test/tck/Collection8Test.java

/*
 * Written by Doug Lea and Martin Buchholz 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/
 */

import static java.util.concurrent.TimeUnit.HOURS;
import static java.util.concurrent.TimeUnit.MILLISECONDS;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Deque;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.Spliterator;
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Executors;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Consumer;
import java.util.function.Predicate;

import junit.framework.Test;

/**
 * Contains tests applicable to all jdk8+ Collection implementations.
 * An extension of CollectionTest.
 */
public class Collection8Test extends JSR166TestCase {
    final CollectionImplementation impl;

    /** Tests are parameterized by a Collection implementation. */
    Collection8Test(CollectionImplementation impl, String methodName) {
        super(methodName);
        this.impl = impl;
    }

    public static Test testSuite(CollectionImplementation impl) {
        return parameterizedTestSuite(Collection8Test.class,
                                      CollectionImplementation.class,
                                      impl);
    }

    Object bomb() {
        return new Object() {
                public boolean equals(Object x) { throw new AssertionError(); }
                public int hashCode() { throw new AssertionError(); }
            };
    }

    /** Checks properties of empty collections. */
    public void testEmptyMeansEmpty() throws InterruptedException {
        Collection c = impl.emptyCollection();
        emptyMeansEmpty(c);

        if (c instanceof java.io.Serializable)
            emptyMeansEmpty(serialClone(c));

        Collection clone = cloneableClone(c);
        if (clone != null)
            emptyMeansEmpty(clone);
    }

    void emptyMeansEmpty(Collection c) throws InterruptedException {
        assertTrue(c.isEmpty());
        assertEquals(0, c.size());
        assertEquals("[]", c.toString());
        {
            Object[] a = c.toArray();
            assertEquals(0, a.length);
            assertSame(Object[].class, a.getClass());
        }
        {
            Object[] a = new Object[0];
            assertSame(a, c.toArray(a));
        }
        {
            Integer[] a = new Integer[0];
            assertSame(a, c.toArray(a));
        }
        {
            Integer[] a = { 1, 2, 3};
            assertSame(a, c.toArray(a));
            assertNull(a[0]);
            assertSame(2, a[1]);
            assertSame(3, a[2]);
        }
        assertIteratorExhausted(c.iterator());
        Consumer alwaysThrows = (e) -> { throw new AssertionError(); };
        c.forEach(alwaysThrows);
        c.iterator().forEachRemaining(alwaysThrows);
        c.spliterator().forEachRemaining(alwaysThrows);
        assertFalse(c.spliterator().tryAdvance(alwaysThrows));
        if (c.spliterator().hasCharacteristics(Spliterator.SIZED))
            assertEquals(0, c.spliterator().estimateSize());
        assertFalse(c.contains(bomb()));
        assertFalse(c.remove(bomb()));
        if (c instanceof Queue) {
            Queue q = (Queue) c;
            assertNull(q.peek());
            assertNull(q.poll());
        }
        if (c instanceof Deque) {
            Deque d = (Deque) c;
            assertNull(d.peekFirst());
            assertNull(d.peekLast());
            assertNull(d.pollFirst());
            assertNull(d.pollLast());
            assertIteratorExhausted(d.descendingIterator());
            d.descendingIterator().forEachRemaining(alwaysThrows);
            assertFalse(d.removeFirstOccurrence(bomb()));
            assertFalse(d.removeLastOccurrence(bomb()));
        }
        if (c instanceof BlockingQueue) {
            BlockingQueue q = (BlockingQueue) c;
            assertNull(q.poll(0L, MILLISECONDS));
        }
        if (c instanceof BlockingDeque) {
            BlockingDeque q = (BlockingDeque) c;
            assertNull(q.pollFirst(0L, MILLISECONDS));
            assertNull(q.pollLast(0L, MILLISECONDS));
        }
    }

    public void testNullPointerExceptions() throws InterruptedException {
        Collection c = impl.emptyCollection();
        assertThrows(
            NullPointerException.class,
            () -> c.addAll(null),
            () -> c.containsAll(null),
            () -> c.retainAll(null),
            () -> c.removeAll(null),
            () -> c.removeIf(null),
            () -> c.forEach(null),
            () -> c.iterator().forEachRemaining(null),
            () -> c.spliterator().forEachRemaining(null),
            () -> c.spliterator().tryAdvance(null),
            () -> c.toArray(null));

