test/tck/CopyOnWriteArraySetTest.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 java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.concurrent.CopyOnWriteArraySet;

import junit.framework.Test;
import junit.framework.TestSuite;

public class CopyOnWriteArraySetTest extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }
    public static Test suite() {
        return new TestSuite(CopyOnWriteArraySetTest.class);
    }

    static CopyOnWriteArraySet<Integer> populatedSet(int n) {
        CopyOnWriteArraySet<Integer> a = new CopyOnWriteArraySet<>();
        assertTrue(a.isEmpty());
        for (int i = 0; i < n; i++)
            a.add(i);
        assertEquals(n == 0, a.isEmpty());
        assertEquals(n, a.size());
        return a;
    }

    static CopyOnWriteArraySet populatedSet(Integer[] elements) {
        CopyOnWriteArraySet<Integer> a = new CopyOnWriteArraySet<>();
        assertTrue(a.isEmpty());
        for (int i = 0; i < elements.length; i++)
            a.add(elements[i]);
        assertFalse(a.isEmpty());
        assertEquals(elements.length, a.size());
        return a;
    }

    /**
     * Default-constructed set is empty
     */
    public void testConstructor() {
        CopyOnWriteArraySet a = new CopyOnWriteArraySet();
        assertTrue(a.isEmpty());
    }

    /**
     * Collection-constructed set holds all of its elements
     */
    public void testConstructor3() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE - 1; ++i)
            ints[i] = new Integer(i);
        CopyOnWriteArraySet a = new CopyOnWriteArraySet(Arrays.asList(ints));
        for (int i = 0; i < SIZE; ++i)
            assertTrue(a.contains(ints[i]));
    }

    /**
     * addAll adds each non-duplicate element from the given collection
     */
    public void testAddAll() {
        Set full = populatedSet(3);
        assertTrue(full.addAll(Arrays.asList(three, four, five)));
        assertEquals(6, full.size());
        assertFalse(full.addAll(Arrays.asList(three, four, five)));
        assertEquals(6, full.size());
    }

    /**
     * addAll adds each non-duplicate element from the given collection
     */
    public void testAddAll2() {
        Set full = populatedSet(3);
        // "one" is duplicate and will not be added
        assertTrue(full.addAll(Arrays.asList(three, four, one)));
        assertEquals(5, full.size());
        assertFalse(full.addAll(Arrays.asList(three, four, one)));
        assertEquals(5, full.size());
    }

    /**
     * add will not add the element if it already exists in the set
     */
    public void testAdd2() {
        Set full = populatedSet(3);
        full.add(one);
        assertEquals(3, full.size());
    }

    /**
     * add adds the element when it does not exist in the set
     */
    public void testAdd3() {
        Set full = populatedSet(3);
        full.add(three);
        assertTrue(full.contains(three));
    }

    /**
     * clear removes all elements from the set
     */
    public void testClear() {
        Collection full = populatedSet(3);
        full.clear();
        assertEquals(0, full.size());
        assertTrue(full.isEmpty());
    }

    /**
     * contains returns true for added elements
     */
    public void testContains() {
        Collection full = populatedSet(3);
        assertTrue(full.contains(one));
        assertFalse(full.contains(five));
    }

    /**
     * Sets with equal elements are equal
     */
    public void testEquals() {
        CopyOnWriteArraySet a = populatedSet(3);
        CopyOnWriteArraySet b = populatedSet(3);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
        assertTrue(a.containsAll(b));
        assertTrue(b.containsAll(a));
        assertEquals(a.hashCode(), b.hashCode());
        assertEquals(a.size(), b.size());

        a.add(m1);
        assertFalse(a.equals(b));
        assertFalse(b.equals(a));
        assertTrue(a.containsAll(b));
        assertFalse(b.containsAll(a));
        b.add(m1);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
        assertTrue(a.containsAll(b));
        assertTrue(b.containsAll(a));
        assertEquals(a.hashCode(), b.hashCode());

        Object x = a.iterator().next();
        a.remove(x);
        assertFalse(a.equals(b));
        assertFalse(b.equals(a));
        assertFalse(a.containsAll(b));
        assertTrue(b.containsAll(a));
        a.add(x);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
        assertTrue(a.containsAll(b));
        assertTrue(b.containsAll(a));
        assertEquals(a.hashCode(), b.hashCode());
        assertEquals(a.size(), b.size());

