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.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.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() {
        Collection c = impl.emptyCollection();
        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 (Queue.class.isAssignableFrom(impl.klazz())) {
            Queue q = (Queue) c;
            assertNull(q.peek());
            assertNull(q.poll());
        }
        if (Deque.class.isAssignableFrom(impl.klazz())) {
            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()));
        }
    }

    public void testNullPointerExceptions() {
        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()
            && Queue.class.isAssignableFrom(impl.klazz())) {
            Queue q = (Queue) c;
            assertThrows(
                NullPointerException.class,
                () -> q.offer(null));
        }
        if (!impl.permitsNulls()
            && Deque.class.isAssignableFrom(impl.klazz())) {
            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));
        }
    }

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

        if (Queue.class.isAssignableFrom(impl.klazz())) {
            Queue q = (Queue) c;
            assertThrows(
                NoSuchElementException.class,
                () -> q.element(),
                () -> q.remove());
        }
        if (Deque.class.isAssignableFrom(impl.klazz())) {
            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 {
            assertFalse(survivors.contains(null));
            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 spliterated = new ArrayList();
        ArrayList foreached = new ArrayList();
        for (Object x : c) iterated.add(x);
        c.iterator().forEachRemaining(e -> iteratedForEachRemaining.add(e));
        c.spliterator().forEachRemaining(e -> spliterated.add(e));
        c.forEach(e -> foreached.add(e));
        boolean ordered =
            c.spliterator().hasCharacteristics(Spliterator.ORDERED);
        if (c instanceof List || c instanceof Deque)
            assertTrue(ordered);
        if (ordered) {
            assertEquals(iterated, iteratedForEachRemaining);
            assertEquals(iterated, spliterated);
            assertEquals(iterated, foreached);
        } else {
            HashSet cset = new HashSet(c);
            assertEquals(cset, new HashSet(iterated));
            assertEquals(cset, new HashSet(iteratedForEachRemaining));
            assertEquals(cset, new HashSet(spliterated));
            assertEquals(cset, new HashSet(foreached));
        }
        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:	1.10
Committed:	Sat Nov 5 01:27:00 2016 UTC (7 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.9:	+11 -0 lines
Log Message:	testEmptyMeansEmpty: more assertions
#	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			import static java.util.concurrent.TimeUnit.MILLISECONDS;
9
10			import java.util.ArrayList;
11			import java.util.Collection;
12			import java.util.Collections;
13	jsr166	1.5	import java.util.Deque;
14			import java.util.HashSet;
15			import java.util.Iterator;
16			import java.util.List;
17			import java.util.NoSuchElementException;
18			import java.util.Queue;
19			import java.util.Spliterator;
20	jsr166	1.2	import java.util.concurrent.CountDownLatch;
21	jsr166	1.1	import java.util.concurrent.Executors;
22			import java.util.concurrent.ExecutorService;
23			import java.util.concurrent.Future;
24	jsr166	1.5	import java.util.concurrent.ThreadLocalRandom;
25	jsr166	1.1	import java.util.concurrent.atomic.AtomicBoolean;
26			import java.util.concurrent.atomic.AtomicLong;
27	jsr166	1.5	import java.util.concurrent.atomic.AtomicReference;
28	jsr166	1.1	import java.util.function.Consumer;
29	jsr166	1.5	import java.util.function.Predicate;
30	jsr166	1.1
31			import junit.framework.Test;
32
33			/**
34			* Contains tests applicable to all jdk8+ Collection implementations.
35			* An extension of CollectionTest.