        if (!impl.permitsNulls()) {
            assertThrows(
                NullPointerException.class,
                () -> c.add(null));
        }
        if (!impl.permitsNulls() && c instanceof Queue) {
            Queue q = (Queue) c;
            assertThrows(
                NullPointerException.class,
                () -> q.offer(null));
        }
        if (!impl.permitsNulls() && c instanceof Deque) {
            Deque d = (Deque) c;
            assertThrows(
                NullPointerException.class,
                () -> d.addFirst(null),
                () -> d.addLast(null),
                () -> d.offerFirst(null),
                () -> d.offerLast(null),
                () -> d.push(null),
                () -> d.descendingIterator().forEachRemaining(null));
        }
        if (c instanceof BlockingQueue) {
            BlockingQueue q = (BlockingQueue) c;
            assertThrows(
                NullPointerException.class,
                () -> {
                    try { q.offer(null, 1L, HOURS); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }},
                () -> {
                    try { q.put(null); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }});
        }
        if (c instanceof BlockingDeque) {
            BlockingDeque q = (BlockingDeque) c;
            assertThrows(
                NullPointerException.class,
                () -> {
                    try { q.offerFirst(null, 1L, HOURS); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }},
                () -> {
                    try { q.offerLast(null, 1L, HOURS); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }},
                () -> {
                    try { q.putFirst(null); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }},
                () -> {
                    try { q.putLast(null); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }});
        }
    }

    public void testNoSuchElementExceptions() {
        Collection c = impl.emptyCollection();
        assertThrows(
            NoSuchElementException.class,
            () -> c.iterator().next());

        if (c instanceof Queue) {
            Queue q = (Queue) c;
            assertThrows(
                NoSuchElementException.class,
                () -> q.element(),
                () -> q.remove());
        }
        if (c instanceof Deque) {
            Deque d = (Deque) c;
            assertThrows(
                NoSuchElementException.class,
                () -> d.getFirst(),
                () -> d.getLast(),
                () -> d.removeFirst(),
                () -> d.removeLast(),
                () -> d.pop(),
                () -> d.descendingIterator().next());
        }
    }

    public void testRemoveIf() {
        Collection c = impl.emptyCollection();
        ThreadLocalRandom rnd = ThreadLocalRandom.current();
        int n = rnd.nextInt(6);
        for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
        AtomicReference threwAt = new AtomicReference(null);
        ArrayList survivors = new ArrayList(c);
        ArrayList accepts = new ArrayList();
        ArrayList rejects = new ArrayList();
        Predicate randomPredicate = (e) -> {
            assertNull(threwAt.get());
            switch (rnd.nextInt(3)) {
            case 0: accepts.add(e); return true;
            case 1: rejects.add(e); return false;
            case 2: threwAt.set(e); throw new ArithmeticException();
            default: throw new AssertionError();
            }
        };
        try {
            try {
                boolean modified = c.removeIf(randomPredicate);
                if (!modified) {
                    assertNull(threwAt.get());
                    assertEquals(n, rejects.size());
                    assertEquals(0, accepts.size());
                }
            } catch (ArithmeticException ok) {}
            survivors.removeAll(accepts);
            assertEquals(n - accepts.size(), c.size());
            assertTrue(c.containsAll(survivors));
            assertTrue(survivors.containsAll(rejects));
            for (Object x : accepts) assertFalse(c.contains(x));
            if (threwAt.get() == null)
                assertEquals(accepts.size() + rejects.size(), n);
        } catch (Throwable ex) {
            System.err.println(impl.klazz());
            System.err.printf("c=%s%n", c);
            System.err.printf("n=%d%n", n);
            System.err.printf("accepts=%s%n", accepts);
            System.err.printf("rejects=%s%n", rejects);
            System.err.printf("survivors=%s%n", survivors);
            System.err.printf("threw=%s%n", threwAt.get());
            throw ex;
        }
    }

    /**
     * Various ways of traversing a collection yield same elements
     */
    public void testIteratorEquivalence() {
        Collection c = impl.emptyCollection();
        ThreadLocalRandom rnd = ThreadLocalRandom.current();
        int n = rnd.nextInt(6);
        for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
        ArrayList iterated = new ArrayList();
        ArrayList iteratedForEachRemaining = new ArrayList();
        ArrayList tryAdvanced = new ArrayList();
        ArrayList spliterated = new ArrayList();
        ArrayList forEached = new ArrayList();
        ArrayList removeIfed = new ArrayList();
        for (Object x : c) iterated.add(x);
        c.iterator().forEachRemaining(e -> iteratedForEachRemaining.add(e));
        for (Spliterator s = c.spliterator();
             s.tryAdvance(e -> tryAdvanced.add(e)); ) {}
        c.spliterator().forEachRemaining(e -> spliterated.add(e));
        c.forEach(e -> forEached.add(e));
        c.removeIf(e -> { removeIfed.add(e); return false; });
        boolean ordered =
            c.spliterator().hasCharacteristics(Spliterator.ORDERED);
        if (c instanceof List || c instanceof Deque)
            assertTrue(ordered);
        if (ordered) {
            assertEquals(iterated, iteratedForEachRemaining);
            assertEquals(iterated, tryAdvanced);
            assertEquals(iterated, spliterated);
            assertEquals(iterated, forEached);
            assertEquals(iterated, removeIfed);
        } else {
            HashSet cset = new HashSet(c);
            assertEquals(cset, new HashSet(iterated));
            assertEquals(cset, new HashSet(iteratedForEachRemaining));
            assertEquals(cset, new HashSet(tryAdvanced));
            assertEquals(cset, new HashSet(spliterated));
            assertEquals(cset, new HashSet(forEached));
            assertEquals(cset, new HashSet(removeIfed));
        }
        if (c instanceof Deque) {
            Deque d = (Deque) c;
            ArrayList descending = new ArrayList();
            ArrayList descendingForEachRemaining = new ArrayList();
            for (Iterator it = d.descendingIterator(); it.hasNext(); )
                descending.add(it.next());
            d.descendingIterator().forEachRemaining(
                e -> descendingForEachRemaining.add(e));
            Collections.reverse(descending);
            Collections.reverse(descendingForEachRemaining);
            assertEquals(iterated, descending);
            assertEquals(iterated, descendingForEachRemaining);
        }
    }

