1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. 7 * 8 * This code is distributed in the hope that it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 11 * version 2 for more details (a copy is included in the LICENSE file that 12 * accompanied this code). 13 * 14 * You should have received a copy of the GNU General Public License version 15 * 2 along with this work; if not, write to the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 17 * 18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 19 * or visit www.oracle.com if you need additional information or have any 20 * questions. 21 */ 22 23 /* 24 * This file is available under and governed by the GNU General Public 25 * License version 2 only, as published by the Free Software Foundation. 26 * However, the following notice accompanied the original version of this 27 * file: 28 * 29 * Written by Doug Lea and Martin Buchholz with assistance from 30 * members of JCP JSR-166 Expert Group and released to the public 31 * domain, as explained at 32 * http://creativecommons.org/publicdomain/zero/1.0/ 33 */ 34 35 import static java.util.concurrent.TimeUnit.HOURS; 36 import static java.util.concurrent.TimeUnit.MILLISECONDS; 37 38 import java.util.ArrayDeque; 39 import java.util.ArrayList; 40 import java.util.Arrays; 41 import java.util.Collection; 42 import java.util.Collections; 43 import java.util.ConcurrentModificationException; 44 import java.util.Deque; 45 import java.util.HashSet; 46 import java.util.Iterator; 47 import java.util.List; 48 import java.util.NoSuchElementException; 49 import java.util.Queue; 50 import java.util.Set; 51 import java.util.Spliterator; 52 import java.util.concurrent.BlockingDeque; 53 import java.util.concurrent.BlockingQueue; 54 import java.util.concurrent.ConcurrentLinkedQueue; 55 import java.util.concurrent.CountDownLatch; 56 import java.util.concurrent.Executors; 57 import java.util.concurrent.ExecutorService; 58 import java.util.concurrent.Future; 59 import java.util.concurrent.Phaser; 60 import java.util.concurrent.ThreadLocalRandom; 61 import java.util.concurrent.atomic.AtomicBoolean; 62 import java.util.concurrent.atomic.AtomicLong; 63 import java.util.concurrent.atomic.AtomicReference; 64 import java.util.function.Consumer; 65 import java.util.function.Predicate; 66 import java.util.stream.Collectors; 67 68 import junit.framework.Test; 69 70 /** 71 * Contains tests applicable to all jdk8+ Collection implementations. 72 * An extension of CollectionTest. 73 */ 74 public class Collection8Test extends JSR166TestCase { 75 final CollectionImplementation impl; 76 77 /** Tests are parameterized by a Collection implementation. */ 78 Collection8Test(CollectionImplementation impl, String methodName) { 79 super(methodName); 80 this.impl = impl; 81 } 82 83 public static Test testSuite(CollectionImplementation impl) { 84 return parameterizedTestSuite(Collection8Test.class, 85 CollectionImplementation.class, 86 impl); 87 } 88 89 Object bomb() { 90 return new Object() { 91 @Override public boolean equals(Object x) { throw new AssertionError(); } 92 @Override public int hashCode() { throw new AssertionError(); } 93 @Override public String toString() { throw new AssertionError(); } 94 }; 95 } 96 97 /** Checks properties of empty collections. */ 98 public void testEmptyMeansEmpty() throws Throwable { 99 Collection c = impl.emptyCollection(); 100 emptyMeansEmpty(c); 101 102 if (c instanceof java.io.Serializable) { 103 try { 104 emptyMeansEmpty(serialClonePossiblyFailing(c)); 105 } catch (java.io.NotSerializableException ex) { 106 // excusable when we have a serializable wrapper around 107 // a non-serializable collection, as can happen with: 108 // Vector.subList() => wrapped AbstractList$RandomAccessSubList 109 if (testImplementationDetails 110 && (! c.getClass().getName().matches( 111 "java.util.Collections.*"))) 112 throw ex; 113 } 114 } 115 116 Collection clone = cloneableClone(c); 117 if (clone != null) 118 emptyMeansEmpty(clone); 119 } 120 121 void emptyMeansEmpty(Collection c) throws InterruptedException { 122 assertTrue(c.isEmpty()); 123 assertEquals(0, c.size()); 124 assertEquals("[]", c.toString()); 125 if (c instanceof List<?