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/licenses/publicdomain
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

import junit.framework.*;
import java.util.*;
import java.util.concurrent.*;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
import java.io.*;

public class SynchronousQueueTest extends JSR166TestCase {

    public static void main(String[] args) {
        junit.textui.TestRunner.run (suite());
    }

    public static Test suite() {
        return new TestSuite(SynchronousQueueTest.class);
    }

    /**
     * A SynchronousQueue is both empty and full
     */
    public void testEmptyFull() {
        SynchronousQueue q = new SynchronousQueue();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        assertEquals(0, q.remainingCapacity());
        assertFalse(q.offer(zero));
    }

    /**
     * A fair SynchronousQueue is both empty and full
     */
    public void testFairEmptyFull() {
        SynchronousQueue q = new SynchronousQueue(true);
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        assertEquals(0, q.remainingCapacity());
        assertFalse(q.offer(zero));
    }

    /**
     * offer(null) throws NPE
     */
    public void testOfferNull() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            q.offer(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * add(null) throws NPE
     */
    public void testAddNull() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            q.add(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * offer fails if no active taker
     */
    public void testOffer() {
        SynchronousQueue q = new SynchronousQueue();
        assertFalse(q.offer(one));
    }

    /**
     * add throws ISE if no active taker
     */
    public void testAdd() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            assertEquals(0, q.remainingCapacity());
            q.add(one);
            shouldThrow();
        } catch (IllegalStateException success) {}
    }

    /**
     * addAll(null) throws NPE
     */
    public void testAddAll1() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            q.addAll(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * addAll(this) throws IAE
     */
    public void testAddAllSelf() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            q.addAll(q);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * addAll of a collection with null elements throws NPE
     */
    public void testAddAll2() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            Integer[] ints = new Integer[1];
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }
    /**
     * addAll throws ISE if no active taker
     */
    public void testAddAll4() {
        try {
            SynchronousQueue q = new SynchronousQueue();
            Integer[] ints = new Integer[1];
            for (int i = 0; i < 1; ++i)
                ints[i] = new Integer(i);
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        } catch (IllegalStateException success) {}
    }

    /**
     * put(null) throws NPE
     */
    public void testPutNull() throws InterruptedException {
        try {
            SynchronousQueue q = new SynchronousQueue();
            q.put(null);
            shouldThrow();
        } catch (NullPointerException success) {}
     }

    /**
     * put blocks interruptibly if no active taker
     */
    public void testBlockingPut() throws InterruptedException {
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                SynchronousQueue q = new SynchronousQueue();
                q.put(zero);
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     * put blocks waiting for take
     */
    public void testPutWithTake() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue();
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                int added = 0;
                try {
                    while (true) {
                        q.put(added);
                        ++added;
                    }
                } catch (InterruptedException success) {
                    assertTrue(added == 1);
                }
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        assertEquals(0, q.take());
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     * timed offer times out if elements not taken
     */
    public void testTimedOffer() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue();
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                assertFalse(q.offer(new Object(), SHORT_DELAY_MS, MILLISECONDS));
                q.offer(new Object(), LONG_DELAY_MS, MILLISECONDS);
            }});

        t.start();
        Thread.sleep(SMALL_DELAY_MS);
        t.interrupt();
        t.join();
    }


    /**
     * take blocks interruptibly when empty
     */
    public void testTakeFromEmpty() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue();
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                q.take();
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }


    /**
     * put blocks interruptibly if no active taker
     */
    public void testFairBlockingPut() throws InterruptedException {
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                SynchronousQueue q = new SynchronousQueue(true);
                q.put(zero);
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     * put blocks waiting for take
     */
    public void testFairPutWithTake() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue(true);
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                int added = 0;
                try {
                    while (true) {
                        q.put(added);
                        ++added;
                    }
                } catch (InterruptedException success) {
                    assertTrue(added == 1);
                }
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        assertEquals(0, q.take());
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     * timed offer times out if elements not taken
     */
    public void testFairTimedOffer() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue(true);
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                assertFalse(q.offer(new Object(), SHORT_DELAY_MS, MILLISECONDS));
                q.offer(new Object(), LONG_DELAY_MS, MILLISECONDS);
            }});

        t.start();
        Thread.sleep(SMALL_DELAY_MS);
        t.interrupt();
        t.join();
    }


