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 ISE 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);
        assertThreadStaysAlive(t);
        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);

                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);
        assertThreadBlocks(t, Thread.State.WAITING);
        t.interrupt();
        awaitTermination(t);
        assertEquals(0, q.remainingCapacity());
    }

    /**
     * timed offer times out if elements not taken
     */
    public void testTimedOffer()      { testTimedOffer(false); }
    public void testTimedOffer_fair() { testTimedOffer(true); }
    public void testTimedOffer(boolean fair) {
        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());
                pleaseInterrupt.countDown();
                try {
                    q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (InterruptedException success) {}
            }});

        await(pleaseInterrupt);
        assertThreadStaysAlive(t);
        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()      { testTimedPoll(false); }
    public void testTimedPoll_fair() { testTimedPoll(true); }
    public void testTimedPoll(boolean fair) {
        final SynchronousQueue q = new SynchronousQueue(fair);
        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()      { testTimedPollWithOffer(false); }
    public void testTimedPollWithOffer_fair() { testTimedPollWithOffer(true); }
    public void testTimedPollWithOffer(boolean fair) {
        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(LONG_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

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

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

        await(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);
        assertThreadStaysAlive(t);
        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(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 ISE
     */
    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 serialized 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:	1.53
Committed:	Sat May 13 21:52:59 2017 UTC (7 years ago) by jsr166
Branch:	MAIN
Changes since 1.52:	+1 -1 lines
Log Message:	claw back some millis using assertThreadBlocks
#	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 ISE 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	assertThreadStaysAlive(t);
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	pleaseInterrupt.countDown();
162	try {
163	q.put(99);
164	shouldThrow();
165	} catch (InterruptedException success) {}
166	assertFalse(Thread.interrupted());
167	}});
168
169	await(pleaseTake);
170	assertEquals(0, q.remainingCapacity());
171	try { assertSame(one, q.take()); }
172	catch (InterruptedException e) { threadUnexpectedException(e); }
173
174	await(pleaseInterrupt);
175	assertThreadBlocks(t, Thread.State.WAITING);
176	t.interrupt();
177	awaitTermination(t);
178	assertEquals(0, q.remainingCapacity());
179	}
180
181	/**
182	* timed offer times out if elements not taken
183	*/
184	public void testTimedOffer() { testTimedOffer(false); }
185	public void testTimedOffer_fair() { testTimedOffer(true); }
186	public void testTimedOffer(boolean fair) {
187	final SynchronousQueue q = new SynchronousQueue(fair);
188	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
189	Thread t = newStartedThread(new CheckedRunnable() {
190	public void realRun() throws InterruptedException {
191	long startTime = System.nanoTime();
192	assertFalse(q.offer(new Object(), timeoutMillis(), MILLISECONDS));
193	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
194	pleaseInterrupt.countDown();
195	try {
196	q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
197	shouldThrow();
198	} catch (InterruptedException success) {}
199	}});
200
201	await(pleaseInterrupt);
202	assertThreadStaysAlive(t);
203	t.interrupt();
204	awaitTermination(t);
205	}
206
207	/**
208	* poll return null if no active putter
209	*/
210	public void testPoll() { testPoll(false); }
211	public void testPoll_fair() { testPoll(true); }
212	public void testPoll(boolean fair) {
213	final SynchronousQueue q = new SynchronousQueue(fair);
214	assertNull(q.poll());
215	}
216
217	/**
218	* timed poll with zero timeout times out if no active putter
219	*/
220	public void testTimedPoll0() { testTimedPoll0(false); }