>) { 126 List x = (List) c; 127 assertEquals(1, x.hashCode()); 128 assertEquals(x, Collections.emptyList()); 129 assertEquals(Collections.emptyList(), x); 130 assertEquals(-1, x.indexOf(impl.makeElement(86))); 131 assertEquals(-1, x.lastIndexOf(impl.makeElement(99))); 132 assertThrows( 133 IndexOutOfBoundsException.class, 134 () -> x.get(0), 135 () -> x.set(0, impl.makeElement(42))); 136 } 137 else if (c instanceof Set<?>) { 138 assertEquals(0, c.hashCode()); 139 assertEquals(c, Collections.emptySet()); 140 assertEquals(Collections.emptySet(), c); 141 } 142 { 143 Object[] a = c.toArray(); 144 assertEquals(0, a.length); 145 assertSame(Object[].class, a.getClass()); 146 } 147 { 148 Object[] a = new Object[0]; 149 assertSame(a, c.toArray(a)); 150 } 151 { 152 Integer[] a = new Integer[0]; 153 assertSame(a, c.toArray(a)); 154 } 155 { 156 Integer[] a = { 1, 2, 3}; 157 assertSame(a, c.toArray(a)); 158 assertNull(a[0]); 159 assertSame(2, a[1]); 160 assertSame(3, a[2]); 161 } 162 assertIteratorExhausted(c.iterator()); 163 Consumer alwaysThrows = e -> { throw new AssertionError(); }; 164 c.forEach(alwaysThrows); 165 c.iterator().forEachRemaining(alwaysThrows); 166 c.spliterator().forEachRemaining(alwaysThrows); 167 assertFalse(c.spliterator().tryAdvance(alwaysThrows)); 168 if (c.spliterator().hasCharacteristics(Spliterator.SIZED)) 169 assertEquals(0, c.spliterator().estimateSize()); 170 assertFalse(c.contains(bomb())); 171 assertFalse(c.remove(bomb())); 172 if (c instanceof Queue) { 173 Queue q = (Queue) c; 174 assertNull(q.peek()); 175 assertNull(q.poll()); 176 } 177 if (c instanceof Deque) { 178 Deque d = (Deque) c; 179 assertNull(d.peekFirst()); 180 assertNull(d.peekLast()); 181 assertNull(d.pollFirst()); 182 assertNull(d.pollLast()); 183 assertIteratorExhausted(d.descendingIterator()); 184 d.descendingIterator().forEachRemaining(alwaysThrows); 185 assertFalse(d.removeFirstOccurrence(bomb())); 186 assertFalse(d.removeLastOccurrence(bomb())); 187 } 188 if (c instanceof BlockingQueue) { 189 BlockingQueue q = (BlockingQueue) c; 190 assertNull(q.poll(randomExpiredTimeout(), randomTimeUnit())); 191 } 192 if (c instanceof BlockingDeque) { 193 BlockingDeque q = (BlockingDeque) c; 194 assertNull(q.pollFirst(randomExpiredTimeout(), randomTimeUnit())); 195 assertNull(q.pollLast(randomExpiredTimeout(), randomTimeUnit())); 196 } 197 } 198 199 public void testNullPointerExceptions() throws InterruptedException { 200 Collection c = impl.emptyCollection(); 201 assertThrows( 202 NullPointerException.class, 203 () -> c.addAll(null), 204 () -> c.containsAll(null), 205 () -> c.retainAll(null), 206 () -> c.removeAll(null), 207 () -> c.removeIf(null), 208 () -> c.forEach(null), 209 () -> c.iterator().forEachRemaining(null), 210 () -> c.spliterator().forEachRemaining(null), 211 () -> c.spliterator().tryAdvance(null), 212 () -> c.toArray((Object[])null)); 213 214 if (!impl.permitsNulls()) { 215 assertThrows( 216 NullPointerException.class, 217 () -> c.add(null)); 218 } 219 if (!impl.permitsNulls() && c instanceof Queue) { 220 Queue q = (Queue) c; 221 assertThrows( 222 NullPointerException.class, 223 () -> q.offer(null)); 224 } 225 if (!impl.permitsNulls() && c instanceof Deque) { 226 Deque d = (Deque) c; 227 assertThrows( 228 NullPointerException.class, 229 () -> d.addFirst(null), 230 () -> d.addLast(null), 231 () -> d.offerFirst(null), 232 () -> d.offerLast(null), 233 () -> d.push(null), 234 () -> d.descendingIterator().forEachRemaining(null)); 235 } 236 if (c instanceof BlockingQueue) { 237 BlockingQueue q = (BlockingQueue) c; 238 assertThrows( 239 NullPointerException.class, 240 () -> q.offer(null, 1L, HOURS), 241 () -> q.put(null)); 242 } 243 if (c instanceof BlockingDeque) { 244 BlockingDeque q = (BlockingDeque) c; 245 assertThrows( 246 NullPointerException.class, 247 () -> q.offerFirst(null, 1L, HOURS), 248 () -> q.offerLast(null, 1L, HOURS), 249 () -> q.putFirst(null), 250 () -> q.putLast(null)); 251 } 252 } 253 254 public void testNoSuchElementExceptions() { 255 Collection c = impl.emptyCollection(); 256 assertThrows( 257 NoSuchElementException.class, 258 () -> c.iterator().next()); 