    /**
     * take blocks interruptibly when empty
     */
    public void testFairTakeFromEmpty() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue(true);
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                q.take();
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     * poll fails unless active taker
     */
    public void testPoll() {
        SynchronousQueue q = new SynchronousQueue();
        assertNull(q.poll());
    }

    /**
     * timed pool with zero timeout times out if no active taker
     */
    public void testTimedPoll0() throws InterruptedException {
        SynchronousQueue q = new SynchronousQueue();
        assertNull(q.poll(0, MILLISECONDS));
    }

    /**
     * timed pool with nonzero timeout times out if no active taker
     */
    public void testTimedPoll() throws InterruptedException {
        SynchronousQueue q = new SynchronousQueue();
        assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
    }

    /**
     * Interrupted timed poll throws InterruptedException instead of
     * returning timeout status
     */
    public void testInterruptedTimedPoll() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue();
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                q.poll(SMALL_DELAY_MS, MILLISECONDS);
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     *  timed poll before a delayed offer fails; after offer succeeds;
     *  on interruption throws
     */
    public void testTimedPollWithOffer() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue();
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
                assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
                try {
                    q.poll(LONG_DELAY_MS, MILLISECONDS);
                    shouldThrow();
                } catch (InterruptedException success) {}
            }});

        t.start();
        Thread.sleep(SMALL_DELAY_MS);
        assertTrue(q.offer(zero, SHORT_DELAY_MS, MILLISECONDS));
        t.interrupt();
        t.join();
    }

    /**
     * Interrupted timed poll throws InterruptedException instead of
     * returning timeout status
     */
    public void testFairInterruptedTimedPoll() throws InterruptedException {
        Thread t = new Thread(new CheckedInterruptedRunnable() {
            public void realRun() throws InterruptedException {
                SynchronousQueue q = new SynchronousQueue(true);
                q.poll(SMALL_DELAY_MS, MILLISECONDS);
            }});

        t.start();
        Thread.sleep(SHORT_DELAY_MS);
        t.interrupt();
        t.join();
    }

    /**
     *  timed poll before a delayed offer fails; after offer succeeds;
     *  on interruption throws
     */
    public void testFairTimedPollWithOffer() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue(true);
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
                assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
                try {
                    q.poll(LONG_DELAY_MS, MILLISECONDS);
                    threadShouldThrow();
                } catch (InterruptedException success) {}
            }});

        t.start();
        Thread.sleep(SMALL_DELAY_MS);
        assertTrue(q.offer(zero, SHORT_DELAY_MS, MILLISECONDS));
        t.interrupt();
        t.join();
    }


    /**
     * peek returns null
     */
    public void testPeek() {
        SynchronousQueue q = new SynchronousQueue();
        assertNull(q.peek());
    }

    /**
     * element throws NSEE
     */
    public void testElement() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            q.element();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove throws NSEE if no active taker
     */
    public void testRemove() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            q.remove();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove(x) returns false
     */
    public void testRemoveElement() {
        SynchronousQueue q = new SynchronousQueue();
        assertFalse(q.remove(zero));
        assertTrue(q.isEmpty());
    }

    /**
     * contains returns false
     */
    public void testContains() {
        SynchronousQueue q = new SynchronousQueue();
        assertFalse(q.contains(zero));
    }

    /**
     * clear ensures isEmpty
     */
    public void testClear() {
        SynchronousQueue q = new SynchronousQueue();
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll returns false unless empty
     */
    public void testContainsAll() {
        SynchronousQueue q = new SynchronousQueue();
        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() {
        SynchronousQueue q = new SynchronousQueue();
        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() {
        SynchronousQueue q = new SynchronousQueue();
        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() {
        SynchronousQueue q = new SynchronousQueue();
        Object[] o = q.toArray();
        assertEquals(o.length, 0);
    }

    /**
     * toArray(a) is nulled at position 0
     */
    public void testToArray2() {
        SynchronousQueue q = new SynchronousQueue();
        Integer[] ints = new Integer[1];
        assertNull(ints[0]);
    }

    /**
     * toArray(null) throws NPE
     */
    public void testToArray_BadArg() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            Object o[] = q.toArray(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }


