test/tck/ConcurrentLinkedQueueTest.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 java.io.*;

public class ConcurrentLinkedQueueTest extends JSR166TestCase {

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

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

    /**
     * Create a queue of given size containing consecutive
     * Integers 0 ... n.
     */
    private ConcurrentLinkedQueue populatedQueue(int n) {
        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        assertTrue(q.isEmpty());
        for (int i = 0; i < n; ++i)
            assertTrue(q.offer(new Integer(i)));
        assertFalse(q.isEmpty());
        assertEquals(n, q.size());
        return q;
    }

    /**
     * new queue is empty
     */
    public void testConstructor1() {
        assertEquals(0, new ConcurrentLinkedQueue().size());
    }

    /**
     *  Initializing from null Collection throws NPE
     */
    public void testConstructor3() {
        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue((Collection)null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Initializing from Collection of null elements throws NPE
     */
    public void testConstructor4() {
        try {
            Integer[] ints = new Integer[SIZE];
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Initializing from Collection with some null elements throws NPE
     */
    public void testConstructor5() {
        try {
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new Integer(i);
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements of collection used to initialize
     */
    public void testConstructor6() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = new Integer(i);
        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * isEmpty is true before add, false after
     */
    public void testEmpty() {
        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        assertTrue(q.isEmpty());
        q.add(one);
        assertFalse(q.isEmpty());
        q.add(two);
        q.remove();
        q.remove();
        assertTrue(q.isEmpty());
    }

    /**
     * size changes when elements added and removed
     */
    public void testSize() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(SIZE-i, q.size());
            q.remove();
        }
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            q.add(new Integer(i));
        }
    }

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

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


    /**
     * Offer returns true
     */
    public void testOffer() {
        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        assertTrue(q.offer(zero));
        assertTrue(q.offer(one));
    }

    /**
     * add returns true
     */
    public void testAdd() {
        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            assertTrue(q.add(new Integer(i)));
        }
    }

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

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

    /**
     * addAll of a collection with null elements throws NPE
     */
    public void testAddAll2() {
        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            Integer[] ints = new Integer[SIZE];
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }
    /**
     *  addAll of a collection with any null elements throws NPE after
     * possibly adding some elements
     */
    public void testAddAll3() {
        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new Integer(i);
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements, in traversal order, of successful addAll
     */
    public void testAddAll5() {
        Integer[] empty = new Integer[0];
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = new Integer(i);
        ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        assertFalse(q.addAll(Arrays.asList(empty)));
        assertTrue(q.addAll(Arrays.asList(ints)));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * poll succeeds unless empty
     */
    public void testPoll() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.poll());
        }
        assertNull(q.poll());
    }

    /**
     * peek returns next element, or null if empty
     */
    public void testPeek() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.peek());
            assertEquals(i, q.poll());
            assertTrue(q.peek() == null ||
                       !q.peek().equals(i));
        }
        assertNull(q.peek());
    }

    /**
     * element returns next element, or throws NSEE if empty
     */
    public void testElement() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.element());
            assertEquals(i, q.poll());
        }
        try {
            q.element();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     *  remove removes next element, or throws NSEE if empty
     */
    public void testRemove() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.remove());
        }
        try {
            q.remove();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove(x) removes x and returns true if present
     */
    public void testRemoveElement() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i+=2) {
            assertTrue(q.remove(new Integer(i)));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.remove(new Integer(i)));
            assertFalse(q.remove(new Integer(i+1)));
        }
        assertTrue(q.isEmpty());
    }

    /**
     * contains(x) reports true when elements added but not yet removed
     */
    public void testContains() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.contains(new Integer(i)));
            q.poll();
            assertFalse(q.contains(new Integer(i)));
        }
    }

    /**
     * clear removes all elements
     */
    public void testClear() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        q.clear();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        q.add(one);
        assertFalse(q.isEmpty());
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll(c) is true when c contains a subset of elements
     */
    public void testContainsAll() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.containsAll(p));
            assertFalse(p.containsAll(q));
            p.add(new Integer(i));
        }
        assertTrue(p.containsAll(q));
    }

    /**
     * retainAll(c) retains only those elements of c and reports true if change
     */
    public void testRetainAll() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        ConcurrentLinkedQueue p = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            boolean changed = q.retainAll(p);
            if (i == 0)
                assertFalse(changed);
            else
                assertTrue(changed);

            assertTrue(q.containsAll(p));
            assertEquals(SIZE-i, q.size());
            p.remove();
        }
    }

