| 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.MILLISECONDS; |
| 9 |
|
| 10 |
import java.util.ArrayList; |
| 11 |
import java.util.Collection; |
| 12 |
import java.util.Collections; |
| 13 |
import java.util.Deque; |
| 14 |
import java.util.HashSet; |
| 15 |
import java.util.Iterator; |
| 16 |
import java.util.List; |
| 17 |
import java.util.NoSuchElementException; |
| 18 |
import java.util.Queue; |
| 19 |
import java.util.Spliterator; |
| 20 |
import java.util.concurrent.CountDownLatch; |
| 21 |
import java.util.concurrent.Executors; |
| 22 |
import java.util.concurrent.ExecutorService; |
| 23 |
import java.util.concurrent.Future; |
| 24 |
import java.util.concurrent.ThreadLocalRandom; |
| 25 |
import java.util.concurrent.atomic.AtomicBoolean; |
| 26 |
import java.util.concurrent.atomic.AtomicLong; |
| 27 |
import java.util.concurrent.atomic.AtomicReference; |
| 28 |
import java.util.function.Consumer; |
| 29 |
import java.util.function.Predicate; |
| 30 |
|
| 31 |
import junit.framework.Test; |
| 32 |
|
| 33 |
/** |
| 34 |
* Contains tests applicable to all jdk8+ Collection implementations. |
| 35 |
* An extension of CollectionTest. |
| 36 |
*/ |
| 37 |
public class Collection8Test extends JSR166TestCase { |
| 38 |
final CollectionImplementation impl; |
| 39 |
|
| 40 |
/** Tests are parameterized by a Collection implementation. */ |
| 41 |
Collection8Test(CollectionImplementation impl, String methodName) { |
| 42 |
super(methodName); |
| 43 |
this.impl = impl; |
| 44 |
} |
| 45 |
|
| 46 |
public static Test testSuite(CollectionImplementation impl) { |
| 47 |
return parameterizedTestSuite(Collection8Test.class, |
| 48 |
CollectionImplementation.class, |
| 49 |
impl); |
| 50 |
} |
| 51 |
|
| 52 |
/** Checks properties of empty collections. */ |
| 53 |
public void testEmptyMeansEmpty() { |
| 54 |
Collection c = impl.emptyCollection(); |
| 55 |
assertTrue(c.isEmpty()); |
| 56 |
assertEquals(0, c.size()); |
| 57 |
assertEquals("[]", c.toString()); |
| 58 |
{ |
| 59 |
Object[] a = c.toArray(); |
| 60 |
assertEquals(0, a.length); |
| 61 |
assertSame(Object[].class, a.getClass()); |
| 62 |
} |
| 63 |
{ |
| 64 |
Object[] a = new Object[0]; |
| 65 |
assertSame(a, c.toArray(a)); |
| 66 |
} |
| 67 |
{ |
| 68 |
Integer[] a = new Integer[0]; |
| 69 |
assertSame(a, c.toArray(a)); |
| 70 |
} |
| 71 |
{ |
| 72 |
Integer[] a = { 1, 2, 3}; |
| 73 |
assertSame(a, c.toArray(a)); |
| 74 |
assertNull(a[0]); |
| 75 |
assertSame(2, a[1]); |
| 76 |
assertSame(3, a[2]); |
| 77 |
} |
| 78 |
assertIteratorExhausted(c.iterator()); |
| 79 |
Consumer alwaysThrows = (e) -> { throw new AssertionError(); }; |
| 80 |
c.forEach(alwaysThrows); |
| 81 |
c.iterator().forEachRemaining(alwaysThrows); |
| 82 |
c.spliterator().forEachRemaining(alwaysThrows); |
| 83 |
assertFalse(c.spliterator().tryAdvance(alwaysThrows)); |
| 84 |
if (Queue.class.isAssignableFrom(impl.klazz())) { |
| 85 |
Queue q = (Queue) c; |
| 86 |
assertNull(q.peek()); |
| 87 |
assertNull(q.poll()); |
| 88 |
} |
| 89 |
if (Deque.class.isAssignableFrom(impl.klazz())) { |
| 90 |
Deque d = (Deque) c; |
| 91 |
assertNull(d.peekFirst()); |
| 92 |
assertNull(d.peekLast()); |
| 93 |
assertNull(d.pollFirst()); |
| 94 |
assertNull(d.pollLast()); |
| 95 |
assertIteratorExhausted(d.descendingIterator()); |
| 96 |
} |
| 97 |
} |
| 98 |
|
| 99 |
public void testNullPointerExceptions() { |
| 100 |
Collection c = impl.emptyCollection(); |
| 101 |
assertThrows( |
| 102 |