259 260 if (c instanceof Queue) { 261 Queue q = (Queue) c; 262 assertThrows( 263 NoSuchElementException.class, 264 () -> q.element(), 265 () -> q.remove()); 266 } 267 if (c instanceof Deque) { 268 Deque d = (Deque) c; 269 assertThrows( 270 NoSuchElementException.class, 271 () -> d.getFirst(), 272 () -> d.getLast(), 273 () -> d.removeFirst(), 274 () -> d.removeLast(), 275 () -> d.pop(), 276 () -> d.descendingIterator().next()); 277 } 278 if (c instanceof List) { 279 List x = (List) c; 280 assertThrows( 281 NoSuchElementException.class, 282 () -> x.iterator().next(), 283 () -> x.listIterator().next(), 284 () -> x.listIterator(0).next(), 285 () -> x.listIterator().previous(), 286 () -> x.listIterator(0).previous()); 287 } 288 } 289 290 public void testRemoveIf() { 291 Collection c = impl.emptyCollection(); 292 boolean ordered = 293 c.spliterator().hasCharacteristics(Spliterator.ORDERED); 294 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 295 int n = rnd.nextInt(6); 296 for (int i = 0; i < n; i++) c.add(impl.makeElement(i)); 297 AtomicReference threwAt = new AtomicReference(null); 298 List orig = rnd.nextBoolean() 299 ? new ArrayList(c) 300 : Arrays.asList(c.toArray()); 301 302 // Merely creating an iterator can change ArrayBlockingQueue behavior 303 Iterator it = rnd.nextBoolean() ? c.iterator() : null; 304 305 ArrayList survivors = new ArrayList(); 306 ArrayList accepts = new ArrayList(); 307 ArrayList rejects = new ArrayList(); 308 309 Predicate randomPredicate = e -> { 310 assertNull(threwAt.get()); 311 switch (rnd.nextInt(3)) { 312 case 0: accepts.add(e); return true; 313 case 1: rejects.add(e); return false; 314 case 2: threwAt.set(e); throw new ArithmeticException(); 315 default: throw new AssertionError(); 316 } 317 }; 318 try { 319 try { 320 boolean modified = c.removeIf(randomPredicate); 321 assertNull(threwAt.get()); 322 assertEquals(modified, accepts.size() > 0); 323 assertEquals(modified, rejects.size() != n); 324 assertEquals(accepts.size() + rejects.size(), n); 325 if (ordered) { 326 assertEquals(rejects, 327 Arrays.asList(c.toArray())); 328 } else { 329 assertEquals(new HashSet(rejects), 330 new HashSet(Arrays.asList(c.toArray()))); 331 } 332 } catch (ArithmeticException ok) { 333 assertNotNull(threwAt.get()); 334 assertTrue(c.contains(threwAt.get())); 335 } 336 if (it != null && impl.isConcurrent()) 337 // check for weakly consistent iterator 338 while (it.hasNext()) assertTrue(orig.contains(it.next())); 339 switch (rnd.nextInt(4)) { 340 case 0: survivors.addAll(c); break; 341 case 1: survivors.addAll(Arrays.asList(c.toArray())); break; 342 case 2: c.forEach(survivors::add); break; 343 case 3: for (Object e : c) survivors.add(e); break; 344 } 345 assertTrue(orig.containsAll(accepts)); 346 assertTrue(orig.containsAll(rejects)); 347 assertTrue(orig.containsAll(survivors)); 348 assertTrue(orig.containsAll(c)); 349 assertTrue(c.containsAll(rejects)); 350 assertTrue(c.containsAll(survivors)); 351 assertTrue(survivors.containsAll(rejects)); 352 if (threwAt.get() == null) { 353 assertEquals(n - accepts.size(), c.size()); 354 for (Object x : accepts) assertFalse(c.contains(x)); 355 } else { 356 // Two acceptable behaviors: entire removeIf call is one 357 // transaction, or each element processed is one transaction. 358 assertTrue(n == c.size() || n == c.size() + accepts.size()); 359 int k = 0; 360 for (Object x : accepts) if (c.contains(x)) k++; 361 assertTrue(k == accepts.size() || k == 0); 362 } 363 } catch (Throwable ex) { 364 System.err.println(impl.klazz()); 365 // c is at risk of corruption if we got here, so be lenient 366 try { System.err.printf("c=%s%n", c); } 367 catch (Throwable t) { t.printStackTrace(); } 368 System.err.printf("n=%d%n", n); 369 System.err.printf("orig=%s%n", orig); 370 System.err.printf("accepts=%s%n", accepts); 371 System.err.printf("rejects=%s%n", rejects); 372 System.err.printf("survivors=%s%n", survivors); 373 System.err.printf("threwAt=%s%n", threwAt.get()); 374 throw ex; 375 } 376 } 377 378 /** 379 * All elements removed in the middle of CONCURRENT traversal. 