    /**
     * removeAll(c) removes only those elements of c and reports true if changed
     */
    public void testRemoveAll() {
        for (int i = 1; i < SIZE; ++i) {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            ConcurrentLinkedQueue p = populatedQueue(i);
            assertTrue(q.removeAll(p));
            assertEquals(SIZE-i, q.size());
            for (int j = 0; j < i; ++j) {
                Integer I = (Integer)(p.remove());
                assertFalse(q.contains(I));
            }
        }
    }

    /**
     * toArray contains all elements
     */
    public void testToArray() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        Arrays.sort(o);
        for (int i = 0; i < o.length; i++)
            assertEquals(o[i], q.poll());
    }

    /**
     *  toArray(a) contains all elements
     */
    public void testToArray2() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        ints = (Integer[])q.toArray(ints);
        Arrays.sort(ints);
        for (int i = 0; i < ints.length; i++)
            assertEquals(ints[i], q.poll());
    }

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

    /**
     * toArray with incompatible array type throws ArrayStoreException
     */
    public void testToArray1_BadArg() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        try {
            Object o[] = q.toArray(new String[10]);
            shouldThrow();
        } catch (ArrayStoreException success) {}
    }

    /**
     *  iterator iterates through all elements
     */
    public void testIterator() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        int i = 0;
        Iterator it = q.iterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
    }

    /**
     * iterator ordering is FIFO
     */
    public void testIteratorOrdering() {
        final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        q.add(one);
        q.add(two);
        q.add(three);

        int k = 0;
        for (Iterator it = q.iterator(); it.hasNext();) {
            assertEquals(++k, it.next());
        }

        assertEquals(3, k);
    }

    /**
     * Modifications do not cause iterators to fail
     */
    public void testWeaklyConsistentIteration () {
        final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        q.add(one);
        q.add(two);
        q.add(three);

        for (Iterator it = q.iterator(); it.hasNext();) {
            q.remove();
            it.next();
        }

        assertEquals("queue should be empty again", 0, q.size());
    }

    /**
     * iterator.remove removes current element
     */
    public void testIteratorRemove () {
        final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
        q.add(one);
        q.add(two);
        q.add(three);
        Iterator it = q.iterator();
        it.next();
        it.remove();
        it = q.iterator();
        assertEquals(it.next(), two);
        assertEquals(it.next(), three);
        assertFalse(it.hasNext());
    }


    /**
     * toString contains toStrings of elements
     */
    public void testToString() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        String s = q.toString();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
        }
    }

    /**
     * A deserialized serialized queue has same elements in same order
     */
    public void testSerialization() throws Exception {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        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));
        ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
        assertEquals(q.size(), r.size());
        while (!q.isEmpty())
            assertEquals(q.remove(), r.remove());
    }