    /**
     * iterator does not traverse any elements
     */
    public void testIterator() {
        SynchronousQueue q = new SynchronousQueue();
        Iterator it = q.iterator();
        assertFalse(it.hasNext());
        try {
            Object x = it.next();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * iterator remove throws ISE
     */
    public void testIteratorRemove() {
        SynchronousQueue q = new SynchronousQueue();
        Iterator it = q.iterator();
        try {
            it.remove();
            shouldThrow();
        } catch (IllegalStateException success) {}
    }

    /**
     * toString returns a non-null string
     */
    public void testToString() {
        SynchronousQueue q = new SynchronousQueue();
        String s = q.toString();
        assertNotNull(s);
    }


    /**
     * offer transfers elements across Executor tasks
     */
    public void testOfferInExecutor() {
        final SynchronousQueue q = new SynchronousQueue();
        ExecutorService executor = Executors.newFixedThreadPool(2);

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

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

        joinPool(executor);

    }

    /**
     * poll retrieves elements across Executor threads
     */
    public void testPollInExecutor() {
        final SynchronousQueue q = new SynchronousQueue();
        ExecutorService executor = Executors.newFixedThreadPool(2);
        executor.execute(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                assertNull(q.poll());
                assertSame(one, q.poll(MEDIUM_DELAY_MS, MILLISECONDS));
                assertTrue(q.isEmpty());
            }});

        executor.execute(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                Thread.sleep(SHORT_DELAY_MS);
                q.put(one);
            }});

        joinPool(executor);
    }

    /**
     * a deserialized serialized queue is usable
     */
    public void testSerialization() throws Exception {
        SynchronousQueue q = new SynchronousQueue();
        ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
        ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
        out.writeObject(q);
        out.close();

        ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
        SynchronousQueue r = (SynchronousQueue)in.readObject();
        assertEquals(q.size(), r.size());
        while (!q.isEmpty())
            assertEquals(q.remove(), r.remove());
    }

    /**
     * drainTo(null) throws NPE
     */
    public void testDrainToNull() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            q.drainTo(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * drainTo(this) throws IAE
     */
    public void testDrainToSelf() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            q.drainTo(q);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * drainTo(c) of empty queue doesn't transfer elements
     */
    public void testDrainTo() {
        SynchronousQueue q = new SynchronousQueue();
        ArrayList l = new ArrayList();
        q.drainTo(l);
        assertEquals(q.size(), 0);
        assertEquals(l.size(), 0);
    }

    /**
     * drainTo empties queue, unblocking a waiting put.
     */
    public void testDrainToWithActivePut() throws InterruptedException {
        final SynchronousQueue q = new SynchronousQueue();
        Thread t = new Thread(new CheckedRunnable() {
            public void realRun() throws InterruptedException {
                q.put(new Integer(1));
            }});

        t.start();
        ArrayList l = new ArrayList();
        Thread.sleep(SHORT_DELAY_MS);
        q.drainTo(l);
        assertTrue(l.size() <= 1);
        if (l.size() > 0)
            assertEquals(l.get(0), new Integer(1));
        t.join();
        assertTrue(l.size() <= 1);
    }

    /**
     * drainTo(null, n) throws NPE
     */
    public void testDrainToNullN() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            q.drainTo(null, 0);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * drainTo(this, n) throws IAE
     */
    public void testDrainToSelfN() {
        SynchronousQueue q = new SynchronousQueue();
        try {
            q.drainTo(q, 0);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

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

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

        t1.start();
        t2.start();
        ArrayList l = new ArrayList();
        Thread.sleep(SHORT_DELAY_MS);
        q.drainTo(l, 1);
        assertTrue(l.size() == 1);
        q.drainTo(l, 1);
        assertTrue(l.size() == 2);
        assertTrue(l.contains(one));
        assertTrue(l.contains(two));
        t1.join();
        t2.join();
    }

