/* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /* * This file is available under and governed by the GNU General Public * License version 2 only, as published by the Free Software Foundation. * However, the following notice accompanied the original version of this * file: * * Written by Doug Lea with assistance from members of JCP JSR-166 * Expert Group and released to the public domain, as explained at * http://creativecommons.org/publicdomain/zero/1.0/ * Other contributors include Andrew Wright, Jeffrey Hayes, * Pat Fisher, Mike Judd. */ import static java.util.concurrent.TimeUnit.MILLISECONDS; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Collections; import java.util.Iterator; import java.util.NoSuchElementException; import java.util.Queue; import java.util.concurrent.ArrayBlockingQueue; import java.util.concurrent.BlockingQueue; import java.util.concurrent.CountDownLatch; import java.util.concurrent.Executors; import java.util.concurrent.ExecutorService; import java.util.concurrent.ThreadLocalRandom; import junit.framework.Test; public class ArrayBlockingQueueTest extends JSR166TestCase { public static void main(String[] args) { main(suite(), args); } public static Test suite() { class Implementation implements CollectionImplementation { public Class klazz() { return ArrayBlockingQueue.class; } public Collection emptyCollection() { boolean fair = randomBoolean(); return populatedQueue(0, SIZE, 2 * SIZE, fair); } public Object makeElement(int i) { return i; } public boolean isConcurrent() { return true; } public boolean permitsNulls() { return false; } } return newTestSuite( ArrayBlockingQueueTest.class, new Fair().testSuite(), new NonFair().testSuite(), CollectionTest.testSuite(new Implementation())); } public static class Fair extends BlockingQueueTest { protected BlockingQueue emptyCollection() { return populatedQueue(0, SIZE, 2 * SIZE, true); } } public static class NonFair extends BlockingQueueTest { protected BlockingQueue emptyCollection() { return populatedQueue(0, SIZE, 2 * SIZE, false); } } /** * Returns a new queue of given size containing consecutive * Integers 0 ... n - 1. */ static ArrayBlockingQueue populatedQueue(int n) { return populatedQueue(n, n, n, false); } /** * Returns a new queue of given size containing consecutive * Integers 0 ... n - 1, with given capacity range and fairness. */ static ArrayBlockingQueue populatedQueue( int size, int minCapacity, int maxCapacity, boolean fair) { ThreadLocalRandom rnd = ThreadLocalRandom.current(); int capacity = rnd.nextInt(minCapacity, maxCapacity + 1); ArrayBlockingQueue q = new ArrayBlockingQueue<>(capacity); assertTrue(q.isEmpty()); // shuffle circular array elements so they wrap { int n = rnd.nextInt(capacity); for (int i = 0; i < n; i++) q.add(42); for (int i = 0; i < n; i++) q.remove(); } for (int i = 0; i < size; i++) assertTrue(q.offer((Integer) i)); assertEquals(size == 0, q.isEmpty()); assertEquals(capacity - size, q.remainingCapacity()); assertEquals(size, q.size()); if (size > 0) assertEquals((Integer) 0, q.peek()); return q; } /** * A new queue has the indicated capacity */ public void testConstructor1() { assertEquals(SIZE, new ArrayBlockingQueue(SIZE).remainingCapacity()); } /** * Constructor throws IllegalArgumentException if capacity argument nonpositive */ public void testConstructor_nonPositiveCapacity() { for (int i : new int[] { 0, -1, Integer.MIN_VALUE }) { try { new ArrayBlockingQueue(i); shouldThrow(); } catch (IllegalArgumentException success) {} for (boolean fair : new boolean[] { true, false }) { try { new ArrayBlockingQueue(i, fair); shouldThrow(); } catch (IllegalArgumentException success) {} } } } /** * Initializing from null Collection throws NPE */ public void testConstructor_nullCollection() { try { new ArrayBlockingQueue(1, true, null); shouldThrow(); } catch (NullPointerException success) {} } /** * Initializing from Collection of null elements throws NPE */ public void testConstructor4() { Collection elements = Arrays.asList(new Integer[SIZE]); try { new