test/tck/CopyOnWriteArrayListTest.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.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.NoSuchElementException;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.ThreadLocalRandom;

import junit.framework.Test;

public class CopyOnWriteArrayListTest extends JSR166TestCase {

    public static void main(String[] args) {
        main(suite(), args);
    }

    public static Test suite() {
        class Implementation implements CollectionImplementation {
            public Class<?> klazz() { return CopyOnWriteArrayList.class; }
            public List emptyCollection() { return new CopyOnWriteArrayList(); }
            public Object makeElement(int i) { return i; }
            public boolean isConcurrent() { return true; }
            public boolean permitsNulls() { return true; }
        }
        class SubListImplementation extends Implementation {
            public List emptyCollection() {
                return super.emptyCollection().subList(0, 0);
            }
        }
        return newTestSuite(
                CopyOnWriteArrayListTest.class,
                CollectionTest.testSuite(new Implementation()),
                CollectionTest.testSuite(new SubListImplementation()));
    }

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

    static CopyOnWriteArrayList<Integer> populatedList(Integer[] elements) {
        CopyOnWriteArrayList<Integer> list = new CopyOnWriteArrayList<>();
        assertTrue(list.isEmpty());
        for (Integer element : elements)
            list.add(element);
        assertFalse(list.isEmpty());
        assertEquals(elements.length, list.size());
        return list;
    }

    /**
     * a new list is empty
     */
    public void testConstructor() {
        List list = new CopyOnWriteArrayList();
        assertTrue(list.isEmpty());
    }

    /**
     * new list contains all elements of initializing array
     */
    public void testConstructor2() {
        Integer[] elts = new Integer[SIZE];
        for (int i = 0; i < SIZE - 1; ++i)
            elts[i] = i;
        List list = new CopyOnWriteArrayList(elts);
        for (int i = 0; i < SIZE; ++i)
            assertEquals(elts[i], list.get(i));
    }

    /**
     * new list contains all elements of initializing collection
     */
    public void testConstructor3() {
        Integer[] elts = new Integer[SIZE];
        for (int i = 0; i < SIZE - 1; ++i)
            elts[i] = i;
        List list = new CopyOnWriteArrayList(Arrays.asList(elts));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(elts[i], list.get(i));
    }

    /**
     * addAll adds each element from the given collection, including duplicates
     */
    public void testAddAll() {
        List list = populatedList(3);
        assertTrue(list.addAll(Arrays.asList(three, four, five)));
        assertEquals(6, list.size());
        assertTrue(list.addAll(Arrays.asList(three, four, five)));
        assertEquals(9, list.size());
    }

    /**
     * addAllAbsent adds each element from the given collection that did not
     * already exist in the List
     */
    public void testAddAllAbsent() {
        CopyOnWriteArrayList list = populatedList(3);
        // "one" is duplicate and will not be added
        assertEquals(2, list.addAllAbsent(Arrays.asList(three, four, one)));
        assertEquals(5, list.size());
        assertEquals(0, list.addAllAbsent(Arrays.asList(three, four, one)));
        assertEquals(5, list.size());
    }

    /**
     * addIfAbsent will not add the element if it already exists in the list
     */
    public void testAddIfAbsent() {
        CopyOnWriteArrayList list = populatedList(SIZE);
        list.addIfAbsent(one);
        assertEquals(SIZE, list.size());
    }

    /**
     * addIfAbsent adds the element when it does not exist in the list
     */
    public void testAddIfAbsent2() {
        CopyOnWriteArrayList list = populatedList(SIZE);
        list.addIfAbsent(three);
        assertTrue(list.contains(three));
    }

    /**
     * clear removes all elements from the list
     */
    public void testClear() {
        List list = populatedList(SIZE);
        list.clear();
        assertEquals(0, list.size());
    }

    /**
     * Cloned list is equal
     */
    public void testClone() {
        CopyOnWriteArrayList l1 = populatedList(SIZE);
        CopyOnWriteArrayList l2 = (CopyOnWriteArrayList)(l1.clone());
        assertEquals(l1, l2);
        l1.clear();
        assertFalse(l1.equals(l2));
    }

    /**
     * contains is true for added elements
     */
    public void testContains() {
        List list = populatedList(3);
        assertTrue(list.contains(one));
        assertFalse(list.contains(five));
    }

    /**
     * adding at an index places it in the indicated index
     */
    public void testAddIndex() {
        List list = populatedList(3);
        list.add(0, m1);
        assertEquals(4, list.size());
        assertEquals(m1, list.get(0));
        assertEquals(zero, list.get(1));

        list.add(2, m2);
        assertEquals(5, list.size());
        assertEquals(m2, list.get(2));
        assertEquals(two, list.get(4));
    }

    /**
     * lists with same elements are equal and have same hashCode
     */
    public void testEquals() {
        List a = populatedList(3);
        List b = populatedList(3);
        assertTrue(a.equals(b));
        assertTrue(b.equals(a));
        assertTrue(a.containsAll(b));
        assertTrue(b.containsAll(a));
        assertEquals(a.hashCode(), b.hashCode());
        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());

        assertFalse(a.equals(null));
    }

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

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

    /**
     * get returns the value at the given index
     */
    public void testGet() {
        List list = populatedList(3);
        assertEquals(0, list.get(0));
    }