}
Revision:	1.19
Committed:	Tue Dec 1 06:03:49 2009 UTC (14 years, 5 months ago) by jsr166
Branch:	MAIN
Changes since 1.18:	+22 -33 lines
Log Message:	Use MILLISECONDS.toNanos instead of multiplying by 1000*1000; use explicit assertEquals instead of assertTrue(...!= null); improve testPutWithTake
#	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/licenses/publicdomain
5	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	* Pat Fisher, Mike Judd.
7	*/
8
9	import junit.framework.*;
10	import java.util.*;
11	import java.util.concurrent.*;
12	import static java.util.concurrent.TimeUnit.MILLISECONDS;
13	import java.io.*;
14
15	public class SynchronousQueueTest extends JSR166TestCase {
16
17	public static void main(String[] args) {
18	junit.textui.TestRunner.run (suite());
19	}
20
21	public static Test suite() {
22	return new TestSuite(SynchronousQueueTest.class);
23	}
24
25	/**
26	* A SynchronousQueue is both empty and full
27	*/
28	public void testEmptyFull() {
29	SynchronousQueue q = new SynchronousQueue();
30	assertTrue(q.isEmpty());
31	assertEquals(0, q.size());
32	assertEquals(0, q.remainingCapacity());
33	assertFalse(q.offer(zero));
34	}
35
36	/**
37	* A fair SynchronousQueue is both empty and full
38	*/
39	public void testFairEmptyFull() {
40	SynchronousQueue q = new SynchronousQueue(true);
41	assertTrue(q.isEmpty());
42	assertEquals(0, q.size());
43	assertEquals(0, q.remainingCapacity());
44	assertFalse(q.offer(zero));
45	}
46
47	/**
48	* offer(null) throws NPE
49	*/
50	public void testOfferNull() {
51	try {
52	SynchronousQueue q = new SynchronousQueue();
53	q.offer(null);
54	shouldThrow();
55	} catch (NullPointerException success) {}
56	}
57
58	/**
59	* add(null) throws NPE
60	*/
61	public void testAddNull() {
62	try {
63	SynchronousQueue q = new SynchronousQueue();
64	q.add(null);
65	shouldThrow();
66	} catch (NullPointerException success) {}
67	}
68
69	/**
70	* offer fails if no active taker
71	*/
72	public void testOffer() {
73	SynchronousQueue q = new SynchronousQueue();
74	assertFalse(q.offer(one));
75	}
76
77	/**
78	* add throws ISE if no active taker
79	*/
80	public void testAdd() {
81	try {
82	SynchronousQueue q = new SynchronousQueue();
83	assertEquals(0, q.remainingCapacity());
84	q.add(one);
85	shouldThrow();
86	} catch (IllegalStateException success) {}
87	}
88
89	/**
90	* addAll(null) throws NPE
91	*/
92	public void testAddAll1() {
93	try {
94	SynchronousQueue q = new SynchronousQueue();
95	q.addAll(null);
96	shouldThrow();
97	} catch (NullPointerException success) {}
98	}
99
100	/**
101	* addAll(this) throws IAE
102	*/
103	public void testAddAllSelf() {
104	try {
105	SynchronousQueue q = new SynchronousQueue();
106	q.addAll(q);
107	shouldThrow();
108	} catch (IllegalArgumentException success) {}
109	}
110
111	/**
112	* addAll of a collection with null elements throws NPE
113	*/
114	public void testAddAll2() {
115	try {
116	SynchronousQueue q = new SynchronousQueue();
117	Integer[] ints = new Integer[1];
118	q.addAll(Arrays.asList(ints));
119	shouldThrow();
120	} catch (NullPointerException success) {}
121	}
122	/**
123	* addAll throws ISE if no active taker
124	*/
125	public void testAddAll4() {
126	try {
127	SynchronousQueue q = new SynchronousQueue();
128	Integer[] ints = new Integer[1];
129	for (int i = 0; i < 1; ++i)
130	ints[i] = new Integer(i);
131	q.addAll(Arrays.asList(ints));
132	shouldThrow();
133	} catch (IllegalStateException success) {}
134	}
135
136	/**
137	* put(null) throws NPE
138	*/
139	public void testPutNull() throws InterruptedException {
140	try {
141	SynchronousQueue q = new SynchronousQueue();
142	q.put(null);
143	shouldThrow();
144	} catch (NullPointerException success) {}
145	}
146
147	/**
148	* put blocks interruptibly if no active taker
149	*/
150	public void testBlockingPut() throws InterruptedException {