    /**
     * Calling Iterator#remove() after Iterator#forEachRemaining
     * should remove last element
     */
    public void testRemoveAfterForEachRemaining() {
        Collection c = impl.emptyCollection();
        ThreadLocalRandom rnd = ThreadLocalRandom.current();
        {
            int n = 3 + rnd.nextInt(2);
            for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
            Iterator it = c.iterator();
            assertTrue(it.hasNext());
            assertEquals(impl.makeElement(0), it.next());
            assertTrue(it.hasNext());
            assertEquals(impl.makeElement(1), it.next());
            it.forEachRemaining((e) -> {});
            it.remove();
            assertEquals(n - 1, c.size());
            for (int i = 0; i < n - 1; i++)
                assertTrue(c.contains(impl.makeElement(i)));
            assertFalse(c.contains(impl.makeElement(n - 1)));
        }
        if (c instanceof Deque) {
            Deque d = (Deque) impl.emptyCollection();
            int n = 3 + rnd.nextInt(2);
            for (int i = 0; i < n; i++) d.add(impl.makeElement(i));
            Iterator it = d.descendingIterator();
            assertTrue(it.hasNext());
            assertEquals(impl.makeElement(n - 1), it.next());
            assertTrue(it.hasNext());
            assertEquals(impl.makeElement(n - 2), it.next());
            it.forEachRemaining((e) -> {});
            it.remove();
            assertEquals(n - 1, d.size());
            for (int i = 1; i < n; i++)
                assertTrue(d.contains(impl.makeElement(i)));
            assertFalse(d.contains(impl.makeElement(0)));
        }
    }

    /**
     * stream().forEach returns elements in the collection
     */
    public void testStreamForEach() throws Throwable {
        final Collection c = impl.emptyCollection();
        final AtomicLong count = new AtomicLong(0L);
        final Object x = impl.makeElement(1);
        final Object y = impl.makeElement(2);
        final ArrayList found = new ArrayList();
        Consumer<Object> spy = (o) -> { found.add(o); };
        c.stream().forEach(spy);
        assertTrue(found.isEmpty());

        assertTrue(c.add(x));
        c.stream().forEach(spy);
        assertEquals(Collections.singletonList(x), found);
        found.clear();

        assertTrue(c.add(y));
        c.stream().forEach(spy);
        assertEquals(2, found.size());
        assertTrue(found.contains(x));
        assertTrue(found.contains(y));
        found.clear();

        c.clear();
        c.stream().forEach(spy);
        assertTrue(found.isEmpty());
    }

    public void testStreamForEachConcurrentStressTest() throws Throwable {
        if (!impl.isConcurrent()) return;
        final Collection c = impl.emptyCollection();
        final long testDurationMillis = timeoutMillis();
        final AtomicBoolean done = new AtomicBoolean(false);
        final Object elt = impl.makeElement(1);
        final Future<?> f1, f2;
        final ExecutorService pool = Executors.newCachedThreadPool();
        try (PoolCleaner cleaner = cleaner(pool, done)) {
            final CountDownLatch threadsStarted = new CountDownLatch(2);
            Runnable checkElt = () -> {
                threadsStarted.countDown();
                while (!done.get())
                    c.stream().forEach((x) -> { assertSame(x, elt); }); };
            Runnable addRemove = () -> {
                threadsStarted.countDown();
                while (!done.get()) {
                    assertTrue(c.add(elt));
                    assertTrue(c.remove(elt));
                }};
            f1 = pool.submit(checkElt);
            f2 = pool.submit(addRemove);
            Thread.sleep(testDurationMillis);
        }
        assertNull(f1.get(0L, MILLISECONDS));
        assertNull(f2.get(0L, MILLISECONDS));
    }

