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.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

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);
    }

    /**
     * Creates 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.contains(String.valueOf(i)));
        }
    }

    /**
     * A deserialized serialized queue has same elements in same order
     */
    public void testSerialization() throws Exception {
        Queue x = populatedQueue(SIZE);
        Queue y = serialClone(x);

        assertTrue(x != y);
        assertEquals(x.size(), y.size());
        assertEquals(x.toString(), y.toString());
        assertTrue(Arrays.equals(x.toArray(), y.toArray()));
        while (!x.isEmpty()) {
            assertFalse(y.isEmpty());
            assertEquals(x.remove(), y.remove());
        }
        assertTrue(y.isEmpty());
    }

}
Revision:	1.28
Committed:	Tue Feb 21 01:54:03 2012 UTC (12 years, 2 months ago) by jsr166
Branch:	MAIN
Changes since 1.27:	+1 -1 lines
Log Message:	use third person in javadoc first sentence
#	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.Arrays;
11	import java.util.Collection;
12	import java.util.Iterator;
13	import java.util.NoSuchElementException;
14	import java.util.Queue;
15	import java.util.concurrent.ConcurrentLinkedQueue;
16
17	public class ConcurrentLinkedQueueTest extends JSR166TestCase {
18
19	public static void main(String[] args) {
20	junit.textui.TestRunner.run(suite());
21	}
22
23	public static Test suite() {
24	return new TestSuite(ConcurrentLinkedQueueTest.class);
25	}
26
27	/**
28	* Creates a queue of given size containing consecutive
29	* Integers 0 ... n.
30	*/
31	private ConcurrentLinkedQueue<Integer> populatedQueue(int n) {
32	ConcurrentLinkedQueue<Integer> q = new ConcurrentLinkedQueue<Integer>();
33	assertTrue(q.isEmpty());
34	for (int i = 0; i < n; ++i)
35	assertTrue(q.offer(new Integer(i)));
36	assertFalse(q.isEmpty());
37	assertEquals(n, q.size());
38	return q;
39	}
40
41	/**
42	* new queue is empty
43	*/
44	public void testConstructor1() {
45	assertEquals(0, new ConcurrentLinkedQueue().size());
46	}
47
48	/**
49	* Initializing from null Collection throws NPE
50	*/
51	public void testConstructor3() {
52	try {
53	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue((Collection)null);
54	shouldThrow();
55	} catch (NullPointerException success) {}
56	}
57
58	/**
59	* Initializing from Collection of null elements throws NPE
60	*/
61	public void testConstructor4() {
62	try {
63	Integer[] ints = new Integer[SIZE];
64	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
65	shouldThrow();
66	} catch (NullPointerException success) {}
67	}
68
69	/**
70	* Initializing from Collection with some null elements throws NPE
71	*/
72	public void testConstructor5() {
73	try {
74	Integer[] ints = new Integer[SIZE];
75	for (int i = 0; i < SIZE-1; ++i)
76	ints[i] = new Integer(i);
77	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
78	shouldThrow();
79	} catch (NullPointerException success) {}
80	}
81
82	/**
83	* Queue contains all elements of collection used to initialize
84	*/
85	public void testConstructor6() {
86	Integer[] ints = new Integer[SIZE];
87	for (int i = 0; i < SIZE; ++i)
88	ints[i] = new Integer(i);
89	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
90	for (int i = 0; i < SIZE; ++i)
91	assertEquals(ints[i], q.poll());
92	}
93
94	/**
95	* isEmpty is true before add, false after
96	*/
97	public void testEmpty() {
