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 java.util.concurrent.ThreadLocalRandom;

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);
        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);
        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 = ThreadLocalRandom.current().nextBoolean();
        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(), 2 * LONG_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());

                pleaseInterrupt.countDown();
                try {
                    q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (InterruptedException success) {}
                assertFalse(Thread.interrupted());
            }});

        await(pleaseInterrupt);
        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 = ThreadLocalRandom.current().nextBoolean();
        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 = ThreadLocalRandom.current().nextBoolean();
        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);
        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(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:	1.61
Committed:	Fri Aug 4 03:30:21 2017 UTC (6 years, 9 months ago) by jsr166
Branch:	MAIN
Changes since 1.60:	+1 -1 lines
Log Message:	improve javadoc wording for testSerialization methods
#	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	import java.util.concurrent.ThreadLocalRandom;
22
23	import junit.framework.Test;
24
25	public class SynchronousQueueTest extends JSR166TestCase {
26
27	public static class Fair extends BlockingQueueTest {
28	protected BlockingQueue emptyCollection() {
29	return new SynchronousQueue(true);
30	}
31	}
32
33	public static class NonFair extends BlockingQueueTest {
34	protected BlockingQueue emptyCollection() {
35	return new SynchronousQueue(false);
36	}
37	}
38
39	public static void main(String[] args) {
40	main(suite(), args);
41	}
42
43	public static Test suite() {
44	return newTestSuite(SynchronousQueueTest.class,
45	new Fair().testSuite(),
46	new NonFair().testSuite());
47	}
48
49	/**
50	* Any SynchronousQueue is both empty and full
51	*/
52	public void testEmptyFull() { testEmptyFull(false); }
53	public void testEmptyFull_fair() { testEmptyFull(true); }
54	public void testEmptyFull(boolean fair) {
55	final SynchronousQueue q = new SynchronousQueue(fair);
56	assertTrue(q.isEmpty());
57	assertEquals(0, q.size());
58	assertEquals(0, q.remainingCapacity());
59	assertFalse(q.offer(zero));
60	}
61
62	/**
63	* offer fails if no active taker
64	*/
65	public void testOffer() { testOffer(false); }
66	public void testOffer_fair() { testOffer(true); }
67	public void testOffer(boolean fair) {
68	SynchronousQueue q = new SynchronousQueue(fair);
69	assertFalse(q.offer(one));
70	}
71
72	/**
73	* add throws IllegalStateException if no active taker
74	*/
75	public void testAdd() { testAdd(false); }
76	public void testAdd_fair() { testAdd(true); }
77	public void testAdd(boolean fair) {
78	SynchronousQueue q = new SynchronousQueue(fair);
79	assertEquals(0, q.remainingCapacity());
80	try {
81	q.add(one);
82	shouldThrow();
83	} catch (IllegalStateException success) {}
84	}
85
86	/**
87	* addAll(this) throws IllegalArgumentException
88	*/
89	public void testAddAll_self() { testAddAll_self(false); }
90	public void testAddAll_self_fair() { testAddAll_self(true); }
91	public void testAddAll_self(boolean fair) {
92	SynchronousQueue q = new SynchronousQueue(fair);
93	try {
94	q.addAll(q);
95	shouldThrow();
96	} catch (IllegalArgumentException success) {}
97	}
98
99	/**
100	* addAll throws IllegalStateException if no active taker
101	*/
102	public void testAddAll_ISE() { testAddAll_ISE(false); }
103	public void testAddAll_ISE_fair() { testAddAll_ISE(true); }
104	public void testAddAll_ISE(boolean fair) {
105	SynchronousQueue q = new SynchronousQueue(fair);