        CopyOnWriteArraySet empty1 = new CopyOnWriteArraySet(Arrays.asList());
        CopyOnWriteArraySet empty2 = new CopyOnWriteArraySet(Arrays.asList());
        assertTrue(empty1.equals(empty1));
        assertTrue(empty1.equals(empty2));

        assertFalse(empty1.equals(a));
        assertFalse(a.equals(empty1));

        assertFalse(a.equals(null));
    }

    /**
     * containsAll returns true for collections with subset of elements
     */
    public void testContainsAll() {
        Collection full = populatedSet(3);
        assertTrue(full.containsAll(full));
        assertTrue(full.containsAll(Arrays.asList()));
        assertTrue(full.containsAll(Arrays.asList(one)));
        assertTrue(full.containsAll(Arrays.asList(one, two)));
        assertFalse(full.containsAll(Arrays.asList(one, two, six)));
        assertFalse(full.containsAll(Arrays.asList(six)));

        CopyOnWriteArraySet empty1 = new CopyOnWriteArraySet(Arrays.asList());
        CopyOnWriteArraySet empty2 = new CopyOnWriteArraySet(Arrays.asList());
        assertTrue(empty1.containsAll(empty2));
        assertTrue(empty1.containsAll(empty1));
        assertFalse(empty1.containsAll(full));
        assertTrue(full.containsAll(empty1));

        try {
            full.containsAll(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * isEmpty is true when empty, else false
     */
    public void testIsEmpty() {
        assertTrue(populatedSet(0).isEmpty());
        assertFalse(populatedSet(3).isEmpty());
    }

    /**
     * iterator() returns an iterator containing the elements of the
     * set in insertion order
     */
    public void testIterator() {
        Collection empty = new CopyOnWriteArraySet();
        assertFalse(empty.iterator().hasNext());
        try {
            empty.iterator().next();
            shouldThrow();
        } catch (NoSuchElementException success) {}

        Integer[] elements = new Integer[SIZE];
        for (int i = 0; i < SIZE; i++)
            elements[i] = i;
        shuffle(elements);
        Collection<Integer> full = populatedSet(elements);

        Iterator it = full.iterator();
        for (int j = 0; j < SIZE; j++) {
            assertTrue(it.hasNext());
            assertEquals(elements[j], it.next());
        }
        assertIteratorExhausted(it);
    }

    /**
     * iterator of empty collection has no elements
     */
    public void testEmptyIterator() {
        assertIteratorExhausted(new CopyOnWriteArraySet().iterator());
    }

    /**
     * iterator remove is unsupported
     */
    public void testIteratorRemove() {
        Collection full = populatedSet(3);
        Iterator it = full.iterator();
        it.next();
        try {
            it.remove();
            shouldThrow();
        } catch (UnsupportedOperationException success) {}
    }

    /**
     * toString holds toString of elements
     */
    public void testToString() {
        assertEquals("[]", new CopyOnWriteArraySet().toString());
        Collection full = populatedSet(3);
        String s = full.toString();
        for (int i = 0; i < 3; ++i)
            assertTrue(s.contains(String.valueOf(i)));
        assertEquals(new ArrayList(full).toString(),
                     full.toString());
    }

    /**
     * removeAll removes all elements from the given collection
     */
    public void testRemoveAll() {
        Set full = populatedSet(3);
        assertTrue(full.removeAll(Arrays.asList(one, two)));
        assertEquals(1, full.size());
        assertFalse(full.removeAll(Arrays.asList(one, two)));
        assertEquals(1, full.size());
    }

    /**
     * remove removes an element
     */
    public void testRemove() {
        Collection full = populatedSet(3);
        full.remove(one);
        assertFalse(full.contains(one));
        assertEquals(2, full.size());
    }

    /**
     * size returns the number of elements
     */
    public void testSize() {
        Collection empty = new CopyOnWriteArraySet();
        Collection full = populatedSet(3);
        assertEquals(3, full.size());
        assertEquals(0, empty.size());
    }