    /**
     * collection.forEach returns elements in the collection
     */
    public void testForEach() throws Throwable {
        final Collection c = impl.emptyCollection();
        final AtomicLong count = new AtomicLong(0L);
        final Object x = impl.makeElement(1);
        final Object y = impl.makeElement(2);
        final ArrayList found = new ArrayList();
        Consumer<Object> spy = (o) -> { found.add(o); };
        c.forEach(spy);
        assertTrue(found.isEmpty());

        assertTrue(c.add(x));
        c.forEach(spy);
        assertEquals(Collections.singletonList(x), found);
        found.clear();

        assertTrue(c.add(y));
        c.forEach(spy);
        assertEquals(2, found.size());
        assertTrue(found.contains(x));
        assertTrue(found.contains(y));
        found.clear();

        c.clear();
        c.forEach(spy);
        assertTrue(found.isEmpty());
    }

    public void testForEachConcurrentStressTest() throws Throwable {
        if (!impl.isConcurrent()) return;
        final Collection c = impl.emptyCollection();
        final long testDurationMillis = timeoutMillis();
        final AtomicBoolean done = new AtomicBoolean(false);
        final Object elt = impl.makeElement(1);
        final Future<?> f1, f2;
        final ExecutorService pool = Executors.newCachedThreadPool();
        try (PoolCleaner cleaner = cleaner(pool, done)) {
            final CountDownLatch threadsStarted = new CountDownLatch(2);
            Runnable checkElt = () -> {
                threadsStarted.countDown();
                while (!done.get())
                    c.forEach((x) -> { assertSame(x, elt); }); };
            Runnable addRemove = () -> {
                threadsStarted.countDown();
                while (!done.get()) {
                    assertTrue(c.add(elt));
                    assertTrue(c.remove(elt));
                }};
            f1 = pool.submit(checkElt);
            f2 = pool.submit(addRemove);
            Thread.sleep(testDurationMillis);
        }
        assertNull(f1.get(0L, MILLISECONDS));
        assertNull(f2.get(0L, MILLISECONDS));
    }

