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() {
        try {
            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());
        }
        finally {}
    }

    /**
     * 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() {
        try {
            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());
        }
        finally {}
    }

    /**
     * poll succeeds unless empty
     */
    public void testPoll() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, ((Integer)q.poll()).intValue());
        }
        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, ((Integer)q.peek()).intValue());
            q.poll();
            assertTrue(q.peek() == null ||
                       i != ((Integer)q.peek()).intValue());
        }
        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, ((Integer)q.element()).intValue());
            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, ((Integer)q.remove()).intValue());
        }
        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() {
        try {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            Object o[] = q.toArray(null);
            shouldThrow();
        } catch(NullPointerException success){}
    }

    /**
     * toArray with incompatable array type throws CCE
     */
    public void testToArray1_BadArg() {
        try {
            ConcurrentLinkedQueue q = populatedQueue(SIZE);
            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();) {
            int i = ((Integer)(it.next())).intValue();
            assertEquals(++k, i);
        }

        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);

        try {
            for (Iterator it = q.iterator(); it.hasNext();) {
                q.remove();
                it.next();
            }
        }
        catch (ConcurrentModificationException e) {
            shouldThrow();
        }

        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() {
        ConcurrentLinkedQueue q = populatedQueue(SIZE);
        try {
            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());
        } catch(Exception e){
            unexpectedException();
        }
    }