380 */ 381 public void testElementRemovalDuringTraversal() { 382 Collection c = impl.emptyCollection(); 383 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 384 int n = rnd.nextInt(6); 385 ArrayList copy = new ArrayList(); 386 for (int i = 0; i < n; i++) { 387 Object x = impl.makeElement(i); 388 copy.add(x); 389 c.add(x); 390 } 391 ArrayList iterated = new ArrayList(); 392 ArrayList spliterated = new ArrayList(); 393 Spliterator s = c.spliterator(); 394 Iterator it = c.iterator(); 395 for (int i = rnd.nextInt(n + 1); --i >= 0; ) { 396 assertTrue(s.tryAdvance(spliterated::add)); 397 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 398 iterated.add(it.next()); 399 } 400 Consumer alwaysThrows = e -> { throw new AssertionError(); }; 401 if (s.hasCharacteristics(Spliterator.CONCURRENT)) { 402 c.clear(); // TODO: many more removal methods 403 if (testImplementationDetails 404 && !(c instanceof java.util.concurrent.ArrayBlockingQueue)) { 405 if (rnd.nextBoolean()) 406 assertFalse(s.tryAdvance(alwaysThrows)); 407 else 408 s.forEachRemaining(alwaysThrows); 409 } 410 if (it.hasNext()) iterated.add(it.next()); 411 if (rnd.nextBoolean()) assertIteratorExhausted(it); 412 } 413 assertTrue(copy.containsAll(iterated)); 414 assertTrue(copy.containsAll(spliterated)); 415 } 416 417 /** 418 * Some elements randomly disappear in the middle of traversal. 419 */ 420 public void testRandomElementRemovalDuringTraversal() { 421 Collection c = impl.emptyCollection(); 422 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 423 int n = rnd.nextInt(6); 424 ArrayList copy = new ArrayList(); 425 for (int i = 0; i < n; i++) { 426 Object x = impl.makeElement(i); 427 copy.add(x); 428 c.add(x); 429 } 430 ArrayList iterated = new ArrayList(); 431 ArrayList spliterated = new ArrayList(); 432 ArrayList removed = new ArrayList(); 433 Spliterator s = c.spliterator(); 434 Iterator it = c.iterator(); 435 if (! (s.hasCharacteristics(Spliterator.CONCURRENT) || 436 s.hasCharacteristics(Spliterator.IMMUTABLE))) 437 return; 438 for (int i = rnd.nextInt(n + 1); --i >= 0; ) { 439 assertTrue(s.tryAdvance(e -> {})); 440 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 441 it.next(); 442 } 443 Consumer alwaysThrows = e -> { throw new AssertionError(); }; 444 // TODO: many more removal methods 445 if (rnd.nextBoolean()) { 446 for (Iterator z = c.iterator(); z.hasNext(); ) { 447 Object e = z.next(); 448 if (rnd.nextBoolean()) { 449 try { 450 z.remove(); 451 } catch (UnsupportedOperationException ok) { return; } 452 removed.add(e); 453 } 454 } 455 } else { 456 Predicate randomlyRemove = e -> { 457 if (rnd.nextBoolean()) { removed.add(e); return true; } 458 else return false; 459 }; 460 c.removeIf(randomlyRemove); 461 } 462 s.forEachRemaining(spliterated::add); 463 while (it.hasNext()) 464 iterated.add(it.next()); 465 assertTrue(copy.containsAll(iterated)); 466 assertTrue(copy.containsAll(spliterated)); 467 assertTrue(copy.containsAll(removed)); 468 if (s.hasCharacteristics(Spliterator.CONCURRENT)) { 469 ArrayList iteratedAndRemoved = new ArrayList(iterated); 470 ArrayList spliteratedAndRemoved = new ArrayList(spliterated); 471 iteratedAndRemoved.retainAll(removed); 472 spliteratedAndRemoved.retainAll(removed); 473 assertTrue(iteratedAndRemoved.size() <= 1); 474 assertTrue(spliteratedAndRemoved.size() <= 1); 475 if (testImplementationDetails 476 && !(c instanceof java.util.concurrent.ArrayBlockingQueue)) 477 assertTrue(spliteratedAndRemoved.isEmpty()); 478 } 479 } 480 481 /** 482 * Various ways of traversing a collection yield same elements 483 */ 484 public void testTraversalEquivalence() { 485 Collection c = impl.emptyCollection(); 486 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 487 int n = rnd.nextInt(6); 488 for (int i = 0; i < n; i++) c.add(impl.makeElement(i)); 489 ArrayList iterated = new ArrayList(); 490 ArrayList iteratedForEachRemaining = new ArrayList(); 491 ArrayList tryAdvanced = new ArrayList(); 492 ArrayList spliterated = new ArrayList(); 493 ArrayList splitonced = new ArrayList(); 494 ArrayList forEached = new ArrayList(); 495 ArrayList streamForEached = new ArrayList(); 496 ConcurrentLinkedQueue parallelStreamForEached = new ConcurrentLinkedQueue(); 497 ArrayList