFalse(q.offer(new Object(), timeoutMillis(), MILLISECONDS));
200	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
201
202	Thread.currentThread().interrupt();
203	try {
204	q.offer(new Object(), randomTimeout(), randomTimeUnit());
205	shouldThrow();
206	} catch (InterruptedException success) {}
207	assertFalse(Thread.interrupted());
208
209	pleaseInterrupt.countDown();
210	try {
211	q.offer(new Object(), LONG_DELAY_MS, MILLISECONDS);
212	shouldThrow();
213	} catch (InterruptedException success) {}
214	assertFalse(Thread.interrupted());
215
216	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
217	}});
218
219	await(pleaseInterrupt);
220	if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
221	t.interrupt();
222	awaitTermination(t);
223	}
224
225	/**
226	* poll return null if no active putter
227	*/
228	public void testPoll() { testPoll(false); }
229	public void testPoll_fair() { testPoll(true); }
230	public void testPoll(boolean fair) {
231	final SynchronousQueue q = new SynchronousQueue(fair);
232	assertNull(q.poll());
233	}
234
235	/**
236	* timed poll with zero timeout times out if no active putter
237	*/
238	public void testTimedPoll0() { testTimedPoll0(false); }
239	public void testTimedPoll0_fair() { testTimedPoll0(true); }
240	public void testTimedPoll0(boolean fair) {
241	final SynchronousQueue q = new SynchronousQueue(fair);
242	try { assertNull(q.poll(0, MILLISECONDS)); }
243	catch (InterruptedException e) { threadUnexpectedException(e); }
244	}
245
246	/**
247	* timed poll with nonzero timeout times out if no active putter
248	*/
249	public void testTimedPoll() {
250	final boolean fair = randomBoolean();
251	final SynchronousQueue q = new SynchronousQueue(fair);
252	final long startTime = System.nanoTime();
253	try { assertNull(q.poll(timeoutMillis(), MILLISECONDS)); }
254	catch (InterruptedException e) { threadUnexpectedException(e); }
255	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
256	}
257
258	/**
259	* timed poll before a delayed offer times out, returning null;
260	* after offer succeeds; on interruption throws
261	*/
262	public void testTimedPollWithOffer() {
263	final boolean fair = randomBoolean();
264	final SynchronousQueue q = new SynchronousQueue(fair);
265	final CountDownLatch pleaseOffer = new CountDownLatch(1);
266	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
267	Thread t = newStartedThread(new CheckedRunnable() {
268	public void realRun() throws InterruptedException {
269	long startTime = System.nanoTime();
270	assertNull(q.poll(timeoutMillis(), MILLISECONDS));
271	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
272
273	pleaseOffer.countDown();
274	startTime = System.nanoTime();
275	assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
276
277	Thread.currentThread().interrupt();
278	try {
279	q.poll(randomTimeout(), randomTimeUnit());
280	shouldThrow();
281	} catch (InterruptedException success) {}
282	assertFalse(Thread.interrupted());
283
284	pleaseInterrupt.countDown();
285	try {
286	q.poll(LONG_DELAY_MS, MILLISECONDS);
287	shouldThrow();
288	} catch (InterruptedException success) {}
289	assertFalse(Thread.interrupted());
290
291	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
292	}});
293
294	await(pleaseOffer);
295	long startTime = System.nanoTime();
296	try { assertTrue(q.offer(zero, LONG_DELAY_MS, MILLISECONDS)); }
297	catch (InterruptedException e) { threadUnexpectedException(e); }
298	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
299
300	await(pleaseInterrupt);
301	if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING);
302	t.interrupt();
303	awaitTermination(t);
304	}
305
306	/**
307	* peek() returns null if no active putter
308	*/
309	public void testPeek() { testPeek(false); }
310	public void testPeek_fair() { testPeek(true); }
311	public void testPeek(boolean fair) {
312	final SynchronousQueue q = new SynchronousQueue(fair);
313	assertNull(q.peek());
314	}
315
316	/**
317	* element() throws NoSuchElementException if no active putter
318	*/
319	public void testElement() { testElement(false); }
320	public void testElement_fair() { testElement(true); }
321	public void testElement(boolean fair) {
322	final SynchronousQueue q = new SynchronousQueue(fair);
323	try {
324	q.element();
325	shouldThrow();
326	} catch (NoSuchElementException success) {}
327	}
328
329	/**
330	* remove() throws NoSuchElementException if no active putter
331	*/
332	public void testRemove() { testRemove(false); }
333	public void testRemove_fair() { testRemove(true); }
334	public void testRemove(boolean fair) {
335	final SynchronousQueue q = new SynchronousQueue(fair);
336	try {
337	q.remove();
338	shouldThrow();
339	} catch (NoSuchElementException success) {}
340	}
341
342	/**