    /**
     * indexOf(Object) returns the index of the first occurrence of the
     * specified element in this list, or -1 if this list does not
     * contain the element
     */
    public void testIndexOf() {
        List list = populatedList(3);
        assertEquals(-1, list.indexOf(-42));
        int size = list.size();
        for (int i = 0; i < size; i++) {
            assertEquals(i, list.indexOf(i));
            assertEquals(i, list.subList(0, size).indexOf(i));
            assertEquals(i, list.subList(0, i + 1).indexOf(i));
            assertEquals(-1, list.subList(0, i).indexOf(i));
            assertEquals(0, list.subList(i, size).indexOf(i));
            assertEquals(-1, list.subList(i + 1, size).indexOf(i));
        }

        list.add(1);
        assertEquals(1, list.indexOf(1));
        assertEquals(1, list.subList(0, size + 1).indexOf(1));
        assertEquals(0, list.subList(1, size + 1).indexOf(1));
        assertEquals(size - 2, list.subList(2, size + 1).indexOf(1));
        assertEquals(0, list.subList(size, size + 1).indexOf(1));
        assertEquals(-1, list.subList(size + 1, size + 1).indexOf(1));
    }

    /**
     * indexOf(E, int) returns the index of the first occurrence of the
     * specified element in this list, searching forwards from index,
     * or returns -1 if the element is not found
     */
    public void testIndexOf2() {
        CopyOnWriteArrayList list = populatedList(3);
        int size = list.size();
        assertEquals(-1, list.indexOf(-42, 0));

        // we might expect IOOBE, but spec says otherwise
        assertEquals(-1, list.indexOf(0, size));
        assertEquals(-1, list.indexOf(0, Integer.MAX_VALUE));

        assertThrows(
            IndexOutOfBoundsException.class,
            () -> list.indexOf(0, -1),
            () -> list.indexOf(0, Integer.MIN_VALUE));

        for (int i = 0; i < size; i++) {
            assertEquals(i, list.indexOf(i, 0));
            assertEquals(i, list.indexOf(i, i));
            assertEquals(-1, list.indexOf(i, i + 1));
        }

        list.add(1);
        assertEquals(1, list.indexOf(1, 0));
        assertEquals(1, list.indexOf(1, 1));
        assertEquals(size, list.indexOf(1, 2));
        assertEquals(size, list.indexOf(1, size));
    }

    /**
     * isEmpty returns true when empty, else false
     */
    public void testIsEmpty() {
        List empty = new CopyOnWriteArrayList();
        assertTrue(empty.isEmpty());
        assertTrue(empty.subList(0, 0).isEmpty());

        List full = populatedList(SIZE);
        assertFalse(full.isEmpty());
        assertTrue(full.subList(0, 0).isEmpty());
        assertTrue(full.subList(SIZE, SIZE).isEmpty());
    }

    /**
     * iterator() returns an iterator containing the elements of the
     * list in insertion order
     */
    public void testIterator() {
        Collection empty = new CopyOnWriteArrayList();
        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 = populatedList(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() {
        Collection c = new CopyOnWriteArrayList();
        assertIteratorExhausted(c.iterator());
    }

    /**
     * iterator.remove throws UnsupportedOperationException
     */
    public void testIteratorRemove() {
        CopyOnWriteArrayList list = populatedList(SIZE);
        Iterator it = list.iterator();
        it.next();
        try {
            it.remove();
            shouldThrow();
        } catch (UnsupportedOperationException success) {}
    }

    /**
     * toString contains toString of elements
     */
    public void testToString() {
        assertEquals("[]", new CopyOnWriteArrayList().toString());
        List list = populatedList(3);
        String s = list.toString();
        for (int i = 0; i < 3; ++i)
            assertTrue(s.contains(String.valueOf(i)));
        assertEquals(new ArrayList(list).toString(),
                     list.toString());
    }

    /**
     * lastIndexOf(Object) returns the index of the last occurrence of
     * the specified element in this list, or -1 if this list does not
     * contain the element
     */
    public void testLastIndexOf1() {
        List list = populatedList(3);
        assertEquals(-1, list.lastIndexOf(-42));
        int size = list.size();
        for (int i = 0; i < size; i++) {
            assertEquals(i, list.lastIndexOf(i));
            assertEquals(i, list.subList(0, size).lastIndexOf(i));
            assertEquals(i, list.subList(0, i + 1).lastIndexOf(i));
            assertEquals(-1, list.subList(0, i).lastIndexOf(i));
            assertEquals(0, list.subList(i, size).lastIndexOf(i));
            assertEquals(-1, list.subList(i + 1, size).lastIndexOf(i));
        }

        list.add(1);
        assertEquals(size, list.lastIndexOf(1));
        assertEquals(size, list.subList(0, size + 1).lastIndexOf(1));
        assertEquals(1, list.subList(0, size).lastIndexOf(1));
        assertEquals(0, list.subList(1, 2).lastIndexOf(1));
        assertEquals(-1, list.subList(0, 1).indexOf(1));
    }

    /**
     * lastIndexOf(E, int) returns the index of the last occurrence of the
     * specified element in this list, searching backwards from index, or
     * returns -1 if the element is not found
     */
    public void testLastIndexOf2() {
        CopyOnWriteArrayList list = populatedList(3);