ArrayBlockingQueue(SIZE, false, elements); shouldThrow(); } catch (NullPointerException success) {} } /** * Initializing from Collection with some null elements throws NPE */ public void testConstructor5() { Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE - 1; ++i) ints[i] = i; Collection elements = Arrays.asList(ints); try { new ArrayBlockingQueue(SIZE, false, elements); shouldThrow(); } catch (NullPointerException success) {} } /** * Initializing from too large collection throws IllegalArgumentException */ public void testConstructor_collectionTooLarge() { // just barely fits - succeeds new ArrayBlockingQueue(SIZE, false, Collections.nCopies(SIZE, "")); try { new ArrayBlockingQueue(SIZE - 1, false, Collections.nCopies(SIZE, "")); shouldThrow(); } catch (IllegalArgumentException success) {} } /** * Queue contains all elements of collection used to initialize */ public void testConstructor7() { Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE; ++i) ints[i] = i; Collection elements = Arrays.asList(ints); ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE, true, elements); for (int i = 0; i < SIZE; ++i) assertEquals(ints[i], q.poll()); } /** * Queue transitions from empty to full when elements added */ public void testEmptyFull() { BlockingQueue q = populatedQueue(0, 2, 2, false); assertTrue(q.isEmpty()); assertEquals(2, q.remainingCapacity()); q.add(one); assertFalse(q.isEmpty()); assertTrue(q.offer(two)); assertFalse(q.isEmpty()); assertEquals(0, q.remainingCapacity()); assertFalse(q.offer(three)); } /** * remainingCapacity decreases on add, increases on remove */ public void testRemainingCapacity() { int size = ThreadLocalRandom.current().nextInt(1, SIZE); BlockingQueue q = populatedQueue(size, size, 2 * size, false); int spare = q.remainingCapacity(); int capacity = spare + size; for (int i = 0; i < size; i++) { assertEquals(spare + i, q.remainingCapacity()); assertEquals(capacity, q.size() + q.remainingCapacity()); assertEquals(i, q.remove()); } for (int i = 0; i < size; i++) { assertEquals(capacity - i, q.remainingCapacity()); assertEquals(capacity, q.size() + q.remainingCapacity()); assertTrue(q.add(i)); } } /** * Offer succeeds if not full; fails if full */ public void testOffer() { ArrayBlockingQueue q = new ArrayBlockingQueue(1); assertTrue(q.offer(zero)); assertFalse(q.offer(one)); } /** * add succeeds if not full; throws IllegalStateException if full */ public void testAdd() { ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE); for (int i = 0; i < SIZE; i++) assertTrue(q.add((Integer) i)); assertEquals(0, q.remainingCapacity()); try { q.add((Integer) SIZE); shouldThrow(); } catch (IllegalStateException success) {} } /** * addAll(this) throws IllegalArgumentException */ public void testAddAllSelf() { ArrayBlockingQueue q = populatedQueue(SIZE); try { q.addAll(q); shouldThrow(); } catch (IllegalArgumentException success) {} } /** * addAll of a collection with any null elements throws NPE after * possibly adding some elements */ public void testAddAll3() { ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE); Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE - 1; ++i) ints[i] = new Integer(i); try { q.addAll(Arrays.asList(ints)); shouldThrow(); } catch (NullPointerException success) {} } /** * addAll throws IllegalStateException if not enough room */ public void testAddAll_insufficientSpace() { int size = ThreadLocalRandom.current().nextInt(1, SIZE); ArrayBlockingQueue q = populatedQueue(0, size, size, false); // Just fits: q.addAll(populatedQueue(size, size, 2 * size, false)); assertEquals(0, q.remainingCapacity()); assertEquals(size, q.size()); assertEquals(0, q.peek()); try { q = populatedQueue(0, size, size, false); q.addAll(Collections.nCopies(size + 1, 42)); shouldThrow(); } catch (IllegalStateException success) {} } /** * Queue contains all elements, in traversal order, of successful addAll */ public void testAddAll5() { Integer[] empty = new Integer[0]; Integer[] ints = new Integer[SIZE]; for (int i = 0; i < SIZE; ++i) ints[i] = new Integer(i); ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE); assertFalse(q.addAll(Arrays.asList(empty))); assertTrue(q.addAll(Arrays.asList(ints))); for (int i = 0; i < SIZE; ++i) assertEquals(ints[i], q.poll()); } /** * all elements successfully put are contained */ public void testPut() throws InterruptedException { ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE); for (int i = 0; i < SIZE; ++i) { Integer x = new Integer(i); q.put(x); assertTrue(q.contains(x)); } assertEquals(0, q.remainingCapacity()); } /** * put blocks interruptibly if full */ public void testBlockingPut() throws InterruptedException { final ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE); final CountDownLatch pleaseInterrupt = new CountDownLatch(1); Thread t = newStartedThread(new CheckedRunnable() { public void realRun() throws InterruptedException { for (int i = 0; i < SIZE; ++i) q.put(i); assertEquals(SIZE, q.size()); assertEquals(0, q.remainingCapacity()); Thread.currentThread().interrupt(); try { q.put(99); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); pleaseInterrupt.countDown(); try { q.put(99); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); }}); await(pleaseInterrupt); if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING); t.interrupt(); awaitTermination(t); assertEquals(SIZE, q.size()); assertEquals(0, q.remainingCapacity()); } /** * put blocks interruptibly waiting for take when full */ public void testPutWithTake() throws InterruptedException { final int capacity = 2; final ArrayBlockingQueue q = new ArrayBlockingQueue(capacity); final CountDownLatch pleaseTake = new CountDownLatch(1); final CountDownLatch pleaseInterrupt = new CountDownLatch(1); Thread t = newStartedThread(new CheckedRunnable() { public void realRun() throws InterruptedException { for (int i = 0; i < capacity; i++) q.put(i); pleaseTake.countDown(); q.put(86); Thread.currentThread().interrupt(); try { q.put(99); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); pleaseInterrupt.countDown(); try { q.put(99); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); }}); await(pleaseTake); assertEquals(0, q.remainingCapacity()); assertEquals(0, q.take()); await(pleaseInterrupt); if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING); t.interrupt(); awaitTermination(t); assertEquals(0, q.remainingCapacity()); } /** * timed offer times out if full and elements not taken */ public void testTimedOffer() { final ArrayBlockingQueue q = new ArrayBlockingQueue(2); final CountDownLatch pleaseInterrupt = new CountDownLatch(1); Thread t = newStartedThread(new CheckedRunnable() { public void realRun() throws InterruptedException { q.put(new Object()); q.put(new Object()); long startTime = System.nanoTime(); assertFalse(q.offer(new Object(), timeoutMillis(), MILLISECONDS)); assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); Thread.currentThread().interrupt(); try { q.offer(new Object(), randomTimeout(), randomTimeUnit()); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); pleaseInterrupt.countDown(); try { q.offer(new Object(), LONGER_DELAY_MS, MILLISECONDS); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); }}); await(pleaseInterrupt); if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING); t.interrupt(); awaitTermination(t); } /** * take retrieves elements in FIFO order */ public void testTake() throws InterruptedException { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.take()); } } /** * Take removes existing elements until empty, then blocks interruptibly */ public void testBlockingTake() throws InterruptedException { final ArrayBlockingQueue q = populatedQueue(SIZE); final CountDownLatch pleaseInterrupt = new CountDownLatch(1); Thread t = newStartedThread(new CheckedRunnable() { public void realRun() throws InterruptedException { for (int i = 0; i < SIZE; i++) assertEquals(i, q.take()); Thread.currentThread().interrupt(); try { q.take(); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); pleaseInterrupt.countDown(); try { q.take(); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); }}); await(pleaseInterrupt); if (randomBoolean()) assertThreadBlocks(t, Thread.State.WAITING); t.interrupt(); awaitTermination(t); } /** * poll succeeds unless empty */ public void testPoll() { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.poll()); } assertNull(q.poll()); } /** * timed poll with zero timeout succeeds when non-empty, else times out */ public void testTimedPoll0() throws InterruptedException { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.poll(0, MILLISECONDS)); } assertNull(q.poll(0, MILLISECONDS)); checkEmpty(q); } /** * timed poll with nonzero timeout succeeds when non-empty, else times out */ public void testTimedPoll() throws InterruptedException { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { long startTime = System.nanoTime(); assertEquals(i, q.poll(LONG_DELAY_MS, MILLISECONDS)); assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS); } long startTime = System.nanoTime(); assertNull(q.poll(timeoutMillis(), MILLISECONDS)); assertTrue(millisElapsedSince(startTime) >= timeoutMillis()); checkEmpty(q); } /** * Interrupted timed poll throws InterruptedException instead of * returning timeout status */ public void testInterruptedTimedPoll() throws InterruptedException { final BlockingQueue q = populatedQueue(SIZE); final CountDownLatch pleaseInterrupt = new CountDownLatch(1); Thread t = newStartedThread(new CheckedRunnable() { public void realRun() throws InterruptedException { for (int i = 0; i < SIZE; i++) assertEquals(i, (int) q.poll(LONG_DELAY_MS, MILLISECONDS)); Thread.currentThread().interrupt(); try { q.poll(randomTimeout(), randomTimeUnit()); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); pleaseInterrupt.countDown(); try { q.poll(LONGER_DELAY_MS, MILLISECONDS); shouldThrow(); } catch (InterruptedException success) {} assertFalse(Thread.interrupted()); }}); await(pleaseInterrupt); if (randomBoolean()) assertThreadBlocks(t, Thread.State.TIMED_WAITING); t.interrupt(); awaitTermination(t); checkEmpty(q); } /** * peek returns next element, or null if empty */ public void testPeek() { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.peek()); assertEquals(i, q.poll()); assertTrue(q.peek() == null || !q.peek().equals(i)); } assertNull(q.peek()); } /** * element returns next element, or throws NSEE if empty */ public void testElement() { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.element()); assertEquals(i, q.poll()); } try { q.element(); shouldThrow(); } catch (NoSuchElementException success) {} } /** * remove removes next element, or throws NSEE if empty */ public void testRemove() { ArrayBlockingQueue q = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertEquals(i, q.remove()); } try { q.remove(); shouldThrow(); } catch (NoSuchElementException success) {} } /** * contains(x) reports true when elements added but not yet removed */ public void testContains() { int size = ThreadLocalRandom.current().nextInt(1, SIZE); ArrayBlockingQueue q = populatedQueue(size, size, 2 * size, false); assertFalse(q.contains(null)); for (int i = 0; i < size; ++i) { assertTrue(q.contains(new Integer(i))); assertEquals(i, q.poll()); assertFalse(q.contains(new Integer(i))); } } /** * clear removes all elements */ public void testClear() { int size = ThreadLocalRandom.current().nextInt(1, 5); ArrayBlockingQueue q = populatedQueue(size, size, 2 * size, false); int capacity = size + q.remainingCapacity(); q.clear(); assertTrue(q.isEmpty()); assertEquals(0, q.size()); assertEquals(capacity, q.remainingCapacity()); q.add(one); assertFalse(q.isEmpty()); assertTrue(q.contains(one)); q.clear(); assertTrue(q.isEmpty()); } /** * containsAll(c) is true when c contains a subset of elements */ public void testContainsAll() { ArrayBlockingQueue q = populatedQueue(SIZE); ArrayBlockingQueue p = new ArrayBlockingQueue(SIZE); for (int i = 0; i < SIZE; ++i) { assertTrue(q.containsAll(p)); assertFalse(p.containsAll(q)); p.add(new Integer(i)); } assertTrue(p.containsAll(q)); } /** * retainAll(c) retains only those elements of c and reports true if changed */ public void testRetainAll() { ArrayBlockingQueue