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/publicdomain/zero/1.0/
 * 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<Integer> populatedQueue(int n) {
        ConcurrentLinkedQueue<Integer> q = new ConcurrentLinkedQueue<Integer>();
        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.contains(i));
            assertTrue(q.remove(i));
            assertFalse(q.contains(i));
            assertTrue(q.contains(i-1));
        }
        for (int i = 0; i < SIZE; i+=2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove(i));
            assertFalse(q.contains(i));
            assertFalse(q.remove(i+1));
            assertFalse(q.contains(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 in FIFO order
     */
    public void testToArray() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        for (int i = 0; i < o.length; i++)
            assertSame(o[i], q.poll());
    }

    /**
     * toArray(a) contains all elements in FIFO order
     */
    public void testToArray2() {
        ConcurrentLinkedQueue<Integer> q = populatedQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        Integer[] array = q.toArray(ints);
        assertSame(ints, array);
        for (int i = 0; i < ints.length; i++)
            assertSame(ints[i], q.poll());
    }

    /**
     * toArray(null) throws NullPointerException
     */
    public void testToArray_NullArg() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        try {
            q.toArray(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * toArray(incompatible array type) throws ArrayStoreException
     */
    public void testToArray1_BadArg() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        try {
            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();
        assertSame(it.next(), two);
        assertSame(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:	1.25
Committed:	Tue Mar 15 19:47:06 2011 UTC (13 years, 2 months ago) by jsr166
Branch:	MAIN
CVS Tags:	release-1_7_0
Changes since 1.24:	+1 -1 lines
Log Message:	Update Creative Commons license URL in legal notices
#	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 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<Integer> populatedQueue(int n) {
29	ConcurrentLinkedQueue<Integer> q = new ConcurrentLinkedQueue<Integer>();
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	/**
198	* addAll of a collection with any null elements throws NPE after
199	* possibly adding some elements
200	*/
201	public void testAddAll3() {
202	try {
203	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
204	Integer[] ints = new Integer[SIZE];
205	for (int i = 0; i < SIZE-1; ++i)
206	ints[i] = new Integer(i);
207	q.addAll(Arrays.asList(ints));
208	shouldThrow();
209	} catch (NullPointerException success) {}
210	}
211
212	/**
213	* Queue contains all elements, in traversal order, of successful addAll
214	*/
215	public void testAddAll5() {
216	Integer[] empty = new Integer[0];
217	Integer[] ints = new Integer[SIZE];
218	for (int i = 0; i < SIZE; ++i)
219	ints[i] = new Integer(i);
220	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
221	assertFalse(q.addAll(Arrays.asList(empty)));
222	assertTrue(q.addAll(Arrays.asList(ints)));
223	for (int i = 0; i < SIZE; ++i)
224	assertEquals(ints[i], q.poll());
225	}
226
227	/**
228	* poll succeeds unless empty
229	*/
230	public void testPoll() {
231	ConcurrentLinkedQueue q = populatedQueue(SIZE);
232	for (int i = 0; i < SIZE; ++i) {
233	assertEquals(i, q.poll());
234	}
235	assertNull(q.poll());
236	}
237
238	/**
239	* peek returns next element, or null if empty
240	*/
241	public void testPeek() {
242	ConcurrentLinkedQueue q = populatedQueue(SIZE);
243	for (int i = 0; i < SIZE; ++i) {
244	assertEquals(i, q.peek());
245	assertEquals(i, q.poll());
246	assertTrue(q.peek() == null \|\|
247	!q.peek().equals(i));
248	}
249	assertNull(q.peek());
250	}
251
252	/**
253	* element returns next element, or throws NSEE if empty
254	*/
255	public void testElement() {
256	ConcurrentLinkedQueue q = populatedQueue(SIZE);
257	for (int i = 0; i < SIZE; ++i) {
258	assertEquals(i, q.element());
259	assertEquals(i, q.poll());
260	}
261	try {
262	q.element();
263	shouldThrow();
264	} catch (NoSuchElementException success) {}
265	}
266
267	/**
268	* remove removes next element, or throws NSEE if empty
269	*/
270	public void testRemove() {
271	ConcurrentLinkedQueue q = populatedQueue(SIZE);
272	for (int i = 0; i < SIZE; ++i) {
273	assertEquals(i, q.remove());
274	}
275	try {
276	q.remove();
277	shouldThrow();
278	} catch (NoSuchElementException success) {}
279	}
280
281	/**
282	* remove(x) removes x and returns true if present
283	*/
284	public void testRemoveElement() {
285	ConcurrentLinkedQueue q = populatedQueue(SIZE);
286	for (int i = 1; i < SIZE; i+=2) {
287	assertTrue(q.contains(i));
288	assertTrue(q.remove(i));
289	assertFalse(q.contains(i));
290	assertTrue(q.contains(i-1));
291	}
292	for (int i = 0; i < SIZE; i+=2) {
293	assertTrue(q.contains(i));
294	assertTrue(q.remove(i));
295	assertFalse(q.contains(i));
296	assertFalse(q.remove(i+1));
297	assertFalse(q.contains(i+1));
298	}
299	assertTrue(q.isEmpty());
300	}
301
302	/**
303	* contains(x) reports true when elements added but not yet removed
304	*/
305	public void testContains() {
306	ConcurrentLinkedQueue q = populatedQueue(SIZE);