221	public void testTimedPoll0_fair() { testTimedPoll0(true); }
222	public void testTimedPoll0(boolean fair) {
223	final SynchronousQueue q = new SynchronousQueue(fair);
224	try { assertNull(q.poll(0, MILLISECONDS)); }
225	catch (InterruptedException e) { threadUnexpectedException(e); }
226	}
227
228	/**
229	* timed poll with nonzero timeout times out if no active putter
230	*/
231	public void testTimedPoll() { testTimedPoll(false); }
232	public void testTimedPoll_fair() { testTimedPoll(true); }
233	public void testTimedPoll(boolean fair) {
234	final SynchronousQueue q = new SynchronousQueue(fair);
235	long startTime = System.nanoTime();
236	try { assertNull(q.poll(timeoutMillis(), MILLISECONDS)); }
237	catch (InterruptedException e) { threadUnexpectedException(e); }
238	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
239	}
240
241	/**
242	* timed poll before a delayed offer times out, returning null;
243	* after offer succeeds; on interruption throws
244	*/
245	public void testTimedPollWithOffer() { testTimedPollWithOffer(false); }
246	public void testTimedPollWithOffer_fair() { testTimedPollWithOffer(true); }
247	public void testTimedPollWithOffer(boolean fair) {
248	final SynchronousQueue q = new SynchronousQueue(fair);
249	final CountDownLatch pleaseOffer = new CountDownLatch(1);
250	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
251	Thread t = newStartedThread(new CheckedRunnable() {
252	public void realRun() throws InterruptedException {
253	long startTime = System.nanoTime();
254	assertNull(q.poll(timeoutMillis(), MILLISECONDS));
255	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
256
257	pleaseOffer.countDown();
258	startTime = System.nanoTime();
259	assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
260
261	Thread.currentThread().interrupt();
262	try {
263	q.poll(LONG_DELAY_MS, MILLISECONDS);
264	shouldThrow();
265	} catch (InterruptedException success) {}
266	assertFalse(Thread.interrupted());
267
268	pleaseInterrupt.countDown();
269	try {
270	q.poll(LONG_DELAY_MS, MILLISECONDS);
271	shouldThrow();
272	} catch (InterruptedException success) {}
273	assertFalse(Thread.interrupted());
274
275	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
276	}});
277
278	await(pleaseOffer);
279	long startTime = System.nanoTime();
280	try { assertTrue(q.offer(zero, LONG_DELAY_MS, MILLISECONDS)); }
281	catch (InterruptedException e) { threadUnexpectedException(e); }
282	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
283
284	await(pleaseInterrupt);
285	assertThreadStaysAlive(t);
286	t.interrupt();
287	awaitTermination(t);
288	}
289
290	/**
291	* peek() returns null if no active putter
292	*/
293	public void testPeek() { testPeek(false); }
294	public void testPeek_fair() { testPeek(true); }
295	public void testPeek(boolean fair) {
296	final SynchronousQueue q = new SynchronousQueue(fair);
297	assertNull(q.peek());
298	}
299
300	/**
301	* element() throws NoSuchElementException if no active putter
302	*/
303	public void testElement() { testElement(false); }
304	public void testElement_fair() { testElement(true); }
305	public void testElement(boolean fair) {
306	final SynchronousQueue q = new SynchronousQueue(fair);
307	try {
308	q.element();
309	shouldThrow();
310	} catch (NoSuchElementException success) {}
311	}
312
313	/**
314	* remove() throws NoSuchElementException if no active putter
315	*/
316	public void testRemove() { testRemove(false); }
317	public void testRemove_fair() { testRemove(true); }
318	public void testRemove(boolean fair) {
319	final SynchronousQueue q = new SynchronousQueue(fair);
320	try {
321	q.remove();
322	shouldThrow();
323	} catch (NoSuchElementException success) {}
324	}
325
326	/**
327	* contains returns false
328	*/
329	public void testContains() { testContains(false); }
330	public void testContains_fair() { testContains(true); }
331	public void testContains(boolean fair) {
332	final SynchronousQueue q = new SynchronousQueue(fair);
333	assertFalse(q.contains(zero));
334	}
335
336	/**
337	* clear ensures isEmpty
338	*/
339	public void testClear() { testClear(false); }
340	public void testClear_fair() { testClear(true); }
341	public void testClear(boolean fair) {
342	final SynchronousQueue q = new SynchronousQueue(fair);
343	q.clear();
344	assertTrue(q.isEmpty());
345	}
346
347	/**
348	* containsAll returns false unless empty
349	*/