removeIfed = new ArrayList(); 498 for (Object x : c) iterated.add(x); 499 c.iterator().forEachRemaining(iteratedForEachRemaining::add); 500 for (Spliterator s = c.spliterator(); 501 s.tryAdvance(tryAdvanced::add); ) {} 502 c.spliterator().forEachRemaining(spliterated::add); 503 { // trySplit returns "strict prefix" 504 Spliterator s1 = c.spliterator(), s2 = s1.trySplit(); 505 if (s2 != null) s2.forEachRemaining(splitonced::add); 506 s1.forEachRemaining(splitonced::add); 507 } 508 c.forEach(forEached::add); 509 c.stream().forEach(streamForEached::add); 510 c.parallelStream().forEach(parallelStreamForEached::add); 511 c.removeIf(e -> { removeIfed.add(e); return false; }); 512 boolean ordered = 513 c.spliterator().hasCharacteristics(Spliterator.ORDERED); 514 if (c instanceof List || c instanceof Deque) 515 assertTrue(ordered); 516 HashSet cset = new HashSet(c); 517 assertEquals(cset, new HashSet(parallelStreamForEached)); 518 if (ordered) { 519 assertEquals(iterated, iteratedForEachRemaining); 520 assertEquals(iterated, tryAdvanced); 521 assertEquals(iterated, spliterated); 522 assertEquals(iterated, splitonced); 523 assertEquals(iterated, forEached); 524 assertEquals(iterated, streamForEached); 525 assertEquals(iterated, removeIfed); 526 } else { 527 assertEquals(cset, new HashSet(iterated)); 528 assertEquals(cset, new HashSet(iteratedForEachRemaining)); 529 assertEquals(cset, new HashSet(tryAdvanced)); 530 assertEquals(cset, new HashSet(spliterated)); 531 assertEquals(cset, new HashSet(splitonced)); 532 assertEquals(cset, new HashSet(forEached)); 533 assertEquals(cset, new HashSet(streamForEached)); 534 assertEquals(cset, new HashSet(removeIfed)); 535 } 536 if (c instanceof Deque) { 537 Deque d = (Deque) c; 538 ArrayList descending = new ArrayList(); 539 ArrayList descendingForEachRemaining = new ArrayList(); 540 for (Iterator it = d.descendingIterator(); it.hasNext(); ) 541 descending.add(it.next()); 542 d.descendingIterator().forEachRemaining( 543 e -> descendingForEachRemaining.add(e)); 544 Collections.reverse(descending); 545 Collections.reverse(descendingForEachRemaining); 546 assertEquals(iterated, descending); 547 assertEquals(iterated, descendingForEachRemaining); 548 } 549 } 550 551 /** 552 * Iterator.forEachRemaining has same behavior as Iterator's 553 * default implementation. 554 */ 555 public void testForEachRemainingConsistentWithDefaultImplementation() { 556 Collection c = impl.emptyCollection(); 557 if (!testImplementationDetails 558 || c.getClass() == java.util.LinkedList.class) 559 return; 560 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 561 int n = 1 + rnd.nextInt(3); 562 for (int i = 0; i < n; i++) c.add(impl.makeElement(i)); 563 ArrayList iterated = new ArrayList(); 564 ArrayList iteratedForEachRemaining = new ArrayList(); 565 Iterator it1 = c.iterator(); 566 Iterator it2 = c.iterator(); 567 assertTrue(it1.hasNext()); 568 assertTrue(it2.hasNext()); 569 c.clear(); 570 Object r1, r2; 571 try { 572 while (it1.hasNext()) iterated.add(it1.next()); 573 r1 = iterated; 574 } catch (ConcurrentModificationException ex) { 575 r1 = ConcurrentModificationException.class; 576 assertFalse(impl.isConcurrent()); 577 } 578 try { 579 it2.forEachRemaining(iteratedForEachRemaining::add); 580 r2 = iteratedForEachRemaining; 581 } catch (ConcurrentModificationException ex) { 582 r2 = ConcurrentModificationException.class; 583 assertFalse(impl.isConcurrent()); 584 } 585 assertEquals(r1, r2); 586 } 587 588 /** 589 * Calling Iterator#remove() after Iterator#forEachRemaining 590 * should (maybe) remove last element 591 */ 592 public void testRemoveAfterForEachRemaining() { 593 Collection c = impl.emptyCollection(); 594 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 595 ArrayList copy = new ArrayList(); 596 boolean ordered = c.spliterator().hasCharacteristics(Spliterator.ORDERED); 597 testCollection: { 598 int n = 3 + rnd.nextInt(2); 599 for (int i = 0; i < n; i++) { 600 Object x = impl.makeElement(i); 601 c.add(x); 602 copy.add(x); 603 } 604 Iterator it = c.iterator(); 605 if (ordered) { 606 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 607 assertEquals(impl.makeElement(0), it.next()); 