        // we might expect IOOBE, but spec says otherwise
        assertEquals(-1, list.lastIndexOf(0, -1));

        int size = list.size();
        assertThrows(
            IndexOutOfBoundsException.class,
            () -> list.lastIndexOf(0, size),
            () -> list.lastIndexOf(0, Integer.MAX_VALUE));

        for (int i = 0; i < size; i++) {
            assertEquals(i, list.lastIndexOf(i, i));
            assertEquals(list.indexOf(i), list.lastIndexOf(i, i));
            if (i > 0)
                assertEquals(-1, list.lastIndexOf(i, i - 1));
        }
        list.add(one);
        list.add(three);
        assertEquals(1, list.lastIndexOf(one, 1));
        assertEquals(1, list.lastIndexOf(one, 2));
        assertEquals(3, list.lastIndexOf(one, 3));
        assertEquals(3, list.lastIndexOf(one, 4));
        assertEquals(-1, list.lastIndexOf(three, 3));
    }

    /**
     * listIterator traverses all elements
     */
    public void testListIterator1() {
        List list = populatedList(SIZE);
        ListIterator i = list.listIterator();
        int j;
        for (j = 0; i.hasNext(); j++)
            assertEquals(j, i.next());
        assertEquals(SIZE, j);
    }

    /**
     * listIterator only returns those elements after the given index
     */
    public void testListIterator2() {
        List list = populatedList(3);
        ListIterator i = list.listIterator(1);
        int j;
        for (j = 0; i.hasNext(); j++)
            assertEquals(j + 1, i.next());
        assertEquals(2, j);
    }

    /**
     * remove(int) removes and returns the object at the given index
     */
    public void testRemove_int() {
        int SIZE = 3;
        for (int i = 0; i < SIZE; i++) {
            List list = populatedList(SIZE);
            assertEquals(i, list.remove(i));
            assertEquals(SIZE - 1, list.size());
            assertFalse(list.contains(new Integer(i)));
        }
    }

    /**
     * remove(Object) removes the object if found and returns true
     */
    public void testRemove_Object() {
        int SIZE = 3;
        for (int i = 0; i < SIZE; i++) {
            List list = populatedList(SIZE);
            assertFalse(list.remove(new Integer(-42)));
            assertTrue(list.remove(new Integer(i)));
            assertEquals(SIZE - 1, list.size());
            assertFalse(list.contains(new Integer(i)));
        }
        CopyOnWriteArrayList x = new CopyOnWriteArrayList(Arrays.asList(4, 5, 6));
        assertTrue(x.remove(new Integer(6)));
        assertEquals(x, Arrays.asList(4, 5));
        assertTrue(x.remove(new Integer(4)));
        assertEquals(x, Arrays.asList(5));
        assertTrue(x.remove(new Integer(5)));
        assertEquals(x, Arrays.asList());
        assertFalse(x.remove(new Integer(5)));
    }

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

    /**
     * set changes the element at the given index
     */
    public void testSet() {
        List list = populatedList(3);
        assertEquals(2, list.set(2, four));
        assertEquals(4, list.get(2));
    }

    /**
     * size returns the number of elements
     */
    public void testSize() {
        List empty = new CopyOnWriteArrayList();
        assertEquals(0, empty.size());
        assertEquals(0, empty.subList(0, 0).size());

        List full = populatedList(SIZE);
        assertEquals(SIZE, full.size());
        assertEquals(0, full.subList(0, 0).size());
        assertEquals(0, full.subList(SIZE, SIZE).size());
    }

    /**
     * toArray() returns an Object array containing all elements from
     * the list in insertion order
     */
    public void testToArray() {
        Object[] a = new CopyOnWriteArrayList().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 = populatedList(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 list in insertion order
     */
    public void testToArray2() {
        Collection empty = new CopyOnWriteArrayList();
        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 = populatedList(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]);
    }

    /**
     * sublists contains elements at indexes offset from their base
     */
    public void testSubList() {
        List a = populatedList(10);
        assertTrue(a.subList(1,1).isEmpty());
        for (int j = 0; j < 9; ++j) {
            for (int i = j ; i < 10; ++i) {
                List b = a.subList(j,i);
                for (int k = j; k < i; ++k) {
                    assertEquals(new Integer(k), b.get(k-j));
                }
            }
        }

        List s = a.subList(2, 5);
        assertEquals(3, s.size());
        s.set(2, m1);
        assertEquals(a.get(4), m1);
        s.clear();
        assertEquals(7, a.size());

        assertThrows(
            IndexOutOfBoundsException.class,
            () -> s.get(0),
            () -> s.set(0, 42));
    }

    // Exception tests

    /**
     * toArray throws an ArrayStoreException when the given array
     * can not store the objects inside the list
     */
    public void testToArray_ArrayStoreException() {
        List list = new CopyOnWriteArrayList();
        // Integers are not auto-converted to Longs
        list.add(86);
        list.add(99);
        assertThrows(
            ArrayStoreException.class,
            () -> list.toArray(new Long[0]),
            () -> list.toArray(new Long[5]));
    }

    void testIndexOutOfBoundsException(List list) {
        int size = list.size();
        assertThrows(
            IndexOutOfBoundsException.class,
            () -> list.get(-1),
            () -> list.get(size),
            () -> list.set(-1, "qwerty"),
            () -> list.set(size, "qwerty"),
            () -> list.add(-1, "qwerty"),
            () -> list.add(size + 1, "qwerty"),
            () -> list.remove(-1),
            () -> list.remove(size),
            () -> list.addAll(-1, Collections.emptyList()),
            () -> list.addAll(size + 1, Collections.emptyList()),
            () -> list.listIterator(-1),
            () -> list.listIterator(size + 1),
            () -> list.subList(-1, size),
            () -> list.subList(0, size + 1));

