test/tck/ConcurrentLinkedQueueTest.java

/*
 * Written by members of JCP JSR-166 Expert Group and released to the
 * public domain. Use, modify, and redistribute this code in any way
 * without acknowledgement. Other contributors include Andrew Wright,
 * Jeffrey Hayes, Pat Fischer, 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;
    }
 
    /**
     *
     */
    public void testConstructor1() {
        assertEquals(0, new ConcurrentLinkedQueue().size());
    }

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

    /**
     *
     */
    public void testConstructor4() {
        try {
            Integer[] ints = new Integer[SIZE];
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
            shouldThrow();
        }
        catch (NullPointerException success) {}
    }

    /**
     *
     */
    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) {}
    }

    /**
     *
     */
    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 {}
    }

    /**
     *
     */
    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());
    }

    /**
     *
     */
    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));
        }
    }

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

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

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

    /**
     *
     */
    public void testAddAll1() {
        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            q.addAll(null);
            shouldThrow();
        }
        catch (NullPointerException success) {}
    }
    /**
     *
     */
    public void testAddAll2() {
        try {
            ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
            Integer[] ints = new Integer[SIZE];
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        }
        catch (NullPointerException success) {}
    }
    /**
     *
     */
    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) {}
    }

    /**
     *
     */
    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 {}
    }

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

    /**
     *
     */
    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());
    }

    /**
     *
     */
    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) {}
    }

    /**
     *
     */
    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){
        }   
    }

    /**
     *
     */
    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());
    }
        
    /**
     *
     */
    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)));
        }
    }

    /**
     *
     */
    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());
    }

    /**
     *
     */
    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));
    }

    /**
     *
     */
    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();
        }
    }

    /**
     *
     */
    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));
            }
        }
    }

    /**
     *
     */
    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());
    }

    /**
     *
     */
    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());
    }
    
    /**
     *
     */
    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);
    }

    /**
     *
     */
    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);
    }

    /**
     *
     */
    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());
    }

    /**
     *
     */
    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());
    }


    /**
     *
     */
    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);
        }
    }        