608 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 609 assertEquals(impl.makeElement(1), it.next()); 610 } else { 611 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 612 assertTrue(copy.contains(it.next())); 613 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 614 assertTrue(copy.contains(it.next())); 615 } 616 if (rnd.nextBoolean()) assertTrue(it.hasNext()); 617 it.forEachRemaining( 618 e -> { 619 assertTrue(c.contains(e)); 620 assertTrue(copy.contains(e));}); 621 if (testImplementationDetails) { 622 if (c instanceof java.util.concurrent.ArrayBlockingQueue) { 623 assertIteratorExhausted(it); 624 } else { 625 try { it.remove(); } 626 catch (UnsupportedOperationException ok) { 627 break testCollection; 628 } 629 assertEquals(n - 1, c.size()); 630 if (ordered) { 631 for (int i = 0; i < n - 1; i++) 632 assertTrue(c.contains(impl.makeElement(i))); 633 assertFalse(c.contains(impl.makeElement(n - 1))); 634 } 635 } 636 } 637 } 638 if (c instanceof Deque) { 639 Deque d = (Deque) impl.emptyCollection(); 640 assertTrue(ordered); 641 int n = 3 + rnd.nextInt(2); 642 for (int i = 0; i < n; i++) d.add(impl.makeElement(i)); 643 Iterator it = d.descendingIterator(); 644 assertTrue(it.hasNext()); 645 assertEquals(impl.makeElement(n - 1), it.next()); 646 assertTrue(it.hasNext()); 647 assertEquals(impl.makeElement(n - 2), it.next()); 648 it.forEachRemaining(e -> assertTrue(c.contains(e))); 649 if (testImplementationDetails) { 650 it.remove(); 651 assertEquals(n - 1, d.size()); 652 for (int i = 1; i < n; i++) 653 assertTrue(d.contains(impl.makeElement(i))); 654 assertFalse(d.contains(impl.makeElement(0))); 655 } 656 } 657 } 658 659 /** 660 * stream().forEach returns elements in the collection 661 */ 662 public void testStreamForEach() throws Throwable { 663 final Collection c = impl.emptyCollection(); 664 final AtomicLong count = new AtomicLong(0L); 665 final Object x = impl.makeElement(1); 666 final Object y = impl.makeElement(2); 667 final ArrayList found = new ArrayList(); 668 Consumer<Object> spy = o -> found.add(o); 669 c.stream().forEach(spy); 670 assertTrue(found.isEmpty()); 671 672 assertTrue(c.add(x)); 673 c.stream().forEach(spy); 674 assertEquals(Collections.singletonList(x), found); 675 found.clear(); 676 677 assertTrue(c.add(y)); 678 c.stream().forEach(spy); 679 assertEquals(2, found.size()); 680 assertTrue(found.contains(x)); 681 assertTrue(found.contains(y)); 682 found.clear(); 683 684 c.clear(); 685 c.stream().forEach(spy); 686 assertTrue(found.isEmpty()); 687 } 688 689 public void testStreamForEachConcurrentStressTest() throws Throwable { 690 if (!impl.isConcurrent()) return; 691 final Collection c = impl.emptyCollection(); 692 final long testDurationMillis = timeoutMillis(); 693 final AtomicBoolean done = new AtomicBoolean(false); 694 final Object elt = impl.makeElement(1); 695 final Future<?> f1, f2; 696 final ExecutorService pool = Executors.newCachedThreadPool(); 697 try (PoolCleaner cleaner = cleaner(pool, done)) { 698 final CountDownLatch threadsStarted = new CountDownLatch(2); 699 Runnable checkElt = () -> { 700 threadsStarted.countDown(); 701 while (!done.get()) 702 c.stream().forEach(x -> assertSame(x, elt)); }; 703 Runnable addRemove = () -> { 704 threadsStarted.countDown(); 705 while (!done.get()) { 706 assertTrue(c.add(elt)); 707 assertTrue(c.remove(elt)); 708 }}; 709 f1 = pool.submit(checkElt); 710 f2 = pool.submit(addRemove); 711 Thread.sleep(testDurationMillis); 712 } 713 assertNull(f1.get(0L, MILLISECONDS)); 714 assertNull(f2.get(0L, MILLISECONDS)); 715 } 716 717 /** 718 * collection.forEach returns elements in the collection 719 */ 720 public void testForEach() throws Throwable { 721 final Collection c = impl.emptyCollection(); 722 final AtomicLong count = new AtomicLong(0L); 723 final Object x = impl.makeElement(1); 724 final Object y = impl.makeElement(2); 725 final ArrayList found = new ArrayList(); 726 Consumer<Object> spy = o -> found.add(o); 727 c.forEach(spy); 728 assertTrue(found.isEmpty()); 729 730 assertTrue(c.add(x)); 731 c.forEach(spy); 732 assertEquals(Collections.singletonList(x), found); 733 found.clear(); 734 735 assertTrue(c.add(y)); 