        // Conversely, operations that must not throw
        list.addAll(0, Collections.emptyList());
        list.addAll(size, Collections.emptyList());
        list.add(0, "qwerty");
        list.add(list.size(), "qwerty");
        list.get(0);
        list.get(list.size() - 1);
        list.set(0, "azerty");
        list.set(list.size() - 1, "azerty");
        list.listIterator(0);
        list.listIterator(list.size());
        list.subList(0, list.size());
        list.remove(list.size() - 1);
    }

    /**
     * IndexOutOfBoundsException is thrown when specified
     */
    public void testIndexOutOfBoundsException() {
        ThreadLocalRandom rnd = ThreadLocalRandom.current();
        List x = populatedList(rnd.nextInt(5));
        testIndexOutOfBoundsException(x);

        int start = rnd.nextInt(x.size() + 1);
        int end = rnd.nextInt(start, x.size() + 1);
        assertThrows(
            IndexOutOfBoundsException.class,
            () -> x.subList(start, start - 1));
        List subList = x.subList(start, end);
        testIndexOutOfBoundsException(x);
    }

    /**
     * a deserialized/reserialized list equals original
     */
    public void testSerialization() throws Exception {
        List x = populatedList(SIZE);
        List y = serialClone(x);

        assertNotSame(x, y);
        assertEquals(x.size(), y.size());
        assertEquals(x.toString(), y.toString());
        assertTrue(Arrays.equals(x.toArray(), y.toArray()));
        assertEquals(x, y);
        assertEquals(y, x);
        while (!x.isEmpty()) {
            assertFalse(y.isEmpty());
            assertEquals(x.remove(0), y.remove(0));
        }
        assertTrue(y.isEmpty());
    }