307	for (int i = 0; i < SIZE; ++i) {
308	assertTrue(q.contains(new Integer(i)));
309	q.poll();
310	assertFalse(q.contains(new Integer(i)));
311	}
312	}
313
314	/**
315	* clear removes all elements
316	*/
317	public void testClear() {
318	ConcurrentLinkedQueue q = populatedQueue(SIZE);
319	q.clear();
320	assertTrue(q.isEmpty());
321	assertEquals(0, q.size());
322	q.add(one);
323	assertFalse(q.isEmpty());
324	q.clear();
325	assertTrue(q.isEmpty());
326	}
327
328	/**
329	* containsAll(c) is true when c contains a subset of elements
330	*/
331	public void testContainsAll() {
332	ConcurrentLinkedQueue q = populatedQueue(SIZE);
333	ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
334	for (int i = 0; i < SIZE; ++i) {
335	assertTrue(q.containsAll(p));
336	assertFalse(p.containsAll(q));
337	p.add(new Integer(i));
338	}
339	assertTrue(p.containsAll(q));
340	}
341
342	/**
343	* retainAll(c) retains only those elements of c and reports true if change
344	*/
345	public void testRetainAll() {
346	ConcurrentLinkedQueue q = populatedQueue(SIZE);
347	ConcurrentLinkedQueue p = populatedQueue(SIZE);
348	for (int i = 0; i < SIZE; ++i) {
349	boolean changed = q.retainAll(p);
350	if (i == 0)
351	assertFalse(changed);
352	else
353	assertTrue(changed);
354
355	assertTrue(q.containsAll(p));
356	assertEquals(SIZE-i, q.size());
357	p.remove();
358	}
359	}
360
361	/**
362	* removeAll(c) removes only those elements of c and reports true if changed
363	*/
364	public void testRemoveAll() {
365	for (int i = 1; i < SIZE; ++i) {
366	ConcurrentLinkedQueue q = populatedQueue(SIZE);
367	ConcurrentLinkedQueue p = populatedQueue(i);
368	assertTrue(q.removeAll(p));
369	assertEquals(SIZE-i, q.size());
370	for (int j = 0; j < i; ++j) {
371	Integer I = (Integer)(p.remove());
372	assertFalse(q.contains(I));
373	}
374	}
375	}
376
377	/**
378	* toArray contains all elements in FIFO order
379	*/
380	public void testToArray() {
381	ConcurrentLinkedQueue q = populatedQueue(SIZE);
382	Object[] o = q.toArray();
383	for (int i = 0; i < o.length; i++)
384	assertSame(o[i], q.poll());
385	}
386
387	/**
388	* toArray(a) contains all elements in FIFO order
389	*/
390	public void testToArray2() {
391	ConcurrentLinkedQueue<Integer> q = populatedQueue(SIZE);
392	Integer[] ints = new Integer[SIZE];
393	Integer[] array = q.toArray(ints);
394	assertSame(ints, array);
395	for (int i = 0; i < ints.length; i++)
396	assertSame(ints[i], q.poll());
397	}
398
399	/**
400	* toArray(null) throws NullPointerException
401	*/
402	public void testToArray_NullArg() {
403	ConcurrentLinkedQueue q = populatedQueue(SIZE);
404	try {
405	q.toArray(null);
406	shouldThrow();
407	} catch (NullPointerException success) {}
408	}
409
410	/**
411	* toArray(incompatible array type) throws ArrayStoreException
412	*/
413	public void testToArray1_BadArg() {
414	ConcurrentLinkedQueue q = populatedQueue(SIZE);
415	try {
416	q.toArray(new String[10]);
417	shouldThrow();
418	} catch (ArrayStoreException success) {}
419	}
420
421	/**
422	* iterator iterates through all elements
423	*/
424	public void testIterator() {
425	ConcurrentLinkedQueue q = populatedQueue(SIZE);
426	int i = 0;
427	Iterator it = q.iterator();
428	while (it.hasNext()) {
429	assertTrue(q.contains(it.next()));
430	++i;
431	}
432	assertEquals(i, SIZE);
433	}
434
435	/**
436	* iterator ordering is FIFO
437	*/
438	public void testIteratorOrdering() {
439	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
440	q.add(one);
441	q.add(two);
442	q.add(three);
443
444	int k = 0;
445	for (Iterator it = q.iterator(); it.hasNext();) {
446	assertEquals(++k, it.next());
447	}
448
449	assertEquals(3, k);
450	}
451
452	/**
453	* Modifications do not cause iterators to fail
454	*/
455	public void testWeaklyConsistentIteration() {
456	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
457	q.add(one);
458	q.add(two);
459	q.add(three);
460
461	for (Iterator it = q.iterator(); it.hasNext();) {
462	q.remove();
463	it.next();
464	}
465
466	assertEquals("queue should be empty again", 0, q.size());
467	}
468
469	/**
470	* iterator.remove removes current element
471	*/
472	public void testIteratorRemove() {
473	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
474	q.add(one);
475	q.add(two);
476	q.add(three);
477	Iterator it = q.iterator();
478	it.next();
479	it.remove();
480	it = q.iterator();
481	assertSame(it.next(), two);
482	assertSame(it.next(), three);
483	assertFalse(it.hasNext());
484	}
485
486
487	/**
488	* toString contains toStrings of elements
489	*/
490	public void testToString() {
491	ConcurrentLinkedQueue q = populatedQueue(SIZE);
492	String s = q.toString();
493	for (int i = 0; i < SIZE; ++i) {
494	assertTrue(s.indexOf(String.valueOf(i)) >= 0);
495	}
496	}
497
498	/**
499	* A deserialized serialized queue has same elements in same order
500	*/
501	public void testSerialization() throws Exception {
502	ConcurrentLinkedQueue q = populatedQueue(SIZE);
503	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
504	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
505	out.writeObject(q);
506	out.close();
507
508	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
509	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
510	ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
511	assertEquals(q.size(), r.size());
512	while (!q.isEmpty())
513	assertEquals(q.remove(), r.remove());
514	}
515
516	}