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root/jsr166/jsr166/src/test/tck/DelayQueueTest.java
Revision: 1.67
Committed: Fri Jan 2 03:52:53 2015 UTC (9 years, 4 months ago) by jsr166
Branch: MAIN
Changes since 1.66: +8 -8 lines
Log Message:
remove unnecessary casts and parens

File Contents

# Content
1 /*
2 * Written by Doug Lea with assistance from members of JCP JSR-166
3 * Expert Group and released to the public domain, as explained at
4 * http://creativecommons.org/publicdomain/zero/1.0/
5 * Other contributors include Andrew Wright, Jeffrey Hayes,
6 * Pat Fisher, Mike Judd.
7 */
8
9 import static java.util.concurrent.TimeUnit.MILLISECONDS;
10
11 import java.util.ArrayList;
12 import java.util.Arrays;
13 import java.util.Collection;
14 import java.util.Iterator;
15 import java.util.NoSuchElementException;
16 import java.util.concurrent.BlockingQueue;
17 import java.util.concurrent.CountDownLatch;
18 import java.util.concurrent.Delayed;
19 import java.util.concurrent.DelayQueue;
20 import java.util.concurrent.Executors;
21 import java.util.concurrent.ExecutorService;
22 import java.util.concurrent.TimeUnit;
23
24 import junit.framework.Test;
25
26 public class DelayQueueTest extends JSR166TestCase {
27
28 public static class Generic extends BlockingQueueTest {
29 protected BlockingQueue emptyCollection() {
30 return new DelayQueue();
31 }
32 protected PDelay makeElement(int i) {
33 return new PDelay(i);
34 }
35 }
36
37 public static void main(String[] args) {
38 junit.textui.TestRunner.run(suite());
39 }
40
41 public static Test suite() {
42 return newTestSuite(DelayQueueTest.class,
43 new Generic().testSuite());
44 }
45
46 private static final int NOCAP = Integer.MAX_VALUE;
47
48 /**
49 * A delayed implementation for testing.
50 * Most tests use Pseudodelays, where delays are all elapsed
51 * (so, no blocking solely for delays) but are still ordered
52 */
53 static class PDelay implements Delayed {
54 int pseudodelay;
55 PDelay(int i) { pseudodelay = i; }
56 public int compareTo(PDelay other) {
57 int a = this.pseudodelay;
58 int b = other.pseudodelay;
59 return (a < b) ? -1 : (a > b) ? 1 : 0;
60 }
61 public int compareTo(Delayed y) {
62 return compareTo((PDelay)y);
63 }
64 public boolean equals(Object other) {
65 return (other instanceof PDelay) &&
66 this.pseudodelay == ((PDelay)other).pseudodelay;
67 }
68 // suppress [overrides] javac warning
69 public int hashCode() { return pseudodelay; }
70 public long getDelay(TimeUnit ignore) {
71 return Integer.MIN_VALUE + pseudodelay;
72 }
73 public String toString() {
74 return String.valueOf(pseudodelay);
75 }
76 }
77
78 /**
79 * Delayed implementation that actually delays
80 */
81 static class NanoDelay implements Delayed {
82 long trigger;
83 NanoDelay(long i) {
84 trigger = System.nanoTime() + i;
85 }
86 public int compareTo(NanoDelay y) {
87 long i = trigger;
88 long j = y.trigger;
89 if (i < j) return -1;
90 if (i > j) return 1;
91 return 0;
92 }
93
94 public int compareTo(Delayed y) {
95 return compareTo((NanoDelay)y);
96 }
97
98 public boolean equals(Object other) {
99 return equals((NanoDelay)other);
100 }
101 public boolean equals(NanoDelay other) {
102 return other.trigger == trigger;
103 }
104
105 // suppress [overrides] javac warning
106 public int hashCode() { return (int) trigger; }
107
108 public long getDelay(TimeUnit unit) {
109 long n = trigger - System.nanoTime();
110 return unit.convert(n, TimeUnit.NANOSECONDS);
111 }
112
113 public long getTriggerTime() {
114 return trigger;
115 }
116
117 public String toString() {
118 return String.valueOf(trigger);
119 }
120 }
121
122 /**
123 * Returns a new queue of given size containing consecutive
124 * PDelays 0 ... n.