}
Revision:	1.48
Committed:	Tue Apr 3 00:58:28 2018 UTC (6 years, 1 month ago) by jsr166
Branch:	MAIN
Changes since 1.47:	+172 -322 lines
Log Message:	many small improvements
#	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.Collections;
13	import java.util.Iterator;
14	import java.util.List;
15	import java.util.ListIterator;
16	import java.util.NoSuchElementException;
17	import java.util.concurrent.CopyOnWriteArrayList;
18	import java.util.concurrent.ThreadLocalRandom;
19
20	import junit.framework.Test;
21
22	public class CopyOnWriteArrayListTest extends JSR166TestCase {
23
24	public static void main(String[] args) {
25	main(suite(), args);
26	}
27
28	public static Test suite() {
29	class Implementation implements CollectionImplementation {
30	public Class<?> klazz() { return CopyOnWriteArrayList.class; }
31	public List emptyCollection() { return new CopyOnWriteArrayList(); }
32	public Object makeElement(int i) { return i; }
33	public boolean isConcurrent() { return true; }
34	public boolean permitsNulls() { return true; }
35	}
36	class SubListImplementation extends Implementation {
37	public List emptyCollection() {
38	return super.emptyCollection().subList(0, 0);
39	}
40	}
41	return newTestSuite(
42	CopyOnWriteArrayListTest.class,
43	CollectionTest.testSuite(new Implementation()),
44	CollectionTest.testSuite(new SubListImplementation()));
45	}
46
47	static CopyOnWriteArrayList<Integer> populatedList(int n) {
48	CopyOnWriteArrayList<Integer> list = new CopyOnWriteArrayList<>();
49	assertTrue(list.isEmpty());
50	for (int i = 0; i < n; i++)
51	list.add(i);
52	assertEquals(n <= 0, list.isEmpty());
53	assertEquals(n, list.size());
54	return list;
55	}
56
57	static CopyOnWriteArrayList<Integer> populatedList(Integer[] elements) {
58	CopyOnWriteArrayList<Integer> list = new CopyOnWriteArrayList<>();
59	assertTrue(list.isEmpty());
60	for (Integer element : elements)
61	list.add(element);
62	assertFalse(list.isEmpty());
63	assertEquals(elements.length, list.size());
64	return list;
65	}
66
67	/**
68	* a new list is empty
69	*/
70	public void testConstructor() {
71	List list = new CopyOnWriteArrayList();
72	assertTrue(list.isEmpty());
73	}
74
75	/**
76	* new list contains all elements of initializing array
77	*/
78	public void testConstructor2() {
79	Integer[] elts = new Integer[SIZE];
80	for (int i = 0; i < SIZE - 1; ++i)
81	elts[i] = i;
82	List list = new CopyOnWriteArrayList(elts);
83	for (int i = 0; i < SIZE; ++i)
84	assertEquals(elts[i], list.get(i));
85	}
86
87	/**
88	* new list contains all elements of initializing collection
89	*/
90	public void testConstructor3() {
91	Integer[] elts = new Integer[SIZE];
92	for (int i = 0; i < SIZE - 1; ++i)
93	elts[i] = i;
94	List list = new CopyOnWriteArrayList(Arrays.asList(elts));
95	for (int i = 0; i < SIZE; ++i)
96	assertEquals(elts[i], list.get(i));
97	}
98
99	/**
100	* addAll adds each element from the given collection, including duplicates
101	*/
102	public void testAddAll() {
103	List list = populatedList(3);
104	assertTrue(list.addAll(Arrays.asList(three, four, five)));
105	assertEquals(6, list.size());
106	assertTrue(list.addAll(Arrays.asList(three, four, five)));
107	assertEquals(9, list.size());
108	}
109
110	/**
111	* addAllAbsent adds each element from the given collection that did not
112	* already exist in the List
113	*/
114	public void testAddAllAbsent() {
115	CopyOnWriteArrayList list = populatedList(3);
116	// "one" is duplicate and will not be added
117	assertEquals(2, list.addAllAbsent(Arrays.asList(three, four, one)));
118	assertEquals(5, list.size());
119	assertEquals(0, list.addAllAbsent(Arrays.asList(three, four, one)));
120	assertEquals(5, list.size());
121	}
122
123	/**
124	* addIfAbsent will not add the element if it already exists in the list
125	*/
126	public void testAddIfAbsent() {
127	CopyOnWriteArrayList list = populatedList(SIZE);
128	list.addIfAbsent(one);
129	assertEquals(SIZE, list.size());
130	}
131
132	/**
133	* addIfAbsent adds the element when it does not exist in the list
134	*/
135	public void testAddIfAbsent2() {
136	CopyOnWriteArrayList list = populatedList(SIZE);
137	list.addIfAbsent(three);
138	assertTrue(list.contains(three));
139	}
140
141	/**
142	* clear removes all elements from the list
143	*/
144	public void testClear() {
145	List list = populatedList(SIZE);
146	list.clear();
147	assertEquals(0, list.size());
148	}
149
150	/**
151	* Cloned list is equal
152	*/
153	public void testClone() {
154	CopyOnWriteArrayList l1 = populatedList(SIZE);
155	CopyOnWriteArrayList l2 = (CopyOnWriteArrayList)(l1.clone());
156	assertEquals(l1, l2);
157	l1.clear();
158	assertFalse(l1.equals(l2));
159	}
160
161	/**
162	* contains is true for added elements
163	*/
164	public void testContains() {
165	List list = populatedList(3);
166	assertTrue(list.contains(one));
167	assertFalse(list.contains(five));
168	}
169
170	/**
171	* adding at an index places it in the indicated index
172	*/
173	public void testAddIndex() {
174	List list = populatedList(3);
175	list.add(0, m1);
176	assertEquals(4, list.size());
177	assertEquals(m1, list.get(0));
178	assertEquals(zero, list.get(1));
179
180	list.add(2, m2);
181	assertEquals(5, list.size());
182	assertEquals(m2, list.get(2));