}
Revision:	1.16
Committed:	Sun Nov 22 18:57:17 2009 UTC (14 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.15:	+11 -12 lines
Log Message:	use autoboxing judiciously for readability
#	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 java.io.*;
13
14	public class ConcurrentLinkedQueueTest extends JSR166TestCase {
15
16	public static void main(String[] args) {
17	junit.textui.TestRunner.run (suite());
18	}
19
20	public static Test suite() {
21	return new TestSuite(ConcurrentLinkedQueueTest.class);
22	}
23
24	/**
25	* Create a queue of given size containing consecutive
26	* Integers 0 ... n.
27	*/
28	private ConcurrentLinkedQueue populatedQueue(int n) {
29	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
30	assertTrue(q.isEmpty());
31	for (int i = 0; i < n; ++i)
32	assertTrue(q.offer(new Integer(i)));
33	assertFalse(q.isEmpty());
34	assertEquals(n, q.size());
35	return q;
36	}
37
38	/**
39	* new queue is empty
40	*/
41	public void testConstructor1() {
42	assertEquals(0, new ConcurrentLinkedQueue().size());
43	}
44
45	/**
46	* Initializing from null Collection throws NPE
47	*/
48	public void testConstructor3() {
49	try {
50	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue((Collection)null);
51	shouldThrow();
52	} catch (NullPointerException success) {}
53	}
54
55	/**
56	* Initializing from Collection of null elements throws NPE
57	*/
58	public void testConstructor4() {
59	try {
60	Integer[] ints = new Integer[SIZE];
61	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
62	shouldThrow();
63	} catch (NullPointerException success) {}
64	}
65
66	/**
67	* Initializing from Collection with some null elements throws NPE
68	*/
69	public void testConstructor5() {
70	try {
71	Integer[] ints = new Integer[SIZE];
72	for (int i = 0; i < SIZE-1; ++i)
73	ints[i] = new Integer(i);
74	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
75	shouldThrow();
76	} catch (NullPointerException success) {}
77	}
78
79	/**
80	* Queue contains all elements of collection used to initialize
81	*/
82	public void testConstructor6() {
83	Integer[] ints = new Integer[SIZE];
84	for (int i = 0; i < SIZE; ++i)
85	ints[i] = new Integer(i);
86	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
87	for (int i = 0; i < SIZE; ++i)
88	assertEquals(ints[i], q.poll());
89	}
90
91	/**
92	* isEmpty is true before add, false after
93	*/
94	public void testEmpty() {
95	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
96	assertTrue(q.isEmpty());
97	q.add(one);
98	assertFalse(q.isEmpty());
99	q.add(two);
100	q.remove();
101	q.remove();
102	assertTrue(q.isEmpty());
103	}
104
105	/**
106	* size changes when elements added and removed
107	*/
108	public void testSize() {
109	ConcurrentLinkedQueue q = populatedQueue(SIZE);
110	for (int i = 0; i < SIZE; ++i) {
111	assertEquals(SIZE-i, q.size());
112	q.remove();
113	}
114	for (int i = 0; i < SIZE; ++i) {
115	assertEquals(i, q.size());
116	q.add(new Integer(i));
117	}
118	}
119
120	/**
121	* offer(null) throws NPE
122	*/
123	public void testOfferNull() {
124	try {
125	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
126	q.offer(null);
127	shouldThrow();
128	} catch (NullPointerException success) {}
129	}
130
131	/**
132	* add(null) throws NPE
133	*/
134	public void testAddNull() {
135	try {
136	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
137	q.add(null);
138	shouldThrow();
139	} catch (NullPointerException success) {}
140	}
141
142
143	/**
144	* Offer returns true
145	*/
146	public void testOffer() {
147	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
148	assertTrue(q.offer(zero));
149	assertTrue(q.offer(one));
150	}
151
152	/**
153	* add returns true
154	*/
155	public void testAdd() {
156	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
157	for (int i = 0; i < SIZE; ++i) {
158	assertEquals(i, q.size());
159	assertTrue(q.add(new Integer(i)));
160	}
161	}
162
163	/**
164	* addAll(null) throws NPE
165	*/
166	public void testAddAll1() {
167	try {
168	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
169	q.addAll(null);
170	shouldThrow();
171	} catch (NullPointerException success) {}
172	}
173
174	/**
175	* addAll(this) throws IAE
176	*/
177	public void testAddAllSelf() {
178	try {
179	ConcurrentLinkedQueue q = populatedQueue(SIZE);
180	q.addAll(q);
181	shouldThrow();
