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root/jsr166/jsr166/src/test/tck/Collection8Test.java
Revision: 1.21
Committed: Mon Nov 7 00:37:53 2016 UTC (7 years, 6 months ago) by jsr166
Branch: MAIN
Changes since 1.20: +21 -13 lines
Log Message:
Optimize Iterator.forEachRemaining, as in ArrayDeque

File Contents

# Content
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.HOURS;
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.Collections;
15 import java.util.Deque;
16 import java.util.HashSet;
17 import java.util.Iterator;
18 import java.util.List;
19 import java.util.NoSuchElementException;
20 import java.util.Queue;
21 import java.util.Spliterator;
22 import java.util.concurrent.BlockingDeque;
23 import java.util.concurrent.BlockingQueue;
24 import java.util.concurrent.CountDownLatch;
25 import java.util.concurrent.Executors;
26 import java.util.concurrent.ExecutorService;
27 import java.util.concurrent.Future;
28 import java.util.concurrent.ThreadLocalRandom;
29 import java.util.concurrent.atomic.AtomicBoolean;
30 import java.util.concurrent.atomic.AtomicLong;
31 import java.util.concurrent.atomic.AtomicReference;
32 import java.util.function.Consumer;
33 import java.util.function.Predicate;
34
35 import junit.framework.Test;
36
37 /**
38 * Contains tests applicable to all jdk8+ Collection implementations.
39 * An extension of CollectionTest.
40 */
41 public class Collection8Test extends JSR166TestCase {
42 final CollectionImplementation impl;
43
44 /** Tests are parameterized by a Collection implementation. */
45 Collection8Test(CollectionImplementation impl, String methodName) {
46 super(methodName);
47 this.impl = impl;
48 }
49
50 public static Test testSuite(CollectionImplementation impl) {
51 return parameterizedTestSuite(Collection8Test.class,
52 CollectionImplementation.class,
53 impl);
54 }
55
56 Object bomb() {
57 return new Object() {
58 public boolean equals(Object x) { throw new AssertionError(); }
59 public int hashCode() { throw new AssertionError(); }
60 };
61 }
62
63 /** Checks properties of empty collections. */
64 public void testEmptyMeansEmpty() throws InterruptedException {
65 Collection c = impl.emptyCollection();
66 emptyMeansEmpty(c);
67
68 if (c instanceof java.io.Serializable)
69 emptyMeansEmpty(serialClone(c));
70
71 Collection clone = cloneableClone(c);
72 if (clone != null)
73 emptyMeansEmpty(clone);
74 }
75
76 void emptyMeansEmpty(Collection c) throws InterruptedException {
77 assertTrue(c.isEmpty());
78 assertEquals(0, c.size());
79 assertEquals("[]", c.toString());
80 {
81 Object[] a = c.toArray();
82 assertEquals(0, a.length);
83 assertSame(Object[].class, a.getClass());
84 }
85 {
86 Object[] a = new Object[0];
87 assertSame(a, c.toArray(a));
88 }
89 {
90 Integer[] a = new Integer[0];
91 assertSame(a, c.toArray(a));
92 }
93 {
94 Integer[] a = { 1, 2, 3};
95 assertSame(a, c.toArray(a));
96 assertNull(a[0]);
97 assertSame(2, a[1]);
98 assertSame(3, a[2]);
99 }
100 assertIteratorExhausted(c.iterator());
101 Consumer alwaysThrows = e -> { throw new AssertionError(); };
102 c.forEach(alwaysThrows);
103 c.iterator().forEachRemaining(alwaysThrows);
104 c.spliterator().forEachRemaining(alwaysThrows);
105 assertFalse(c.spliterator().tryAdvance(alwaysThrows));
106 if (c.spliterator().hasCharacteristics(Spliterator.SIZED))
107 assertEquals(0, c.spliterator().estimateSize());
108 assertFalse(c.contains(bomb()));
109 assertFalse(c.remove(bomb()));
110 if (c instanceof Queue) {