125 */
126 private DelayQueue<PDelay> populatedQueue(int n) {
127 DelayQueue<PDelay> q = new DelayQueue<PDelay>();
128 assertTrue(q.isEmpty());
129 for (int i = n-1; i >= 0; i -= 2)
130 assertTrue(q.offer(new PDelay(i)));
131 for (int i = (n & 1); i < n; i += 2)
132 assertTrue(q.offer(new PDelay(i)));
133 assertFalse(q.isEmpty());
134 assertEquals(NOCAP, q.remainingCapacity());
135 assertEquals(n, q.size());
136 return q;
137 }
138
139 /**
140 * A new queue has unbounded capacity
141 */
142 public void testConstructor1() {
143 assertEquals(NOCAP, new DelayQueue().remainingCapacity());
144 }
145
146 /**
147 * Initializing from null Collection throws NPE
148 */
149 public void testConstructor3() {
150 try {
151 DelayQueue q = new DelayQueue(null);
152 shouldThrow();
153 } catch (NullPointerException success) {}
154 }
155
156 /**
157 * Initializing from Collection of null elements throws NPE
158 */
159 public void testConstructor4() {
160 try {
161 PDelay[] ints = new PDelay[SIZE];
162 DelayQueue q = new DelayQueue(Arrays.asList(ints));
163 shouldThrow();
164 } catch (NullPointerException success) {}
165 }
166
167 /**
168 * Initializing from Collection with some null elements throws NPE
169 */
170 public void testConstructor5() {
171 try {
172 PDelay[] ints = new PDelay[SIZE];
173 for (int i = 0; i < SIZE-1; ++i)
174 ints[i] = new PDelay(i);
175 DelayQueue q = new DelayQueue(Arrays.asList(ints));
176 shouldThrow();
177 } catch (NullPointerException success) {}
178 }
179
180 /**
181 * Queue contains all elements of collection used to initialize
182 */
183 public void testConstructor6() {
184 PDelay[] ints = new PDelay[SIZE];
185 for (int i = 0; i < SIZE; ++i)
186 ints[i] = new PDelay(i);
187 DelayQueue q = new DelayQueue(Arrays.asList(ints));
188 for (int i = 0; i < SIZE; ++i)
189 assertEquals(ints[i], q.poll());
190 }
191
192 /**
193 * isEmpty is true before add, false after
194 */
195 public void testEmpty() {
196 DelayQueue q = new DelayQueue();
197 assertTrue(q.isEmpty());
198 assertEquals(NOCAP, q.remainingCapacity());
199 q.add(new PDelay(1));
200 assertFalse(q.isEmpty());
201 q.add(new PDelay(2));
202 q.remove();
203 q.remove();
204 assertTrue(q.isEmpty());
205 }
206
207 /**
208 * remainingCapacity does not change when elements added or removed,
209 * but size does
210 */
211 public void testRemainingCapacity() {
212 DelayQueue q = populatedQueue(SIZE);
213 for (int i = 0; i < SIZE; ++i) {
214 assertEquals(NOCAP, q.remainingCapacity());
215 assertEquals(SIZE-i, q.size());
216 q.remove();
217 }
218 for (int i = 0; i < SIZE; ++i) {
219 assertEquals(NOCAP, q.remainingCapacity());
220 assertEquals(i, q.size());
221 q.add(new PDelay(i));
222 }
223 }
224
225 /**
226 * offer non-null succeeds
227 */
228 public void testOffer() {
229 DelayQueue q = new DelayQueue();
230 assertTrue(q.offer(new PDelay(0)));
231 assertTrue(q.offer(new PDelay(1)));
232 }
233
234 /**
235 * add succeeds
236 */
237 public void testAdd() {
238 DelayQueue q = new DelayQueue();
239 for (int i = 0; i < SIZE; ++i) {
240 assertEquals(i, q.size());
241 assertTrue(q.add(new PDelay(i)));
242 }
243 }
244
245 /**
246 * addAll(this) throws IAE
247 */
248 public void testAddAllSelf() {
249 try {
250 DelayQueue q = populatedQueue(SIZE);
251 q.addAll(q);
252 shouldThrow();
253 } catch (IllegalArgumentException success) {}
254 }
255
256 /**
257 * addAll of a collection with any null elements throws NPE after
258 * possibly adding some elements
259 */
260 public void testAddAll3() {
261 try {
262 DelayQueue q = new DelayQueue();
