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.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, MILLISECONDS); }
                    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, MILLISECONDS); }
                    catch (InterruptedException ex) {
                        throw new AssertionError(ex);
                    }},
                () -> {
                    try { q.offerLast(null, 1L, MILLISECONDS); }
                    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 {
            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 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:	1.15
Committed:	Sun Nov 6 04:15:45 2016 UTC (7 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.14:	+17 -2 lines
Log Message:	improve testNullPointerExceptions
#	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	1.14	import java.util.concurrent.BlockingDeque;
21			import java.util.concurrent.BlockingQueue;
22	jsr166	1.2	import java.util.concurrent.CountDownLatch;
23	jsr166	1.1	import java.util.concurrent.Executors;
24			import java.util.concurrent.ExecutorService;
25			import java.util.concurrent.Future;
26	jsr166	1.5	import java.util.concurrent.ThreadLocalRandom;
27	jsr166	1.1	import java.util.concurrent.atomic.AtomicBoolean;
28			import java.util.concurrent.atomic.AtomicLong;
29	jsr166	1.5	import java.util.concurrent.atomic.AtomicReference;
30	jsr166	1.1	import java.util.function.Consumer;
31	jsr166	1.5	import java.util.function.Predicate;
32	jsr166	1.1
33			import junit.framework.Test;
34
35			/**
36			* Contains tests applicable to all jdk8+ Collection implementations.
37			* An extension of CollectionTest.
38			*/
39			public class Collection8Test extends JSR166TestCase {
40			final CollectionImplementation impl;
41
42			/** Tests are parameterized by a Collection implementation. */
43			Collection8Test(CollectionImplementation impl, String methodName) {
44			super(methodName);
45			this.impl = impl;
46			}
47
48			public static Test testSuite(CollectionImplementation impl) {
49			return parameterizedTestSuite(Collection8Test.class,
50			CollectionImplementation.class,
51			impl);
52			}
53
54	jsr166	1.10	Object bomb() {
55			return new Object() {
56			public boolean equals(Object x) { throw new AssertionError(); }
57			public int hashCode() { throw new AssertionError(); }
58			};
59			}
60
61	jsr166	1.5	/** Checks properties of empty collections. */
62	jsr166	1.14	public void testEmptyMeansEmpty() throws InterruptedException {
63	jsr166	1.5	Collection c = impl.emptyCollection();
64	jsr166	1.12	emptyMeansEmpty(c);
65
66			if (c instanceof java.io.Serializable)
67			emptyMeansEmpty(serialClone(c));
68
69			Collection clone = cloneableClone(c);
70			if (clone != null)
71			emptyMeansEmpty(clone);
72			}
73
74	jsr166	1.14	void emptyMeansEmpty(Collection c) throws InterruptedException {
75	jsr166	1.5	assertTrue(c.isEmpty());
76			assertEquals(0, c.size());
77			assertEquals("[]", c.toString());
78			{
79			Object[] a = c.toArray();
80			assertEquals(0, a.length);
81			assertSame(Object[].class, a.getClass());
82			}
83			{
84			Object[] a = new Object[0];
85			assertSame(a, c.toArray(a));
86			}
87			{
88			Integer[] a = new Integer[0];
89			assertSame(a, c.toArray(a));
90			}
91			{
92			Integer[] a = { 1, 2, 3};
93			assertSame(a, c.toArray(a));
94			assertNull(a[0]);
95			assertSame(2, a[1]);
96			assertSame(3, a[2]);
97			}
98			assertIteratorExhausted(c.iterator());
99			Consumer alwaysThrows = (e) -> { throw new AssertionError(); };
100			c.forEach(alwaysThrows);
101			c.iterator().forEachRemaining(alwaysThrows);
102			c.spliterator().forEachRemaining(alwaysThrows);
103			assertFalse(c.spliterator().tryAdvance(alwaysThrows));
104	jsr166	1.9	if (c.spliterator().hasCharacteristics(Spliterator.SIZED))
105			assertEquals(0, c.spliterator().estimateSize());
106	jsr166	1.10	assertFalse(c.contains(bomb()));
107			assertFalse(c.remove(bomb()));
108	jsr166	1.11	if (c instanceof Queue) {
109	jsr166	1.5	Queue q = (Queue) c;
110			assertNull(q.peek());
111			assertNull(q.poll());
112			}
113	jsr166	1.11	if (c instanceof Deque) {
114	jsr166	1.5	Deque d = (Deque) c;
115			assertNull(d.peekFirst());
116			assertNull(d.peekLast());
117			assertNull(d.pollFirst());
118			assertNull(d.pollLast());
119			assertIteratorExhausted(d.descendingIterator());
120	jsr166	1.9	d.descendingIterator().forEachRemaining(alwaysThrows);
121	jsr166	1.10	assertFalse(d.removeFirstOccurrence(bomb()));