350	public void testContainsAll() { testContainsAll(false); }
351	public void testContainsAll_fair() { testContainsAll(true); }
352	public void testContainsAll(boolean fair) {
353	final SynchronousQueue q = new SynchronousQueue(fair);
354	Integer[] empty = new Integer[0];
355	assertTrue(q.containsAll(Arrays.asList(empty)));
356	Integer[] ints = new Integer[1]; ints[0] = zero;
357	assertFalse(q.containsAll(Arrays.asList(ints)));
358	}
359
360	/**
361	* retainAll returns false
362	*/
363	public void testRetainAll() { testRetainAll(false); }
364	public void testRetainAll_fair() { testRetainAll(true); }
365	public void testRetainAll(boolean fair) {
366	final SynchronousQueue q = new SynchronousQueue(fair);
367	Integer[] empty = new Integer[0];
368	assertFalse(q.retainAll(Arrays.asList(empty)));
369	Integer[] ints = new Integer[1]; ints[0] = zero;
370	assertFalse(q.retainAll(Arrays.asList(ints)));
371	}
372
373	/**
374	* removeAll returns false
375	*/
376	public void testRemoveAll() { testRemoveAll(false); }
377	public void testRemoveAll_fair() { testRemoveAll(true); }
378	public void testRemoveAll(boolean fair) {
379	final SynchronousQueue q = new SynchronousQueue(fair);
380	Integer[] empty = new Integer[0];
381	assertFalse(q.removeAll(Arrays.asList(empty)));
382	Integer[] ints = new Integer[1]; ints[0] = zero;
383	assertFalse(q.containsAll(Arrays.asList(ints)));
384	}
385
386	/**
387	* toArray is empty
388	*/
389	public void testToArray() { testToArray(false); }
390	public void testToArray_fair() { testToArray(true); }
391	public void testToArray(boolean fair) {
392	final SynchronousQueue q = new SynchronousQueue(fair);
393	Object[] o = q.toArray();
394	assertEquals(0, o.length);
395	}
396
397	/**
398	* toArray(Integer array) returns its argument with the first
399	* element (if present) nulled out
400	*/
401	public void testToArray2() { testToArray2(false); }
402	public void testToArray2_fair() { testToArray2(true); }
403	public void testToArray2(boolean fair) {
404	final SynchronousQueue<Integer> q = new SynchronousQueue<>(fair);
405	Integer[] a;
406
407	a = new Integer[0];
408	assertSame(a, q.toArray(a));
409
410	a = new Integer[3];
411	Arrays.fill(a, 42);
412	assertSame(a, q.toArray(a));
413	assertNull(a[0]);
414	for (int i = 1; i < a.length; i++)
415	assertEquals(42, (int) a[i]);
416	}
417
418	/**
419	* toArray(null) throws NPE
420	*/
421	public void testToArray_null() { testToArray_null(false); }
422	public void testToArray_null_fair() { testToArray_null(true); }
423	public void testToArray_null(boolean fair) {
424	final SynchronousQueue q = new SynchronousQueue(fair);
425	try {
426	Object[] o = q.toArray(null);
427	shouldThrow();
428	} catch (NullPointerException success) {}
429	}
430
431	/**
432	* iterator does not traverse any elements
433	*/
434	public void testIterator() { testIterator(false); }
435	public void testIterator_fair() { testIterator(true); }
436	public void testIterator(boolean fair) {
437	assertIteratorExhausted(new SynchronousQueue(fair).iterator());
438	}
439
440	/**
441	* iterator remove throws ISE
442	*/
443	public void testIteratorRemove() { testIteratorRemove(false); }
444	public void testIteratorRemove_fair() { testIteratorRemove(true); }
445	public void testIteratorRemove(boolean fair) {
446	final SynchronousQueue q = new SynchronousQueue(fair);
447	Iterator it = q.iterator();
448	try {
449	it.remove();
450	shouldThrow();
451	} catch (IllegalStateException success) {}
452	}
453
454	/**
455	* toString returns a non-null string
456	*/
457	public void testToString() { testToString(false); }
458	public void testToString_fair() { testToString(true); }
459	public void testToString(boolean fair) {
460	final SynchronousQueue q = new SynchronousQueue(fair);
461	String s = q.toString();
462	assertNotNull(s);
463	}
464
465	/**
466	* offer transfers elements across Executor tasks
467	*/
468	public void testOfferInExecutor() { testOfferInExecutor(false); }
469	public void testOfferInExecutor_fair() { testOfferInExecutor(true); }
470	public void testOfferInExecutor(boolean fair) {
471	final SynchronousQueue q = new SynchronousQueue(fair);
472	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
473	final ExecutorService executor = Executors.newFixedThreadPool(2);
474	try (PoolCleaner cleaner = cleaner(executor)) {
475
476	executor.execute(new CheckedRunnable() {
477	public void realRun() throws InterruptedException {