98	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
99	assertTrue(q.isEmpty());
100	q.add(one);
101	assertFalse(q.isEmpty());
102	q.add(two);
103	q.remove();
104	q.remove();
105	assertTrue(q.isEmpty());
106	}
107
108	/**
109	* size changes when elements added and removed
110	*/
111	public void testSize() {
112	ConcurrentLinkedQueue q = populatedQueue(SIZE);
113	for (int i = 0; i < SIZE; ++i) {
114	assertEquals(SIZE-i, q.size());
115	q.remove();
116	}
117	for (int i = 0; i < SIZE; ++i) {
118	assertEquals(i, q.size());
119	q.add(new Integer(i));
120	}
121	}
122
123	/**
124	* offer(null) throws NPE
125	*/
126	public void testOfferNull() {
127	try {
128	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
129	q.offer(null);
130	shouldThrow();
131	} catch (NullPointerException success) {}
132	}
133
134	/**
135	* add(null) throws NPE
136	*/
137	public void testAddNull() {
138	try {
139	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
140	q.add(null);
141	shouldThrow();
142	} catch (NullPointerException success) {}
143	}
144
145	/**
146	* Offer returns true
147	*/
148	public void testOffer() {
149	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
150	assertTrue(q.offer(zero));
151	assertTrue(q.offer(one));
152	}
153
154	/**
155	* add returns true
156	*/
157	public void testAdd() {
158	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
159	for (int i = 0; i < SIZE; ++i) {
160	assertEquals(i, q.size());
161	assertTrue(q.add(new Integer(i)));
162	}
163	}
164
165	/**
166	* addAll(null) throws NPE
167	*/
168	public void testAddAll1() {
169	try {
170	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
171	q.addAll(null);
172	shouldThrow();
173	} catch (NullPointerException success) {}
174	}
175
176	/**
177	* addAll(this) throws IAE
178	*/
179	public void testAddAllSelf() {
180	try {
181	ConcurrentLinkedQueue q = populatedQueue(SIZE);
182	q.addAll(q);
183	shouldThrow();
184	} catch (IllegalArgumentException success) {}
185	}
186
187	/**
188	* addAll of a collection with null elements throws NPE
189	*/
190	public void testAddAll2() {
191	try {
192	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
193	Integer[] ints = new Integer[SIZE];
194	q.addAll(Arrays.asList(ints));
195	shouldThrow();
196	} catch (NullPointerException success) {}
197	}
198
199	/**
200	* addAll of a collection with any null elements throws NPE after
201	* possibly adding some elements
202	*/
203	public void testAddAll3() {
204	try {
205	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
206	Integer[] ints = new Integer[SIZE];
207	for (int i = 0; i < SIZE-1; ++i)
208	ints[i] = new Integer(i);
209	q.addAll(Arrays.asList(ints));
210	shouldThrow();
211	} catch (NullPointerException success) {}
212	}
213
214	/**
215	* Queue contains all elements, in traversal order, of successful addAll
216	*/
217	public void testAddAll5() {
218	Integer[] empty = new Integer[0];
219	Integer[] ints = new Integer[SIZE];
220	for (int i = 0; i < SIZE; ++i)
221	ints[i] = new Integer(i);
222	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
223	assertFalse(q.addAll(Arrays.asList(empty)));
224	assertTrue(q.addAll(Arrays.asList(ints)));
225	for (int i = 0; i < SIZE; ++i)
226	assertEquals(ints[i], q.poll());
227	}
228
229	/**
230	* poll succeeds unless empty
231	*/
232	public void testPoll() {
233	ConcurrentLinkedQueue q = populatedQueue(SIZE);
234	for (int i = 0; i < SIZE; ++i) {
235	assertEquals(i, q.poll());
236	}
237	assertNull(q.poll());
238	}
239
240	/**
241	* peek returns next element, or null if empty