    /**
     *
     */
    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:	1.4
Committed:	Sat Sep 20 18:20:07 2003 UTC (20 years, 7 months ago) by dl
Branch:	MAIN
Changes since 1.3:	+133 -38 lines
Log Message:	Documentation scaffolding
#	Content
1	/*
2	* Written by members of JCP JSR-166 Expert Group and released to the
3	* public domain. Use, modify, and redistribute this code in any way
4	* without acknowledgement. Other contributors include Andrew Wright,
5	* Jeffrey Hayes, Pat Fischer, Mike Judd.
6	*/
7
8	import junit.framework.*;
9	import java.util.*;
10	import java.util.concurrent.*;
11	import java.io.*;
12
13	public class ConcurrentLinkedQueueTest extends JSR166TestCase {
14
15	public static void main(String[] args) {
16	junit.textui.TestRunner.run (suite());
17	}
18
19	public static Test suite() {
20	return new TestSuite(ConcurrentLinkedQueueTest.class);
21	}
22
23	/**
24	* Create a queue of given size containing consecutive
25	* Integers 0 ... n.
26	*/
27	private ConcurrentLinkedQueue populatedQueue(int n) {
28	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
29	assertTrue(q.isEmpty());
30	for(int i = 0; i < n; ++i)
31	assertTrue(q.offer(new Integer(i)));
32	assertFalse(q.isEmpty());
33	assertEquals(n, q.size());
34	return q;
35	}
36
37	/**
38	*
39	*/
40	public void testConstructor1() {
41	assertEquals(0, new ConcurrentLinkedQueue().size());
42	}
43
44	/**
45	*
46	*/
47	public void testConstructor3() {
48	try {
49	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue((Collection)null);
50	shouldThrow();
51	}
52	catch (NullPointerException success) {}
53	}
54
55	/**
56	*
57	*/
58	public void testConstructor4() {
59	try {
60	Integer[] ints = new Integer[SIZE];
61	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
62	shouldThrow();
63	}
64	catch (NullPointerException success) {}
65	}
66
67	/**
68	*
69	*/
70	public void testConstructor5() {
71	try {
72	Integer[] ints = new Integer[SIZE];
73	for (int i = 0; i < SIZE-1; ++i)
74	ints[i] = new Integer(i);
75	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue(Arrays.asList(ints));
76	shouldThrow();
77	}
78	catch (NullPointerException success) {}
79	}
80
81	/**
82	*
83	*/
84	public void testConstructor6() {
85	try {
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	finally {}
94	}
95
96	/**
97	*
98	*/
99	public void testEmpty() {
100	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
101	assertTrue(q.isEmpty());
102	q.add(one);
103	assertFalse(q.isEmpty());
104	q.add(two);
105	q.remove();
106	q.remove();
107	assertTrue(q.isEmpty());
108	}
109
110	/**
111	*
112	*/
113	public void testSize() {
114	ConcurrentLinkedQueue q = populatedQueue(SIZE);
115	for (int i = 0; i < SIZE; ++i) {
116	assertEquals(SIZE-i, q.size());
117	q.remove();
118	}
119	for (int i = 0; i < SIZE; ++i) {
120	assertEquals(i, q.size());
121	q.add(new Integer(i));
122	}
123	}
124
125	/**
126	*
127	*/
128	public void testOfferNull() {
129	try {
130	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
131	q.offer(null);
132	shouldThrow();
133	} catch (NullPointerException success) { }
134	}
135
136	/**
137	*
138	*/
139	public void testOffer() {
140	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
141	assertTrue(q.offer(zero));
142	assertTrue(q.offer(one));
143	}
144
145	/**
146	*
147	*/
148	public void testAdd() {
149	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
150	for (int i = 0; i < SIZE; ++i) {
151	assertEquals(i, q.size());
152	assertTrue(q.add(new Integer(i)));
153	}
154	}
155
156	/**
157	*
158	*/
159	public void testAddAll1() {
160	try {
161	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
162	q.addAll(null);
163	shouldThrow();
164	}
165	catch (NullPointerException success) {}
166	}
167	/**
168	*
169	*/
170	public void testAddAll2() {
171	try {
172	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
173	Integer[] ints = new Integer[SIZE];
174	q.addAll(Arrays.asList(ints));
175	shouldThrow();
176	}
177	catch (NullPointerException success) {}
178	}
179	/**
180	*
181	*/
182	public void testAddAll3() {
183	try {
184	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
185	Integer[] ints = new Integer[SIZE];
186	for (int i = 0; i < SIZE-1; ++i)
187	ints[i] = new Integer(i);
188	q.addAll(Arrays.asList(ints));
189	shouldThrow();
190	}
191	catch (NullPointerException success) {}
192	}
193
194	/**
195	*
196	*/
197	public void testAddAll5() {
198	try {
199	Integer[] empty = new Integer[0];
200	Integer[] ints = new Integer[SIZE];
201	for (int i = 0; i < SIZE; ++i)
202	ints[i] = new Integer(i);
203	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
204	assertFalse(q.addAll(Arrays.asList(empty)));
205	assertTrue(q.addAll(Arrays.asList(ints)));
206	for (int i = 0; i < SIZE; ++i)
207	assertEquals(ints[i], q.poll());
208	}
209	finally {}
210	}
211
212	/**
213	*
214	*/
215	public void testPoll() {
216	ConcurrentLinkedQueue q = populatedQueue(SIZE);
217	for (int i = 0; i < SIZE; ++i) {
218	assertEquals(i, ((Integer)q.poll()).intValue());
219	}
220	assertNull(q.poll());
221	}
222
223	/**
224	*
225	*/
226	public void testPeek() {
227	ConcurrentLinkedQueue q = populatedQueue(SIZE);
228	for (int i = 0; i < SIZE; ++i) {
229	assertEquals(i, ((Integer)q.peek()).intValue());
230	q.poll();
231	assertTrue(q.peek() == null \|\|
232	i != ((Integer)q.peek()).intValue());
233	}
234	assertNull(q.peek());
235	}
236
237	/**
238	*
239	*/
240	public void testElement() {
241	ConcurrentLinkedQueue q = populatedQueue(SIZE);