183	assertEquals(two, list.get(4));
184	}
185
186	/**
187	* lists with same elements are equal and have same hashCode
188	*/
189	public void testEquals() {
190	List a = populatedList(3);
191	List b = populatedList(3);
192	assertTrue(a.equals(b));
193	assertTrue(b.equals(a));
194	assertTrue(a.containsAll(b));
195	assertTrue(b.containsAll(a));
196	assertEquals(a.hashCode(), b.hashCode());
197	a.add(m1);
198	assertFalse(a.equals(b));
199	assertFalse(b.equals(a));
200	assertTrue(a.containsAll(b));
201	assertFalse(b.containsAll(a));
202	b.add(m1);
203	assertTrue(a.equals(b));
204	assertTrue(b.equals(a));
205	assertTrue(a.containsAll(b));
206	assertTrue(b.containsAll(a));
207	assertEquals(a.hashCode(), b.hashCode());
208
209	assertFalse(a.equals(null));
210	}
211
212	/**
213	* containsAll returns true for collections with subset of elements
214	*/
215	public void testContainsAll() {
216	List list = populatedList(3);
217	assertTrue(list.containsAll(Arrays.asList()));
218	assertTrue(list.containsAll(Arrays.asList(one)));
219	assertTrue(list.containsAll(Arrays.asList(one, two)));
220	assertFalse(list.containsAll(Arrays.asList(one, two, six)));
221	assertFalse(list.containsAll(Arrays.asList(six)));
222
223	try {
224	list.containsAll(null);
225	shouldThrow();
226	} catch (NullPointerException success) {}
227	}
228
229	/**
230	* get returns the value at the given index
231	*/
232	public void testGet() {
233	List list = populatedList(3);
234	assertEquals(0, list.get(0));
235	}
236
237	/**
238	* indexOf(Object) returns the index of the first occurrence of the
239	* specified element in this list, or -1 if this list does not
240	* contain the element
241	*/
242	public void testIndexOf() {
243	List list = populatedList(3);
244	assertEquals(-1, list.indexOf(-42));
245	int size = list.size();
246	for (int i = 0; i < size; i++) {
247	assertEquals(i, list.indexOf(i));
248	assertEquals(i, list.subList(0, size).indexOf(i));
249	assertEquals(i, list.subList(0, i + 1).indexOf(i));
250	assertEquals(-1, list.subList(0, i).indexOf(i));
251	assertEquals(0, list.subList(i, size).indexOf(i));
252	assertEquals(-1, list.subList(i + 1, size).indexOf(i));
253	}
254
255	list.add(1);
256	assertEquals(1, list.indexOf(1));
257	assertEquals(1, list.subList(0, size + 1).indexOf(1));
258	assertEquals(0, list.subList(1, size + 1).indexOf(1));
259	assertEquals(size - 2, list.subList(2, size + 1).indexOf(1));
260	assertEquals(0, list.subList(size, size + 1).indexOf(1));
261	assertEquals(-1, list.subList(size + 1, size + 1).indexOf(1));
262	}
263
264	/**
265	* indexOf(E, int) returns the index of the first occurrence of the
266	* specified element in this list, searching forwards from index,
267	* or returns -1 if the element is not found
268	*/
269	public void testIndexOf2() {
270	CopyOnWriteArrayList list = populatedList(3);
271	int size = list.size();
272	assertEquals(-1, list.indexOf(-42, 0));
273
274	// we might expect IOOBE, but spec says otherwise
275	assertEquals(-1, list.indexOf(0, size));
276	assertEquals(-1, list.indexOf(0, Integer.MAX_VALUE));
277
278	assertThrows(
279	IndexOutOfBoundsException.class,
280	() -> list.indexOf(0, -1),
281	() -> list.indexOf(0, Integer.MIN_VALUE));
282
283	for (int i = 0; i < size; i++) {
284	assertEquals(i, list.indexOf(i, 0));
285	assertEquals(i, list.indexOf(i, i));
286	assertEquals(-1, list.indexOf(i, i + 1));
287	}
288
289	list.add(1);
290	assertEquals(1, list.indexOf(1, 0));
291	assertEquals(1, list.indexOf(1, 1));
292	assertEquals(size, list.indexOf(1, 2));
293	assertEquals(size, list.indexOf(1, size));
294	}
295
296	/**
297	* isEmpty returns true when empty, else false
298	*/
299	public void testIsEmpty() {
300	List empty = new CopyOnWriteArrayList();
301	assertTrue(empty.isEmpty());
302	assertTrue(empty.subList(0, 0).isEmpty());
303
304	List full = populatedList(SIZE);
305	assertFalse(full.isEmpty());
306	assertTrue(full.subList(0, 0).isEmpty());
307	assertTrue(full.subList(SIZE, SIZE).isEmpty());
308	}
309
310	/**
311	* iterator() returns an iterator containing the elements of the
312	* list in insertion order
313	*/
314	public void testIterator() {
315	Collection empty = new CopyOnWriteArrayList();
316	assertFalse(empty.iterator().hasNext());
317	try {
318	empty.iterator().next();
319	shouldThrow();
320	} catch (NoSuchElementException success) {}
321
322	Integer[] elements = new Integer[SIZE];
323	for (int i = 0; i < SIZE; i++)
324	elements[i] = i;
325	shuffle(elements);
326	Collection<Integer> full = populatedList(elements);
327
328	Iterator it = full.iterator();
329	for (int j = 0; j < SIZE; j++) {
330	assertTrue(it.hasNext());
331	assertEquals(elements[j], it.next());
332	}
333	assertIteratorExhausted(it);
334	}
335
336	/**
337	* iterator of empty collection has no elements
338	*/
339	public void testEmptyIterator() {
340	Collection c = new CopyOnWriteArrayList();
341	assertIteratorExhausted(c.iterator());
342	}
343
344	/**
345	* iterator.remove throws UnsupportedOperationException
346	*/
347	public void testIteratorRemove() {
348	CopyOnWriteArrayList list = populatedList(SIZE);
349	Iterator it = list.iterator();
350	it.next();
351	try {
352	it.remove();
353	shouldThrow();