242	*/
243	public void testPeek() {
244	ConcurrentLinkedQueue q = populatedQueue(SIZE);
245	for (int i = 0; i < SIZE; ++i) {
246	assertEquals(i, q.peek());
247	assertEquals(i, q.poll());
248	assertTrue(q.peek() == null \|\|
249	!q.peek().equals(i));
250	}
251	assertNull(q.peek());
252	}
253
254	/**
255	* element returns next element, or throws NSEE if empty
256	*/
257	public void testElement() {
258	ConcurrentLinkedQueue q = populatedQueue(SIZE);
259	for (int i = 0; i < SIZE; ++i) {
260	assertEquals(i, q.element());
261	assertEquals(i, q.poll());
262	}
263	try {
264	q.element();
265	shouldThrow();
266	} catch (NoSuchElementException success) {}
267	}
268
269	/**
270	* remove removes next element, or throws NSEE if empty
271	*/
272	public void testRemove() {
273	ConcurrentLinkedQueue q = populatedQueue(SIZE);
274	for (int i = 0; i < SIZE; ++i) {
275	assertEquals(i, q.remove());
276	}
277	try {
278	q.remove();
279	shouldThrow();
280	} catch (NoSuchElementException success) {}
281	}
282
283	/**
284	* remove(x) removes x and returns true if present
285	*/
286	public void testRemoveElement() {
287	ConcurrentLinkedQueue q = populatedQueue(SIZE);
288	for (int i = 1; i < SIZE; i+=2) {
289	assertTrue(q.contains(i));
290	assertTrue(q.remove(i));
291	assertFalse(q.contains(i));
292	assertTrue(q.contains(i-1));
293	}
294	for (int i = 0; i < SIZE; i+=2) {
295	assertTrue(q.contains(i));
296	assertTrue(q.remove(i));
297	assertFalse(q.contains(i));
298	assertFalse(q.remove(i+1));
299	assertFalse(q.contains(i+1));
300	}
301	assertTrue(q.isEmpty());
302	}
303
304	/**
305	* contains(x) reports true when elements added but not yet removed
306	*/
307	public void testContains() {
308	ConcurrentLinkedQueue q = populatedQueue(SIZE);
309	for (int i = 0; i < SIZE; ++i) {
310	assertTrue(q.contains(new Integer(i)));
311	q.poll();
312	assertFalse(q.contains(new Integer(i)));
313	}
314	}
315
316	/**
317	* clear removes all elements
318	*/
319	public void testClear() {
320	ConcurrentLinkedQueue q = populatedQueue(SIZE);
321	q.clear();
322	assertTrue(q.isEmpty());
323	assertEquals(0, q.size());
324	q.add(one);
325	assertFalse(q.isEmpty());
326	q.clear();
327	assertTrue(q.isEmpty());
328	}
329
330	/**
331	* containsAll(c) is true when c contains a subset of elements
332	*/
333	public void testContainsAll() {
334	ConcurrentLinkedQueue q = populatedQueue(SIZE);
335	ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
336	for (int i = 0; i < SIZE; ++i) {
337	assertTrue(q.containsAll(p));
338	assertFalse(p.containsAll(q));
339	p.add(new Integer(i));
340	}
341	assertTrue(p.containsAll(q));
342	}
343
344	/**
345	* retainAll(c) retains only those elements of c and reports true if change
346	*/
347	public void testRetainAll() {
348	ConcurrentLinkedQueue q = populatedQueue(SIZE);
349	ConcurrentLinkedQueue p = populatedQueue(SIZE);
350	for (int i = 0; i < SIZE; ++i) {
351	boolean changed = q.retainAll(p);
352	if (i == 0)
353	assertFalse(changed);
354	else
355	assertTrue(changed);
356
357	assertTrue(q.containsAll(p));
358	assertEquals(SIZE-i, q.size());
359	p.remove();
360	}
361	}
362
363	/**
364	* removeAll(c) removes only those elements of c and reports true if changed
365	*/
366	public void testRemoveAll() {
367	for (int i = 1; i < SIZE; ++i) {
368	ConcurrentLinkedQueue q = populatedQueue(SIZE);
369	ConcurrentLinkedQueue p = populatedQueue(i);
370	assertTrue(q.removeAll(p));
371	assertEquals(SIZE-i, q.size());
372	for (int j = 0; j < i; ++j) {