263 PDelay[] ints = new PDelay[SIZE];
264 for (int i = 0; i < SIZE-1; ++i)
265 ints[i] = new PDelay(i);
266 q.addAll(Arrays.asList(ints));
267 shouldThrow();
268 } catch (NullPointerException success) {}
269 }
270
271 /**
272 * Queue contains all elements of successful addAll
273 */
274 public void testAddAll5() {
275 PDelay[] empty = new PDelay[0];
276 PDelay[] ints = new PDelay[SIZE];
277 for (int i = SIZE-1; i >= 0; --i)
278 ints[i] = new PDelay(i);
279 DelayQueue q = new DelayQueue();
280 assertFalse(q.addAll(Arrays.asList(empty)));
281 assertTrue(q.addAll(Arrays.asList(ints)));
282 for (int i = 0; i < SIZE; ++i)
283 assertEquals(ints[i], q.poll());
284 }
285
286 /**
287 * all elements successfully put are contained
288 */
289 public void testPut() {
290 DelayQueue q = new DelayQueue();
291 for (int i = 0; i < SIZE; ++i) {
292 PDelay x = new PDelay(i);
293 q.put(x);
294 assertTrue(q.contains(x));
295 }
296 assertEquals(SIZE, q.size());
297 }
298
299 /**
300 * put doesn't block waiting for take
301 */
302 public void testPutWithTake() throws InterruptedException {
303 final DelayQueue q = new DelayQueue();
304 Thread t = newStartedThread(new CheckedRunnable() {
305 public void realRun() {
306 q.put(new PDelay(0));
307 q.put(new PDelay(0));
308 q.put(new PDelay(0));
309 q.put(new PDelay(0));
310 }});
311
312 awaitTermination(t);
313 assertEquals(4, q.size());
314 }
315
316 /**
317 * timed offer does not time out
318 */
319 public void testTimedOffer() throws InterruptedException {
320 final DelayQueue q = new DelayQueue();
321 Thread t = newStartedThread(new CheckedRunnable() {
322 public void realRun() throws InterruptedException {
323 q.put(new PDelay(0));
324 q.put(new PDelay(0));
325 assertTrue(q.offer(new PDelay(0), SHORT_DELAY_MS, MILLISECONDS));
326 assertTrue(q.offer(new PDelay(0), LONG_DELAY_MS, MILLISECONDS));
327 }});
328
329 awaitTermination(t);
330 }
331
332 /**
333 * take retrieves elements in priority order
334 */
335 public void testTake() throws InterruptedException {
336 DelayQueue q = populatedQueue(SIZE);
337 for (int i = 0; i < SIZE; ++i) {
338 assertEquals(new PDelay(i), q.take());
339 }
340 }
341
342 /**
343 * Take removes existing elements until empty, then blocks interruptibly
344 */
345 public void testBlockingTake() throws InterruptedException {
346 final DelayQueue q = populatedQueue(SIZE);
347 final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
348 Thread t = newStartedThread(new CheckedRunnable() {
349 public void realRun() throws InterruptedException {
350 for (int i = 0; i < SIZE; ++i) {
351 assertEquals(new PDelay(i), ((PDelay)q.take()));
352 }
353
354 Thread.currentThread().interrupt();
355 try {
356 q.take();
357 shouldThrow();
358 } catch (InterruptedException success) {}
359 assertFalse(Thread.interrupted());
360
361 pleaseInterrupt.countDown();
362 try {
363 q.take();
364 shouldThrow();
365 } catch (InterruptedException success) {}
366 assertFalse(Thread.interrupted());
367 }});
368
369 await(pleaseInterrupt);
370 assertThreadStaysAlive(t);
371 t.interrupt();
372 awaitTermination(t);
373 }
374
375 /**
376 * poll succeeds unless empty
377 */
378 public void testPoll() {
379 DelayQueue q = populatedQueue(SIZE);
380 for (int i = 0; i < SIZE; ++i) {
381 assertEquals(new PDelay(i), q.poll());
382 }
383 assertNull(q.poll());
384 }
385
386 /**
387 * timed poll with zero timeout succeeds when non-empty, else times out
388 */
389 public void testTimedPoll0() throws InterruptedException {
390 DelayQueue q = populatedQueue(SIZE);