106	Integer[] ints = new Integer[1];
107	for (int i = 0; i < ints.length; i++)
108	ints[i] = i;
109	Collection<Integer> coll = Arrays.asList(ints);
110	try {
111	q.addAll(coll);
112	shouldThrow();
113	} catch (IllegalStateException success) {}
114	}
115
116	/**
117	* put blocks interruptibly if no active taker
118	*/
119	public void testBlockingPut() { testBlockingPut(false); }
120	public void testBlockingPut_fair() { testBlockingPut(true); }
121	public void testBlockingPut(boolean fair) {
122	final SynchronousQueue q = new SynchronousQueue(fair);
123	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
124	Thread t = newStartedThread(new CheckedRunnable() {
125	public void realRun() throws InterruptedException {
126	Thread.currentThread().interrupt();
127	try {
128	q.put(99);
129	shouldThrow();
130	} catch (InterruptedException success) {}
131	assertFalse(Thread.interrupted());
132
133	pleaseInterrupt.countDown();
134	try {
135	q.put(99);
136	shouldThrow();
137	} catch (InterruptedException success) {}
138	assertFalse(Thread.interrupted());
139	}});
140
141	await(pleaseInterrupt);
142	assertThreadBlocks(t, Thread.State.WAITING);
143	t.interrupt();
144	awaitTermination(t);
145	assertEquals(0, q.remainingCapacity());
146	}
147
148	/**
149	* put blocks interruptibly waiting for take
150	*/
151	public void testPutWithTake() { testPutWithTake(false); }
152	public void testPutWithTake_fair() { testPutWithTake(true); }
153	public void testPutWithTake(boolean fair) {
154	final SynchronousQueue q = new SynchronousQueue(fair);
155	final CountDownLatch pleaseTake = new CountDownLatch(1);
156	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
157	Thread t = newStartedThread(new CheckedRunnable() {
158	public void realRun() throws InterruptedException {
159	pleaseTake.countDown();
160	q.put(one);
161
162	Thread.currentThread().interrupt();
163	try {
164	q.put(99);
165	shouldThrow();
166	} catch (InterruptedException success) {}
167	assertFalse(Thread.interrupted());
168
169	pleaseInterrupt.countDown();
170	try {
171	q.put(99);
172	shouldThrow();
173	} catch (InterruptedException success) {}
174	assertFalse(Thread.interrupted());
175	}});
176
177	await(pleaseTake);
178	assertEquals(0, q.remainingCapacity());
179	try { assertSame(one, q.take()); }
180	catch (InterruptedException e) { threadUnexpectedException(e); }
181
182	await(pleaseInterrupt);
183	assertThreadBlocks(t, Thread.State.WAITING);
184	t.interrupt();
185	awaitTermination(t);
186	assertEquals(0, q.remainingCapacity());
187	}
188
189	/**
190	* timed offer times out if elements not taken
191	*/
192	public void testTimedOffer() {
193	final boolean fair = ThreadLocalRandom.current().nextBoolean();
194	final SynchronousQueue q = new SynchronousQueue(fair);
195	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
196	Thread t = newStartedThread(new CheckedRunnable() {
197	public void realRun() throws InterruptedException {
198	long startTime = System.nanoTime();
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(), 2 * LONG_DELAY_MS, MILLISECONDS);
205	shouldThrow();
206	} catch (InterruptedException success) {}
207	assertFalse(Thread.interrupted());
208
209	pleaseInterrupt.countDown();
210	try {
211	q.offer(new Object(), 2 * LONG_DELAY_MS, MILLISECONDS);
212	shouldThrow();
213	} catch (InterruptedException success) {}
214	assertFalse(Thread.interrupted());
215	}});
216
217	await(pleaseInterrupt);
218	assertThreadBlocks(t, Thread.State.TIMED_WAITING);
219	t.interrupt();
220	awaitTermination(t);
221	}
222
223	/**
224	* poll return null if no active putter
225	*/
226	public void testPoll() { testPoll(false); }
227	public void testPoll_fair() { testPoll(true); }
228	public void testPoll(boolean fair) {
229	final SynchronousQueue q = new SynchronousQueue(fair);
230	assertNull(q.poll());
231	}
232
233	/**
234	* timed poll with zero timeout times out if no active putter