//     public void testCollection8DebugFail() {
//         fail(impl.klazz().getSimpleName());
//     }
}
Revision:	1.17
Committed:	Sun Nov 6 18:51:53 2016 UTC (7 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.16:	+0 -1 lines
Log Message:	remove bogus assertion
#	User	Rev	Content
1	jsr166	1.1	/*
2			* Written by Doug Lea and Martin Buchholz with assistance from
3			* members of JCP JSR-166 Expert Group and released to the public
4			* domain, as explained at
5			* http://creativecommons.org/publicdomain/zero/1.0/
6			*/
7
8	jsr166	1.16	import static java.util.concurrent.TimeUnit.HOURS;
9	jsr166	1.1	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10
11			import java.util.ArrayList;
12			import java.util.Collection;
13			import java.util.Collections;
14	jsr166	1.5	import java.util.Deque;
15			import java.util.HashSet;
16			import java.util.Iterator;
17			import java.util.List;
18			import java.util.NoSuchElementException;
19			import java.util.Queue;
20			import java.util.Spliterator;
21	jsr166	1.14	import java.util.concurrent.BlockingDeque;
22			import java.util.concurrent.BlockingQueue;
23	jsr166	1.2	import java.util.concurrent.CountDownLatch;
24	jsr166	1.1	import java.util.concurrent.Executors;
25			import java.util.concurrent.ExecutorService;
26			import java.util.concurrent.Future;
27	jsr166	1.5	import java.util.concurrent.ThreadLocalRandom;
28	jsr166	1.1	import java.util.concurrent.atomic.AtomicBoolean;
29			import java.util.concurrent.atomic.AtomicLong;
30	jsr166	1.5	import java.util.concurrent.atomic.AtomicReference;
31	jsr166	1.1	import java.util.function.Consumer;
32	jsr166	1.5	import java.util.function.Predicate;
33	jsr166	1.1
34			import junit.framework.Test;
35
36			/**
37			* Contains tests applicable to all jdk8+ Collection implementations.
38			* An extension of CollectionTest.
39			*/
40			public class Collection8Test extends JSR166TestCase {
41			final CollectionImplementation impl;
42
43			/** Tests are parameterized by a Collection implementation. */
44			Collection8Test(CollectionImplementation impl, String methodName) {
45			super(methodName);
46			this.impl = impl;
47			}
48
49			public static Test testSuite(CollectionImplementation impl) {
50			return parameterizedTestSuite(Collection8Test.class,
51			CollectionImplementation.class,
52			impl);
53			}
54
55	jsr166	1.10	Object bomb() {
56			return new Object() {
57			public boolean equals(Object x) { throw new AssertionError(); }
58			public int hashCode() { throw new AssertionError(); }
59			};
60			}
61
62	jsr166	1.5	/** Checks properties of empty collections. */
63	jsr166	1.14	public void testEmptyMeansEmpty() throws InterruptedException {
64	jsr166	1.5	Collection c = impl.emptyCollection();
65	jsr166	1.12	emptyMeansEmpty(c);
66
67			if (c instanceof java.io.Serializable)
68			emptyMeansEmpty(serialClone(c));
69
70			Collection clone = cloneableClone(c);
71			if (clone != null)
72			emptyMeansEmpty(clone);
73			}
74
75	jsr166	1.14	void emptyMeansEmpty(Collection c) throws InterruptedException {
76	jsr166	1.5	assertTrue(c.isEmpty());
77			assertEquals(0, c.size());
78			assertEquals("[]", c.toString());
79			{
80			Object[] a = c.toArray();
81			assertEquals(0, a.length);
82			assertSame(Object[].class, a.getClass());
83			}
84			{
85			Object[] a = new Object[0];
86			assertSame(a, c.toArray(a));
87			}
88			{
89			Integer[] a = new Integer[0];
90			assertSame(a, c.toArray(a));
91			}
92			{
93			Integer[] a = { 1, 2, 3};
94			assertSame(a, c.toArray(a));
95			assertNull(a[0]);
96			assertSame(2, a[1]);
97			assertSame(3, a[2]);
98			}
99			assertIteratorExhausted(c.iterator());
100			Consumer alwaysThrows = (e) -> { throw new AssertionError(); };
101			c.forEach(alwaysThrows);
102			c.iterator().forEachRemaining(alwaysThrows);
103			c.spliterator().forEachRemaining(alwaysThrows);
104			assertFalse(c.spliterator().tryAdvance(alwaysThrows));
105	jsr166	1.9	if (c.spliterator().hasCharacteristics(Spliterator.SIZED))
106			assertEquals(0, c.spliterator().estimateSize());
107	jsr166	1.10	assertFalse(c.contains(bomb()));
108			assertFalse(c.remove(bomb()));
109	jsr166	1.11	if (c instanceof Queue) {
110	jsr166	1.5	Queue q = (Queue) c;
111			assertNull(q.peek());
112			assertNull(q.poll());
113			}
114	jsr166	1.11	if (c instanceof Deque) {
115	jsr166	1.5	Deque d = (Deque) c;
116			assertNull(d.peekFirst());
117			assertNull(d.peekLast());
118			assertNull(d.pollFirst());
119			assertNull(d.pollLast());
120			assertIteratorExhausted(d.descendingIterator());
121	jsr166	1.9	d.descendingIterator().forEachRemaining(alwaysThrows);
