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;
    }
 
    /**
     * 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:	1.5
Committed:	Sun Oct 5 23:00:40 2003 UTC (20 years, 7 months ago) by dl
Branch:	MAIN
CVS Tags:	JSR166_NOV3_FREEZE, JSR166_DEC9_PRE_ES_SUBMIT, JSR166_DEC9_POST_ES_SUBMIT
Changes since 1.4:	+80 -32 lines
Log Message:	Added tests and documentation
#	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	* new queue is empty
39	*/
40	public void testConstructor1() {
41	assertEquals(0, new ConcurrentLinkedQueue().size());
42	}
43
44	/**
45	* Initializing from null Collection throws NPE
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	* 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	}
64	catch (NullPointerException success) {}
65	}
66
67	/**
68	* Initializing from Collection with some null elements throws NPE
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	* Queue contains all elements of collection used to initialize
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	* isEmpty is true before add, false after
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	* size changes when elements added and removed
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	* offer(null) throws NPE
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	* add(null) throws NPE
138	*/
139	public void testAddNull() {
140	try {
141	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
142	q.add(null);
143	shouldThrow();
144	} catch (NullPointerException success) { }
145	}
146
147
148	/**
149	* Offer returns true
150	*/
151	public void testOffer() {
152	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
153	assertTrue(q.offer(zero));
154	assertTrue(q.offer(one));
155	}
156
157	/**
158	* add returns true
159	*/
160	public void testAdd() {
161	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
162	for (int i = 0; i < SIZE; ++i) {
163	assertEquals(i, q.size());
164	assertTrue(q.add(new Integer(i)));
165	}
166	}
167
168	/**
169	* addAll(null) throws NPE
170	*/
171	public void testAddAll1() {
172	try {
173	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
174	q.addAll(null);
175	shouldThrow();
176	}
177	catch (NullPointerException success) {}
178	}
179
180	/**
181	* addAll(this) throws IAE
182	*/
183	public void testAddAllSelf() {
184	try {
185	ConcurrentLinkedQueue q = populatedQueue(SIZE);
186	q.addAll(q);
187	shouldThrow();
188	}
189	catch (IllegalArgumentException success) {}
190	}
191
192	/**
193	* addAll of a collection with null elements throws NPE
194	*/
195	public void testAddAll2() {
196	try {
197	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
198	Integer[] ints = new Integer[SIZE];
199	q.addAll(Arrays.asList(ints));
200	shouldThrow();
201	}
202	catch (NullPointerException success) {}
203	}
204	/**
205	* addAll of a collection with any null elements throws NPE after
206	* possibly adding some elements
207	*/
208	public void testAddAll3() {
209	try {
210	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
211	Integer[] ints = new Integer[SIZE];
212	for (int i = 0; i < SIZE-1; ++i)
213	ints[i] = new Integer(i);
214	q.addAll(Arrays.asList(ints));
215	shouldThrow();
216	}
217	catch (NullPointerException success) {}
218	}
219
220	/**
221	* Queue contains all elements, in traversal order, of successful addAll
222	*/
223	public void testAddAll5() {
224	try {
225	Integer[] empty = new Integer[0];
226	Integer[] ints = new Integer[SIZE];
227	for (int i = 0; i < SIZE; ++i)
228	ints[i] = new Integer(i);
229	ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
230	assertFalse(q.addAll(Arrays.asList(empty)));
231	assertTrue(q.addAll(Arrays.asList(ints)));
232	for (int i = 0; i < SIZE; ++i)
233	assertEquals(ints[i], q.poll());
234	}
235	finally {}
236	}