343	* contains returns false
344	*/
345	public void testContains() { testContains(false); }
346	public void testContains_fair() { testContains(true); }
347	public void testContains(boolean fair) {
348	final SynchronousQueue q = new SynchronousQueue(fair);
349	assertFalse(q.contains(zero));
350	}
351
352	/**
353	* clear ensures isEmpty
354	*/
355	public void testClear() { testClear(false); }
356	public void testClear_fair() { testClear(true); }
357	public void testClear(boolean fair) {
358	final SynchronousQueue q = new SynchronousQueue(fair);
359	q.clear();
360	assertTrue(q.isEmpty());
361	}
362
363	/**
364	* containsAll returns false unless empty
365	*/
366	public void testContainsAll() { testContainsAll(false); }
367	public void testContainsAll_fair() { testContainsAll(true); }
368	public void testContainsAll(boolean fair) {
369	final SynchronousQueue q = new SynchronousQueue(fair);
370	Integer[] empty = new Integer[0];
371	assertTrue(q.containsAll(Arrays.asList(empty)));
372	Integer[] ints = new Integer[1]; ints[0] = zero;
373	assertFalse(q.containsAll(Arrays.asList(ints)));
374	}
375
376	/**
377	* retainAll returns false
378	*/
379	public void testRetainAll() { testRetainAll(false); }
380	public void testRetainAll_fair() { testRetainAll(true); }
381	public void testRetainAll(boolean fair) {
382	final SynchronousQueue q = new SynchronousQueue(fair);
383	Integer[] empty = new Integer[0];
384	assertFalse(q.retainAll(Arrays.asList(empty)));
385	Integer[] ints = new Integer[1]; ints[0] = zero;
386	assertFalse(q.retainAll(Arrays.asList(ints)));
387	}
388
389	/**
390	* removeAll returns false
391	*/
392	public void testRemoveAll() { testRemoveAll(false); }
393	public void testRemoveAll_fair() { testRemoveAll(true); }
394	public void testRemoveAll(boolean fair) {
395	final SynchronousQueue q = new SynchronousQueue(fair);
396	Integer[] empty = new Integer[0];
397	assertFalse(q.removeAll(Arrays.asList(empty)));
398	Integer[] ints = new Integer[1]; ints[0] = zero;
399	assertFalse(q.containsAll(Arrays.asList(ints)));
400	}
401
402	/**
403	* toArray is empty
404	*/
405	public void testToArray() { testToArray(false); }
406	public void testToArray_fair() { testToArray(true); }
407	public void testToArray(boolean fair) {
408	final SynchronousQueue q = new SynchronousQueue(fair);
409	Object[] o = q.toArray();
410	assertEquals(0, o.length);
411	}
412
413	/**
414	* toArray(Integer array) returns its argument with the first
415	* element (if present) nulled out
416	*/
417	public void testToArray2() { testToArray2(false); }
418	public void testToArray2_fair() { testToArray2(true); }
419	public void testToArray2(boolean fair) {
420	final SynchronousQueue<Integer> q = new SynchronousQueue<>(fair);
421	Integer[] a;
422
423	a = new Integer[0];
424	assertSame(a, q.toArray(a));
425
426	a = new Integer[3];
427	Arrays.fill(a, 42);
428	assertSame(a, q.toArray(a));
429	assertNull(a[0]);
430	for (int i = 1; i < a.length; i++)
431	assertEquals(42, (int) a[i]);
432	}
433
434	/**
435	* toArray(null) throws NPE
436	*/
437	public void testToArray_null() { testToArray_null(false); }
438	public void testToArray_null_fair() { testToArray_null(true); }
439	public void testToArray_null(boolean fair) {
440	final SynchronousQueue q = new SynchronousQueue(fair);
441	try {
442	Object[] o = q.toArray((Object[])null);
443	shouldThrow();
444	} catch (NullPointerException success) {}
445	}
446
447	/**
448	* iterator does not traverse any elements
449	*/
450	public void testIterator() { testIterator(false); }
451	public void testIterator_fair() { testIterator(true); }
452	public void testIterator(boolean fair) {
453	assertIteratorExhausted(new SynchronousQueue(fair).iterator());
454	}
455
456	/**
457	* iterator remove throws IllegalStateException
458	*/
459	public void testIteratorRemove() { testIteratorRemove(false); }
460	public void testIteratorRemove_fair() { testIteratorRemove(true); }
461	public void testIteratorRemove(boolean fair) {
462	final SynchronousQueue q = new SynchronousQueue(fair);
463	Iterator it = q.iterator();
464	try {
465	it.remove();
466	shouldThrow();
467	} catch (IllegalStateException success) {}
468	}
469
470	/**
471	* toString returns a non-null string
472	*/
473	public void testToString() { testToString(false); }
474	public void testToString_fair() { testToString(true); }
475	public void testToString(boolean fair) {
476	final SynchronousQueue q = new SynchronousQueue(fair);
477	String s = q.toString();
478	assertNotNull(s);
479	}
480
481	/**
482	* offer transfers elements across Executor tasks
483	*/
484	public void testOfferInExecutor() { testOfferInExecutor(false); }
485	public void testOfferInExecutor_fair() { testOfferInExecutor(true); }