NullPointerException.class, |
| 103 |
() -> c.addAll(null), |
| 104 |
() -> c.containsAll(null), |
| 105 |
() -> c.retainAll(null), |
| 106 |
() -> c.removeAll(null), |
| 107 |
() -> c.removeIf(null), |
| 108 |
() -> c.toArray(null)); |
| 109 |
|
| 110 |
if (!impl.permitsNulls()) { |
| 111 |
assertThrows( |
| 112 |
NullPointerException.class, |
| 113 |
() -> c.add(null)); |
| 114 |
} |
| 115 |
if (!impl.permitsNulls() |
| 116 |
&& Queue.class.isAssignableFrom(impl.klazz())) { |
| 117 |
Queue q = (Queue) c; |
| 118 |
assertThrows( |
| 119 |
NullPointerException.class, |
| 120 |
() -> q.offer(null)); |
| 121 |
} |
| 122 |
if (!impl.permitsNulls() |
| 123 |
&& Deque.class.isAssignableFrom(impl.klazz())) { |
| 124 |
Deque d = (Deque) c; |
| 125 |
assertThrows( |
| 126 |
NullPointerException.class, |
| 127 |
() -> d.addFirst(null), |
| 128 |
() -> d.addLast(null), |
| 129 |
() -> d.offerFirst(null), |
| 130 |
() -> d.offerLast(null), |
| 131 |
() -> d.push(null)); |
| 132 |
} |
| 133 |
} |
| 134 |
|
| 135 |
public void testNoSuchElementExceptions() { |
| 136 |
Collection c = impl.emptyCollection(); |
| 137 |
assertThrows( |
| 138 |
NoSuchElementException.class, |
| 139 |
() -> c.iterator().next()); |
| 140 |
|
| 141 |
if (Queue.class.isAssignableFrom(impl.klazz())) { |
| 142 |
Queue q = (Queue) c; |
| 143 |
assertThrows( |
| 144 |
NoSuchElementException.class, |
| 145 |
() -> q.element(), |
| 146 |
() -> q.remove()); |
| 147 |
} |
| 148 |
if (Deque.class.isAssignableFrom(impl.klazz())) { |
| 149 |
Deque d = (Deque) c; |
| 150 |
assertThrows( |
| 151 |
NoSuchElementException.class, |
| 152 |
() -> d.getFirst(), |
| 153 |
() -> d.getLast(), |
| 154 |
() -> d.removeFirst(), |
| 155 |
() -> d.removeLast(), |
| 156 |
() -> d.pop(), |
| 157 |
() -> d.descendingIterator().next()); |
| 158 |
} |
| 159 |
} |
| 160 |
|
| 161 |
public void testRemoveIf() { |
| 162 |
Collection c = impl.emptyCollection(); |
| 163 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
| 164 |
int n = rnd.nextInt(6); |
| 165 |
for (int i = 0; i < n; i++) c.add(impl.makeElement(i)); |
| 166 |
AtomicReference threwAt = new AtomicReference(null); |
| 167 |
ArrayList survivors = new ArrayList(c); |
| 168 |
ArrayList accepts = new ArrayList(); |
| 169 |
ArrayList rejects = new ArrayList(); |
| 170 |
Predicate randomPredicate = (e) -> { |
| 171 |
assertNull(threwAt.get()); |
| 172 |
switch (rnd.nextInt(3)) { |
| 173 |
case 0: accepts.add(e); return true; |
| 174 |
case 1: rejects.add(e); return false; |
| 175 |
case 2: threwAt.set(e); throw new ArithmeticException(); |
| 176 |
default: throw new AssertionError(); |
| 177 |
} |
| 178 |
}; |
| 179 |
try { |
| 180 |
boolean modified = c.removeIf(randomPredicate); |
| 181 |
if (!modified) { |
| 182 |
assertNull(threwAt.get()); |
| 183 |
assertEquals(n, rejects.size()); |
| 184 |
assertEquals(0, accepts.size()); |
| 185 |
} |
| 186 |
} catch (ArithmeticException ok) {} |
| 187 |
survivors.removeAll(accepts); |
| 188 |
if (n - accepts.size() != c.size()) { |
| 189 |
System.err.println(impl.klazz()); |
| 190 |
System.err.println(c); |
| 191 |
System.err.println(accepts); |
| 192 |
System.err.println(rejects); |
| 193 |
System.err.println(survivors); |
| 194 |
System.err.println(threwAt.get()); |
| 195 |
} |
| 196 |
assertEquals(n - accepts.size(), c.size()); |
| 197 |
assertTrue(c.containsAll(survivors)); |
| 198 |
assertTrue(survivors.containsAll(rejects)); |
| 199 |
for (Object x : accepts) assertFalse(c.contains(x)); |