122	jsr166	1.10	assertFalse(d.removeFirstOccurrence(bomb()));
123			assertFalse(d.removeLastOccurrence(bomb()));
124	jsr166	1.5	}
125	jsr166	1.14	if (c instanceof BlockingQueue) {
126			BlockingQueue q = (BlockingQueue) c;
127			assertNull(q.poll(0L, MILLISECONDS));
128			}
129			if (c instanceof BlockingDeque) {
130			BlockingDeque q = (BlockingDeque) c;
131			assertNull(q.pollFirst(0L, MILLISECONDS));
132			assertNull(q.pollLast(0L, MILLISECONDS));
133			}
134	jsr166	1.5	}
135
136	jsr166	1.14	public void testNullPointerExceptions() throws InterruptedException {
137	jsr166	1.5	Collection c = impl.emptyCollection();
138			assertThrows(
139			NullPointerException.class,
140			() -> c.addAll(null),
141			() -> c.containsAll(null),
142			() -> c.retainAll(null),
143			() -> c.removeAll(null),
144			() -> c.removeIf(null),
145	jsr166	1.6	() -> c.forEach(null),
146			() -> c.iterator().forEachRemaining(null),
147			() -> c.spliterator().forEachRemaining(null),
148			() -> c.spliterator().tryAdvance(null),
149	jsr166	1.5	() -> c.toArray(null));
150
151			if (!impl.permitsNulls()) {
152			assertThrows(
153			NullPointerException.class,
154			() -> c.add(null));
155			}
156	jsr166	1.14	if (!impl.permitsNulls() && c instanceof Queue) {
157	jsr166	1.5	Queue q = (Queue) c;
158			assertThrows(
159			NullPointerException.class,
160			() -> q.offer(null));
161			}
162	jsr166	1.14	if (!impl.permitsNulls() && c instanceof Deque) {
163	jsr166	1.5	Deque d = (Deque) c;
164			assertThrows(
165			NullPointerException.class,
166			() -> d.addFirst(null),
167			() -> d.addLast(null),
168			() -> d.offerFirst(null),
169			() -> d.offerLast(null),
170	jsr166	1.6	() -> d.push(null),
171			() -> d.descendingIterator().forEachRemaining(null));
172	jsr166	1.5	}
173	jsr166	1.15	if (c instanceof BlockingQueue) {
174	jsr166	1.14	BlockingQueue q = (BlockingQueue) c;
175			assertThrows(
176			NullPointerException.class,
177			() -> {
178	jsr166	1.16	try { q.offer(null, 1L, HOURS); }
179	jsr166	1.14	catch (InterruptedException ex) {
180			throw new AssertionError(ex);
181	jsr166	1.15	}},
182			() -> {
183			try { q.put(null); }
184			catch (InterruptedException ex) {
185			throw new AssertionError(ex);
186	jsr166	1.14	}});
187			}
188	jsr166	1.15	if (c instanceof BlockingDeque) {
189	jsr166	1.14	BlockingDeque q = (BlockingDeque) c;
190			assertThrows(
191			NullPointerException.class,
192			() -> {
193	jsr166	1.16	try { q.offerFirst(null, 1L, HOURS); }
194	jsr166	1.14	catch (InterruptedException ex) {
195			throw new AssertionError(ex);
196			}},
197			() -> {
198	jsr166	1.16	try { q.offerLast(null, 1L, HOURS); }
199	jsr166	1.14	catch (InterruptedException ex) {
200			throw new AssertionError(ex);
201	jsr166	1.15	}},
202			() -> {
203			try { q.putFirst(null); }
204			catch (InterruptedException ex) {
205			throw new AssertionError(ex);
206			}},
207			() -> {
208			try { q.putLast(null); }
209			catch (InterruptedException ex) {
210			throw new AssertionError(ex);
211	jsr166	1.14	}});
212			}
213	jsr166	1.5	}
214
215			public void testNoSuchElementExceptions() {
216			Collection c = impl.emptyCollection();
217			assertThrows(
218			NoSuchElementException.class,
219			() -> c.iterator().next());
220
221	jsr166	1.14	if (c instanceof Queue) {
222	jsr166	1.5	Queue q = (Queue) c;
223			assertThrows(
224			NoSuchElementException.class,
225			() -> q.element(),
226			() -> q.remove());
227			}
228	jsr166	1.14	if (c instanceof Deque) {
229	jsr166	1.5	Deque d = (Deque) c;
230			assertThrows(
231			NoSuchElementException.class,
232			() -> d.getFirst(),
233			() -> d.getLast(),
234			() -> d.removeFirst(),
235			() -> d.removeLast(),
236			() -> d.pop(),
237			() -> d.descendingIterator().next());
238			}
239			}
240
241			public void testRemoveIf() {
242			Collection c = impl.emptyCollection();
243			ThreadLocalRandom rnd = ThreadLocalRandom.current();
244			int n = rnd.nextInt(6);
245			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
246			AtomicReference threwAt = new AtomicReference(null);
247			ArrayList survivors = new ArrayList(c);
248			ArrayList accepts = new ArrayList();
249			ArrayList rejects = new ArrayList();
250			Predicate randomPredicate = (e) -> {
251			assertNull(threwAt.get());
252			switch (rnd.nextInt(3)) {
253			case 0: accepts.add(e); return true;
254			case 1: rejects.add(e); return false;
255			case 2: threwAt.set(e); throw new ArithmeticException();
256			default: throw new AssertionError();
257			}
258			};
259			try {
260	jsr166	1.7	try {
261			boolean modified = c.removeIf(randomPredicate);