151	Thread t = new Thread(new CheckedInterruptedRunnable() {
152	public void realRun() throws InterruptedException {
153	SynchronousQueue q = new SynchronousQueue();
154	q.put(zero);
155	}});
156
157	t.start();
158	Thread.sleep(SHORT_DELAY_MS);
159	t.interrupt();
160	t.join();
161	}
162
163	/**
164	* put blocks waiting for take
165	*/
166	public void testPutWithTake() throws InterruptedException {
167	final SynchronousQueue q = new SynchronousQueue();
168	Thread t = new Thread(new CheckedRunnable() {
169	public void realRun() throws InterruptedException {
170	int added = 0;
171	try {
172	while (true) {
173	q.put(added);
174	++added;
175	}
176	} catch (InterruptedException success) {
177	assertTrue(added == 1);
178	}
179	}});
180
181	t.start();
182	Thread.sleep(SHORT_DELAY_MS);
183	assertEquals(0, q.take());
184	Thread.sleep(SHORT_DELAY_MS);
185	t.interrupt();
186	t.join();
187	}
188
189	/**
190	* timed offer times out if elements not taken
191	*/
192	public void testTimedOffer() throws InterruptedException {
193	final SynchronousQueue q = new SynchronousQueue();
194	Thread t = new Thread(new CheckedInterruptedRunnable() {
195	public void realRun() throws InterruptedException {
196	assertFalse(q.offer(new Object(), SHORT_DELAY_MS, MILLISECONDS));
197	q.offer(new Object(), LONG_DELAY_MS, MILLISECONDS);
198	}});
199
200	t.start();
201	Thread.sleep(SMALL_DELAY_MS);
202	t.interrupt();
203	t.join();
204	}
205
206
207	/**
208	* take blocks interruptibly when empty
209	*/
210	public void testTakeFromEmpty() throws InterruptedException {
211	final SynchronousQueue q = new SynchronousQueue();
212	Thread t = new Thread(new CheckedInterruptedRunnable() {
213	public void realRun() throws InterruptedException {
214	q.take();
215	}});
216
217	t.start();
218	Thread.sleep(SHORT_DELAY_MS);
219	t.interrupt();
220	t.join();
221	}
222
223
224	/**
225	* put blocks interruptibly if no active taker
226	*/
227	public void testFairBlockingPut() throws InterruptedException {
228	Thread t = new Thread(new CheckedInterruptedRunnable() {
229	public void realRun() throws InterruptedException {
230	SynchronousQueue q = new SynchronousQueue(true);
231	q.put(zero);
232	}});
233
234	t.start();
235	Thread.sleep(SHORT_DELAY_MS);
236	t.interrupt();
237	t.join();
238	}
239
240	/**
241	* put blocks waiting for take
242	*/
243	public void testFairPutWithTake() throws InterruptedException {
244	final SynchronousQueue q = new SynchronousQueue(true);
245	Thread t = new Thread(new CheckedRunnable() {
246	public void realRun() throws InterruptedException {
247	int added = 0;
248	try {
249	while (true) {
250	q.put(added);
251	++added;
252	}
253	} catch (InterruptedException success) {
254	assertTrue(added == 1);
255	}
256	}});
257
258	t.start();
259	Thread.sleep(SHORT_DELAY_MS);
260	assertEquals(0, q.take());
261	Thread.sleep(SHORT_DELAY_MS);
262	t.interrupt();
263	t.join();
264	}
265
266	/**
267	* timed offer times out if elements not taken
268	*/
269	public void testFairTimedOffer() throws InterruptedException {
270	final SynchronousQueue q = new SynchronousQueue(true);
271	Thread t = new Thread(new CheckedInterruptedRunnable() {
272	public void realRun() throws InterruptedException {
273	assertFalse(q.offer(new Object(), SHORT_DELAY_MS, MILLISECONDS));
274	q.offer(new Object(), LONG_DELAY_MS, MILLISECONDS);
275	}});
276
277	t.start();
278	Thread.sleep(SMALL_DELAY_MS);
279	t.interrupt();
280	t.join();
281	}
282
283
284	/**
285	* take blocks interruptibly when empty
286	*/
287	public void testFairTakeFromEmpty() throws InterruptedException {
288	final SynchronousQueue q = new SynchronousQueue(true);
289	Thread t = new Thread(new CheckedInterruptedRunnable() {
290	public void realRun() throws InterruptedException {
291	q.take();
292	}});
293
294	t.start();
295	Thread.sleep(SHORT_DELAY_MS);