237
238	/**
239	* poll succeeds unless empty
240	*/
241	public void testPoll() {
242	ConcurrentLinkedQueue q = populatedQueue(SIZE);
243	for (int i = 0; i < SIZE; ++i) {
244	assertEquals(i, ((Integer)q.poll()).intValue());
245	}
246	assertNull(q.poll());
247	}
248
249	/**
250	* peek returns next element, or null if empty
251	*/
252	public void testPeek() {
253	ConcurrentLinkedQueue q = populatedQueue(SIZE);
254	for (int i = 0; i < SIZE; ++i) {
255	assertEquals(i, ((Integer)q.peek()).intValue());
256	q.poll();
257	assertTrue(q.peek() == null \|\|
258	i != ((Integer)q.peek()).intValue());
259	}
260	assertNull(q.peek());
261	}
262
263	/**
264	* element returns next element, or throws NSEE if empty
265	*/
266	public void testElement() {
267	ConcurrentLinkedQueue q = populatedQueue(SIZE);
268	for (int i = 0; i < SIZE; ++i) {
269	assertEquals(i, ((Integer)q.element()).intValue());
270	q.poll();
271	}
272	try {
273	q.element();
274	shouldThrow();
275	}
276	catch (NoSuchElementException success) {}
277	}
278
279	/**
280	* remove removes next element, or throws NSEE if empty
281	*/
282	public void testRemove() {
283	ConcurrentLinkedQueue q = populatedQueue(SIZE);
284	for (int i = 0; i < SIZE; ++i) {
285	assertEquals(i, ((Integer)q.remove()).intValue());
286	}
287	try {
288	q.remove();
289	shouldThrow();
290	} catch (NoSuchElementException success){
291	}
292	}
293
294	/**
295	* remove(x) removes x and returns true if present
296	*/
297	public void testRemoveElement() {
298	ConcurrentLinkedQueue q = populatedQueue(SIZE);
299	for (int i = 1; i < SIZE; i+=2) {
300	assertTrue(q.remove(new Integer(i)));
301	}
302	for (int i = 0; i < SIZE; i+=2) {
303	assertTrue(q.remove(new Integer(i)));
304	assertFalse(q.remove(new Integer(i+1)));
305	}
306	assertTrue(q.isEmpty());
307	}
308
309	/**
310	* contains(x) reports true when elements added but not yet removed
311	*/
312	public void testContains() {
313	ConcurrentLinkedQueue q = populatedQueue(SIZE);
314	for (int i = 0; i < SIZE; ++i) {
315	assertTrue(q.contains(new Integer(i)));
316	q.poll();
317	assertFalse(q.contains(new Integer(i)));
318	}
319	}
320
321	/**
322	* clear removes all elements
323	*/
324	public void testClear() {
325	ConcurrentLinkedQueue q = populatedQueue(SIZE);
326	q.clear();
327	assertTrue(q.isEmpty());
328	assertEquals(0, q.size());
329	q.add(one);
330	assertFalse(q.isEmpty());
331	q.clear();
332	assertTrue(q.isEmpty());
333	}
334
335	/**
336	* containsAll(c) is true when c contains a subset of elements
337	*/
338	public void testContainsAll() {
339	ConcurrentLinkedQueue q = populatedQueue(SIZE);
340	ConcurrentLinkedQueue p = new ConcurrentLinkedQueue();
341	for (int i = 0; i < SIZE; ++i) {
342	assertTrue(q.containsAll(p));
343	assertFalse(p.containsAll(q));
344	p.add(new Integer(i));
345	}
346	assertTrue(p.containsAll(q));
347	}
348
349	/**
350	* retainAll(c) retains only those elements of c and reports true if change
351	*/
352	public void testRetainAll() {
353	ConcurrentLinkedQueue q = populatedQueue(SIZE);
354	ConcurrentLinkedQueue p = populatedQueue(SIZE);
355	for (int i = 0; i < SIZE; ++i) {
356	boolean changed = q.retainAll(p);
357	if (i == 0)
358	assertFalse(changed);
359	else
360	assertTrue(changed);
361
362	assertTrue(q.containsAll(p));
363	assertEquals(SIZE-i, q.size());
364	p.remove();
365	}
366	}
367
368	/**
369	* removeAll(c) removes only those elements of c and reports true if changed
370	*/
371	public void testRemoveAll() {
372	for (int i = 1; i < SIZE; ++i) {
373	ConcurrentLinkedQueue q = populatedQueue(SIZE);
374	ConcurrentLinkedQueue p = populatedQueue(i);
375	assertTrue(q.removeAll(p));
376	assertEquals(SIZE-i, q.size());
377	for (int j = 0; j < i; ++j) {
378	Integer I = (Integer)(p.remove());
379	assertFalse(q.contains(I));