373	Integer I = (Integer)(p.remove());
374	assertFalse(q.contains(I));
375	}
376	}
377	}
378
379	/**
380	* toArray contains all elements in FIFO order
381	*/
382	public void testToArray() {
383	ConcurrentLinkedQueue q = populatedQueue(SIZE);
384	Object[] o = q.toArray();
385	for (int i = 0; i < o.length; i++)
386	assertSame(o[i], q.poll());
387	}
388
389	/**
390	* toArray(a) contains all elements in FIFO order
391	*/
392	public void testToArray2() {
393	ConcurrentLinkedQueue<Integer> q = populatedQueue(SIZE);
394	Integer[] ints = new Integer[SIZE];
395	Integer[] array = q.toArray(ints);
396	assertSame(ints, array);
397	for (int i = 0; i < ints.length; i++)
398	assertSame(ints[i], q.poll());
399	}
400
401	/**
402	* toArray(null) throws NullPointerException
403	*/
404	public void testToArray_NullArg() {
405	ConcurrentLinkedQueue q = populatedQueue(SIZE);
406	try {
407	q.toArray(null);
408	shouldThrow();
409	} catch (NullPointerException success) {}
410	}
411
412	/**
413	* toArray(incompatible array type) throws ArrayStoreException
414	*/
415	public void testToArray1_BadArg() {
416	ConcurrentLinkedQueue q = populatedQueue(SIZE);
417	try {
418	q.toArray(new String[10]);
419	shouldThrow();
420	} catch (ArrayStoreException success) {}
421	}
422
423	/**
424	* iterator iterates through all elements
425	*/
426	public void testIterator() {
427	ConcurrentLinkedQueue q = populatedQueue(SIZE);
428	int i = 0;
429	Iterator it = q.iterator();
430	while (it.hasNext()) {
431	assertTrue(q.contains(it.next()));
432	++i;
433	}
434	assertEquals(i, SIZE);
435	}
436
437	/**
438	* iterator ordering is FIFO
439	*/
440	public void testIteratorOrdering() {
441	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
442	q.add(one);
443	q.add(two);
444	q.add(three);
445
446	int k = 0;
447	for (Iterator it = q.iterator(); it.hasNext();) {
448	assertEquals(++k, it.next());
449	}
450
451	assertEquals(3, k);
452	}
453
454	/**
455	* Modifications do not cause iterators to fail
456	*/
457	public void testWeaklyConsistentIteration() {
458	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
459	q.add(one);
460	q.add(two);
461	q.add(three);
462
463	for (Iterator it = q.iterator(); it.hasNext();) {
464	q.remove();
465	it.next();
466	}
467
468	assertEquals("queue should be empty again", 0, q.size());
469	}
470
471	/**
472	* iterator.remove removes current element
473	*/
474	public void testIteratorRemove() {
475	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
476	q.add(one);
477	q.add(two);
478	q.add(three);
479	Iterator it = q.iterator();
480	it.next();
481	it.remove();
482	it = q.iterator();
483	assertSame(it.next(), two);
484	assertSame(it.next(), three);
485	assertFalse(it.hasNext());
486	}
487
488	/**
489	* toString contains toStrings of elements
490	*/
491	public void testToString() {
492	ConcurrentLinkedQueue q = populatedQueue(SIZE);
493	String s = q.toString();
494	for (int i = 0; i < SIZE; ++i) {
495	assertTrue(s.contains(String.valueOf(i)));
496	}
497	}
498
499	/**
500	* A deserialized serialized queue has same elements in same order
501	*/
502	public void testSerialization() throws Exception {
503	Queue x = populatedQueue(SIZE);
504	Queue y = serialClone(x);
505
506	assertTrue(x != y);
507	assertEquals(x.size(), y.size());
508	assertEquals(x.toString(), y.toString());
509	assertTrue(Arrays.equals(x.toArray(), y.toArray()));
510	while (!x.isEmpty()) {
511	assertFalse(y.isEmpty());
512	assertEquals(x.remove(), y.remove());
513	}
514	assertTrue(y.isEmpty());
515	}
516
517	}