36			*/
37			public class Collection8Test extends JSR166TestCase {
38			final CollectionImplementation impl;
39
40			/** Tests are parameterized by a Collection implementation. */
41			Collection8Test(CollectionImplementation impl, String methodName) {
42			super(methodName);
43			this.impl = impl;
44			}
45
46			public static Test testSuite(CollectionImplementation impl) {
47			return parameterizedTestSuite(Collection8Test.class,
48			CollectionImplementation.class,
49			impl);
50			}
51
52	jsr166	1.10	Object bomb() {
53			return new Object() {
54			public boolean equals(Object x) { throw new AssertionError(); }
55			public int hashCode() { throw new AssertionError(); }
56			};
57			}
58
59	jsr166	1.5	/** Checks properties of empty collections. */
60			public void testEmptyMeansEmpty() {
61			Collection c = impl.emptyCollection();
62			assertTrue(c.isEmpty());
63			assertEquals(0, c.size());
64			assertEquals("[]", c.toString());
65			{
66			Object[] a = c.toArray();
67			assertEquals(0, a.length);
68			assertSame(Object[].class, a.getClass());
69			}
70			{
71			Object[] a = new Object[0];
72			assertSame(a, c.toArray(a));
73			}
74			{
75			Integer[] a = new Integer[0];
76			assertSame(a, c.toArray(a));
77			}
78			{
79			Integer[] a = { 1, 2, 3};
80			assertSame(a, c.toArray(a));
81			assertNull(a[0]);
82			assertSame(2, a[1]);
83			assertSame(3, a[2]);
84			}
85			assertIteratorExhausted(c.iterator());
86			Consumer alwaysThrows = (e) -> { throw new AssertionError(); };
87			c.forEach(alwaysThrows);
88			c.iterator().forEachRemaining(alwaysThrows);
89			c.spliterator().forEachRemaining(alwaysThrows);
90			assertFalse(c.spliterator().tryAdvance(alwaysThrows));
91	jsr166	1.9	if (c.spliterator().hasCharacteristics(Spliterator.SIZED))
92			assertEquals(0, c.spliterator().estimateSize());
93	jsr166	1.10	assertFalse(c.contains(bomb()));
94			assertFalse(c.remove(bomb()));
95	jsr166	1.5	if (Queue.class.isAssignableFrom(impl.klazz())) {
96			Queue q = (Queue) c;
97			assertNull(q.peek());
98			assertNull(q.poll());
99			}
100			if (Deque.class.isAssignableFrom(impl.klazz())) {
101			Deque d = (Deque) c;
102			assertNull(d.peekFirst());
103			assertNull(d.peekLast());
104			assertNull(d.pollFirst());
105			assertNull(d.pollLast());
106			assertIteratorExhausted(d.descendingIterator());
107	jsr166	1.9	d.descendingIterator().forEachRemaining(alwaysThrows);
108	jsr166	1.10	assertFalse(d.removeFirstOccurrence(bomb()));
109			assertFalse(d.removeLastOccurrence(bomb()));
110	jsr166	1.5	}
111			}
112
113			public void testNullPointerExceptions() {
114			Collection c = impl.emptyCollection();
115			assertThrows(
116			NullPointerException.class,
117			() -> c.addAll(null),
118			() -> c.containsAll(null),
119			() -> c.retainAll(null),
120			() -> c.removeAll(null),
121			() -> c.removeIf(null),
122	jsr166	1.6	() -> c.forEach(null),
123			() -> c.iterator().forEachRemaining(null),
124			() -> c.spliterator().forEachRemaining(null),
125			() -> c.spliterator().tryAdvance(null),
126	jsr166	1.5	() -> c.toArray(null));
127
128			if (!impl.permitsNulls()) {
129			assertThrows(
130			NullPointerException.class,
131			() -> c.add(null));
132			}
133			if (!impl.permitsNulls()
134			&& Queue.class.isAssignableFrom(impl.klazz())) {
135			Queue q = (Queue) c;
136			assertThrows(
137			NullPointerException.class,
138			() -> q.offer(null));
139			}
140			if (!impl.permitsNulls()
141			&& Deque.class.isAssignableFrom(impl.klazz())) {
142			Deque d = (Deque) c;