296	t.interrupt();
297	t.join();
298	}
299
300	/**
301	* poll fails unless active taker
302	*/
303	public void testPoll() {
304	SynchronousQueue q = new SynchronousQueue();
305	assertNull(q.poll());
306	}
307
308	/**
309	* timed pool with zero timeout times out if no active taker
310	*/
311	public void testTimedPoll0() throws InterruptedException {
312	SynchronousQueue q = new SynchronousQueue();
313	assertNull(q.poll(0, MILLISECONDS));
314	}
315
316	/**
317	* timed pool with nonzero timeout times out if no active taker
318	*/
319	public void testTimedPoll() throws InterruptedException {
320	SynchronousQueue q = new SynchronousQueue();
321	assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
322	}
323
324	/**
325	* Interrupted timed poll throws InterruptedException instead of
326	* returning timeout status
327	*/
328	public void testInterruptedTimedPoll() throws InterruptedException {
329	final SynchronousQueue q = new SynchronousQueue();
330	Thread t = new Thread(new CheckedInterruptedRunnable() {
331	public void realRun() throws InterruptedException {
332	q.poll(SMALL_DELAY_MS, MILLISECONDS);
333	}});
334
335	t.start();
336	Thread.sleep(SHORT_DELAY_MS);
337	t.interrupt();
338	t.join();
339	}
340
341	/**
342	* timed poll before a delayed offer fails; after offer succeeds;
343	* on interruption throws
344	*/
345	public void testTimedPollWithOffer() throws InterruptedException {
346	final SynchronousQueue q = new SynchronousQueue();
347	Thread t = new Thread(new CheckedRunnable() {
348	public void realRun() throws InterruptedException {
349	assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
350	assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
351	try {
352	q.poll(LONG_DELAY_MS, MILLISECONDS);
353	shouldThrow();
354	} catch (InterruptedException success) {}
355	}});
356
357	t.start();
358	Thread.sleep(SMALL_DELAY_MS);
359	assertTrue(q.offer(zero, SHORT_DELAY_MS, MILLISECONDS));
360	t.interrupt();
361	t.join();
362	}
363
364	/**
365	* Interrupted timed poll throws InterruptedException instead of
366	* returning timeout status
367	*/
368	public void testFairInterruptedTimedPoll() throws InterruptedException {
369	Thread t = new Thread(new CheckedInterruptedRunnable() {
370	public void realRun() throws InterruptedException {
371	SynchronousQueue q = new SynchronousQueue(true);
372	q.poll(SMALL_DELAY_MS, MILLISECONDS);
373	}});
374
375	t.start();
376	Thread.sleep(SHORT_DELAY_MS);
377	t.interrupt();
378	t.join();
379	}
380
381	/**
382	* timed poll before a delayed offer fails; after offer succeeds;
383	* on interruption throws
384	*/
385	public void testFairTimedPollWithOffer() throws InterruptedException {
386	final SynchronousQueue q = new SynchronousQueue(true);
387	Thread t = new Thread(new CheckedRunnable() {
388	public void realRun() throws InterruptedException {
389	assertNull(q.poll(SHORT_DELAY_MS, MILLISECONDS));
390	assertSame(zero, q.poll(LONG_DELAY_MS, MILLISECONDS));
391	try {
392	q.poll(LONG_DELAY_MS, MILLISECONDS);
393	threadShouldThrow();
394	} catch (InterruptedException success) {}
395	}});
396
397	t.start();
398	Thread.sleep(SMALL_DELAY_MS);
399	assertTrue(q.offer(zero, SHORT_DELAY_MS, MILLISECONDS));
400	t.interrupt();
401	t.join();
402	}
403
404
405	/**
406	* peek returns null
407	*/
408	public void testPeek() {
409	SynchronousQueue q = new SynchronousQueue();
410	assertNull(q.peek());
411	}
412
413	/**
414	* element throws NSEE
415	*/
416	public void testElement() {
417	SynchronousQueue q = new SynchronousQueue();
418	try {
419	q.element();
420	shouldThrow();
421	} catch (NoSuchElementException success) {}
422	}
423
424	/**
425	* remove throws NSEE if no active taker
426	*/
427	public void testRemove() {
428	SynchronousQueue q = new SynchronousQueue();
429	try {
430	q.remove();
431	shouldThrow();
432	} catch (NoSuchElementException success) {}