391 for (int i = 0; i < SIZE; ++i) {
392 assertEquals(new PDelay(i), q.poll(0, MILLISECONDS));
393 }
394 assertNull(q.poll(0, MILLISECONDS));
395 }
396
397 /**
398 * timed poll with nonzero timeout succeeds when non-empty, else times out
399 */
400 public void testTimedPoll() throws InterruptedException {
401 DelayQueue q = populatedQueue(SIZE);
402 for (int i = 0; i < SIZE; ++i) {
403 long startTime = System.nanoTime();
404 assertEquals(new PDelay(i), q.poll(LONG_DELAY_MS, MILLISECONDS));
405 assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
406 }
407 long startTime = System.nanoTime();
408 assertNull(q.poll(timeoutMillis(), MILLISECONDS));
409 assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
410 checkEmpty(q);
411 }
412
413 /**
414 * Interrupted timed poll throws InterruptedException instead of
415 * returning timeout status
416 */
417 public void testInterruptedTimedPoll() throws InterruptedException {
418 final CountDownLatch pleaseInterrupt = new CountDownLatch(1);
419 Thread t = newStartedThread(new CheckedRunnable() {
420 public void realRun() throws InterruptedException {
421 DelayQueue q = populatedQueue(SIZE);
422 for (int i = 0; i < SIZE; ++i) {
423 assertEquals(new PDelay(i), ((PDelay)q.poll(SHORT_DELAY_MS, MILLISECONDS)));
424 }
425
426 Thread.currentThread().interrupt();
427 try {
428 q.poll(LONG_DELAY_MS, MILLISECONDS);
429 shouldThrow();
430 } catch (InterruptedException success) {}
431 assertFalse(Thread.interrupted());
432
433 pleaseInterrupt.countDown();
434 try {
435 q.poll(LONG_DELAY_MS, MILLISECONDS);
436 shouldThrow();
437 } catch (InterruptedException success) {}
438 assertFalse(Thread.interrupted());
439 }});
440
441 await(pleaseInterrupt);
442 assertThreadStaysAlive(t);
443 t.interrupt();
444 awaitTermination(t);
445 }
446
447 /**
448 * peek returns next element, or null if empty
449 */
450 public void testPeek() {
451 DelayQueue q = populatedQueue(SIZE);
452 for (int i = 0; i < SIZE; ++i) {
453 assertEquals(new PDelay(i), q.peek());
454 assertEquals(new PDelay(i), q.poll());
455 if (q.isEmpty())
456 assertNull(q.peek());
457 else
458 assertFalse(new PDelay(i).equals(q.peek()));
459 }
460 assertNull(q.peek());
461 }
462
463 /**
464 * element returns next element, or throws NSEE if empty
465 */
466 public void testElement() {
467 DelayQueue q = populatedQueue(SIZE);
468 for (int i = 0; i < SIZE; ++i) {
469 assertEquals(new PDelay(i), q.element());
470 q.poll();
471 }
472 try {
473 q.element();
474 shouldThrow();
475 } catch (NoSuchElementException success) {}
476 }
477
478 /**
479 * remove removes next element, or throws NSEE if empty
480 */
481 public void testRemove() {
482 DelayQueue q = populatedQueue(SIZE);
483 for (int i = 0; i < SIZE; ++i) {
484 assertEquals(new PDelay(i), q.remove());
485 }
486 try {
487 q.remove();
488 shouldThrow();
489 } catch (NoSuchElementException success) {}
490 }
491
492 /**
493 * contains(x) reports true when elements added but not yet removed
494 */
495 public void testContains() {
496 DelayQueue q = populatedQueue(SIZE);
497 for (int i = 0; i < SIZE; ++i) {
498 assertTrue(q.contains(new PDelay(i)));
499 q.poll();
500 assertFalse(q.contains(new PDelay(i)));
501 }
502 }
503
504 /**
505 * clear removes all elements
506 */
507 public void testClear() {
508 DelayQueue q = populatedQueue(SIZE);
509 q.clear();
510 assertTrue(q.isEmpty());
511 assertEquals(0, q.size());
512 assertEquals(NOCAP, q.remainingCapacity());
513 PDelay x = new PDelay(1);
514 q.add(x);
515 assertFalse(q.isEmpty());
516 assertTrue(q.contains(x));
517 q.clear();