380	}
381	}
382	}
383
384	/**
385	* toArray contains all elements
386	*/
387	public void testToArray() {
388	ConcurrentLinkedQueue q = populatedQueue(SIZE);
389	Object[] o = q.toArray();
390	Arrays.sort(o);
391	for(int i = 0; i < o.length; i++)
392	assertEquals(o[i], q.poll());
393	}
394
395	/**
396	* toArray(a) contains all elements
397	*/
398	public void testToArray2() {
399	ConcurrentLinkedQueue q = populatedQueue(SIZE);
400	Integer[] ints = new Integer[SIZE];
401	ints = (Integer[])q.toArray(ints);
402	Arrays.sort(ints);
403	for(int i = 0; i < ints.length; i++)
404	assertEquals(ints[i], q.poll());
405	}
406
407	/**
408	* toArray(null) throws NPE
409	*/
410	public void testToArray_BadArg() {
411	try {
412	ConcurrentLinkedQueue q = populatedQueue(SIZE);
413	Object o[] = q.toArray(null);
414	shouldThrow();
415	} catch(NullPointerException success){}
416	}
417
418	/**
419	* toArray with incompatable array type throws CCE
420	*/
421	public void testToArray1_BadArg() {
422	try {
423	ConcurrentLinkedQueue q = populatedQueue(SIZE);
424	Object o[] = q.toArray(new String[10] );
425	shouldThrow();
426	} catch(ArrayStoreException success){}
427	}
428
429	/**
430	* iterator iterates through all elements
431	*/
432	public void testIterator() {
433	ConcurrentLinkedQueue q = populatedQueue(SIZE);
434	int i = 0;
435	Iterator it = q.iterator();
436	while(it.hasNext()) {
437	assertTrue(q.contains(it.next()));
438	++i;
439	}
440	assertEquals(i, SIZE);
441	}
442
443	/**
444	* iterator ordering is FIFO
445	*/
446	public void testIteratorOrdering() {
447	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
448	q.add(one);
449	q.add(two);
450	q.add(three);
451
452	int k = 0;
453	for (Iterator it = q.iterator(); it.hasNext();) {
454	int i = ((Integer)(it.next())).intValue();
455	assertEquals(++k, i);
456	}
457
458	assertEquals(3, k);
459	}
460
461	/**
462	* Modifications do not cause iterators to fail
463	*/
464	public void testWeaklyConsistentIteration () {
465	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
466	q.add(one);
467	q.add(two);
468	q.add(three);
469
470	try {
471	for (Iterator it = q.iterator(); it.hasNext();) {
472	q.remove();
473	it.next();
474	}
475	}
476	catch (ConcurrentModificationException e) {
477	shouldThrow();
478	}
479
480	assertEquals("queue should be empty again", 0, q.size());
481	}
482
483	/**
484	* iterator.remove removes current element
485	*/
486	public void testIteratorRemove () {
487	final ConcurrentLinkedQueue q = new ConcurrentLinkedQueue();
488	q.add(one);
489	q.add(two);
490	q.add(three);
491	Iterator it = q.iterator();
492	it.next();
493	it.remove();
494	it = q.iterator();
495	assertEquals(it.next(), two);
496	assertEquals(it.next(), three);
497	assertFalse(it.hasNext());
498	}
499
500
501	/**
502	* toString contains toStrings of elements
503	*/
504	public void testToString() {
505	ConcurrentLinkedQueue q = populatedQueue(SIZE);
506	String s = q.toString();
507	for (int i = 0; i < SIZE; ++i) {
508	assertTrue(s.indexOf(String.valueOf(i)) >= 0);
509	}
510	}
511
512	/**
513	* A deserialized serialized queue has same elements in same order
514	*/
515	public void testSerialization() {
516	ConcurrentLinkedQueue q = populatedQueue(SIZE);
517	try {
518	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
519	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
520	out.writeObject(q);
521	out.close();
522
523	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
524	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
525	ConcurrentLinkedQueue r = (ConcurrentLinkedQueue)in.readObject();
526	assertEquals(q.size(), r.size());
527	while (!q.isEmpty())
528	assertEquals(q.remove(), r.remove());
529	} catch(Exception e){
530	unexpectedException();
531	}
532	}
533
534	}