235	*/
236	public void testTimedPoll0() { testTimedPoll0(false); }
237	public void testTimedPoll0_fair() { testTimedPoll0(true); }
238	public void testTimedPoll0(boolean fair) {
239	final SynchronousQueue q = new SynchronousQueue(fair);
240	try { assertNull(q.poll(0, MILLISECONDS)); }
241	catch (InterruptedException e) { threadUnexpectedException(e); }
242	}
243
244	/**
245	* timed poll with nonzero timeout times out if no active putter
246	*/
247	public void testTimedPoll() {
248	final boolean fair = ThreadLocalRandom.current().nextBoolean();
249	final SynchronousQueue q = new SynchronousQueue(fair);
250	final long startTime = System.nanoTime();
251	try { assertNull(q.poll(timeoutMillis(), MILLISECONDS)); }
252	catch (InterruptedException e) { threadUnexpectedException(e); }
253	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
254	}
255
256	/**
257	* timed poll before a delayed offer times out, returning null;
258	* after offer succeeds; on interruption throws
259	*/
260	public void testTimedPollWithOffer() {
261	final boolean fair = ThreadLocalRandom.current().nextBoolean();
262	final SynchronousQueue q = new SynchronousQueue(fair);
263	final CountDownLatch pleaseOffer = new CountDownLatch(1);
264	final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
265	Thread t = newStartedThread(new CheckedRunnable() {
266	public void realRun() throws InterruptedException {
267	long startTime = System.nanoTime();
268	assertNull(q.poll(timeoutMillis(), MILLISECONDS));
269	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
270
271	pleaseOffer.countDown();
272	startTime = System.nanoTime();
273	assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
274
275	Thread.currentThread().interrupt();
276	try {
277	q.poll(LONG_DELAY_MS, MILLISECONDS);
278	shouldThrow();
279	} catch (InterruptedException success) {}
280	assertFalse(Thread.interrupted());
281
282	pleaseInterrupt.countDown();
283	try {
284	q.poll(LONG_DELAY_MS, MILLISECONDS);
285	shouldThrow();
286	} catch (InterruptedException success) {}
287	assertFalse(Thread.interrupted());
288
289	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
290	}});
291
292	await(pleaseOffer);
293	long startTime = System.nanoTime();
294	try { assertTrue(q.offer(zero, LONG_DELAY_MS, MILLISECONDS)); }
295	catch (InterruptedException e) { threadUnexpectedException(e); }
296	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
297
298	await(pleaseInterrupt);
299	assertThreadBlocks(t, Thread.State.TIMED_WAITING);
300	t.interrupt();
301	awaitTermination(t);
302	}
303
304	/**
305	* peek() returns null if no active putter
306	*/
307	public void testPeek() { testPeek(false); }
308	public void testPeek_fair() { testPeek(true); }
309	public void testPeek(boolean fair) {
310	final SynchronousQueue q = new SynchronousQueue(fair);
311	assertNull(q.peek());
312	}
313
314	/**
315	* element() throws NoSuchElementException if no active putter
316	*/
317	public void testElement() { testElement(false); }
318	public void testElement_fair() { testElement(true); }
319	public void testElement(boolean fair) {
320	final SynchronousQueue q = new SynchronousQueue(fair);
321	try {
322	q.element();
323	shouldThrow();
324	} catch (NoSuchElementException success) {}
325	}
326
327	/**
328	* remove() throws NoSuchElementException if no active putter
329	*/
330	public void testRemove() { testRemove(false); }
331	public void testRemove_fair() { testRemove(true); }
332	public void testRemove(boolean fair) {
333	final SynchronousQueue q = new SynchronousQueue(fair);
334	try {
335	q.remove();
336	shouldThrow();
337	} catch (NoSuchElementException success) {}
338	}
339
340	/**
341	* contains returns false
342	*/
343	public void testContains() { testContains(false); }
344	public void testContains_fair() { testContains(true); }
345	public void testContains(boolean fair) {