}
Revision:	1.6
Committed:	Sat Dec 27 19:26:43 2003 UTC (20 years, 4 months ago) by dl
Branch:	MAIN
Changes since 1.5:	+5 -4 lines
Log Message:	Headers reference Creative Commons
#	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	}
53	catch (NullPointerException success) {}
54	}
55
56	/**
57	* Initializing from Collection of null elements throws NPE
58	*/
59	public void testConstructor4() {
60	try {
61	Integer[] ints = new Integer[SIZE];
62	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
63	shouldThrow();
64	}
65	catch (NullPointerException success) {}
66	}
67
68	/**
69	* Initializing from Collection with some null elements throws NPE
70	*/
71	public void testConstructor5() {
72	try {
73	Integer[] ints = new Integer[SIZE];
74	for (int i = 0; i < SIZE-1; ++i)
75	ints[i] = new Integer(i);
76	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
77	shouldThrow();
78	}
79	catch (NullPointerException success) {}
80	}
81
82	/**
83	* Queue contains all elements of collection used to initialize
84	*/
85	public void testConstructor6() {
86	try {
87	Integer[] ints = new Integer[SIZE];
88	for (int i = 0; i < SIZE; ++i)
89	ints[i] = new Integer(i);
90	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
91	for (int i = 0; i < SIZE; ++i)
92	assertEquals(ints[i], q.poll());
93	}
94	finally {}
95	}
96
97	/**
98	* isEmpty is true before add, false after
99	*/
100	public void testEmpty() {
101	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
102	assertTrue(q.isEmpty());
103	q.add(one);
104	assertFalse(q.isEmpty());
105	q.add(two);
106	q.remove();
107	q.remove();
108	assertTrue(q.isEmpty());
109	}
110
111	/**
112	* size changes when elements added and removed
113	*/
114	public void testSize() {
115	ConcurrentLinkedQueue q = populatedQueue(SIZE);
116	for (int i = 0; i < SIZE; ++i) {
117	assertEquals(SIZE-i, q.size());
118	q.remove();
119	}
120	for (int i = 0; i < SIZE; ++i) {
121	assertEquals(i, q.size());
122	q.add(new Integer(i));
123	}
124	}
125
126	/**
127	* offer(null) throws NPE
128	*/
129	public void testOfferNull() {
130	try {
131	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
132	q.offer(null);
133	shouldThrow();
134	} catch (NullPointerException success) { }
135	}
136
137	/**
138	* add(null) throws NPE
139	*/
140	public void testAddNull() {
141	try {
142	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
143	q.add(null);
144	shouldThrow();
145	} catch (NullPointerException success) { }
146	}
147
148
149	/**
150	* Offer returns true
151	*/
152	public void testOffer() {
153	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
154	assertTrue(q.offer(zero));
155	assertTrue(q.offer(one));
156	}
157
158	/**
159	* add returns true
160	*/
161	public void testAdd() {
162	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
163	for (int i = 0; i < SIZE; ++i) {
164	assertEquals(i, q.size());
165	assertTrue(q.add(new Integer(i)));
166	}
167	}
168
169	/**
170	* addAll(null) throws NPE
171	*/
172	public void testAddAll1() {
173	try {
174	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
175	q.addAll(null);
176	shouldThrow();
177	}
178	catch (NullPointerException success) {}
179	}
180
181	/**
182	* addAll(this) throws IAE
183	*/
184	public void testAddAllSelf() {
185	try {
186	ConcurrentLinkedQueue q = populatedQueue(SIZE);
187	q.addAll(q);
188	shouldThrow();
189	}
190	catch (IllegalArgumentException success) {}
191	}
192
193	/**
194	* addAll of a collection with null elements throws NPE
195	*/
196	public void testAddAll2() {
197	try {
198	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
199	Integer[] ints = new Integer[SIZE];
200	q.addAll(Arrays.asList(ints));
201	shouldThrow();
202	}
203	catch (NullPointerException success) {}
204	}
205	/**
206	* addAll of a collection with any null elements throws NPE after
207	* possibly adding some elements
208	*/
209	public void testAddAll3() {
210	try {
211	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
212	Integer[] ints = new Integer[SIZE];
213	for (int i = 0; i < SIZE-1; ++i)
214	ints[i] = new Integer(i);
215	q.addAll(Arrays.asList(ints));
216	shouldThrow();
217	}
218	catch (NullPointerException success) {}
219	}
220
221	/**
222	* Queue contains all elements, in traversal order, of successful addAll
223	*/
224	public void testAddAll5() {
225	try {
226	Integer[] empty = new Integer[0];
227	Integer[] ints = new Integer[SIZE];
228	for (int i = 0; i < SIZE; ++i)
229	ints[i] = new Integer(i);
230	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
231	assertFalse(q.addAll(Arrays.asList(empty)));
232	assertTrue(q.addAll(Arrays.asList(ints)));
233	for (int i = 0; i < SIZE; ++i)
234	assertEquals(ints[i], q.poll());
235	}
236	finally {}
237	}
238
239	/**
240	* poll succeeds unless empty
241	*/
242	public void testPoll() {
243	ConcurrentLinkedQueue q = populatedQueue(SIZE);
244	for (int i = 0; i < SIZE; ++i) {
245	assertEquals(i, ((Integer)q.poll()).intValue());
246	}
247	assertNull(q.poll());
248	}
249
250	/**
251	* peek returns next element, or null if empty
252	*/
253	public void testPeek() {
254	ConcurrentLinkedQueue q = populatedQueue(SIZE);
255	for (int i = 0; i < SIZE; ++i) {
256	assertEquals(i, ((Integer)q.peek()).intValue());
257	q.poll();
258	assertTrue(q.peek() == null \|\|
259	i != ((Integer)q.peek()).intValue());
260	}
261	assertNull(q.peek());
262	}
263
264	/**
265	* element returns next element, or throws NSEE if empty
266	*/
267	public void testElement() {
268	ConcurrentLinkedQueue q = populatedQueue(SIZE);
269	for (int i = 0; i < SIZE; ++i) {
270	assertEquals(i, ((Integer)q.element()).intValue());
271	q.poll();
272	}
273	try {
274	q.element();
275	shouldThrow();
276	}
277	catch (NoSuchElementException success) {}
278	}
279
280	/**
281	* remove removes next element, or throws NSEE if empty
282	*/
283	public void testRemove() {
284	ConcurrentLinkedQueue q = populatedQueue(SIZE);
285	for (int i = 0; i < SIZE; ++i) {
286	assertEquals(i, ((Integer)q.remove()).intValue());
287	}
288	try {
289	q.remove();
290	shouldThrow();
291	} catch (NoSuchElementException success){
292	}
293	}
294
295	/**