262			if (!modified) {
263			assertNull(threwAt.get());
264			assertEquals(n, rejects.size());
265			assertEquals(0, accepts.size());
266			}
267			} catch (ArithmeticException ok) {}
268			survivors.removeAll(accepts);
269			assertEquals(n - accepts.size(), c.size());
270			assertTrue(c.containsAll(survivors));
271			assertTrue(survivors.containsAll(rejects));
272			for (Object x : accepts) assertFalse(c.contains(x));
273			if (threwAt.get() == null)
274			assertEquals(accepts.size() + rejects.size(), n);
275			} catch (Throwable ex) {
276	jsr166	1.5	System.err.println(impl.klazz());
277	jsr166	1.7	System.err.printf("c=%s%n", c);
278			System.err.printf("n=%d%n", n);
279			System.err.printf("accepts=%s%n", accepts);
280			System.err.printf("rejects=%s%n", rejects);
281	jsr166	1.8	System.err.printf("survivors=%s%n", survivors);
282	jsr166	1.7	System.err.printf("threw=%s%n", threwAt.get());
283			throw ex;
284	jsr166	1.5	}
285			}
286
287			/**
288			* Various ways of traversing a collection yield same elements
289			*/
290			public void testIteratorEquivalence() {
291			Collection c = impl.emptyCollection();
292			ThreadLocalRandom rnd = ThreadLocalRandom.current();
293			int n = rnd.nextInt(6);
294			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
295			ArrayList iterated = new ArrayList();
296			ArrayList iteratedForEachRemaining = new ArrayList();
297	jsr166	1.13	ArrayList tryAdvanced = new ArrayList();
298	jsr166	1.5	ArrayList spliterated = new ArrayList();
299	jsr166	1.13	ArrayList forEached = new ArrayList();
300			ArrayList removeIfed = new ArrayList();
301	jsr166	1.5	for (Object x : c) iterated.add(x);
302			c.iterator().forEachRemaining(e -> iteratedForEachRemaining.add(e));
303	jsr166	1.13	for (Spliterator s = c.spliterator();
304			s.tryAdvance(e -> tryAdvanced.add(e)); ) {}
305	jsr166	1.5	c.spliterator().forEachRemaining(e -> spliterated.add(e));
306	jsr166	1.13	c.forEach(e -> forEached.add(e));
307			c.removeIf(e -> { removeIfed.add(e); return false; });
308	jsr166	1.5	boolean ordered =
309			c.spliterator().hasCharacteristics(Spliterator.ORDERED);
310			if (c instanceof List \|\| c instanceof Deque)
311			assertTrue(ordered);
312			if (ordered) {
313			assertEquals(iterated, iteratedForEachRemaining);
314	jsr166	1.13	assertEquals(iterated, tryAdvanced);
315	jsr166	1.5	assertEquals(iterated, spliterated);
316	jsr166	1.13	assertEquals(iterated, forEached);
317			assertEquals(iterated, removeIfed);
318	jsr166	1.5	} else {
319			HashSet cset = new HashSet(c);
320			assertEquals(cset, new HashSet(iterated));
321			assertEquals(cset, new HashSet(iteratedForEachRemaining));
322	jsr166	1.13	assertEquals(cset, new HashSet(tryAdvanced));
323	jsr166	1.5	assertEquals(cset, new HashSet(spliterated));
324	jsr166	1.13	assertEquals(cset, new HashSet(forEached));
325			assertEquals(cset, new HashSet(removeIfed));
326	jsr166	1.5	}
327			if (c instanceof Deque) {
328			Deque d = (Deque) c;
329			ArrayList descending = new ArrayList();
330			ArrayList descendingForEachRemaining = new ArrayList();
331			for (Iterator it = d.descendingIterator(); it.hasNext(); )
332			descending.add(it.next());
333			d.descendingIterator().forEachRemaining(
334			e -> descendingForEachRemaining.add(e));
335			Collections.reverse(descending);
336			Collections.reverse(descendingForEachRemaining);
337			assertEquals(iterated, descending);
338			assertEquals(iterated, descendingForEachRemaining);
339			}
340			}
341
342			/**
343			* Calling Iterator#remove() after Iterator#forEachRemaining
344			* should remove last element
345			*/
346			public void testRemoveAfterForEachRemaining() {
347			Collection c = impl.emptyCollection();
348			ThreadLocalRandom rnd = ThreadLocalRandom.current();
349			{
350			int n = 3 + rnd.nextInt(2);
351			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
352			Iterator it = c.iterator();
353			assertTrue(it.hasNext());
354			assertEquals(impl.makeElement(0), it.next());
355			assertTrue(it.hasNext());
356			assertEquals(impl.makeElement(1), it.next());
357			it.forEachRemaining((e) -> {});
358			it.remove();
359			assertEquals(n - 1, c.size());
360			for (int i = 0; i < n - 1; i++)
361			assertTrue(c.contains(impl.makeElement(i)));
362			assertFalse(c.contains(impl.makeElement(n - 1)));
363			}
364			if (c instanceof Deque) {
365			Deque d = (Deque) impl.emptyCollection();
366			int n = 3 + rnd.nextInt(2);
367			for (int i = 0; i < n; i++) d.add(impl.makeElement(i));
368			Iterator it = d.descendingIterator();
369			assertTrue(it.hasNext());
370			assertEquals(impl.makeElement(n - 1), it.next());