518 assertTrue(q.isEmpty());
519 }
520
521 /**
522 * containsAll(c) is true when c contains a subset of elements
523 */
524 public void testContainsAll() {
525 DelayQueue q = populatedQueue(SIZE);
526 DelayQueue p = new DelayQueue();
527 for (int i = 0; i < SIZE; ++i) {
528 assertTrue(q.containsAll(p));
529 assertFalse(p.containsAll(q));
530 p.add(new PDelay(i));
531 }
532 assertTrue(p.containsAll(q));
533 }
534
535 /**
536 * retainAll(c) retains only those elements of c and reports true if changed
537 */
538 public void testRetainAll() {
539 DelayQueue q = populatedQueue(SIZE);
540 DelayQueue p = populatedQueue(SIZE);
541 for (int i = 0; i < SIZE; ++i) {
542 boolean changed = q.retainAll(p);
543 if (i == 0)
544 assertFalse(changed);
545 else
546 assertTrue(changed);
547
548 assertTrue(q.containsAll(p));
549 assertEquals(SIZE-i, q.size());
550 p.remove();
551 }
552 }
553
554 /**
555 * removeAll(c) removes only those elements of c and reports true if changed
556 */
557 public void testRemoveAll() {
558 for (int i = 1; i < SIZE; ++i) {
559 DelayQueue q = populatedQueue(SIZE);
560 DelayQueue p = populatedQueue(i);
561 assertTrue(q.removeAll(p));
562 assertEquals(SIZE-i, q.size());
563 for (int j = 0; j < i; ++j) {
564 PDelay x = (PDelay)(p.remove());
565 assertFalse(q.contains(x));
566 }
567 }
568 }
569
570 /**
571 * toArray contains all elements
572 */
573 public void testToArray() throws InterruptedException {
574 DelayQueue q = populatedQueue(SIZE);
575 Object[] o = q.toArray();
576 Arrays.sort(o);
577 for (int i = 0; i < o.length; i++)
578 assertSame(o[i], q.take());
579 }
580
581 /**
582 * toArray(a) contains all elements
583 */
584 public void testToArray2() {
585 DelayQueue<PDelay> q = populatedQueue(SIZE);
586 PDelay[] ints = new PDelay[SIZE];
587 PDelay[] array = q.toArray(ints);
588 assertSame(ints, array);
589 Arrays.sort(ints);
590 for (int i = 0; i < ints.length; i++)
591 assertSame(ints[i], q.remove());
592 }
593
594 /**
595 * toArray(incompatible array type) throws ArrayStoreException
596 */
597 public void testToArray1_BadArg() {
598 DelayQueue q = populatedQueue(SIZE);
599 try {
600 q.toArray(new String[10]);
601 shouldThrow();
602 } catch (ArrayStoreException success) {}
603 }
604
605 /**
606 * iterator iterates through all elements
607 */
608 public void testIterator() {
609 DelayQueue q = populatedQueue(SIZE);
610 int i = 0;
611 Iterator it = q.iterator();
612 while (it.hasNext()) {
613 assertTrue(q.contains(it.next()));
614 ++i;
615 }
616 assertEquals(i, SIZE);
617 }
618
619 /**
620 * iterator.remove removes current element
621 */
622 public void testIteratorRemove() {
623 final DelayQueue q = new DelayQueue();
624 q.add(new PDelay(2));
625 q.add(new PDelay(1));
626 q.add(new PDelay(3));
627 Iterator it = q.iterator();
628 it.next();
629 it.remove();
630 it = q.iterator();
631 assertEquals(new PDelay(2), it.next());
632 assertEquals(new PDelay(3), it.next());
633 assertFalse(it.hasNext());
634 }
635
636 /**
637 * toString contains toStrings of elements
638 */
639 public void testToString() {
640 DelayQueue q = populatedQueue(SIZE);
641 String s = q.toString();
642 for (Object e : q)
643 assertTrue(s.contains(e.toString()));
644 }
645
646 /**
647 * timed poll transfers elements across Executor tasks
648 */
649 public void testPollInExecutor() {
650 final DelayQueue q = new DelayQueue();
651 final CheckedBarrier threadsStarted = new CheckedBarrier(2);
652 ExecutorService executor = Executors.newFixedThreadPool(2);
653 executor.execute(new CheckedRunnable() {