182	} catch (IllegalArgumentException success) {}
183	}
184
185	/**
186	* addAll of a collection with null elements throws NPE
187	*/
188	public void testAddAll2() {
189	try {
190	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
191	Integer[] ints = new Integer[SIZE];
192	q.addAll(Arrays.asList(ints));
193	shouldThrow();
194	} catch (NullPointerException success) {}
195	}
196	/**
197	* addAll of a collection with any null elements throws NPE after
198	* possibly adding some elements
199	*/
200	public void testAddAll3() {
201	try {
202	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
203	Integer[] ints = new Integer[SIZE];
204	for (int i = 0; i < SIZE-1; ++i)
205	ints[i] = new Integer(i);
206	q.addAll(Arrays.asList(ints));
207	shouldThrow();
208	} catch (NullPointerException success) {}
209	}
210
211	/**
212	* Queue contains all elements, in traversal order, of successful addAll
213	*/
214	public void testAddAll5() {
215	Integer[] empty = new Integer[0];
216	Integer[] ints = new Integer[SIZE];
217	for (int i = 0; i < SIZE; ++i)
218	ints[i] = new Integer(i);
219	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
220	assertFalse(q.addAll(Arrays.asList(empty)));
221	assertTrue(q.addAll(Arrays.asList(ints)));
222	for (int i = 0; i < SIZE; ++i)
223	assertEquals(ints[i], q.poll());
224	}
225
226	/**
227	* poll succeeds unless empty
228	*/
229	public void testPoll() {
230	ConcurrentLinkedQueue q = populatedQueue(SIZE);
231	for (int i = 0; i < SIZE; ++i) {
232	assertEquals(i, q.poll());
233	}
234	assertNull(q.poll());
235	}
236
237	/**
238	* peek returns next element, or null if empty
239	*/
240	public void testPeek() {
241	ConcurrentLinkedQueue q = populatedQueue(SIZE);
242	for (int i = 0; i < SIZE; ++i) {
243	assertEquals(i, q.peek());
244	assertEquals(i, q.poll());
245	assertTrue(q.peek() == null \|\|
246	!q.peek().equals(i));
247	}
248	assertNull(q.peek());
249	}
250
251	/**
252	* element returns next element, or throws NSEE if empty
253	*/
254	public void testElement() {
255	ConcurrentLinkedQueue q = populatedQueue(SIZE);
256	for (int i = 0; i < SIZE; ++i) {
257	assertEquals(i, q.element());
258	assertEquals(i, q.poll());
259	}
260	try {
261	q.element();
262	shouldThrow();
263	} catch (NoSuchElementException success) {}
264	}
265
266	/**
267	* remove removes next element, or throws NSEE if empty
268	*/
269	public void testRemove() {
270	ConcurrentLinkedQueue q = populatedQueue(SIZE);
271	for (int i = 0; i < SIZE; ++i) {
272	assertEquals(i, q.remove());
273	}
274	try {
275	q.remove();
276	shouldThrow();
277	} catch (NoSuchElementException success) {}
278	}
279
280	/**
281	* remove(x) removes x and returns true if present
282	*/
283	public void testRemoveElement() {
284	ConcurrentLinkedQueue q = populatedQueue(SIZE);
285	for (int i = 1; i < SIZE; i+=2) {
286	assertTrue(q.remove(new Integer(i)));
287	}
288	for (int i = 0; i < SIZE; i+=2) {
289	assertTrue(q.remove(new Integer(i)));
290	assertFalse(q.remove(new Integer(i+1)));
291	}
292	assertTrue(q.isEmpty());
293	}
294
295	/**
296	* contains(x) reports true when elements added but not yet removed
297	*/
298	public void testContains() {
299	ConcurrentLinkedQueue q = populatedQueue(SIZE);
300	for (int i = 0; i < SIZE; ++i) {
301	assertTrue(q.contains(new Integer(i)));
302	q.poll();
303	assertFalse(q.contains(new Integer(i)));
304	}
305	}
306
307	/**
308	* clear removes all elements
309	*/
310	public void testClear() {
311	ConcurrentLinkedQueue q = populatedQueue(SIZE);
312	q.clear();
313	assertTrue(q.isEmpty());
314	assertEquals(0, q.size());
315	q.add(one);
316	assertFalse(q.isEmpty());
317	q.clear();
318	assertTrue(q.isEmpty());
319	}
320
321	/**
322	* containsAll(c) is true when c contains a subset of elements
323	*/
324	public void testContainsAll() {
325	ConcurrentLinkedQueue q = populatedQueue(SIZE);
326	ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
327	for (int i = 0; i < SIZE; ++i) {
328	assertTrue(q.containsAll(p));
329	assertFalse(p.containsAll(q));
330	p.add(new Integer(i));
331	}
332	assertTrue(p.containsAll(q));
333	}
334
335	/**
336	* retainAll(c) retains only those elements of c and reports true if change
337	*/
338	public void testRetainAll() {
339	ConcurrentLinkedQueue q = populatedQueue(SIZE);
340	ConcurrentLinkedQueue p = populatedQueue(SIZE);