    /**
     * toArray() returns an Object array containing all elements from
     * the set in insertion order
     */
    public void testToArray() {
        Object[] a = new CopyOnWriteArraySet().toArray();
        assertTrue(Arrays.equals(new Object[0], a));
        assertSame(Object[].class, a.getClass());

        Integer[] elements = new Integer[SIZE];
        for (int i = 0; i < SIZE; i++)
            elements[i] = i;
        shuffle(elements);
        Collection<Integer> full = populatedSet(elements);

        assertTrue(Arrays.equals(elements, full.toArray()));
        assertSame(Object[].class, full.toArray().getClass());
    }

    /**
     * toArray(Integer array) returns an Integer array containing all
     * elements from the set in insertion order
     */
    public void testToArray2() {
        Collection empty = new CopyOnWriteArraySet();
        Integer[] a;

        a = new Integer[0];
        assertSame(a, empty.toArray(a));

        a = new Integer[SIZE / 2];
        Arrays.fill(a, 42);
        assertSame(a, empty.toArray(a));
        assertNull(a[0]);
        for (int i = 1; i < a.length; i++)
            assertEquals(42, (int) a[i]);

        Integer[] elements = new Integer[SIZE];
        for (int i = 0; i < SIZE; i++)
            elements[i] = i;
        shuffle(elements);
        Collection<Integer> full = populatedSet(elements);

        Arrays.fill(a, 42);
        assertTrue(Arrays.equals(elements, full.toArray(a)));
        for (int i = 0; i < a.length; i++)
            assertEquals(42, (int) a[i]);
        assertSame(Integer[].class, full.toArray(a).getClass());

        a = new Integer[SIZE];
        Arrays.fill(a, 42);
        assertSame(a, full.toArray(a));
        assertTrue(Arrays.equals(elements, a));

        a = new Integer[2 * SIZE];
        Arrays.fill(a, 42);
        assertSame(a, full.toArray(a));
        assertTrue(Arrays.equals(elements, Arrays.copyOf(a, SIZE)));
        assertNull(a[SIZE]);
        for (int i = SIZE + 1; i < a.length; i++)
            assertEquals(42, (int) a[i]);
    }

    /**
     * toArray throws an ArrayStoreException when the given array can
     * not store the objects inside the set
     */
    public void testToArray_ArrayStoreException() {
        CopyOnWriteArraySet c = new CopyOnWriteArraySet();
        c.add("zfasdfsdf");
        c.add("asdadasd");
        try {
            c.toArray(new Long[5]);
            shouldThrow();
        } catch (ArrayStoreException success) {}
    }

    /**
     * A deserialized/reserialized set equals original
     */
    public void testSerialization() throws Exception {
        Set x = populatedSet(SIZE);
        Set y = serialClone(x);

        assertNotSame(y, x);
        assertEquals(x.size(), y.size());
        assertEquals(x.toString(), y.toString());
        assertTrue(Arrays.equals(x.toArray(), y.toArray()));
        assertEquals(x, y);
        assertEquals(y, x);
    }

    /**
     * addAll is idempotent
     */
    public void testAddAll_idempotent() throws Exception {
        Set x = populatedSet(SIZE);
        Set y = new CopyOnWriteArraySet(x);
        y.addAll(x);
        assertEquals(x, y);
        assertEquals(y, x);
    }