346	final SynchronousQueue q = new SynchronousQueue(fair);
347	assertFalse(q.contains(zero));
348	}
349
350	/**
351	* clear ensures isEmpty
352	*/
353	public void testClear() { testClear(false); }
354	public void testClear_fair() { testClear(true); }
355	public void testClear(boolean fair) {
356	final SynchronousQueue q = new SynchronousQueue(fair);
357	q.clear();
358	assertTrue(q.isEmpty());
359	}
360
361	/**
362	* containsAll returns false unless empty
363	*/
364	public void testContainsAll() { testContainsAll(false); }
365	public void testContainsAll_fair() { testContainsAll(true); }
366	public void testContainsAll(boolean fair) {
367	final SynchronousQueue q = new SynchronousQueue(fair);
368	Integer[] empty = new Integer[0];
369	assertTrue(q.containsAll(Arrays.asList(empty)));
370	Integer[] ints = new Integer[1]; ints[0] = zero;
371	assertFalse(q.containsAll(Arrays.asList(ints)));
372	}
373
374	/**
375	* retainAll returns false
376	*/
377	public void testRetainAll() { testRetainAll(false); }
378	public void testRetainAll_fair() { testRetainAll(true); }
379	public void testRetainAll(boolean fair) {
380	final SynchronousQueue q = new SynchronousQueue(fair);
381	Integer[] empty = new Integer[0];
382	assertFalse(q.retainAll(Arrays.asList(empty)));
383	Integer[] ints = new Integer[1]; ints[0] = zero;
384	assertFalse(q.retainAll(Arrays.asList(ints)));
385	}
386
387	/**
388	* removeAll returns false
389	*/
390	public void testRemoveAll() { testRemoveAll(false); }
391	public void testRemoveAll_fair() { testRemoveAll(true); }
392	public void testRemoveAll(boolean fair) {
393	final SynchronousQueue q = new SynchronousQueue(fair);
394	Integer[] empty = new Integer[0];
395	assertFalse(q.removeAll(Arrays.asList(empty)));
396	Integer[] ints = new Integer[1]; ints[0] = zero;
397	assertFalse(q.containsAll(Arrays.asList(ints)));
398	}
399
400	/**
401	* toArray is empty
402	*/
403	public void testToArray() { testToArray(false); }
404	public void testToArray_fair() { testToArray(true); }
405	public void testToArray(boolean fair) {
406	final SynchronousQueue q = new SynchronousQueue(fair);
407	Object[] o = q.toArray();
408	assertEquals(0, o.length);
409	}
410
411	/**
412	* toArray(Integer array) returns its argument with the first
413	* element (if present) nulled out
414	*/
415	public void testToArray2() { testToArray2(false); }
416	public void testToArray2_fair() { testToArray2(true); }
417	public void testToArray2(boolean fair) {
418	final SynchronousQueue<Integer> q = new SynchronousQueue<>(fair);
419	Integer[] a;
420
421	a = new Integer[0];
422	assertSame(a, q.toArray(a));
423
424	a = new Integer[3];
425	Arrays.fill(a, 42);
426	assertSame(a, q.toArray(a));
427	assertNull(a[0]);
428	for (int i = 1; i < a.length; i++)
429	assertEquals(42, (int) a[i]);
430	}
431
432	/**
433	* toArray(null) throws NPE
434	*/
435	public void testToArray_null() { testToArray_null(false); }
436	public void testToArray_null_fair() { testToArray_null(true); }
437	public void testToArray_null(boolean fair) {
438	final SynchronousQueue q = new SynchronousQueue(fair);
439	try {
440	Object[] o = q.toArray(null);
441	shouldThrow();
442	} catch (NullPointerException success) {}
443	}
444
445	/**
446	* iterator does not traverse any elements
447	*/
448	public void testIterator() { testIterator(false); }
449	public void testIterator_fair() { testIterator(true); }
450	public void testIterator(boolean fair) {
451	assertIteratorExhausted(new SynchronousQueue(fair).iterator());
452	}
453
454	/**
455	* iterator remove throws IllegalStateException
456	*/
457	public void testIteratorRemove() { testIteratorRemove(false); }
458	public void testIteratorRemove_fair() { testIteratorRemove(true); }
459	public void testIteratorRemove(boolean fair) {
460	final SynchronousQueue q = new SynchronousQueue(fair);
461	Iterator it = q.iterator();
462	try {
463	it.remove();