296	* remove(x) removes x and returns true if present
297	*/
298	public void testRemoveElement() {
299	ConcurrentLinkedQueue q = populatedQueue(SIZE);
300	for (int i = 1; i < SIZE; i+=2) {
301	assertTrue(q.remove(new Integer(i)));
302	}
303	for (int i = 0; i < SIZE; i+=2) {
304	assertTrue(q.remove(new Integer(i)));
305	assertFalse(q.remove(new Integer(i+1)));
306	}
307	assertTrue(q.isEmpty());
308	}
309
310	/**
311	* contains(x) reports true when elements added but not yet removed
312	*/
313	public void testContains() {
314	ConcurrentLinkedQueue q = populatedQueue(SIZE);
315	for (int i = 0; i < SIZE; ++i) {
316	assertTrue(q.contains(new Integer(i)));
317	q.poll();
318	assertFalse(q.contains(new Integer(i)));
319	}
320	}
321
322	/**
323	* clear removes all elements
324	*/
325	public void testClear() {
326	ConcurrentLinkedQueue q = populatedQueue(SIZE);
327	q.clear();
328	assertTrue(q.isEmpty());
329	assertEquals(0, q.size());
330	q.add(one);
331	assertFalse(q.isEmpty());
332	q.clear();
333	assertTrue(q.isEmpty());
334	}
335
336	/**
337	* containsAll(c) is true when c contains a subset of elements
338	*/
339	public void testContainsAll() {
340	ConcurrentLinkedQueue q = populatedQueue(SIZE);
341	ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
342	for (int i = 0; i < SIZE; ++i) {
343	assertTrue(q.containsAll(p));
344	assertFalse(p.containsAll(q));
345	p.add(new Integer(i));
346	}
347	assertTrue(p.containsAll(q));
348	}
349
350	/**
351	* retainAll(c) retains only those elements of c and reports true if change
352	*/
353	public void testRetainAll() {
354	ConcurrentLinkedQueue q = populatedQueue(SIZE);
355	ConcurrentLinkedQueue p = populatedQueue(SIZE);
356	for (int i = 0; i < SIZE; ++i) {
357	boolean changed = q.retainAll(p);
358	if (i == 0)
359	assertFalse(changed);
360	else
361	assertTrue(changed);
362
363	assertTrue(q.containsAll(p));
364	assertEquals(SIZE-i, q.size());
365	p.remove();
366	}
367	}
368
369	/**
370	* removeAll(c) removes only those elements of c and reports true if changed
371	*/
372	public void testRemoveAll() {
373	for (int i = 1; i < SIZE; ++i) {
374	ConcurrentLinkedQueue q = populatedQueue(SIZE);
375	ConcurrentLinkedQueue p = populatedQueue(i);
376	assertTrue(q.removeAll(p));
377	assertEquals(SIZE-i, q.size());
378	for (int j = 0; j < i; ++j) {
379	Integer I = (Integer)(p.remove());
380	assertFalse(q.contains(I));
381	}
382	}
383	}
384
385	/**
386	* toArray contains all elements
387	*/
388	public void testToArray() {
389	ConcurrentLinkedQueue q = populatedQueue(SIZE);
390	Object[] o = q.toArray();
391	Arrays.sort(o);
392	for(int i = 0; i < o.length; i++)
393	assertEquals(o[i], q.poll());
394	}
395
396	/**
397	* toArray(a) contains all elements
398	*/
399	public void testToArray2() {
400	ConcurrentLinkedQueue q = populatedQueue(SIZE);
401	Integer[] ints = new Integer[SIZE];
402	ints = (Integer[])q.toArray(ints);
403	Arrays.sort(ints);
404	for(int i = 0; i < ints.length; i++)
405	assertEquals(ints[i], q.poll());
406	}
407
408	/**
409	* toArray(null) throws NPE
410	*/
411	public void testToArray_BadArg() {
412	try {
413	ConcurrentLinkedQueue q = populatedQueue(SIZE);
414	Object o[] = q.toArray(null);
415	shouldThrow();
416	} catch(NullPointerException success){}
417	}
418
419	/**
420	* toArray with incompatable array type throws CCE
421	*/
422	public void testToArray1_BadArg() {
423	try {
424	ConcurrentLinkedQueue q = populatedQueue(SIZE);
425	Object o[] = q.toArray(new String[10] );
426	shouldThrow();
427	} catch(ArrayStoreException success){}
428	}
429
430	/**
431	* iterator iterates through all elements
432	*/
433	public void testIterator() {
434	ConcurrentLinkedQueue q = populatedQueue(SIZE);
435	int i = 0;
436	Iterator it = q.iterator();
437	while(it.hasNext()) {
438	assertTrue(q.contains(it.next()));
439	++i;
440	}
441	assertEquals(i, SIZE);
442	}
443
444	/**
445	* iterator ordering is FIFO
446	*/
447	public void testIteratorOrdering() {
448	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
449	q.add(one);
450	q.add(two);
451	q.add(three);
452
453	int k = 0;
454	for (Iterator it = q.iterator(); it.hasNext();) {
455	int i = ((Integer)(it.next())).intValue();
456	assertEquals(++k, i);
457	}
458
459	assertEquals(3, k);
460	}
461
462	/**
463	* Modifications do not cause iterators to fail
464	*/
465	public void testWeaklyConsistentIteration () {
466	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
467	q.add(one);
468	q.add(two);
469	q.add(three);
470
471	try {
472	for (Iterator it = q.iterator(); it.hasNext();) {
473	q.remove();
474	it.next();
475	}
476	}
477	catch (ConcurrentModificationException e) {
478	shouldThrow();
479	}
480
481	assertEquals("queue should be empty again", 0, q.size());
482	}
483
484	/**
485	* iterator.remove removes current element
486	*/
487	public void testIteratorRemove () {
488	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
489	q.add(one);
490	q.add(two);
491	q.add(three);
492	Iterator it = q.iterator();
493	it.next();
494	it.remove();
495	it = q.iterator();
496	assertEquals(it.next(), two);
497	assertEquals(it.next(), three);
498	assertFalse(it.hasNext());
499	}
500
501
502	/**
503	* toString contains toStrings of elements
504	*/
505	public void testToString() {
506	ConcurrentLinkedQueue q = populatedQueue(SIZE);
507	String s = q.toString();
508	for (int i = 0; i < SIZE; ++i) {
509	assertTrue(s.indexOf(String.valueOf(i)) >= 0);
510	}
511	}
512
513	/**
514	* A deserialized serialized queue has same elements in same order
515	*/
516	public void testSerialization() {
517	ConcurrentLinkedQueue q = populatedQueue(SIZE);
518	try {
519	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
520	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
521	out.writeObject(q);
522	out.close();
523
524	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
525	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
526	ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
527	assertEquals(q.size(), r.size());
528	while (!q.isEmpty())
529	assertEquals(q.remove(), r.remove());
530	} catch(Exception e){
531	unexpectedException();
532	}
533	}
534
535	}