111 Queue q = (Queue) c;
112 assertNull(q.peek());
113 assertNull(q.poll());
114 }
115 if (c instanceof Deque) {
116 Deque d = (Deque) c;
117 assertNull(d.peekFirst());
118 assertNull(d.peekLast());
119 assertNull(d.pollFirst());
120 assertNull(d.pollLast());
121 assertIteratorExhausted(d.descendingIterator());
122 d.descendingIterator().forEachRemaining(alwaysThrows);
123 assertFalse(d.removeFirstOccurrence(bomb()));
124 assertFalse(d.removeLastOccurrence(bomb()));
125 }
126 if (c instanceof BlockingQueue) {
127 BlockingQueue q = (BlockingQueue) c;
128 assertNull(q.poll(0L, MILLISECONDS));
129 }
130 if (c instanceof BlockingDeque) {
131 BlockingDeque q = (BlockingDeque) c;
132 assertNull(q.pollFirst(0L, MILLISECONDS));
133 assertNull(q.pollLast(0L, MILLISECONDS));
134 }
135 }
136
137 public void testNullPointerExceptions() throws InterruptedException {
138 Collection c = impl.emptyCollection();
139 assertThrows(
140 NullPointerException.class,
141 () -> c.addAll(null),
142 () -> c.containsAll(null),
143 () -> c.retainAll(null),
144 () -> c.removeAll(null),
145 () -> c.removeIf(null),
146 () -> c.forEach(null),
147 () -> c.iterator().forEachRemaining(null),
148 () -> c.spliterator().forEachRemaining(null),
149 () -> c.spliterator().tryAdvance(null),
150 () -> c.toArray(null));
151
152 if (!impl.permitsNulls()) {
153 assertThrows(
154 NullPointerException.class,
155 () -> c.add(null));
156 }
157 if (!impl.permitsNulls() && c instanceof Queue) {
158 Queue q = (Queue) c;
159 assertThrows(
160 NullPointerException.class,
161 () -> q.offer(null));
162 }
163 if (!impl.permitsNulls() && c instanceof Deque) {
164 Deque d = (Deque) c;
165 assertThrows(
166 NullPointerException.class,
167 () -> d.addFirst(null),
168 () -> d.addLast(null),
169 () -> d.offerFirst(null),
170 () -> d.offerLast(null),
171 () -> d.push(null),
172 () -> d.descendingIterator().forEachRemaining(null));
173 }
174 if (c instanceof BlockingQueue) {
175 BlockingQueue q = (BlockingQueue) c;
176 assertThrows(
177 NullPointerException.class,
178 () -> {
179 try { q.offer(null, 1L, HOURS); }
180 catch (InterruptedException ex) {
181 throw new AssertionError(ex);
182 }},
183 () -> {
184 try { q.put(null); }
185 catch (InterruptedException ex) {
186 throw new AssertionError(ex);
187 }});
188 }
189 if (c instanceof BlockingDeque) {
190 BlockingDeque q = (BlockingDeque) c;
191 assertThrows(
192 NullPointerException.class,
193 () -> {
194 try { q.offerFirst(null, 1L, HOURS); }
195 catch (InterruptedException ex) {
196 throw new AssertionError(ex);
197 }},
198 () -> {
199 try { q.offerLast(null, 1L, HOURS); }
200 catch (InterruptedException ex) {
201 throw new AssertionError(ex);
202 }},
203 () -> {
204 try { q.putFirst(null); }
205 catch (InterruptedException ex) {
206 throw new AssertionError(ex);
207 }},
208 () -> {
209 try { q.putLast(null); }
210 catch (InterruptedException ex) {
211 throw new AssertionError(ex);
212 }});
213 }
214 }
215
216 public void testNoSuchElementExceptions() {
217 Collection c = impl.emptyCollection();
218 assertThrows(
219 NoSuchElementException.class,
220 () -> c.iterator().next());
221
222 if (c instanceof Queue) {
223 Queue q = (Queue) c;
224 assertThrows(
225 NoSuchElementException.class,
226 () -> q.element(),
227 () -> q.remove());
228 }
229 if (c instanceof Deque) {
230 Deque d = (Deque) c;
231 assertThrows(
232 NoSuchElementException.class,
233 () -> d.getFirst(),
234 () -> d.getLast(),
235 () -> d.removeFirst(),