}
Revision:	1.39
Committed:	Fri Aug 4 03:30:21 2017 UTC (6 years, 9 months ago) by jsr166
Branch:	MAIN
Changes since 1.38:	+1 -1 lines
Log Message:	improve javadoc wording for testSerialization methods
#	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 java.util.ArrayList;
10	import java.util.Arrays;
11	import java.util.Collection;
12	import java.util.Iterator;
13	import java.util.NoSuchElementException;
14	import java.util.Set;
15	import java.util.concurrent.CopyOnWriteArraySet;
16
17	import junit.framework.Test;
18	import junit.framework.TestSuite;
19
20	public class CopyOnWriteArraySetTest extends JSR166TestCase {
21	public static void main(String[] args) {
22	main(suite(), args);
23	}
24	public static Test suite() {
25	return new TestSuite(CopyOnWriteArraySetTest.class);
26	}
27
28	static CopyOnWriteArraySet<Integer> populatedSet(int n) {
29	CopyOnWriteArraySet<Integer> a = new CopyOnWriteArraySet<>();
30	assertTrue(a.isEmpty());
31	for (int i = 0; i < n; i++)
32	a.add(i);
33	assertEquals(n == 0, a.isEmpty());
34	assertEquals(n, a.size());
35	return a;
36	}
37
38	static CopyOnWriteArraySet populatedSet(Integer[] elements) {
39	CopyOnWriteArraySet<Integer> a = new CopyOnWriteArraySet<>();
40	assertTrue(a.isEmpty());
41	for (int i = 0; i < elements.length; i++)
42	a.add(elements[i]);
43	assertFalse(a.isEmpty());
44	assertEquals(elements.length, a.size());
45	return a;
46	}
47
48	/**
49	* Default-constructed set is empty
50	*/
51	public void testConstructor() {
52	CopyOnWriteArraySet a = new CopyOnWriteArraySet();
53	assertTrue(a.isEmpty());
54	}
55
56	/**
57	* Collection-constructed set holds all of its elements
58	*/
59	public void testConstructor3() {
60	Integer[] ints = new Integer[SIZE];
61	for (int i = 0; i < SIZE - 1; ++i)
62	ints[i] = new Integer(i);
63	CopyOnWriteArraySet a = new CopyOnWriteArraySet(Arrays.asList(ints));
64	for (int i = 0; i < SIZE; ++i)
65	assertTrue(a.contains(ints[i]));
66	}
67
68	/**
69	* addAll adds each non-duplicate element from the given collection
70	*/
71	public void testAddAll() {
72	Set full = populatedSet(3);
73	assertTrue(full.addAll(Arrays.asList(three, four, five)));
74	assertEquals(6, full.size());
75	assertFalse(full.addAll(Arrays.asList(three, four, five)));
76	assertEquals(6, full.size());
77	}
78
79	/**
80	* addAll adds each non-duplicate element from the given collection
81	*/
82	public void testAddAll2() {
83	Set full = populatedSet(3);
84	// "one" is duplicate and will not be added
85	assertTrue(full.addAll(Arrays.asList(three, four, one)));
86	assertEquals(5, full.size());
87	assertFalse(full.addAll(Arrays.asList(three, four, one)));
88	assertEquals(5, full.size());
89	}
90
91	/**
92	* add will not add the element if it already exists in the set
93	*/
94	public void testAdd2() {
95	Set full = populatedSet(3);
96	full.add(one);
97	assertEquals(3, full.size());
98	}
99
100	/**
101	* add adds the element when it does not exist in the set
102	*/
103	public void testAdd3() {
104	Set full = populatedSet(3);
105	full.add(three);
106	assertTrue(full.contains(three));
107	}
108
109	/**
110	* clear removes all elements from the set
111	*/
112	public void testClear() {
113	Collection full = populatedSet(3);
114	full.clear();
115	assertEquals(0, full.size());
116	assertTrue(full.isEmpty());
117	}
118
119	/**
120	* contains returns true for added elements
121	*/
122	public void testContains() {
123	Collection full = populatedSet(3);
124	assertTrue(full.contains(one));
125	assertFalse(full.contains(five));
126	}
127
128	/**
129	* Sets with equal elements are equal
130	*/
131	public void testEquals() {
132	CopyOnWriteArraySet a = populatedSet(3);
133	CopyOnWriteArraySet b = populatedSet(3);
134	assertTrue(a.equals(b));
135	assertTrue(b.equals(a));
136	assertTrue(a.containsAll(b));
137	assertTrue(b.containsAll(a));