736 c.forEach(spy); 737 assertEquals(2, found.size()); 738 assertTrue(found.contains(x)); 739 assertTrue(found.contains(y)); 740 found.clear(); 741 742 c.clear(); 743 c.forEach(spy); 744 assertTrue(found.isEmpty()); 745 } 746 747 /** TODO: promote to a common utility */ 748 static <T> T chooseOne(T ... ts) { 749 return ts[ThreadLocalRandom.current().nextInt(ts.length)]; 750 } 751 752 /** TODO: more random adders and removers */ 753 static <E> Runnable adderRemover(Collection<E> c, E e) { 754 return chooseOne( 755 () -> { 756 assertTrue(c.add(e)); 757 assertTrue(c.contains(e)); 758 assertTrue(c.remove(e)); 759 assertFalse(c.contains(e)); 760 }, 761 () -> { 762 assertTrue(c.add(e)); 763 assertTrue(c.contains(e)); 764 assertTrue(c.removeIf(x -> x == e)); 765 assertFalse(c.contains(e)); 766 }, 767 () -> { 768 assertTrue(c.add(e)); 769 assertTrue(c.contains(e)); 770 for (Iterator it = c.iterator();; ) 771 if (it.next() == e) { 772 try { it.remove(); } 773 catch (UnsupportedOperationException ok) { 774 c.remove(e); 775 } 776 break; 777 } 778 assertFalse(c.contains(e)); 779 }); 780 } 781 782 /** 783 * Concurrent Spliterators, once exhausted, stay exhausted. 784 */ 785 public void testStickySpliteratorExhaustion() throws Throwable { 786 if (!impl.isConcurrent()) return; 787 if (!testImplementationDetails) return; 788 final ThreadLocalRandom rnd = ThreadLocalRandom.current(); 789 final Consumer alwaysThrows = e -> { throw new AssertionError(); }; 790 final Collection c = impl.emptyCollection(); 791 final Spliterator s = c.spliterator(); 792 if (rnd.nextBoolean()) { 793 assertFalse(s.tryAdvance(alwaysThrows)); 794 } else { 795 s.forEachRemaining(alwaysThrows); 796 } 797 final Object one = impl.makeElement(1); 798 // Spliterator should not notice added element 799 c.add(one); 800 if (rnd.nextBoolean()) { 801 assertFalse(s.tryAdvance(alwaysThrows)); 802 } else { 803 s.forEachRemaining(alwaysThrows); 804 } 805 } 806 807 /** 808 * Motley crew of threads concurrently randomly hammer the collection. 809 */ 810 public void testDetectRaces() throws Throwable { 811 if (!impl.isConcurrent()) return; 812 final ThreadLocalRandom rnd = ThreadLocalRandom.current(); 813 final Collection c = impl.emptyCollection(); 814 final long testDurationMillis 815 = expensiveTests ? LONG_DELAY_MS : timeoutMillis(); 816 final AtomicBoolean done = new AtomicBoolean(false); 817 final Object one = impl.makeElement(1); 818 final Object two = impl.makeElement(2); 819 final Consumer checkSanity = x -> assertTrue(x == one || x == two); 820 final Consumer<Object[]> checkArraySanity = array -> { 821 // assertTrue(array.length <= 2); // duplicates are permitted 822 for (Object x : array) assertTrue(x == one || x == two); 823 }; 824 final Object[] emptyArray = 825 (Object[]) java.lang.reflect.Array.newInstance(one.getClass(), 0); 826 final List<Future<?>> futures; 827 final Phaser threadsStarted = new Phaser(1); // register this thread 828 final Runnable[] frobbers = { 829 () -> c.forEach(checkSanity), 830 () -> c.stream().forEach(checkSanity), 831 () -> c.parallelStream().forEach(checkSanity), 832 () -> c.spliterator().trySplit(), 833 () -> { 834 Spliterator s = c.spliterator(); 835 s.tryAdvance(checkSanity); 836 s.trySplit(); 837 }, 838 () -> { 839 Spliterator s = c.spliterator(); 840 do {} while (s.tryAdvance(checkSanity)); 841 }, 842 () -> { for (Object x : c) checkSanity.accept(x); }, 843 () -> checkArraySanity.accept(c.toArray()), 844 () -> checkArraySanity.accept(c.toArray(emptyArray)), 845 () -> { 846 Object[] a = new Object[5]; 847 Object three = impl.makeElement(3); 848 Arrays.fill(a, 0, a.length, three); 849 Object[] x = c.toArray(a); 850 if (x == a) 851 for (int i = 0; i < a.length && a[i] != null; i++) 852 checkSanity.accept(a[i]); 853 // A careful reading of the spec does not support: 854 // for (i++; i < a.length; i++) assertSame(three, a[i]); 855 else 856 checkArraySanity.accept(x); 857 }, 858 adderRemover(c, one), 859 adderRemover(c, two), 860 }; 861 final List<Runnable> tasks = 862 Arrays.stream(frobbers) 863 .filter(task -> rnd.nextBoolean()) // random subset 864 .map(task -> (Runnable) () -> { 865 