236 () -> d.removeLast(),
237 () -> d.pop(),
238 () -> d.descendingIterator().next());
239 }
240 }
241
242 public void testRemoveIf() {
243 Collection c = impl.emptyCollection();
244 ThreadLocalRandom rnd = ThreadLocalRandom.current();
245 int n = rnd.nextInt(6);
246 for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
247 AtomicReference threwAt = new AtomicReference(null);
248 List orig = rnd.nextBoolean()
249 ? new ArrayList(c)
250 : Arrays.asList(c.toArray());
251
252 // Merely creating an iterator can change ArrayBlockingQueue behavior
253 Iterator it = rnd.nextBoolean() ? c.iterator() : null;
254
255 ArrayList survivors = new ArrayList();
256 ArrayList accepts = new ArrayList();
257 ArrayList rejects = new ArrayList();
258
259 Predicate randomPredicate = e -> {
260 assertNull(threwAt.get());
261 switch (rnd.nextInt(3)) {
262 case 0: accepts.add(e); return true;
263 case 1: rejects.add(e); return false;
264 case 2: threwAt.set(e); throw new ArithmeticException();
265 default: throw new AssertionError();
266 }
267 };
268 try {
269 try {
270 boolean modified = c.removeIf(randomPredicate);
271 assertNull(threwAt.get());
272 assertEquals(modified, accepts.size() > 0);
273 assertEquals(modified, rejects.size() != n);
274 assertEquals(accepts.size() + rejects.size(), n);
275 assertEquals(rejects, Arrays.asList(c.toArray()));
276 } catch (ArithmeticException ok) {
277 assertNotNull(threwAt.get());
278 assertTrue(c.contains(threwAt.get()));
279 }
280 if (it != null && impl.isConcurrent())
281 // check for weakly consistent iterator
282 while (it.hasNext()) assertTrue(orig.contains(it.next()));
283 switch (rnd.nextInt(4)) {
284 case 0: survivors.addAll(c); break;
285 case 1: survivors.addAll(Arrays.asList(c.toArray())); break;
286 case 2: c.forEach(e -> survivors.add(e)); break;
287 case 3: for (Object e : c) survivors.add(e); break;
288 }
289 assertTrue(orig.containsAll(accepts));
290 assertTrue(orig.containsAll(rejects));
291 assertTrue(orig.containsAll(survivors));
292 assertTrue(orig.containsAll(c));
293 assertTrue(c.containsAll(rejects));
294 assertTrue(c.containsAll(survivors));
295 assertTrue(survivors.containsAll(rejects));
296 assertEquals(n - accepts.size(), c.size());
297 for (Object x : accepts) assertFalse(c.contains(x));
298 } catch (Throwable ex) {
299 System.err.println(impl.klazz());
300 System.err.printf("c=%s%n", c);
301 System.err.printf("n=%d%n", n);
302 System.err.printf("orig=%s%n", orig);
303 System.err.printf("accepts=%s%n", accepts);
304 System.err.printf("rejects=%s%n", rejects);
305 System.err.printf("survivors=%s%n", survivors);
306 System.err.printf("threwAt=%s%n", threwAt.get());
307 throw ex;
308 }
309 }
310
311 /**
312 * Various ways of traversing a collection yield same elements
313 */
314 public void testIteratorEquivalence() {
315 Collection c = impl.emptyCollection();
316 ThreadLocalRandom rnd = ThreadLocalRandom.current();
317 int n = rnd.nextInt(6);
318 for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
319 ArrayList iterated = new ArrayList();
320 ArrayList iteratedForEachRemaining = new ArrayList();
321 ArrayList tryAdvanced = new ArrayList();
322 ArrayList spliterated = new ArrayList();
323 ArrayList forEached = new ArrayList();
324 ArrayList removeIfed = new ArrayList();
325 for (Object x : c) iterated.add(x);
326 c.iterator().forEachRemaining(e -> iteratedForEachRemaining.add(e));
327 for (Spliterator s = c.spliterator();
328 s.tryAdvance(e -> tryAdvanced.add(e)); ) {}