486	public void testOfferInExecutor(boolean fair) {
487	final SynchronousQueue q = new SynchronousQueue(fair);
488	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
489	final ExecutorService executor = Executors.newFixedThreadPool(2);
490	try (PoolCleaner cleaner = cleaner(executor)) {
491
492	executor.execute(new CheckedRunnable() {
493	public void realRun() throws InterruptedException {
494	assertFalse(q.offer(one));
495	threadsStarted.await();
496	assertTrue(q.offer(one, LONG_DELAY_MS, MILLISECONDS));
497	assertEquals(0, q.remainingCapacity());
498	}});
499
500	executor.execute(new CheckedRunnable() {
501	public void realRun() throws InterruptedException {
502	threadsStarted.await();
503	assertSame(one, q.take());
504	}});
505	}
506	}
507
508	/**
509	* timed poll retrieves elements across Executor threads
510	*/
511	public void testPollInExecutor() { testPollInExecutor(false); }
512	public void testPollInExecutor_fair() { testPollInExecutor(true); }
513	public void testPollInExecutor(boolean fair) {
514	final SynchronousQueue q = new SynchronousQueue(fair);
515	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
516	final ExecutorService executor = Executors.newFixedThreadPool(2);
517	try (PoolCleaner cleaner = cleaner(executor)) {
518	executor.execute(new CheckedRunnable() {
519	public void realRun() throws InterruptedException {
520	assertNull(q.poll());
521	threadsStarted.await();
522	assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
523	assertTrue(q.isEmpty());
524	}});
525
526	executor.execute(new CheckedRunnable() {
527	public void realRun() throws InterruptedException {
528	threadsStarted.await();
529	q.put(one);
530	}});
531	}
532	}
533
534	/**
535	* a deserialized/reserialized queue is usable
536	*/
537	public void testSerialization() {
538	final SynchronousQueue x = new SynchronousQueue();
539	final SynchronousQueue y = new SynchronousQueue(false);
540	final SynchronousQueue z = new SynchronousQueue(true);
541	assertSerialEquals(x, y);
542	assertNotSerialEquals(x, z);
543	SynchronousQueue[] qs = { x, y, z };
544	for (SynchronousQueue q : qs) {
545	SynchronousQueue clone = serialClone(q);
546	assertNotSame(q, clone);
547	assertSerialEquals(q, clone);
548	assertTrue(clone.isEmpty());
549	assertEquals(0, clone.size());
550	assertEquals(0, clone.remainingCapacity());
551	assertFalse(clone.offer(zero));
552	}
553	}
554
555	/**
556	* drainTo(c) of empty queue doesn't transfer elements
557	*/
558	public void testDrainTo() { testDrainTo(false); }
559	public void testDrainTo_fair() { testDrainTo(true); }
560	public void testDrainTo(boolean fair) {
561	final SynchronousQueue q = new SynchronousQueue(fair);
562	ArrayList l = new ArrayList();
563	q.drainTo(l);
564	assertEquals(0, q.size());
565	assertEquals(0, l.size());
566	}
567
568	/**
569	* drainTo empties queue, unblocking a waiting put.
570	*/
571	public void testDrainToWithActivePut() { testDrainToWithActivePut(false); }
572	public void testDrainToWithActivePut_fair() { testDrainToWithActivePut(true); }
573	public void testDrainToWithActivePut(boolean fair) {
574	final SynchronousQueue q = new SynchronousQueue(fair);
575	Thread t = newStartedThread(new CheckedRunnable() {
576	public void realRun() throws InterruptedException {
577	q.put(one);
578	}});
579
580	ArrayList l = new ArrayList();
581	long startTime = System.nanoTime();
582	while (l.isEmpty()) {
583	q.drainTo(l);
584	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
585	fail("timed out");
586	Thread.yield();
587	}
588	assertEquals(1, l.size());
589	assertSame(one, l.get(0));
590	awaitTermination(t);
591	}
592
593	/**
594	* drainTo(c, n) empties up to n elements of queue into c
595	*/
596	public void testDrainToN() throws InterruptedException {
597	final SynchronousQueue q = new SynchronousQueue();
598	Thread t1 = newStartedThread(new CheckedRunnable() {
599	public void realRun() throws InterruptedException {
600	q.put(one);
601	}});
602
603	Thread t2 = newStartedThread(new CheckedRunnable() {
604	public void realRun() throws InterruptedException {
605	q.put(two);
606	}});
607
608	ArrayList l = new ArrayList();
609	int drained;
610	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
611	assertEquals(1, drained);
612	assertEquals(1, l.size());
613	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
614	assertEquals(1, drained);
615	assertEquals(2, l.size());
616	assertTrue(l.contains(one));
617	assertTrue(l.contains(two));
618	awaitTermination(t1);
619	awaitTermination(t2);
620	}
621
622	/**
623	* remove(null), contains(null) always return false
624	*/
625	public void testNeverContainsNull() {
626	Collection<?> q = new SynchronousQueue();
627	assertFalse(q.contains(null));
628	assertFalse(q.remove(null));
629	}
630
631	}