threadsStarted.arriveAndAwaitAdvance(); 866 while (!done.get()) 867 task.run(); 868 }) 869 .collect(Collectors.toList()); 870 final ExecutorService pool = Executors.newCachedThreadPool(); 871 try (PoolCleaner cleaner = cleaner(pool, done)) { 872 threadsStarted.bulkRegister(tasks.size()); 873 futures = tasks.stream() 874 .map(pool::submit) 875 .collect(Collectors.toList()); 876 threadsStarted.arriveAndDeregister(); 877 Thread.sleep(testDurationMillis); 878 } 879 for (Future future : futures) 880 assertNull(future.get(0L, MILLISECONDS)); 881 } 882 883 /** 884 * Spliterators are either IMMUTABLE or truly late-binding or, if 885 * concurrent, use the same "late-binding style" of returning 886 * elements added between creation and first use. 887 */ 888 public void testLateBindingStyle() { 889 if (!testImplementationDetails) return; 890 if (impl.klazz() == ArrayList.class) return; // for jdk8 891 // Immutable (snapshot) spliterators are exempt 892 if (impl.emptyCollection().spliterator() 893 .hasCharacteristics(Spliterator.IMMUTABLE)) 894 return; 895 final Object one = impl.makeElement(1); 896 { 897 final Collection c = impl.emptyCollection(); 898 final Spliterator split = c.spliterator(); 899 c.add(one); 900 assertTrue(split.tryAdvance(e -> { assertSame(e, one); })); 901 assertFalse(split.tryAdvance(e -> { throw new AssertionError(); })); 902 assertTrue(c.contains(one)); 903 } 904 { 905 final AtomicLong count = new AtomicLong(0); 906 final Collection c = impl.emptyCollection(); 907 final Spliterator split = c.spliterator(); 908 c.add(one); 909 split.forEachRemaining( 910 e -> { assertSame(e, one); count.getAndIncrement(); }); 911 assertEquals(1L, count.get()); 912 assertFalse(split.tryAdvance(e -> { throw new AssertionError(); })); 913 assertTrue(c.contains(one)); 914 } 915 } 916 917 /** 918 * Spliterator.getComparator throws IllegalStateException iff the 919 * spliterator does not report SORTED. 920 */ 921 public void testGetComparator_IllegalStateException() { 922 Collection c = impl.emptyCollection(); 923 Spliterator s = c.spliterator(); 924 boolean reportsSorted = s.hasCharacteristics(Spliterator.SORTED); 925 try { 926 s.getComparator(); 927 assertTrue(reportsSorted); 928 } catch (IllegalStateException ex) { 929 assertFalse(reportsSorted); 930 } 931 } 932 933 public void testCollectionCopies() throws Exception { 934 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 935 Collection c = impl.emptyCollection(); 936 for (int n = rnd.nextInt(4); n--> 0; ) 937 c.add(impl.makeElement(rnd.nextInt())); 938 assertEquals(c, c); 939 if (c instanceof List) 940 assertCollectionsEquals(c, new ArrayList(c)); 941 else if (c instanceof Set) 942 assertCollectionsEquals(c, new HashSet(c)); 943 else if (c instanceof Deque) 944 assertCollectionsEquivalent(c, new ArrayDeque(c)); 945 946 Collection clone = cloneableClone(c); 947 if (clone != null) { 948 assertSame(c.getClass(), clone.getClass()); 949 assertCollectionsEquivalent(c, clone); 950 } 951 try { 952 Collection serialClone = serialClonePossiblyFailing(c); 953 assertSame(c.getClass(), serialClone.getClass()); 954 assertCollectionsEquivalent(c, serialClone); 955 } catch (java.io.NotSerializableException acceptable) {} 956 } 957 958 /** 959 * TODO: move out of limbo 960 * 8203662: remove increment of modCount from ArrayList and Vector replaceAll() 961 */ 962 public void DISABLED_testReplaceAllIsNotStructuralModification() { 963 Collection c = impl.emptyCollection(); 964 if (!(c instanceof List)) 965 return; 966 List list = (List) c; 967 ThreadLocalRandom rnd = ThreadLocalRandom.current(); 968 for (int n = rnd.nextInt(2, 10); n--> 0; ) 969 list.add(impl.makeElement(rnd.nextInt())); 970 ArrayList copy = new ArrayList(list); 971 int size = list.size(), half = size / 2; 972 Iterator it = list.iterator(); 973 for (int i = 0; i < half; i++) 974 assertEquals(it.next(), copy.get(i)); 975 list.replaceAll(n -> n); 976 // ConcurrentModificationException must not be thrown here. 977 for (int i = half; i < size; i++) 978 assertEquals(it.next(), copy.get(i)); 979 } 980 981 // public void testCollection8DebugFail() { 982 // fail(impl.klazz().getSimpleName()); 983 // } 984 }