329 c.spliterator().forEachRemaining(e -> spliterated.add(e));
330 c.forEach(e -> forEached.add(e));
331 c.removeIf(e -> { removeIfed.add(e); return false; });
332 boolean ordered =
333 c.spliterator().hasCharacteristics(Spliterator.ORDERED);
334 if (c instanceof List || c instanceof Deque)
335 assertTrue(ordered);
336 if (ordered) {
337 assertEquals(iterated, iteratedForEachRemaining);
338 assertEquals(iterated, tryAdvanced);
339 assertEquals(iterated, spliterated);
340 assertEquals(iterated, forEached);
341 assertEquals(iterated, removeIfed);
342 } else {
343 HashSet cset = new HashSet(c);
344 assertEquals(cset, new HashSet(iterated));
345 assertEquals(cset, new HashSet(iteratedForEachRemaining));
346 assertEquals(cset, new HashSet(tryAdvanced));
347 assertEquals(cset, new HashSet(spliterated));
348 assertEquals(cset, new HashSet(forEached));
349 assertEquals(cset, new HashSet(removeIfed));
350 }
351 if (c instanceof Deque) {
352 Deque d = (Deque) c;
353 ArrayList descending = new ArrayList();
354 ArrayList descendingForEachRemaining = new ArrayList();
355 for (Iterator it = d.descendingIterator(); it.hasNext(); )
356 descending.add(it.next());
357 d.descendingIterator().forEachRemaining(
358 e -> descendingForEachRemaining.add(e));
359 Collections.reverse(descending);
360 Collections.reverse(descendingForEachRemaining);
361 assertEquals(iterated, descending);
362 assertEquals(iterated, descendingForEachRemaining);
363 }
364 }
365
366 /**
367 * Calling Iterator#remove() after Iterator#forEachRemaining
368 * should (maybe) remove last element
369 */
370 public void testRemoveAfterForEachRemaining() {
371 Collection c = impl.emptyCollection();
372 ThreadLocalRandom rnd = ThreadLocalRandom.current();
373 {
374 int n = 3 + rnd.nextInt(2);
375 for (int i = 0; i < n; i++) c.add(impl.makeElement(i));
376 Iterator it = c.iterator();
377 assertTrue(it.hasNext());
378 assertEquals(impl.makeElement(0), it.next());
379 assertTrue(it.hasNext());
380 assertEquals(impl.makeElement(1), it.next());
381 it.forEachRemaining(e -> assertTrue(c.contains(e)));
382 if (testImplementationDetails) {
383 if (c instanceof java.util.concurrent.ArrayBlockingQueue) {
384 assertIteratorExhausted(it);
385 } else {
386 it.remove();
387 assertEquals(n - 1, c.size());
388 for (int i = 0; i < n - 1; i++)
389 assertTrue(c.contains(impl.makeElement(i)));
390 assertFalse(c.contains(impl.makeElement(n - 1)));
391 }
392 }
393 }
394 if (c instanceof Deque) {
395 Deque d = (Deque) impl.emptyCollection();
396 int n = 3 + rnd.nextInt(2);
397 for (int i = 0; i < n; i++) d.add(impl.makeElement(i));
398 Iterator it = d.descendingIterator();
399 assertTrue(it.hasNext());
400 assertEquals(impl.makeElement(n - 1), it.next());
401 assertTrue(it.hasNext());
402 assertEquals(impl.makeElement(n - 2), it.next());
403 it.forEachRemaining(e -> assertTrue(c.contains(e)));
404 if (testImplementationDetails) {
405 it.remove();
406 assertEquals(n - 1, d.size());
407 for (int i = 1; i < n; i++)
408 assertTrue(d.contains(impl.makeElement(i)));
409 assertFalse(d.contains(impl.makeElement(0)));
410 }
411 }
412 }
413
414 /**
415 * stream().forEach returns elements in the collection
416 */
417 public void testStreamForEach() throws Throwable {
418 final Collection c = impl.emptyCollection();
419 final AtomicLong count = new AtomicLong(0L);
420 final Object x = impl.makeElement(1);
421 final Object y = impl.makeElement(2);
422 final ArrayList found = new ArrayList();