464	shouldThrow();
465	} catch (IllegalStateException success) {}
466	}
467
468	/**
469	* toString returns a non-null string
470	*/
471	public void testToString() { testToString(false); }
472	public void testToString_fair() { testToString(true); }
473	public void testToString(boolean fair) {
474	final SynchronousQueue q = new SynchronousQueue(fair);
475	String s = q.toString();
476	assertNotNull(s);
477	}
478
479	/**
480	* offer transfers elements across Executor tasks
481	*/
482	public void testOfferInExecutor() { testOfferInExecutor(false); }
483	public void testOfferInExecutor_fair() { testOfferInExecutor(true); }
484	public void testOfferInExecutor(boolean fair) {
485	final SynchronousQueue q = new SynchronousQueue(fair);
486	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
487	final ExecutorService executor = Executors.newFixedThreadPool(2);
488	try (PoolCleaner cleaner = cleaner(executor)) {
489
490	executor.execute(new CheckedRunnable() {
491	public void realRun() throws InterruptedException {
492	assertFalse(q.offer(one));
493	threadsStarted.await();
494	assertTrue(q.offer(one, LONG_DELAY_MS, MILLISECONDS));
495	assertEquals(0, q.remainingCapacity());
496	}});
497
498	executor.execute(new CheckedRunnable() {
499	public void realRun() throws InterruptedException {
500	threadsStarted.await();
501	assertSame(one, q.take());
502	}});
503	}
504	}
505
506	/**
507	* timed poll retrieves elements across Executor threads
508	*/
509	public void testPollInExecutor() { testPollInExecutor(false); }
510	public void testPollInExecutor_fair() { testPollInExecutor(true); }
511	public void testPollInExecutor(boolean fair) {
512	final SynchronousQueue q = new SynchronousQueue(fair);
513	final CheckedBarrier threadsStarted = new CheckedBarrier(2);
514	final ExecutorService executor = Executors.newFixedThreadPool(2);
515	try (PoolCleaner cleaner = cleaner(executor)) {
516	executor.execute(new CheckedRunnable() {
517	public void realRun() throws InterruptedException {
518	assertNull(q.poll());
519	threadsStarted.await();
520	assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS));
521	assertTrue(q.isEmpty());
522	}});
523
524	executor.execute(new CheckedRunnable() {
525	public void realRun() throws InterruptedException {
526	threadsStarted.await();
527	q.put(one);
528	}});
529	}
530	}
531
532	/**
533	* a deserialized/reserialized queue is usable
534	*/
535	public void testSerialization() {
536	final SynchronousQueue x = new SynchronousQueue();
537	final SynchronousQueue y = new SynchronousQueue(false);
538	final SynchronousQueue z = new SynchronousQueue(true);
539	assertSerialEquals(x, y);
540	assertNotSerialEquals(x, z);
541	SynchronousQueue[] qs = { x, y, z };
542	for (SynchronousQueue q : qs) {
543	SynchronousQueue clone = serialClone(q);
544	assertNotSame(q, clone);
545	assertSerialEquals(q, clone);
546	assertTrue(clone.isEmpty());
547	assertEquals(0, clone.size());
548	assertEquals(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 q = new SynchronousQueue(fair);
560	ArrayList l = new ArrayList();
561	q.drainTo(l);
562	assertEquals(0, q.size());
563	assertEquals(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 q = new SynchronousQueue(fair);
573	Thread t = newStartedThread(new CheckedRunnable() {
574	public void realRun() throws InterruptedException {
575	q.put(one);
576	}});
577
578	ArrayList 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	assertEquals(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 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 l = new ArrayList();
607	int drained;
608	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
609	assertEquals(1, drained);
610	assertEquals(1, l.size());
611	while ((drained = q.drainTo(l, 1)) == 0) Thread.yield();
612	assertEquals(1, drained);
613	assertEquals(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	}