143			assertThrows(
144			NullPointerException.class,
145			() -> d.addFirst(null),
146			() -> d.addLast(null),
147			() -> d.offerFirst(null),
148			() -> d.offerLast(null),
149	jsr166	1.6	() -> d.push(null),
150			() -> d.descendingIterator().forEachRemaining(null));
151	jsr166	1.5	}
152			}
153
154			public void testNoSuchElementExceptions() {
155			Collection c = impl.emptyCollection();
156			assertThrows(
157			NoSuchElementException.class,
158			() -> c.iterator().next());
159
160			if (Queue.class.isAssignableFrom(impl.klazz())) {
161			Queue q = (Queue) c;
162			assertThrows(
163			NoSuchElementException.class,
164			() -> q.element(),
165			() -> q.remove());
166			}
167			if (Deque.class.isAssignableFrom(impl.klazz())) {
168			Deque d = (Deque) c;
169			assertThrows(
170			NoSuchElementException.class,
171			() -> d.getFirst(),
172			() -> d.getLast(),
173			() -> d.removeFirst(),
174			() -> d.removeLast(),
175			() -> d.pop(),
176			() -> d.descendingIterator().next());
177			}
178			}
179
180			public void testRemoveIf() {
181			Collection c = impl.emptyCollection();
182			ThreadLocalRandom rnd = ThreadLocalRandom.current();
183			int n = rnd.nextInt(6);
184			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
185			AtomicReference threwAt = new AtomicReference(null);
186			ArrayList survivors = new ArrayList(c);
187			ArrayList accepts = new ArrayList();
188			ArrayList rejects = new ArrayList();
189			Predicate randomPredicate = (e) -> {
190			assertNull(threwAt.get());
191			switch (rnd.nextInt(3)) {
192			case 0: accepts.add(e); return true;
193			case 1: rejects.add(e); return false;
194			case 2: threwAt.set(e); throw new ArithmeticException();
195			default: throw new AssertionError();
196			}
197			};
198			try {
199	jsr166	1.8	assertFalse(survivors.contains(null));
200	jsr166	1.7	try {
201			boolean modified = c.removeIf(randomPredicate);
202			if (!modified) {
203			assertNull(threwAt.get());
204			assertEquals(n, rejects.size());
205			assertEquals(0, accepts.size());
206			}
207			} catch (ArithmeticException ok) {}
208			survivors.removeAll(accepts);
209			assertEquals(n - accepts.size(), c.size());
210			assertTrue(c.containsAll(survivors));
211			assertTrue(survivors.containsAll(rejects));
212			for (Object x : accepts) assertFalse(c.contains(x));
213			if (threwAt.get() == null)
214			assertEquals(accepts.size() + rejects.size(), n);
215			} catch (Throwable ex) {
216	jsr166	1.5	System.err.println(impl.klazz());
217	jsr166	1.7	System.err.printf("c=%s%n", c);
218			System.err.printf("n=%d%n", n);
219			System.err.printf("accepts=%s%n", accepts);
220			System.err.printf("rejects=%s%n", rejects);
221	jsr166	1.8	System.err.printf("survivors=%s%n", survivors);
222	jsr166	1.7	System.err.printf("threw=%s%n", threwAt.get());
223			throw ex;
224	jsr166	1.5	}
225			}
226
227			/**
228			* Various ways of traversing a collection yield same elements
229			*/
230			public void testIteratorEquivalence() {
231			Collection c = impl.emptyCollection();
232			ThreadLocalRandom rnd = ThreadLocalRandom.current();
233			int n = rnd.nextInt(6);
234			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
235			ArrayList iterated = new ArrayList();
236			ArrayList iteratedForEachRemaining = new ArrayList();
237			ArrayList spliterated = new ArrayList();
238			ArrayList foreached = new ArrayList();
239			for (Object x : c) iterated.add(x);
240			c.iterator().forEachRemaining(e -> iteratedForEachRemaining.add(e));