| 200 |
if (threwAt.get() == null) |
| 201 |
assertEquals(accepts.size() + rejects.size(), n); |
| 202 |
} |
| 203 |
|
| 204 |
/** |
| 205 |
* Various ways of traversing a collection yield same elements |
| 206 |
*/ |
| 207 |
public void testIteratorEquivalence() { |
| 208 |
Collection c = impl.emptyCollection(); |
| 209 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
| 210 |
int n = rnd.nextInt(6); |
| 211 |
for (int i = 0; i < n; i++) c.add(impl.makeElement(i)); |
| 212 |
ArrayList iterated = new ArrayList(); |
| 213 |
ArrayList iteratedForEachRemaining = new ArrayList(); |
| 214 |
ArrayList spliterated = new ArrayList(); |
| 215 |
ArrayList foreached = new ArrayList(); |
| 216 |
for (Object x : c) iterated.add(x); |
| 217 |
c.iterator().forEachRemaining(e -> iteratedForEachRemaining.add(e)); |
| 218 |
c.spliterator().forEachRemaining(e -> spliterated.add(e)); |
| 219 |
c.forEach(e -> foreached.add(e)); |
| 220 |
boolean ordered = |
| 221 |
c.spliterator().hasCharacteristics(Spliterator.ORDERED); |
| 222 |
if (c instanceof List || c instanceof Deque) |
| 223 |
assertTrue(ordered); |
| 224 |
if (ordered) { |
| 225 |
assertEquals(iterated, iteratedForEachRemaining); |
| 226 |
assertEquals(iterated, spliterated); |
| 227 |
assertEquals(iterated, foreached); |
| 228 |
} else { |
| 229 |
HashSet cset = new HashSet(c); |
| 230 |
assertEquals(cset, new HashSet(iterated)); |
| 231 |
assertEquals(cset, new HashSet(iteratedForEachRemaining)); |
| 232 |
assertEquals(cset, new HashSet(spliterated)); |
| 233 |
assertEquals(cset, new HashSet(foreached)); |
| 234 |
} |
| 235 |
if (c instanceof Deque) { |
| 236 |
Deque d = (Deque) c; |
| 237 |
ArrayList descending = new ArrayList(); |
| 238 |
ArrayList descendingForEachRemaining = new ArrayList(); |
| 239 |
for (Iterator it = d.descendingIterator(); it.hasNext(); ) |
| 240 |
descending.add(it.next()); |
| 241 |
d.descendingIterator().forEachRemaining( |
| 242 |
e -> descendingForEachRemaining.add(e)); |
| 243 |
Collections.reverse(descending); |
| 244 |
Collections.reverse(descendingForEachRemaining); |
| 245 |
assertEquals(iterated, descending); |
| 246 |
assertEquals(iterated, descendingForEachRemaining); |
| 247 |
} |
| 248 |
} |
| 249 |
|
| 250 |
/** |
| 251 |
* Calling Iterator#remove() after Iterator#forEachRemaining |
| 252 |
* should remove last element |
| 253 |
*/ |
| 254 |
public void testRemoveAfterForEachRemaining() { |
| 255 |
Collection c = impl.emptyCollection(); |
| 256 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
| 257 |
{ |
| 258 |
int n = 3 + rnd.nextInt(2); |
| 259 |
for (int i = 0; i < n; i++) c.add(impl.makeElement(i)); |
| 260 |
Iterator it = c.iterator(); |
| 261 |
assertTrue(it.hasNext()); |
| 262 |
assertEquals(impl.makeElement(0), it.next()); |
| 263 |
assertTrue(it.hasNext()); |
| 264 |
assertEquals(impl.makeElement(1), it.next()); |
| 265 |
it.forEachRemaining((e) -> {}); |
| 266 |
it.remove(); |
| 267 |
assertEquals(n - 1, c.size()); |
| 268 |
for (int i = 0; i < n - 1; i++) |
| 269 |
assertTrue(c.contains(impl.makeElement(i))); |
| 270 |
assertFalse(c.contains(impl.makeElement(n - 1))); |
| 271 |
} |
| 272 |
if (c instanceof Deque) { |
| 273 |
Deque d = (Deque) impl.emptyCollection(); |
| 274 |
int n = 3 + rnd.nextInt(2); |
| 275 |
for (int i = 0; i < n; i++) d.add(impl.makeElement(i)); |
| 276 |
Iterator it = d.descendingIterator(); |
| 277 |
assertTrue(it.hasNext()); |
| 278 |
assertEquals(impl.makeElement(n - 1), it.next()); |