138	assertEquals(a.hashCode(), b.hashCode());
139	assertEquals(a.size(), b.size());
140
141	a.add(m1);
142	assertFalse(a.equals(b));
143	assertFalse(b.equals(a));
144	assertTrue(a.containsAll(b));
145	assertFalse(b.containsAll(a));
146	b.add(m1);
147	assertTrue(a.equals(b));
148	assertTrue(b.equals(a));
149	assertTrue(a.containsAll(b));
150	assertTrue(b.containsAll(a));
151	assertEquals(a.hashCode(), b.hashCode());
152
153	Object x = a.iterator().next();
154	a.remove(x);
155	assertFalse(a.equals(b));
156	assertFalse(b.equals(a));
157	assertFalse(a.containsAll(b));
158	assertTrue(b.containsAll(a));
159	a.add(x);
160	assertTrue(a.equals(b));
161	assertTrue(b.equals(a));
162	assertTrue(a.containsAll(b));
163	assertTrue(b.containsAll(a));
164	assertEquals(a.hashCode(), b.hashCode());
165	assertEquals(a.size(), b.size());
166
167	CopyOnWriteArraySet empty1 = new CopyOnWriteArraySet(Arrays.asList());
168	CopyOnWriteArraySet empty2 = new CopyOnWriteArraySet(Arrays.asList());
169	assertTrue(empty1.equals(empty1));
170	assertTrue(empty1.equals(empty2));
171
172	assertFalse(empty1.equals(a));
173	assertFalse(a.equals(empty1));
174
175	assertFalse(a.equals(null));
176	}
177
178	/**
179	* containsAll returns true for collections with subset of elements
180	*/
181	public void testContainsAll() {
182	Collection full = populatedSet(3);
183	assertTrue(full.containsAll(full));
184	assertTrue(full.containsAll(Arrays.asList()));
185	assertTrue(full.containsAll(Arrays.asList(one)));
186	assertTrue(full.containsAll(Arrays.asList(one, two)));
187	assertFalse(full.containsAll(Arrays.asList(one, two, six)));
188	assertFalse(full.containsAll(Arrays.asList(six)));
189
190	CopyOnWriteArraySet empty1 = new CopyOnWriteArraySet(Arrays.asList());
191	CopyOnWriteArraySet empty2 = new CopyOnWriteArraySet(Arrays.asList());
192	assertTrue(empty1.containsAll(empty2));
193	assertTrue(empty1.containsAll(empty1));
194	assertFalse(empty1.containsAll(full));
195	assertTrue(full.containsAll(empty1));
196
197	try {
198	full.containsAll(null);
199	shouldThrow();
200	} catch (NullPointerException success) {}
201	}
202
203	/**
204	* isEmpty is true when empty, else false
205	*/
206	public void testIsEmpty() {
207	assertTrue(populatedSet(0).isEmpty());
208	assertFalse(populatedSet(3).isEmpty());
209	}
210
211	/**
212	* iterator() returns an iterator containing the elements of the
213	* set in insertion order
214	*/
215	public void testIterator() {
216	Collection empty = new CopyOnWriteArraySet();
217	assertFalse(empty.iterator().hasNext());
218	try {
219	empty.iterator().next();
220	shouldThrow();
221	} catch (NoSuchElementException success) {}
222
223	Integer[] elements = new Integer[SIZE];
224	for (int i = 0; i < SIZE; i++)
225	elements[i] = i;
226	shuffle(elements);
227	Collection<Integer> full = populatedSet(elements);
228
229	Iterator it = full.iterator();
230	for (int j = 0; j < SIZE; j++) {
231	assertTrue(it.hasNext());
232	assertEquals(elements[j], it.next());
233	}
234	assertIteratorExhausted(it);
235	}
236
237	/**
238	* iterator of empty collection has no elements
239	*/
240	public void testEmptyIterator() {
241	assertIteratorExhausted(new CopyOnWriteArraySet().iterator());
242	}
243
244	/**
245	* iterator remove is unsupported
246	*/
247	public void testIteratorRemove() {
248	Collection full = populatedSet(3);
249	Iterator it = full.iterator();
250	it.next();
251	try {
252	it.remove();
253	shouldThrow();
254	} catch (UnsupportedOperationException success) {}
255	}
256
257	/**
258	* toString holds toString of elements
259	*/
260	public void testToString() {
261	assertEquals("[]", new CopyOnWriteArraySet().toString());
262	Collection full = populatedSet(3);
263	String s = full.toString();
264	for (int i = 0; i < 3; ++i)
265	assertTrue(s.contains(String.valueOf(i)));
266	assertEquals(new ArrayList(full).toString(),