241			c.spliterator().forEachRemaining(e -> spliterated.add(e));
242			c.forEach(e -> foreached.add(e));
243			boolean ordered =
244			c.spliterator().hasCharacteristics(Spliterator.ORDERED);
245			if (c instanceof List \|\| c instanceof Deque)
246			assertTrue(ordered);
247			if (ordered) {
248			assertEquals(iterated, iteratedForEachRemaining);
249			assertEquals(iterated, spliterated);
250			assertEquals(iterated, foreached);
251			} else {
252			HashSet cset = new HashSet(c);
253			assertEquals(cset, new HashSet(iterated));
254			assertEquals(cset, new HashSet(iteratedForEachRemaining));
255			assertEquals(cset, new HashSet(spliterated));
256			assertEquals(cset, new HashSet(foreached));
257			}
258			if (c instanceof Deque) {
259			Deque d = (Deque) c;
260			ArrayList descending = new ArrayList();
261			ArrayList descendingForEachRemaining = new ArrayList();
262			for (Iterator it = d.descendingIterator(); it.hasNext(); )
263			descending.add(it.next());
264			d.descendingIterator().forEachRemaining(
265			e -> descendingForEachRemaining.add(e));
266			Collections.reverse(descending);
267			Collections.reverse(descendingForEachRemaining);
268			assertEquals(iterated, descending);
269			assertEquals(iterated, descendingForEachRemaining);
270			}
271			}
272
273			/**
274			* Calling Iterator#remove() after Iterator#forEachRemaining
275			* should remove last element
276			*/
277			public void testRemoveAfterForEachRemaining() {
278			Collection c = impl.emptyCollection();
279			ThreadLocalRandom rnd = ThreadLocalRandom.current();
280			{
281			int n = 3 + rnd.nextInt(2);
282			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
283			Iterator it = c.iterator();
284			assertTrue(it.hasNext());
285			assertEquals(impl.makeElement(0), it.next());
286			assertTrue(it.hasNext());
287			assertEquals(impl.makeElement(1), it.next());
288			it.forEachRemaining((e) -> {});
289			it.remove();
290			assertEquals(n - 1, c.size());
291			for (int i = 0; i < n - 1; i++)
292			assertTrue(c.contains(impl.makeElement(i)));
293			assertFalse(c.contains(impl.makeElement(n - 1)));
294			}
295			if (c instanceof Deque) {
296			Deque d = (Deque) impl.emptyCollection();
297			int n = 3 + rnd.nextInt(2);
298			for (int i = 0; i < n; i++) d.add(impl.makeElement(i));
299			Iterator it = d.descendingIterator();
300			assertTrue(it.hasNext());
301			assertEquals(impl.makeElement(n - 1), it.next());
302			assertTrue(it.hasNext());
303			assertEquals(impl.makeElement(n - 2), it.next());
304			it.forEachRemaining((e) -> {});
305			it.remove();
306			assertEquals(n - 1, d.size());
307			for (int i = 1; i < n; i++)
308			assertTrue(d.contains(impl.makeElement(i)));
309			assertFalse(d.contains(impl.makeElement(0)));
310			}
311			}
312
313	jsr166	1.1	/**
314			* stream().forEach returns elements in the collection
315			*/
316	jsr166	1.3	public void testStreamForEach() throws Throwable {
317	jsr166	1.1	final Collection c = impl.emptyCollection();
318			final AtomicLong count = new AtomicLong(0L);
319			final Object x = impl.makeElement(1);
320			final Object y = impl.makeElement(2);
321			final ArrayList found = new ArrayList();
322			Consumer<Object> spy = (o) -> { found.add(o); };
323			c.stream().forEach(spy);
324			assertTrue(found.isEmpty());
325
326			assertTrue(c.add(x));
327			c.stream().forEach(spy);
328			assertEquals(Collections.singletonList(x), found);
329			found.clear();
330
331			assertTrue(c.add(y));
332			c.stream().forEach(spy);
