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root/jsr166/jsr166/src/test/tck/Collection8Test.java
Revision: 1.16
Committed: Sun Nov 6 05:45:09 2016 UTC (7 years, 6 months ago) by jsr166
Branch: MAIN
Changes since 1.15: +4 -3 lines
Log Message:
improve testNullPointerExceptions

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