478	assertFalse(q.offer(one));
479	threadsStarted.await();
480	assertTrue(q.offer(one, LONG_DELAY_MS, MILLISECONDS));
481	assertEquals(0, q.remainingCapacity());
482	}});
483
484	executor.execute(new CheckedRunnable() {
485	public void realRun() throws InterruptedException {
486	threadsStarted.await();
487	assertSame(one, q.take());
488	}});
489	}
490	}
491
492	/**
493	* timed poll retrieves elements across Executor threads
494	*/
495	public void testPollInExecutor() { testPollInExecutor(false); }
496	public void testPollInExecutor_fair() { testPollInExecutor(true); }
497	public void testPollInExecutor(boolean fair) {
498	final SynchronousQueue q = new SynchronousQueue(fair);
499	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
500	final ExecutorService executor = Executors.newFixedThreadPool(2);
501	try (PoolCleaner cleaner = cleaner(executor)) {
502	executor.execute(new CheckedRunnable() {
503	public void realRun() throws InterruptedException {
504	assertNull(q.poll());
505	threadsStarted.await();
506	assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
507	assertTrue(q.isEmpty());
508	}});
509
510	executor.execute(new CheckedRunnable() {
511	public void realRun() throws InterruptedException {
512	threadsStarted.await();
513	q.put(one);
514	}});
515	}
516	}
517
518	/**
519	* a deserialized serialized queue is usable
520	*/
521	public void testSerialization() {
522	final SynchronousQueue x = new SynchronousQueue();
523	final SynchronousQueue y = new SynchronousQueue(false);
524	final SynchronousQueue z = new SynchronousQueue(true);
525	assertSerialEquals(x, y);
526	assertNotSerialEquals(x, z);
527	SynchronousQueue[] qs = { x, y, z };
528	for (SynchronousQueue q : qs) {
529	SynchronousQueue clone = serialClone(q);
530	assertNotSame(q, clone);
531	assertSerialEquals(q, clone);
532	assertTrue(clone.isEmpty());
533	assertEquals(0, clone.size());
534	assertEquals(0, clone.remainingCapacity());
535	assertFalse(clone.offer(zero));
536	}
537	}
538
539	/**
540	* drainTo(c) of empty queue doesn't transfer elements
541	*/
542	public void testDrainTo() { testDrainTo(false); }
543	public void testDrainTo_fair() { testDrainTo(true); }
544	public void testDrainTo(boolean fair) {
545	final SynchronousQueue q = new SynchronousQueue(fair);
546	ArrayList l = new ArrayList();
547	q.drainTo(l);
548	assertEquals(0, q.size());
549	assertEquals(0, l.size());
550	}
551
552	/**
553	* drainTo empties queue, unblocking a waiting put.
554	*/
555	public void testDrainToWithActivePut() { testDrainToWithActivePut(false); }
556	public void testDrainToWithActivePut_fair() { testDrainToWithActivePut(true); }
557	public void testDrainToWithActivePut(boolean fair) {
558	final SynchronousQueue q = new SynchronousQueue(fair);
559	Thread t = newStartedThread(new CheckedRunnable() {
560	public void realRun() throws InterruptedException {
561	q.put(one);
562	}});
563
564	ArrayList l = new ArrayList();
565	long startTime = System.nanoTime();
566	while (l.isEmpty()) {
567	q.drainTo(l);
568	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
569	fail("timed out");
570	Thread.yield();
571	}
572	assertEquals(1, l.size());
573	assertSame(one, l.get(0));
574	awaitTermination(t);
575	}
576
577	/**
578	* drainTo(c, n) empties up to n elements of queue into c
579	*/
580	public void testDrainToN() throws InterruptedException {
581	final SynchronousQueue q = new SynchronousQueue();
582	Thread t1 = newStartedThread(new CheckedRunnable() {
583	public void realRun() throws InterruptedException {
584	q.put(one);
585	}});
586
587	Thread t2 = newStartedThread(new CheckedRunnable() {
588	public void realRun() throws InterruptedException {
589	q.put(two);
590	}});
591
592	ArrayList l = new ArrayList();
593	int drained;
594	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
595	assertEquals(1, drained);
596	assertEquals(1, l.size());
597	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
598	assertEquals(1, drained);
599	assertEquals(2, l.size());
600	assertTrue(l.contains(one));
601	assertTrue(l.contains(two));
602	awaitTermination(t1);
603	awaitTermination(t2);
604	}
605
606	/**
607	* remove(null), contains(null) always return false
608	*/
609	public void testNeverContainsNull() {
610	Collection<?> q = new SynchronousQueue();
611	assertFalse(q.contains(null));
612	assertFalse(q.remove(null));
613	}
614
615	}