423 Consumer<Object> spy = o -> found.add(o);
424 c.stream().forEach(spy);
425 assertTrue(found.isEmpty());
426
427 assertTrue(c.add(x));
428 c.stream().forEach(spy);
429 assertEquals(Collections.singletonList(x), found);
430 found.clear();
431
432 assertTrue(c.add(y));
433 c.stream().forEach(spy);
434 assertEquals(2, found.size());
435 assertTrue(found.contains(x));
436 assertTrue(found.contains(y));
437 found.clear();
438
439 c.clear();
440 c.stream().forEach(spy);
441 assertTrue(found.isEmpty());
442 }
443
444 public void testStreamForEachConcurrentStressTest() throws Throwable {
445 if (!impl.isConcurrent()) return;
446 final Collection c = impl.emptyCollection();
447 final long testDurationMillis = timeoutMillis();
448 final AtomicBoolean done = new AtomicBoolean(false);
449 final Object elt = impl.makeElement(1);
450 final Future<?> f1, f2;
451 final ExecutorService pool = Executors.newCachedThreadPool();
452 try (PoolCleaner cleaner = cleaner(pool, done)) {
453 final CountDownLatch threadsStarted = new CountDownLatch(2);
454 Runnable checkElt = () -> {
455 threadsStarted.countDown();
456 while (!done.get())
457 c.stream().forEach(x -> assertSame(x, elt)); };
458 Runnable addRemove = () -> {
459 threadsStarted.countDown();
460 while (!done.get()) {
461 assertTrue(c.add(elt));
462 assertTrue(c.remove(elt));
463 }};
464 f1 = pool.submit(checkElt);
465 f2 = pool.submit(addRemove);
466 Thread.sleep(testDurationMillis);
467 }
468 assertNull(f1.get(0L, MILLISECONDS));
469 assertNull(f2.get(0L, MILLISECONDS));
470 }
471
472 /**
473 * collection.forEach returns elements in the collection
474 */
475 public void testForEach() throws Throwable {
476 final Collection c = impl.emptyCollection();
477 final AtomicLong count = new AtomicLong(0L);
478 final Object x = impl.makeElement(1);
479 final Object y = impl.makeElement(2);
480 final ArrayList found = new ArrayList();
481 Consumer<Object> spy = o -> found.add(o);
482 c.forEach(spy);
483 assertTrue(found.isEmpty());
484
485 assertTrue(c.add(x));
486 c.forEach(spy);
487 assertEquals(Collections.singletonList(x), found);
488 found.clear();
489
490 assertTrue(c.add(y));
491 c.forEach(spy);
492 assertEquals(2, found.size());
493 assertTrue(found.contains(x));
494 assertTrue(found.contains(y));
495 found.clear();
496
497 c.clear();
498 c.forEach(spy);
499 assertTrue(found.isEmpty());
500 }
501
502 public void testForEachConcurrentStressTest() throws Throwable {
503 if (!impl.isConcurrent()) return;
504 final Collection c = impl.emptyCollection();
505 final long testDurationMillis = timeoutMillis();
506 final AtomicBoolean done = new AtomicBoolean(false);
507 final Object elt = impl.makeElement(1);
508 final Future<?> f1, f2;
509 final ExecutorService pool = Executors.newCachedThreadPool();
510 try (PoolCleaner cleaner = cleaner(pool, done)) {
511 final CountDownLatch threadsStarted = new CountDownLatch(2);
512 Runnable checkElt = () -> {
513 threadsStarted.countDown();
514 while (!done.get())
515 c.forEach(x -> assertSame(x, elt)); };
516 Runnable addRemove = () -> {
517 threadsStarted.countDown();
518 while (!done.get()) {
519 assertTrue(c.add(elt));
520 assertTrue(c.remove(elt));
521 }};
522 f1 = pool.submit(checkElt);
523 f2 = pool.submit(addRemove);
524 Thread.sleep(testDurationMillis);
525 }
526 assertNull(f1.get(0L, MILLISECONDS));
527 assertNull(f2.get(0L, MILLISECONDS));
528 }
529
530 // public void testCollection8DebugFail() {
531 // fail(impl.klazz().getSimpleName());
532 // }
533 }