433	}
434
435	/**
436	* remove(x) returns false
437	*/
438	public void testRemoveElement() {
439	SynchronousQueue q = new SynchronousQueue();
440	assertFalse(q.remove(zero));
441	assertTrue(q.isEmpty());
442	}
443
444	/**
445	* contains returns false
446	*/
447	public void testContains() {
448	SynchronousQueue q = new SynchronousQueue();
449	assertFalse(q.contains(zero));
450	}
451
452	/**
453	* clear ensures isEmpty
454	*/
455	public void testClear() {
456	SynchronousQueue q = new SynchronousQueue();
457	q.clear();
458	assertTrue(q.isEmpty());
459	}
460
461	/**
462	* containsAll returns false unless empty
463	*/
464	public void testContainsAll() {
465	SynchronousQueue q = new SynchronousQueue();
466	Integer[] empty = new Integer[0];
467	assertTrue(q.containsAll(Arrays.asList(empty)));
468	Integer[] ints = new Integer[1]; ints[0] = zero;
469	assertFalse(q.containsAll(Arrays.asList(ints)));
470	}
471
472	/**
473	* retainAll returns false
474	*/
475	public void testRetainAll() {
476	SynchronousQueue q = new SynchronousQueue();
477	Integer[] empty = new Integer[0];
478	assertFalse(q.retainAll(Arrays.asList(empty)));
479	Integer[] ints = new Integer[1]; ints[0] = zero;
480	assertFalse(q.retainAll(Arrays.asList(ints)));
481	}
482
483	/**
484	* removeAll returns false
485	*/
486	public void testRemoveAll() {
487	SynchronousQueue q = new SynchronousQueue();
488	Integer[] empty = new Integer[0];
489	assertFalse(q.removeAll(Arrays.asList(empty)));
490	Integer[] ints = new Integer[1]; ints[0] = zero;
491	assertFalse(q.containsAll(Arrays.asList(ints)));
492	}
493
494
495	/**
496	* toArray is empty
497	*/
498	public void testToArray() {
499	SynchronousQueue q = new SynchronousQueue();
500	Object[] o = q.toArray();
501	assertEquals(o.length, 0);
502	}
503
504	/**
505	* toArray(a) is nulled at position 0
506	*/
507	public void testToArray2() {
508	SynchronousQueue q = new SynchronousQueue();
509	Integer[] ints = new Integer[1];
510	assertNull(ints[0]);
511	}
512
513	/**
514	* toArray(null) throws NPE
515	*/
516	public void testToArray_BadArg() {
517	SynchronousQueue q = new SynchronousQueue();
518	try {
519	Object o[] = q.toArray(null);
520	shouldThrow();
521	} catch (NullPointerException success) {}
522	}
523
524
525	/**
526	* iterator does not traverse any elements
527	*/
528	public void testIterator() {
529	SynchronousQueue q = new SynchronousQueue();
530	Iterator it = q.iterator();
531	assertFalse(it.hasNext());
532	try {
533	Object x = it.next();
534	shouldThrow();
535	} catch (NoSuchElementException success) {}
536	}
537
538	/**
539	* iterator remove throws ISE
540	*/
541	public void testIteratorRemove() {
542	SynchronousQueue q = new SynchronousQueue();
543	Iterator it = q.iterator();
544	try {
545	it.remove();
546	shouldThrow();
547	} catch (IllegalStateException success) {}
548	}
549
550	/**
551	* toString returns a non-null string
552	*/
553	public void testToString() {
554	SynchronousQueue q = new SynchronousQueue();
555	String s = q.toString();
556	assertNotNull(s);
557	}
558
559
560	/**
561	* offer transfers elements across Executor tasks
562	*/
563	public void testOfferInExecutor() {
564	final SynchronousQueue q = new SynchronousQueue();
565	ExecutorService executor = Executors.newFixedThreadPool(2);
566
567	executor.execute(new CheckedRunnable() {
568	public void realRun() throws InterruptedException {
569	assertFalse(q.offer(one));
570	assertTrue(q.offer(one, MEDIUM_DELAY_MS, MILLISECONDS));
571	assertEquals(0, q.remainingCapacity());
572	}});
573
574	executor.execute(new CheckedRunnable() {
575	public void realRun() throws InterruptedException {
576	Thread.sleep(SMALL_DELAY_MS);
577	assertSame(one, q.take());
578	}});
579
580	joinPool(executor);
581
582	}
583
584	/**
585	* poll retrieves elements across Executor threads
586	*/