122			assertFalse(d.removeLastOccurrence(bomb()));
123	jsr166	1.5	}
124	jsr166	1.14	if (c instanceof BlockingQueue) {
125			BlockingQueue q = (BlockingQueue) c;
126			assertNull(q.poll(0L, MILLISECONDS));
127			}
128			if (c instanceof BlockingDeque) {
129			BlockingDeque q = (BlockingDeque) c;
130			assertNull(q.pollFirst(0L, MILLISECONDS));
131			assertNull(q.pollLast(0L, MILLISECONDS));
132			}
133	jsr166	1.5	}
134
135	jsr166	1.14	public void testNullPointerExceptions() throws InterruptedException {
136	jsr166	1.5	Collection c = impl.emptyCollection();
137			assertThrows(
138			NullPointerException.class,
139			() -> c.addAll(null),
140			() -> c.containsAll(null),
141			() -> c.retainAll(null),
142			() -> c.removeAll(null),
143			() -> c.removeIf(null),
144	jsr166	1.6	() -> c.forEach(null),
145			() -> c.iterator().forEachRemaining(null),
146			() -> c.spliterator().forEachRemaining(null),
147			() -> c.spliterator().tryAdvance(null),
148	jsr166	1.5	() -> c.toArray(null));
149
150			if (!impl.permitsNulls()) {
151			assertThrows(
152			NullPointerException.class,
153			() -> c.add(null));
154			}
155	jsr166	1.14	if (!impl.permitsNulls() && c instanceof Queue) {
156	jsr166	1.5	Queue q = (Queue) c;
157			assertThrows(
158			NullPointerException.class,
159			() -> q.offer(null));
160			}
161	jsr166	1.14	if (!impl.permitsNulls() && c instanceof Deque) {
162	jsr166	1.5	Deque d = (Deque) c;
163			assertThrows(
164			NullPointerException.class,
165			() -> d.addFirst(null),
166			() -> d.addLast(null),
167			() -> d.offerFirst(null),
168			() -> d.offerLast(null),
169	jsr166	1.6	() -> d.push(null),
170			() -> d.descendingIterator().forEachRemaining(null));
171	jsr166	1.5	}
172	jsr166	1.15	if (c instanceof BlockingQueue) {
173	jsr166	1.14	BlockingQueue q = (BlockingQueue) c;
174			assertThrows(
175			NullPointerException.class,
176			() -> {
177			try { q.offer(null, 1L, MILLISECONDS); }
178			catch (InterruptedException ex) {
179			throw new AssertionError(ex);
180	jsr166	1.15	}},
181			() -> {
182			try { q.put(null); }
183			catch (InterruptedException ex) {
184			throw new AssertionError(ex);
185	jsr166	1.14	}});
186			}
187	jsr166	1.15	if (c instanceof BlockingDeque) {
188	jsr166	1.14	BlockingDeque q = (BlockingDeque) c;
189			assertThrows(
190			NullPointerException.class,
191			() -> {
192			try { q.offerFirst(null, 1L, MILLISECONDS); }
193			catch (InterruptedException ex) {
194			throw new AssertionError(ex);
195			}},
196			() -> {
197			try { q.offerLast(null, 1L, MILLISECONDS); }
198			catch (InterruptedException ex) {
199			throw new AssertionError(ex);
200	jsr166	1.15	}},
201			() -> {
202			try { q.putFirst(null); }
203			catch (InterruptedException ex) {
204			throw new AssertionError(ex);
205			}},
206			() -> {
207			try { q.putLast(null); }
208			catch (InterruptedException ex) {
209			throw new AssertionError(ex);
210	jsr166	1.14	}});
211			}
212	jsr166	1.5	}
213
214			public void testNoSuchElementExceptions() {
215			Collection c = impl.emptyCollection();
216			assertThrows(
217			NoSuchElementException.class,
218			() -> c.iterator().next());
219
220	jsr166	1.14	if (c instanceof Queue) {
221	jsr166	1.5	Queue q = (Queue) c;
222			assertThrows(
223			NoSuchElementException.class,
224			() -> q.element(),
225			() -> q.remove());
226			}
227	jsr166	1.14	if (c instanceof Deque) {
228	jsr166	1.5	Deque d = (Deque) c;
229			assertThrows(
230			NoSuchElementException.class,
231			() -> d.getFirst(),
232			() -> d.getLast(),
233			() -> d.removeFirst(),
234			() -> d.removeLast(),
235			() -> d.pop(),
236			() -> d.descendingIterator().next());
237			}
238			}
239
240			public void testRemoveIf() {
241			Collection c = impl.emptyCollection();
242			ThreadLocalRandom rnd = ThreadLocalRandom.current();
243			int n = rnd.nextInt(6);
244			for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
245			AtomicReference threwAt = new AtomicReference(null);
246			ArrayList survivors = new ArrayList(c);
247			ArrayList accepts = new ArrayList();
248			ArrayList rejects = new ArrayList();
249			Predicate randomPredicate = (e) -> {
250			assertNull(threwAt.get());
251			switch (rnd.nextInt(3)) {
252			case 0: accepts.add(e); return true;
253			case 1: rejects.add(e); return false;
254			case 2: threwAt.set(e); throw new ArithmeticException();
255			default: throw new AssertionError();
256			}
257			};
258			try {
259	jsr166	1.8	assertFalse(survivors.contains(null));
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	}