354	} catch (UnsupportedOperationException success) {}
355	}
356
357	/**
358	* toString contains toString of elements
359	*/
360	public void testToString() {
361	assertEquals("[]", new CopyOnWriteArrayList().toString());
362	List list = populatedList(3);
363	String s = list.toString();
364	for (int i = 0; i < 3; ++i)
365	assertTrue(s.contains(String.valueOf(i)));
366	assertEquals(new ArrayList(list).toString(),
367	list.toString());
368	}
369
370	/**
371	* lastIndexOf(Object) returns the index of the last occurrence of
372	* the specified element in this list, or -1 if this list does not
373	* contain the element
374	*/
375	public void testLastIndexOf1() {
376	List list = populatedList(3);
377	assertEquals(-1, list.lastIndexOf(-42));
378	int size = list.size();
379	for (int i = 0; i < size; i++) {
380	assertEquals(i, list.lastIndexOf(i));
381	assertEquals(i, list.subList(0, size).lastIndexOf(i));
382	assertEquals(i, list.subList(0, i + 1).lastIndexOf(i));
383	assertEquals(-1, list.subList(0, i).lastIndexOf(i));
384	assertEquals(0, list.subList(i, size).lastIndexOf(i));
385	assertEquals(-1, list.subList(i + 1, size).lastIndexOf(i));
386	}
387
388	list.add(1);
389	assertEquals(size, list.lastIndexOf(1));
390	assertEquals(size, list.subList(0, size + 1).lastIndexOf(1));
391	assertEquals(1, list.subList(0, size).lastIndexOf(1));
392	assertEquals(0, list.subList(1, 2).lastIndexOf(1));
393	assertEquals(-1, list.subList(0, 1).indexOf(1));
394	}
395
396	/**
397	* lastIndexOf(E, int) returns the index of the last occurrence of the
398	* specified element in this list, searching backwards from index, or
399	* returns -1 if the element is not found
400	*/
401	public void testLastIndexOf2() {
402	CopyOnWriteArrayList list = populatedList(3);
403
404	// we might expect IOOBE, but spec says otherwise
405	assertEquals(-1, list.lastIndexOf(0, -1));
406
407	int size = list.size();
408	assertThrows(
409	IndexOutOfBoundsException.class,
410	() -> list.lastIndexOf(0, size),
411	() -> list.lastIndexOf(0, Integer.MAX_VALUE));
412
413	for (int i = 0; i < size; i++) {
414	assertEquals(i, list.lastIndexOf(i, i));
415	assertEquals(list.indexOf(i), list.lastIndexOf(i, i));
416	if (i > 0)
417	assertEquals(-1, list.lastIndexOf(i, i - 1));
418	}
419	list.add(one);
420	list.add(three);
421	assertEquals(1, list.lastIndexOf(one, 1));
422	assertEquals(1, list.lastIndexOf(one, 2));
423	assertEquals(3, list.lastIndexOf(one, 3));
424	assertEquals(3, list.lastIndexOf(one, 4));
425	assertEquals(-1, list.lastIndexOf(three, 3));
426	}
427
428	/**
429	* listIterator traverses all elements
430	*/
431	public void testListIterator1() {
432	List list = populatedList(SIZE);
433	ListIterator i = list.listIterator();
434	int j;
435	for (j = 0; i.hasNext(); j++)
436	assertEquals(j, i.next());
437	assertEquals(SIZE, j);
438	}
439
440	/**
441	* listIterator only returns those elements after the given index
442	*/
443	public void testListIterator2() {
444	List list = populatedList(3);
445	ListIterator i = list.listIterator(1);
446	int j;
447	for (j = 0; i.hasNext(); j++)
448	assertEquals(j + 1, i.next());
449	assertEquals(2, j);
450	}
451
452	/**
453	* remove(int) removes and returns the object at the given index
454	*/
455	public void testRemove_int() {
456	int SIZE = 3;
457	for (int i = 0; i < SIZE; i++) {
458	List list = populatedList(SIZE);
459	assertEquals(i, list.remove(i));
460	assertEquals(SIZE - 1, list.size());
461	assertFalse(list.contains(new Integer(i)));
462	}
463	}
464
465	/**
466	* remove(Object) removes the object if found and returns true
467	*/
468	public void testRemove_Object() {
469	int SIZE = 3;
470	for (int i = 0; i < SIZE; i++) {
471	List list = populatedList(SIZE);
472	assertFalse(list.remove(new Integer(-42)));
473	assertTrue(list.remove(new Integer(i)));
474	assertEquals(SIZE - 1, list.size());
475	assertFalse(list.contains(new Integer(i)));
476	}
477	CopyOnWriteArrayList x = new CopyOnWriteArrayList(Arrays.asList(4, 5, 6));
478	assertTrue(x.remove(new Integer(6)));
479	assertEquals(x, Arrays.asList(4, 5));
480	assertTrue(x.remove(new Integer(4)));
481	assertEquals(x, Arrays.asList(5));
482	assertTrue(x.remove(new Integer(5)));
483	assertEquals(x, Arrays.asList());
484	assertFalse(x.remove(new Integer(5)));
485	}
486
487	/**
488	* removeAll removes all elements from the given collection
489	*/
490	public void testRemoveAll() {
491	List list = populatedList(3);
492	assertTrue(list.removeAll(Arrays.asList(one, two)));
493	assertEquals(1, list.size());
494	assertFalse(list.removeAll(Arrays.asList(one, two)));
495	assertEquals(1, list.size());
496	}
497
498	/**
499	* set changes the element at the given index
500	*/
501	public void testSet() {
502	List list = populatedList(3);
503	assertEquals(2, list.set(2, four));
504	assertEquals(4, list.get(2));
505	}
506
507	/**
508	* size returns the number of elements
509	*/
510	public void testSize() {
511	List empty = new CopyOnWriteArrayList();
512	assertEquals(0, empty.size());
513	assertEquals(0, empty.subList(0, 0).size());
514
515	List full = populatedList(SIZE);
516	assertEquals(SIZE, full.size());
517	assertEquals(0, full.subList(0, 0).size());
518	assertEquals(0, full.subList(SIZE, SIZE).size());
519	}
520
521	/**