654 public void realRun() throws InterruptedException {
655 assertNull(q.poll());
656 threadsStarted.await();
657 assertNotNull(q.poll(LONG_DELAY_MS, MILLISECONDS));
658 checkEmpty(q);
659 }});
660
661 executor.execute(new CheckedRunnable() {
662 public void realRun() throws InterruptedException {
663 threadsStarted.await();
664 q.put(new PDelay(1));
665 }});
666
667 joinPool(executor);
668 }
669
670 /**
671 * Delayed actions do not occur until their delay elapses
672 */
673 public void testDelay() throws InterruptedException {
674 DelayQueue<NanoDelay> q = new DelayQueue<NanoDelay>();
675 for (int i = 0; i < SIZE; ++i)
676 q.add(new NanoDelay(1000000L * (SIZE - i)));
677
678 long last = 0;
679 for (int i = 0; i < SIZE; ++i) {
680 NanoDelay e = q.take();
681 long tt = e.getTriggerTime();
682 assertTrue(System.nanoTime() - tt >= 0);
683 if (i != 0)
684 assertTrue(tt >= last);
685 last = tt;
686 }
687 assertTrue(q.isEmpty());
688 }
689
690 /**
691 * peek of a non-empty queue returns non-null even if not expired
692 */
693 public void testPeekDelayed() {
694 DelayQueue q = new DelayQueue();
695 q.add(new NanoDelay(Long.MAX_VALUE));
696 assertNotNull(q.peek());
697 }
698
699 /**
700 * poll of a non-empty queue returns null if no expired elements.
701 */
702 public void testPollDelayed() {
703 DelayQueue q = new DelayQueue();
704 q.add(new NanoDelay(Long.MAX_VALUE));
705 assertNull(q.poll());
706 }
707
708 /**
709 * timed poll of a non-empty queue returns null if no expired elements.
710 */
711 public void testTimedPollDelayed() throws InterruptedException {
712 DelayQueue q = new DelayQueue();
713 q.add(new NanoDelay(LONG_DELAY_MS * 1000000L));
714 assertNull(q.poll(timeoutMillis(), MILLISECONDS));
715 }
716
717 /**
718 * drainTo(c) empties queue into another collection c
719 */
720 public void testDrainTo() {
721 DelayQueue q = new DelayQueue();
722 PDelay[] elems = new PDelay[SIZE];
723 for (int i = 0; i < SIZE; ++i) {
724 elems[i] = new PDelay(i);
725 q.add(elems[i]);
726 }
727 ArrayList l = new ArrayList();
728 q.drainTo(l);
729 assertEquals(0, q.size());
730 for (int i = 0; i < SIZE; ++i)
731 assertEquals(elems[i], l.get(i));
732 q.add(elems[0]);
733 q.add(elems[1]);
734 assertFalse(q.isEmpty());
735 assertTrue(q.contains(elems[0]));
736 assertTrue(q.contains(elems[1]));
737 l.clear();
738 q.drainTo(l);
739 assertEquals(0, q.size());
740 assertEquals(2, l.size());
741 for (int i = 0; i < 2; ++i)
742 assertEquals(elems[i], l.get(i));
743 }
744
745 /**
746 * drainTo empties queue
747 */
748 public void testDrainToWithActivePut() throws InterruptedException {
749 final DelayQueue q = populatedQueue(SIZE);
750 Thread t = new Thread(new CheckedRunnable() {
751 public void realRun() {
752 q.put(new PDelay(SIZE+1));
753 }});
754
755 t.start();
756 ArrayList l = new ArrayList();
757 q.drainTo(l);
758 assertTrue(l.size() >= SIZE);
759 t.join();
760 assertTrue(q.size() + l.size() >= SIZE);
761 }
762
763 /**
764 * drainTo(c, n) empties first min(n, size) elements of queue into c
765 */
766 public void testDrainToN() {
767 for (int i = 0; i < SIZE + 2; ++i) {
768 DelayQueue q = populatedQueue(SIZE);
769 ArrayList l = new ArrayList();
770 q.drainTo(l, i);
771 int k = (i < SIZE) ? i : SIZE;
772 assertEquals(SIZE-k, q.size());
773 assertEquals(k, l.size());
774 }
775 }
776
777 /**
778 * remove(null), contains(null) always return false
779 */
780 public void testNeverContainsNull() {
781 Collection<?> q = populatedQueue(SIZE);
782 assertFalse(q.contains(null));
783 assertFalse(q.remove(null));
784 }
785 }