333			assertEquals(2, found.size());
334			assertTrue(found.contains(x));
335			assertTrue(found.contains(y));
336			found.clear();
337
338			c.clear();
339			c.stream().forEach(spy);
340			assertTrue(found.isEmpty());
341			}
342
343	jsr166	1.3	public void testStreamForEachConcurrentStressTest() throws Throwable {
344			if (!impl.isConcurrent()) return;
345			final Collection c = impl.emptyCollection();
346			final long testDurationMillis = timeoutMillis();
347			final AtomicBoolean done = new AtomicBoolean(false);
348			final Object elt = impl.makeElement(1);
349			final Future<?> f1, f2;
350			final ExecutorService pool = Executors.newCachedThreadPool();
351			try (PoolCleaner cleaner = cleaner(pool, done)) {
352			final CountDownLatch threadsStarted = new CountDownLatch(2);
353			Runnable checkElt = () -> {
354			threadsStarted.countDown();
355			while (!done.get())
356			c.stream().forEach((x) -> { assertSame(x, elt); }); };
357			Runnable addRemove = () -> {
358			threadsStarted.countDown();
359			while (!done.get()) {
360			assertTrue(c.add(elt));
361			assertTrue(c.remove(elt));
362			}};
363			f1 = pool.submit(checkElt);
364			f2 = pool.submit(addRemove);
365			Thread.sleep(testDurationMillis);
366			}
367			assertNull(f1.get(0L, MILLISECONDS));
368			assertNull(f2.get(0L, MILLISECONDS));
369			}
370
371			/**
372			* collection.forEach returns elements in the collection
373			*/
374			public void testForEach() throws Throwable {
375			final Collection c = impl.emptyCollection();
376			final AtomicLong count = new AtomicLong(0L);
377			final Object x = impl.makeElement(1);
378			final Object y = impl.makeElement(2);
379			final ArrayList found = new ArrayList();
380			Consumer<Object> spy = (o) -> { found.add(o); };
381			c.forEach(spy);
382			assertTrue(found.isEmpty());
383
384			assertTrue(c.add(x));
385			c.forEach(spy);
386			assertEquals(Collections.singletonList(x), found);
387			found.clear();
388
389			assertTrue(c.add(y));
390			c.forEach(spy);
391			assertEquals(2, found.size());
392			assertTrue(found.contains(x));
393			assertTrue(found.contains(y));
394			found.clear();
395
396			c.clear();
397			c.forEach(spy);
398			assertTrue(found.isEmpty());
399			}
400
401	jsr166	1.1	public void testForEachConcurrentStressTest() throws Throwable {
402			if (!impl.isConcurrent()) return;
403			final Collection c = impl.emptyCollection();
404	jsr166	1.2	final long testDurationMillis = timeoutMillis();
405	jsr166	1.1	final AtomicBoolean done = new AtomicBoolean(false);
406			final Object elt = impl.makeElement(1);
407	jsr166	1.2	final Future<?> f1, f2;
408			final ExecutorService pool = Executors.newCachedThreadPool();
409			try (PoolCleaner cleaner = cleaner(pool, done)) {
410			final CountDownLatch threadsStarted = new CountDownLatch(2);
411			Runnable checkElt = () -> {
412			threadsStarted.countDown();
413			while (!done.get())
414	jsr166	1.3	c.forEach((x) -> { assertSame(x, elt); }); };
415	jsr166	1.2	Runnable addRemove = () -> {
416			threadsStarted.countDown();
417			while (!done.get()) {
418			assertTrue(c.add(elt));
419			assertTrue(c.remove(elt));
420			}};
421			f1 = pool.submit(checkElt);
422			f2 = pool.submit(addRemove);
423			Thread.sleep(testDurationMillis);
424			}
425			assertNull(f1.get(0L, MILLISECONDS));
426			assertNull(f2.get(0L, MILLISECONDS));
427	jsr166	1.1	}
428
429	jsr166	1.4	// public void testCollection8DebugFail() {
430			// fail(impl.klazz().getSimpleName());
431			// }
432	jsr166	1.1	}