587	public void testPollInExecutor() {
588	final SynchronousQueue q = new SynchronousQueue();
589	ExecutorService executor = Executors.newFixedThreadPool(2);
590	executor.execute(new CheckedRunnable() {
591	public void realRun() throws InterruptedException {
592	assertNull(q.poll());
593	assertSame(one, q.poll(MEDIUM_DELAY_MS, MILLISECONDS));
594	assertTrue(q.isEmpty());
595	}});
596
597	executor.execute(new CheckedRunnable() {
598	public void realRun() throws InterruptedException {
599	Thread.sleep(SHORT_DELAY_MS);
600	q.put(one);
601	}});
602
603	joinPool(executor);
604	}
605
606	/**
607	* a deserialized serialized queue is usable
608	*/
609	public void testSerialization() throws Exception {
610	SynchronousQueue q = new SynchronousQueue();
611	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
612	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
613	out.writeObject(q);
614	out.close();
615
616	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
617	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
618	SynchronousQueue r = (SynchronousQueue)in.readObject();
619	assertEquals(q.size(), r.size());
620	while (!q.isEmpty())
621	assertEquals(q.remove(), r.remove());
622	}
623
624	/**
625	* drainTo(null) throws NPE
626	*/
627	public void testDrainToNull() {
628	SynchronousQueue q = new SynchronousQueue();
629	try {
630	q.drainTo(null);
631	shouldThrow();
632	} catch (NullPointerException success) {}
633	}
634
635	/**
636	* drainTo(this) throws IAE
637	*/
638	public void testDrainToSelf() {
639	SynchronousQueue q = new SynchronousQueue();
640	try {
641	q.drainTo(q);
642	shouldThrow();
643	} catch (IllegalArgumentException success) {}
644	}
645
646	/**
647	* drainTo(c) of empty queue doesn't transfer elements
648	*/
649	public void testDrainTo() {
650	SynchronousQueue q = new SynchronousQueue();
651	ArrayList l = new ArrayList();
652	q.drainTo(l);
653	assertEquals(q.size(), 0);
654	assertEquals(l.size(), 0);
655	}
656
657	/**
658	* drainTo empties queue, unblocking a waiting put.
659	*/
660	public void testDrainToWithActivePut() throws InterruptedException {
661	final SynchronousQueue q = new SynchronousQueue();
662	Thread t = new Thread(new CheckedRunnable() {
663	public void realRun() throws InterruptedException {
664	q.put(new Integer(1));
665	}});
666
667	t.start();
668	ArrayList l = new ArrayList();
669	Thread.sleep(SHORT_DELAY_MS);
670	q.drainTo(l);
671	assertTrue(l.size() <= 1);
672	if (l.size() > 0)
673	assertEquals(l.get(0), new Integer(1));
674	t.join();
675	assertTrue(l.size() <= 1);
676	}
677
678	/**
679	* drainTo(null, n) throws NPE
680	*/
681	public void testDrainToNullN() {
682	SynchronousQueue q = new SynchronousQueue();
683	try {
684	q.drainTo(null, 0);
685	shouldThrow();
686	} catch (NullPointerException success) {}
687	}
688
689	/**
690	* drainTo(this, n) throws IAE
691	*/
692	public void testDrainToSelfN() {
693	SynchronousQueue q = new SynchronousQueue();
694	try {
695	q.drainTo(q, 0);
696	shouldThrow();
697	} catch (IllegalArgumentException success) {}
698	}
699
700	/**
701	* drainTo(c, n) empties up to n elements of queue into c
702	*/
703	public void testDrainToN() throws InterruptedException {
704	final SynchronousQueue q = new SynchronousQueue();
705	Thread t1 = new Thread(new CheckedRunnable() {
706	public void realRun() throws InterruptedException {
707	q.put(one);
708	}});
709
710	Thread t2 = new Thread(new CheckedRunnable() {
711	public void realRun() throws InterruptedException {
712	q.put(two);
713	}});
714
715	t1.start();
716	t2.start();
717	ArrayList l = new ArrayList();
718	Thread.sleep(SHORT_DELAY_MS);
719	q.drainTo(l, 1);
720	assertTrue(l.size() == 1);
721	q.drainTo(l, 1);
722	assertTrue(l.size() == 2);
723	assertTrue(l.contains(one));
724	assertTrue(l.contains(two));
725	t1.join();
726	t2.join();
727	}
728
729	}