371			assertTrue(it.hasNext());
372			assertEquals(impl.makeElement(n - 2), it.next());
373			it.forEachRemaining((e) -> {});
374			it.remove();
375			assertEquals(n - 1, d.size());
376			for (int i = 1; i < n; i++)
377			assertTrue(d.contains(impl.makeElement(i)));
378			assertFalse(d.contains(impl.makeElement(0)));
379			}
380			}
381
382	jsr166	1.1	/**
383			* stream().forEach returns elements in the collection
384			*/
385	jsr166	1.3	public void testStreamForEach() throws Throwable {
386	jsr166	1.1	final Collection c = impl.emptyCollection();
387			final AtomicLong count = new AtomicLong(0L);
388			final Object x = impl.makeElement(1);
389			final Object y = impl.makeElement(2);
390			final ArrayList found = new ArrayList();
391			Consumer<Object> spy = (o) -> { found.add(o); };
392			c.stream().forEach(spy);
393			assertTrue(found.isEmpty());
394
395			assertTrue(c.add(x));
396			c.stream().forEach(spy);
397			assertEquals(Collections.singletonList(x), found);
398			found.clear();
399
400			assertTrue(c.add(y));
401			c.stream().forEach(spy);
402			assertEquals(2, found.size());
403			assertTrue(found.contains(x));
404			assertTrue(found.contains(y));
405			found.clear();
406
407			c.clear();
408			c.stream().forEach(spy);
409			assertTrue(found.isEmpty());
410			}
411
412	jsr166	1.3	public void testStreamForEachConcurrentStressTest() throws Throwable {
413			if (!impl.isConcurrent()) return;
414			final Collection c = impl.emptyCollection();
415			final long testDurationMillis = timeoutMillis();
416			final AtomicBoolean done = new AtomicBoolean(false);
417			final Object elt = impl.makeElement(1);
418			final Future<?> f1, f2;
419			final ExecutorService pool = Executors.newCachedThreadPool();
420			try (PoolCleaner cleaner = cleaner(pool, done)) {
421			final CountDownLatch threadsStarted = new CountDownLatch(2);
422			Runnable checkElt = () -> {
423			threadsStarted.countDown();
424			while (!done.get())
425			c.stream().forEach((x) -> { assertSame(x, elt); }); };
426			Runnable addRemove = () -> {
427			threadsStarted.countDown();
428			while (!done.get()) {
429			assertTrue(c.add(elt));
430			assertTrue(c.remove(elt));
431			}};
432			f1 = pool.submit(checkElt);
433			f2 = pool.submit(addRemove);
434			Thread.sleep(testDurationMillis);
435			}
436			assertNull(f1.get(0L, MILLISECONDS));
437			assertNull(f2.get(0L, MILLISECONDS));
438			}
439
440			/**
441			* collection.forEach returns elements in the collection
442			*/
443			public void testForEach() throws Throwable {
444			final Collection c = impl.emptyCollection();
445			final AtomicLong count = new AtomicLong(0L);
446			final Object x = impl.makeElement(1);
447			final Object y = impl.makeElement(2);
448			final ArrayList found = new ArrayList();
449			Consumer<Object> spy = (o) -> { found.add(o); };
450			c.forEach(spy);
451			assertTrue(found.isEmpty());
452
453			assertTrue(c.add(x));
454			c.forEach(spy);
455			assertEquals(Collections.singletonList(x), found);
456			found.clear();
457
458			assertTrue(c.add(y));
459			c.forEach(spy);
460			assertEquals(2, found.size());
461			assertTrue(found.contains(x));
462			assertTrue(found.contains(y));
463			found.clear();
464
465			c.clear();
466			c.forEach(spy);
467			assertTrue(found.isEmpty());
468			}
469
470	jsr166	1.1	public void testForEachConcurrentStressTest() throws Throwable {
471			if (!impl.isConcurrent()) return;
472			final Collection c = impl.emptyCollection();
473	jsr166	1.2	final long testDurationMillis = timeoutMillis();
474	jsr166	1.1	final AtomicBoolean done = new AtomicBoolean(false);
475			final Object elt = impl.makeElement(1);
476	jsr166	1.2	final Future<?> f1, f2;
477			final ExecutorService pool = Executors.newCachedThreadPool();
478			try (PoolCleaner cleaner = cleaner(pool, done)) {
479			final CountDownLatch threadsStarted = new CountDownLatch(2);
480			Runnable checkElt = () -> {
481			threadsStarted.countDown();
482			while (!done.get())
483	jsr166	1.3	c.forEach((x) -> { assertSame(x, elt); }); };
484	jsr166	1.2	Runnable addRemove = () -> {
485			threadsStarted.countDown();
486			while (!done.get()) {
487			assertTrue(c.add(elt));
488			assertTrue(c.remove(elt));
489			}};
490			f1 = pool.submit(checkElt);
491			f2 = pool.submit(addRemove);
492			Thread.sleep(testDurationMillis);
493			}
494			assertNull(f1.get(0L, MILLISECONDS));
495			assertNull(f2.get(0L, MILLISECONDS));
496	jsr166	1.1	}
497
498	jsr166	1.4	// public void testCollection8DebugFail() {
499			// fail(impl.klazz().getSimpleName());
500			// }
501	jsr166	1.1	}