522	* toArray() returns an Object array containing all elements from
523	* the list in insertion order
524	*/
525	public void testToArray() {
526	Object[] a = new CopyOnWriteArrayList().toArray();
527	assertTrue(Arrays.equals(new Object[0], a));
528	assertSame(Object[].class, a.getClass());
529
530	Integer[] elements = new Integer[SIZE];
531	for (int i = 0; i < SIZE; i++)
532	elements[i] = i;
533	shuffle(elements);
534	Collection<Integer> full = populatedList(elements);
535
536	assertTrue(Arrays.equals(elements, full.toArray()));
537	assertSame(Object[].class, full.toArray().getClass());
538	}
539
540	/**
541	* toArray(Integer array) returns an Integer array containing all
542	* elements from the list in insertion order
543	*/
544	public void testToArray2() {
545	Collection empty = new CopyOnWriteArrayList();
546	Integer[] a;
547
548	a = new Integer[0];
549	assertSame(a, empty.toArray(a));
550
551	a = new Integer[SIZE / 2];
552	Arrays.fill(a, 42);
553	assertSame(a, empty.toArray(a));
554	assertNull(a[0]);
555	for (int i = 1; i < a.length; i++)
556	assertEquals(42, (int) a[i]);
557
558	Integer[] elements = new Integer[SIZE];
559	for (int i = 0; i < SIZE; i++)
560	elements[i] = i;
561	shuffle(elements);
562	Collection<Integer> full = populatedList(elements);
563
564	Arrays.fill(a, 42);
565	assertTrue(Arrays.equals(elements, full.toArray(a)));
566	for (int i = 0; i < a.length; i++)
567	assertEquals(42, (int) a[i]);
568	assertSame(Integer[].class, full.toArray(a).getClass());
569
570	a = new Integer[SIZE];
571	Arrays.fill(a, 42);
572	assertSame(a, full.toArray(a));
573	assertTrue(Arrays.equals(elements, a));
574
575	a = new Integer[2 * SIZE];
576	Arrays.fill(a, 42);
577	assertSame(a, full.toArray(a));
578	assertTrue(Arrays.equals(elements, Arrays.copyOf(a, SIZE)));
579	assertNull(a[SIZE]);
580	for (int i = SIZE + 1; i < a.length; i++)
581	assertEquals(42, (int) a[i]);
582	}
583
584	/**
585	* sublists contains elements at indexes offset from their base
586	*/
587	public void testSubList() {
588	List a = populatedList(10);
589	assertTrue(a.subList(1,1).isEmpty());
590	for (int j = 0; j < 9; ++j) {
591	for (int i = j ; i < 10; ++i) {
592	List b = a.subList(j,i);
593	for (int k = j; k < i; ++k) {
594	assertEquals(new Integer(k), b.get(k-j));
595	}
596	}
597	}
598
599	List s = a.subList(2, 5);
600	assertEquals(3, s.size());
601	s.set(2, m1);
602	assertEquals(a.get(4), m1);
603	s.clear();
604	assertEquals(7, a.size());
605
606	assertThrows(
607	IndexOutOfBoundsException.class,
608	() -> s.get(0),
609	() -> s.set(0, 42));
610	}
611
612	// Exception tests
613
614	/**
615	* toArray throws an ArrayStoreException when the given array
616	* can not store the objects inside the list
617	*/
618	public void testToArray_ArrayStoreException() {
619	List list = new CopyOnWriteArrayList();
620	// Integers are not auto-converted to Longs
621	list.add(86);
622	list.add(99);
623	assertThrows(
624	ArrayStoreException.class,
625	() -> list.toArray(new Long[0]),
626	() -> list.toArray(new Long[5]));
627	}
628
629	void testIndexOutOfBoundsException(List list) {
630	int size = list.size();
631	assertThrows(
632	IndexOutOfBoundsException.class,
633	() -> list.get(-1),
634	() -> list.get(size),
635	() -> list.set(-1, "qwerty"),
636	() -> list.set(size, "qwerty"),
637	() -> list.add(-1, "qwerty"),
638	() -> list.add(size + 1, "qwerty"),
639	() -> list.remove(-1),
640	() -> list.remove(size),
641	() -> list.addAll(-1, Collections.emptyList()),
642	() -> list.addAll(size + 1, Collections.emptyList()),
643	() -> list.listIterator(-1),
644	() -> list.listIterator(size + 1),
645	() -> list.subList(-1, size),
646	() -> list.subList(0, size + 1));
647
648	// Conversely, operations that must not throw
649	list.addAll(0, Collections.emptyList());
650	list.addAll(size, Collections.emptyList());
651	list.add(0, "qwerty");
652	list.add(list.size(), "qwerty");
653	list.get(0);
654	list.get(list.size() - 1);
655	list.set(0, "azerty");
656	list.set(list.size() - 1, "azerty");
657	list.listIterator(0);
658	list.listIterator(list.size());
659	list.subList(0, list.size());
660	list.remove(list.size() - 1);
661	}
662
663	/**
664	* IndexOutOfBoundsException is thrown when specified
665	*/
666	public void testIndexOutOfBoundsException() {
667	ThreadLocalRandom rnd = ThreadLocalRandom.current();
668	List x = populatedList(rnd.nextInt(5));
669	testIndexOutOfBoundsException(x);
670
671	int start = rnd.nextInt(x.size() + 1);
672	int end = rnd.nextInt(start, x.size() + 1);
673	assertThrows(
674	IndexOutOfBoundsException.class,
675	() -> x.subList(start, start - 1));
676	List subList = x.subList(start, end);
677	testIndexOutOfBoundsException(x);
678	}
679
680	/**
681	* a deserialized/reserialized list equals original
682	*/
683	public void testSerialization() throws Exception {
684	List x = populatedList(SIZE);
685	List y = serialClone(x);
686
687	assertNotSame(x, y);
688	assertEquals(x.size(), y.size());
689	assertEquals(x.toString(), y.toString());
690	assertTrue(Arrays.equals(x.toArray(), y.toArray()));
691	assertEquals(x, y);
692	assertEquals(y, x);
693	while (!x.isEmpty()) {
694	assertFalse(y.isEmpty());
695	assertEquals(x.remove(0), y.remove(0));
696	}
697	assertTrue(y.isEmpty());
698	}
699
700	}