q = populatedQueue(SIZE); ArrayBlockingQueue p = populatedQueue(SIZE); for (int i = 0; i < SIZE; ++i) { boolean changed = q.retainAll(p); if (i == 0) assertFalse(changed); else assertTrue(changed); assertTrue(q.containsAll(p)); assertEquals(SIZE - i, q.size()); p.remove(); } } /** * removeAll(c) removes only those elements of c and reports true if changed */ public void testRemoveAll() { for (int i = 1; i < SIZE; ++i) { ArrayBlockingQueue q = populatedQueue(SIZE); ArrayBlockingQueue p = populatedQueue(i); assertTrue(q.removeAll(p)); assertEquals(SIZE - i, q.size()); for (int j = 0; j < i; ++j) { Integer x = (Integer)(p.remove()); assertFalse(q.contains(x)); } } } void checkToArray(ArrayBlockingQueue q) { int size = q.size(); Object[] a1 = q.toArray(); assertEquals(size, a1.length); Integer[] a2 = q.toArray(new Integer[0]); assertEquals(size, a2.length); Integer[] a3 = q.toArray(new Integer[Math.max(0, size - 1)]); assertEquals(size, a3.length); Integer[] a4 = new Integer[size]; assertSame(a4, q.toArray(a4)); Integer[] a5 = new Integer[size + 1]; Arrays.fill(a5, 42); assertSame(a5, q.toArray(a5)); Integer[] a6 = new Integer[size + 2]; Arrays.fill(a6, 42); assertSame(a6, q.toArray(a6)); Object[][] as = { a1, a2, a3, a4, a5, a6 }; for (Object[] a : as) { if (a.length > size) assertNull(a[size]); if (a.length > size + 1) assertEquals(42, a[size + 1]); } Iterator it = q.iterator(); Integer s = q.peek(); for (int i = 0; i < size; i++) { Integer x = (Integer) it.next(); assertEquals(s + i, (int) x); for (Object[] a : as) assertSame(a[i], x); } } /** * toArray() and toArray(a) contain all elements in FIFO order */ public void testToArray() { final ThreadLocalRandom rnd = ThreadLocalRandom.current(); final int size = rnd.nextInt(6); final int capacity = Math.max(1, size + rnd.nextInt(size + 1)); ArrayBlockingQueue q = new ArrayBlockingQueue<>(capacity); for (int i = 0; i < size; i++) { checkToArray(q); q.add(i); } // Provoke wraparound int added = size * 2; for (int i = 0; i < added; i++) { checkToArray(q); assertEquals((Integer) i, q.poll()); q.add(size + i); } for (int i = 0; i < size; i++) { checkToArray(q); assertEquals((Integer) (added + i), q.poll()); } } /** * toArray(incompatible array type) throws ArrayStoreException */ public void testToArray_incompatibleArrayType() { ArrayBlockingQueue q = populatedQueue(SIZE); try { q.toArray(new String[10]); shouldThrow(); } catch (ArrayStoreException success) {} try { q.toArray(new String[0]); shouldThrow(); } catch (ArrayStoreException success) {} } /** * iterator iterates through all elements */ public void testIterator() throws InterruptedException { ArrayBlockingQueue q = populatedQueue(SIZE); Iterator it = q.iterator(); int i; for (i = 0; it.hasNext(); i++) assertTrue(q.contains(it.next())); assertEquals(i, SIZE); assertIteratorExhausted(it); it = q.iterator(); for (i = 0; it.hasNext(); i++) assertEquals(it.next(), q.take()); assertEquals(i, SIZE); assertIteratorExhausted(it); } /** * iterator of empty collection has no elements */ public void testEmptyIterator() { assertIteratorExhausted(new ArrayBlockingQueue(SIZE).iterator()); } /** * iterator.remove removes current element */ public void testIteratorRemove() { final ArrayBlockingQueue q = new ArrayBlockingQueue(3); q.add(two); q.add(one); q.add(three); Iterator it = q.iterator(); it.next(); it.remove(); it = q.iterator(); assertSame(it.next(), one); assertSame(it.next(), three); assertFalse(it.hasNext()); } /** * iterator ordering is FIFO */ public void testIteratorOrdering() { final ArrayBlockingQueue q = new ArrayBlockingQueue(3); q.add(one); q.add(two); q.add(three); assertEquals("queue should be full", 0, q.remainingCapacity()); int k = 0; for (Iterator it = q.iterator(); it.hasNext();) { assertEquals(++k, it.next()); } assertEquals(3, k); } /** * Modifications do not cause iterators to fail */ public void testWeaklyConsistentIteration() { final ArrayBlockingQueue q = new ArrayBlockingQueue(3); q.add(one); q.add(two); q.add(three); for (Iterator it = q.iterator(); it.hasNext();) { q.remove(); it.next(); } assertEquals(0, q.size()); } /** * toString contains toStrings of elements */ public void testToString() { ArrayBlockingQueue q = populatedQueue(SIZE); String s = q.toString(); for (int i = 0; i < SIZE; ++i) { assertTrue(s.contains(String.valueOf(i))); } } /** * offer transfers elements across Executor tasks */ public void testOfferInExecutor() { final ArrayBlockingQueue q = new ArrayBlockingQueue(2); q.add(one); q.add(two); final CheckedBarrier threadsStarted = new CheckedBarrier(2); final ExecutorService executor = Executors.newFixedThreadPool(2); try (PoolCleaner cleaner = cleaner(executor)) { executor.execute(new CheckedRunnable() { public void realRun() throws InterruptedException { assertFalse(q.offer(three)); threadsStarted.await(); assertTrue(q.offer(three, LONG_DELAY_MS, MILLISECONDS)); assertEquals(0, q.remainingCapacity()); }}); executor.execute(new CheckedRunnable() { public void realRun() throws InterruptedException { threadsStarted.await(); assertEquals(0, q.remainingCapacity()); assertSame(one, q.take()); }}); } } /** * timed poll retrieves elements across Executor threads */ public void testPollInExecutor() { final ArrayBlockingQueue q = new ArrayBlockingQueue(2); final CheckedBarrier threadsStarted = new CheckedBarrier(2); final ExecutorService executor = Executors.newFixedThreadPool(2); try (PoolCleaner cleaner = cleaner(executor)) { executor.execute(new CheckedRunnable() { public void realRun() throws InterruptedException { assertNull(q.poll()); threadsStarted.await(); assertSame(one, q.poll(LONG_DELAY_MS, MILLISECONDS)); checkEmpty(q); }}); executor.execute(new CheckedRunnable() { public void realRun() throws InterruptedException { threadsStarted.await(); q.put(one); }}); } } /** * A deserialized/reserialized queue has same elements in same order */ public void testSerialization() throws Exception { Queue x = populatedQueue(SIZE); Queue y = serialClone(x); assertNotSame(x, y); assertEquals(x.size(), y.size()); assertEquals(x.toString(), y.toString()); assertTrue(Arrays.equals(x.toArray(), y.toArray())); while (!x.isEmpty()) { assertFalse(y.isEmpty()); assertEquals(x.remove(), y.remove()); } assertTrue(y.isEmpty()); } /** * drainTo(c) empties queue into another collection c */ public void testDrainTo() { ArrayBlockingQueue q = populatedQueue(SIZE); ArrayList l = new ArrayList(); q.drainTo(l); assertEquals(0, q.size()); assertEquals(SIZE, l.size()); for (int i = 0; i < SIZE; ++i) assertEquals(l.get(i), new Integer(i)); q.add(zero); q.add(one); assertFalse(q.isEmpty()); assertTrue(q.contains(zero)); assertTrue(q.contains(one)); l.clear(); q.drainTo(l); assertEquals(0, q.size()); assertEquals(2, l.size()); for (int i = 0; i < 2; ++i) assertEquals(l.get(i), new Integer(i)); } /** * drainTo empties full queue, unblocking a waiting put. */ public void testDrainToWithActivePut() throws InterruptedException { final ArrayBlockingQueue q = populatedQueue(SIZE); Thread t = new Thread(new CheckedRunnable() { public void realRun() throws InterruptedException { q.put(new Integer(SIZE + 1)); }}); t.start(); ArrayList l = new ArrayList(); q.drainTo(l); assertTrue(l.size() >= SIZE); for (int i = 0; i < SIZE; ++i) assertEquals(l.get(i), new Integer(i)); t.join(); assertTrue(q.size() + l.size() >= SIZE); } /** * drainTo(c, n) empties first min(n, size) elements of queue into c */ public void testDrainToN() { ArrayBlockingQueue q = new ArrayBlockingQueue(SIZE * 2); for (int i = 0; i < SIZE + 2; ++i) { for (int j = 0; j < SIZE; j++) assertTrue(q.offer(new Integer(j))); ArrayList l = new ArrayList(); q.drainTo(l, i); int k = (i < SIZE) ? i : SIZE; assertEquals(k, l.size()); assertEquals(SIZE - k, q.size()); for (int j = 0; j < k; ++j) assertEquals(l.get(j), new Integer(j)); do {} while (q.poll() != null); } } /** * remove(null), contains(null) always return false */ public void testNeverContainsNull() { Collection[] qs = { populatedQueue(0, 1, 10, false), populatedQueue(2, 2, 10, true), }; for (Collection q : qs) { assertFalse(q.contains(null)); assertFalse(q.remove(null)); } } }