341	for (int i = 0; i < SIZE; ++i) {
342	boolean changed = q.retainAll(p);
343	if (i == 0)
344	assertFalse(changed);
345	else
346	assertTrue(changed);
347
348	assertTrue(q.containsAll(p));
349	assertEquals(SIZE-i, q.size());
350	p.remove();
351	}
352	}
353
354	/**
355	* removeAll(c) removes only those elements of c and reports true if changed
356	*/
357	public void testRemoveAll() {
358	for (int i = 1; i < SIZE; ++i) {
359	ConcurrentLinkedQueue q = populatedQueue(SIZE);
360	ConcurrentLinkedQueue p = populatedQueue(i);
361	assertTrue(q.removeAll(p));
362	assertEquals(SIZE-i, q.size());
363	for (int j = 0; j < i; ++j) {
364	Integer I = (Integer)(p.remove());
365	assertFalse(q.contains(I));
366	}
367	}
368	}
369
370	/**
371	* toArray contains all elements
372	*/
373	public void testToArray() {
374	ConcurrentLinkedQueue q = populatedQueue(SIZE);
375	Object[] o = q.toArray();
376	Arrays.sort(o);
377	for (int i = 0; i < o.length; i++)
378	assertEquals(o[i], q.poll());
379	}
380
381	/**
382	* toArray(a) contains all elements
383	*/
384	public void testToArray2() {
385	ConcurrentLinkedQueue q = populatedQueue(SIZE);
386	Integer[] ints = new Integer[SIZE];
387	ints = (Integer[])q.toArray(ints);
388	Arrays.sort(ints);
389	for (int i = 0; i < ints.length; i++)
390	assertEquals(ints[i], q.poll());
391	}
392
393	/**
394	* toArray(null) throws NPE
395	*/
396	public void testToArray_BadArg() {
397	ConcurrentLinkedQueue q = populatedQueue(SIZE);
398	try {
399	Object o[] = q.toArray(null);
400	shouldThrow();
401	} catch (NullPointerException success) {}
402	}
403
404	/**
405	* toArray with incompatible array type throws ArrayStoreException
406	*/
407	public void testToArray1_BadArg() {
408	ConcurrentLinkedQueue q = populatedQueue(SIZE);
409	try {
410	Object o[] = q.toArray(new String[10]);
411	shouldThrow();
412	} catch (ArrayStoreException success) {}
413	}
414
415	/**
416	* iterator iterates through all elements
417	*/
418	public void testIterator() {
419	ConcurrentLinkedQueue q = populatedQueue(SIZE);
420	int i = 0;
421	Iterator it = q.iterator();
422	while (it.hasNext()) {
423	assertTrue(q.contains(it.next()));
424	++i;
425	}
426	assertEquals(i, SIZE);
427	}
428
429	/**
430	* iterator ordering is FIFO
431	*/
432	public void testIteratorOrdering() {
433	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
434	q.add(one);
435	q.add(two);
436	q.add(three);
437
438	int k = 0;
439	for (Iterator it = q.iterator(); it.hasNext();) {
440	assertEquals(++k, it.next());
441	}
442
443	assertEquals(3, k);
444	}
445
446	/**
447	* Modifications do not cause iterators to fail
448	*/
449	public void testWeaklyConsistentIteration () {
450	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
451	q.add(one);
452	q.add(two);
453	q.add(three);
454
455	for (Iterator it = q.iterator(); it.hasNext();) {
456	q.remove();
457	it.next();
458	}
459
460	assertEquals("queue should be empty again", 0, q.size());
461	}
462
463	/**
464	* iterator.remove removes current element
465	*/
466	public void testIteratorRemove () {
467	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
468	q.add(one);
469	q.add(two);
470	q.add(three);
471	Iterator it = q.iterator();
472	it.next();
473	it.remove();
474	it = q.iterator();
475	assertEquals(it.next(), two);
476	assertEquals(it.next(), three);
477	assertFalse(it.hasNext());
478	}
479
480
481	/**
482	* toString contains toStrings of elements
483	*/
484	public void testToString() {
485	ConcurrentLinkedQueue q = populatedQueue(SIZE);
486	String s = q.toString();
487	for (int i = 0; i < SIZE; ++i) {
488	assertTrue(s.indexOf(String.valueOf(i)) >= 0);
489	}
490	}
491
492	/**
493	* A deserialized serialized queue has same elements in same order
494	*/
495	public void testSerialization() throws Exception {
496	ConcurrentLinkedQueue q = populatedQueue(SIZE);
497	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
498	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
499	out.writeObject(q);
500	out.close();
501
502	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
503	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
504	ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
505	assertEquals(q.size(), r.size());
506	while (!q.isEmpty())
507	assertEquals(q.remove(), r.remove());
508	}
509
510	}