267	full.toString());
268	}
269
270	/**
271	* removeAll removes all elements from the given collection
272	*/
273	public void testRemoveAll() {
274	Set full = populatedSet(3);
275	assertTrue(full.removeAll(Arrays.asList(one, two)));
276	assertEquals(1, full.size());
277	assertFalse(full.removeAll(Arrays.asList(one, two)));
278	assertEquals(1, full.size());
279	}
280
281	/**
282	* remove removes an element
283	*/
284	public void testRemove() {
285	Collection full = populatedSet(3);
286	full.remove(one);
287	assertFalse(full.contains(one));
288	assertEquals(2, full.size());
289	}
290
291	/**
292	* size returns the number of elements
293	*/
294	public void testSize() {
295	Collection empty = new CopyOnWriteArraySet();
296	Collection full = populatedSet(3);
297	assertEquals(3, full.size());
298	assertEquals(0, empty.size());
299	}
300
301	/**
302	* toArray() returns an Object array containing all elements from
303	* the set in insertion order
304	*/
305	public void testToArray() {
306	Object[] a = new CopyOnWriteArraySet().toArray();
307	assertTrue(Arrays.equals(new Object[0], a));
308	assertSame(Object[].class, a.getClass());
309
310	Integer[] elements = new Integer[SIZE];
311	for (int i = 0; i < SIZE; i++)
312	elements[i] = i;
313	shuffle(elements);
314	Collection<Integer> full = populatedSet(elements);
315
316	assertTrue(Arrays.equals(elements, full.toArray()));
317	assertSame(Object[].class, full.toArray().getClass());
318	}
319
320	/**
321	* toArray(Integer array) returns an Integer array containing all
322	* elements from the set in insertion order
323	*/
324	public void testToArray2() {
325	Collection empty = new CopyOnWriteArraySet();
326	Integer[] a;
327
328	a = new Integer[0];
329	assertSame(a, empty.toArray(a));
330
331	a = new Integer[SIZE / 2];
332	Arrays.fill(a, 42);
333	assertSame(a, empty.toArray(a));
334	assertNull(a[0]);
335	for (int i = 1; i < a.length; i++)
336	assertEquals(42, (int) a[i]);
337
338	Integer[] elements = new Integer[SIZE];
339	for (int i = 0; i < SIZE; i++)
340	elements[i] = i;
341	shuffle(elements);
342	Collection<Integer> full = populatedSet(elements);
343
344	Arrays.fill(a, 42);
345	assertTrue(Arrays.equals(elements, full.toArray(a)));
346	for (int i = 0; i < a.length; i++)
347	assertEquals(42, (int) a[i]);
348	assertSame(Integer[].class, full.toArray(a).getClass());
349
350	a = new Integer[SIZE];
351	Arrays.fill(a, 42);
352	assertSame(a, full.toArray(a));
353	assertTrue(Arrays.equals(elements, a));
354
355	a = new Integer[2 * SIZE];
356	Arrays.fill(a, 42);
357	assertSame(a, full.toArray(a));
358	assertTrue(Arrays.equals(elements, Arrays.copyOf(a, SIZE)));
359	assertNull(a[SIZE]);
360	for (int i = SIZE + 1; i < a.length; i++)
361	assertEquals(42, (int) a[i]);
362	}
363
364	/**
365	* toArray throws an ArrayStoreException when the given array can
366	* not store the objects inside the set
367	*/
368	public void testToArray_ArrayStoreException() {
369	CopyOnWriteArraySet c = new CopyOnWriteArraySet();
370	c.add("zfasdfsdf");
371	c.add("asdadasd");
372	try {
373	c.toArray(new Long[5]);
374	shouldThrow();
375	} catch (ArrayStoreException success) {}
376	}
377
378	/**
379	* A deserialized/reserialized set equals original
380	*/
381	public void testSerialization() throws Exception {
382	Set x = populatedSet(SIZE);
383	Set y = serialClone(x);
384
385	assertNotSame(y, x);
386	assertEquals(x.size(), y.size());
387	assertEquals(x.toString(), y.toString());
388	assertTrue(Arrays.equals(x.toArray(), y.toArray()));
389	assertEquals(x, y);
390	assertEquals(y, x);
391	}
392
393	/**
394	* addAll is idempotent
395	*/
396	public void testAddAll_idempotent() throws Exception {
397	Set x = populatedSet(SIZE);
398	Set y = new CopyOnWriteArraySet(x);
399	y.addAll(x);
400	assertEquals(x, y);
401	assertEquals(y, x);
402	}
403
404	}