242	for (int i = 0; i < SIZE; ++i) {
243	assertEquals(i, ((Integer)q.element()).intValue());
244	q.poll();
245	}
246	try {
247	q.element();
248	shouldThrow();
249	}
250	catch (NoSuchElementException success) {}
251	}
252
253	/**
254	*
255	*/
256	public void testRemove() {
257	ConcurrentLinkedQueue q = populatedQueue(SIZE);
258	for (int i = 0; i < SIZE; ++i) {
259	assertEquals(i, ((Integer)q.remove()).intValue());
260	}
261	try {
262	q.remove();
263	shouldThrow();
264	} catch (NoSuchElementException success){
265	}
266	}
267
268	/**
269	*
270	*/
271	public void testRemoveElement() {
272	ConcurrentLinkedQueue q = populatedQueue(SIZE);
273	for (int i = 1; i < SIZE; i+=2) {
274	assertTrue(q.remove(new Integer(i)));
275	}
276	for (int i = 0; i < SIZE; i+=2) {
277	assertTrue(q.remove(new Integer(i)));
278	assertFalse(q.remove(new Integer(i+1)));
279	}
280	assertTrue(q.isEmpty());
281	}
282
283	/**
284	*
285	*/
286	public void testContains() {
287	ConcurrentLinkedQueue q = populatedQueue(SIZE);
288	for (int i = 0; i < SIZE; ++i) {
289	assertTrue(q.contains(new Integer(i)));
290	q.poll();
291	assertFalse(q.contains(new Integer(i)));
292	}
293	}
294
295	/**
296	*
297	*/
298	public void testClear() {
299	ConcurrentLinkedQueue q = populatedQueue(SIZE);
300	q.clear();
301	assertTrue(q.isEmpty());
302	assertEquals(0, q.size());
303	q.add(one);
304	assertFalse(q.isEmpty());
305	q.clear();
306	assertTrue(q.isEmpty());
307	}
308
309	/**
310	*
311	*/
312	public void testContainsAll() {
313	ConcurrentLinkedQueue q = populatedQueue(SIZE);
314	ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
315	for (int i = 0; i < SIZE; ++i) {
316	assertTrue(q.containsAll(p));
317	assertFalse(p.containsAll(q));
318	p.add(new Integer(i));
319	}
320	assertTrue(p.containsAll(q));
321	}
322
323	/**
324	*
325	*/
326	public void testRetainAll() {
327	ConcurrentLinkedQueue q = populatedQueue(SIZE);
328	ConcurrentLinkedQueue p = populatedQueue(SIZE);
329	for (int i = 0; i < SIZE; ++i) {
330	boolean changed = q.retainAll(p);
331	if (i == 0)
332	assertFalse(changed);
333	else
334	assertTrue(changed);
335
336	assertTrue(q.containsAll(p));
337	assertEquals(SIZE-i, q.size());
338	p.remove();
339	}
340	}
341
342	/**
343	*
344	*/
345	public void testRemoveAll() {
346	for (int i = 1; i < SIZE; ++i) {
347	ConcurrentLinkedQueue q = populatedQueue(SIZE);
348	ConcurrentLinkedQueue p = populatedQueue(i);
349	assertTrue(q.removeAll(p));
350	assertEquals(SIZE-i, q.size());
351	for (int j = 0; j < i; ++j) {
352	Integer I = (Integer)(p.remove());
353	assertFalse(q.contains(I));
354	}
355	}
356	}
357
358	/**
359	*
360	*/
361	public void testToArray() {
362	ConcurrentLinkedQueue q = populatedQueue(SIZE);
363	Object[] o = q.toArray();
364	Arrays.sort(o);
365	for(int i = 0; i < o.length; i++)
366	assertEquals(o[i], q.poll());
367	}
368
369	/**
370	*
371	*/
372	public void testToArray2() {
373	ConcurrentLinkedQueue q = populatedQueue(SIZE);
374	Integer[] ints = new Integer[SIZE];
375	ints = (Integer[])q.toArray(ints);
376	Arrays.sort(ints);
377	for(int i = 0; i < ints.length; i++)
378	assertEquals(ints[i], q.poll());
379	}
380
381	/**
382	*
383	*/
384	public void testIterator() {
385	ConcurrentLinkedQueue q = populatedQueue(SIZE);
386	int i = 0;
387	Iterator it = q.iterator();
388	while(it.hasNext()) {
389	assertTrue(q.contains(it.next()));
390	++i;
391	}
392	assertEquals(i, SIZE);
393	}
394
395	/**
396	*
397	*/
398	public void testIteratorOrdering() {
399	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
400	q.add(one);
401	q.add(two);
402	q.add(three);
403
404	int k = 0;
405	for (Iterator it = q.iterator(); it.hasNext();) {
406	int i = ((Integer)(it.next())).intValue();
407	assertEquals(++k, i);
408	}
409
410	assertEquals(3, k);
411	}
412
413	/**
414	*
415	*/
416	public void testWeaklyConsistentIteration () {
417	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
418	q.add(one);
419	q.add(two);
420	q.add(three);
421
422	try {
423	for (Iterator it = q.iterator(); it.hasNext();) {
424	q.remove();
425	it.next();
426	}
427	}
428	catch (ConcurrentModificationException e) {
429	shouldThrow();
430	}
431
432	assertEquals("queue should be empty again", 0, q.size());
433	}
434
435	/**
436	*
437	*/
438	public void testIteratorRemove () {
439	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
440	q.add(one);
441	q.add(two);
442	q.add(three);
443	Iterator it = q.iterator();
444	it.next();
445	it.remove();
446	it = q.iterator();
447	assertEquals(it.next(), two);
448	assertEquals(it.next(), three);
449	assertFalse(it.hasNext());
450	}
451
452
453	/**
454	*
455	*/
456	public void testToString() {
457	ConcurrentLinkedQueue q = populatedQueue(SIZE);
458	String s = q.toString();
459	for (int i = 0; i < SIZE; ++i) {
460	assertTrue(s.indexOf(String.valueOf(i)) >= 0);
461	}
462	}
463
464	/**
465	*
466	*/
467	public void testSerialization() {
468	ConcurrentLinkedQueue q = populatedQueue(SIZE);
469	try {
470	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
471	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
472	out.writeObject(q);
473	out.close();
474
475	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
476	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
477	ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
478	assertEquals(q.size(), r.size());
479	while (!q.isEmpty())
480	assertEquals(q.remove(), r.remove());
481	} catch(Exception e){
482	unexpectedException();
483	}
484	}
485
486	}