| 279 |
assertTrue(it.hasNext()); |
| 280 |
assertEquals(impl.makeElement(n - 2), it.next()); |
| 281 |
it.forEachRemaining((e) -> {}); |
| 282 |
it.remove(); |
| 283 |
assertEquals(n - 1, d.size()); |
| 284 |
for (int i = 1; i < n; i++) |
| 285 |
assertTrue(d.contains(impl.makeElement(i))); |
| 286 |
assertFalse(d.contains(impl.makeElement(0))); |
| 287 |
} |
| 288 |
} |
| 289 |
|
| 290 |
/** |
| 291 |
* stream().forEach returns elements in the collection |
| 292 |
*/ |
| 293 |
public void testStreamForEach() throws Throwable { |
| 294 |
final Collection c = impl.emptyCollection(); |
| 295 |
final AtomicLong count = new AtomicLong(0L); |
| 296 |
final Object x = impl.makeElement(1); |
| 297 |
final Object y = impl.makeElement(2); |
| 298 |
final ArrayList found = new ArrayList(); |
| 299 |
Consumer<Object> spy = (o) -> { found.add(o); }; |
| 300 |
c.stream().forEach(spy); |
| 301 |
assertTrue(found.isEmpty()); |
| 302 |
|
| 303 |
assertTrue(c.add(x)); |
| 304 |
c.stream().forEach(spy); |
| 305 |
assertEquals(Collections.singletonList(x), found); |
| 306 |
found.clear(); |
| 307 |
|
| 308 |
assertTrue(c.add(y)); |
| 309 |
c.stream().forEach(spy); |
| 310 |
assertEquals(2, found.size()); |
| 311 |
assertTrue(found.contains(x)); |
| 312 |
assertTrue(found.contains(y)); |
| 313 |
found.clear(); |
| 314 |
|
| 315 |
c.clear(); |
| 316 |
c.stream().forEach(spy); |
| 317 |
assertTrue(found.isEmpty()); |
| 318 |
} |
| 319 |
|
| 320 |
public void testStreamForEachConcurrentStressTest() throws Throwable { |
| 321 |
if (!impl.isConcurrent()) return; |
| 322 |
final Collection c = impl.emptyCollection(); |
| 323 |
final long testDurationMillis = timeoutMillis(); |
| 324 |
final AtomicBoolean done = new AtomicBoolean(false); |
| 325 |
final Object elt = impl.makeElement(1); |
| 326 |
final Future<?> f1, f2; |
| 327 |
final ExecutorService pool = Executors.newCachedThreadPool(); |
| 328 |
try (PoolCleaner cleaner = cleaner(pool, done)) { |
| 329 |
final CountDownLatch threadsStarted = new CountDownLatch(2); |
| 330 |
Runnable checkElt = () -> { |
| 331 |
threadsStarted.countDown(); |
| 332 |
while (!done.get()) |
| 333 |
c.stream().forEach((x) -> { assertSame(x, elt); }); }; |
| 334 |
Runnable addRemove = () -> { |
| 335 |
threadsStarted.countDown(); |
| 336 |
while (!done.get()) { |
| 337 |
assertTrue(c.add(elt)); |
| 338 |
assertTrue(c.remove(elt)); |
| 339 |
}}; |
| 340 |
f1 = pool.submit(checkElt); |
| 341 |
f2 = pool.submit(addRemove); |
| 342 |
Thread.sleep(testDurationMillis); |
| 343 |
} |
| 344 |
assertNull(f1.get(0L, MILLISECONDS)); |
| 345 |
assertNull(f2.get(0L, MILLISECONDS)); |
| 346 |
} |
| 347 |
|
| 348 |
/** |
| 349 |
* collection.forEach returns elements in the collection |
| 350 |
*/ |
| 351 |
public void testForEach() throws Throwable { |
| 352 |
final Collection c = impl.emptyCollection(); |
| 353 |
final AtomicLong count = new AtomicLong(0L); |
| 354 |
final Object x = impl.makeElement(1); |
| 355 |
final Object y = impl.makeElement(2); |
| 356 |
final ArrayList found = new ArrayList(); |
| 357 |
Consumer<Object> spy = (o) -> { found.add(o); }; |
| 358 |
c.forEach(spy); |
| 359 |
assertTrue(found.isEmpty()); |
| 360 |
|
| 361 |
assertTrue(c.add(x)); |
| 362 |
c.forEach(spy); |
| 363 |
assertEquals(Collections.singletonList(x), found); |
| 364 |
found.clear(); |
| 365 |
|
| 366 |
assertTrue(c.add(y)); |
| 367 |
c.forEach(spy); |
| 368 |
assertEquals(2, found.size()); |
| 369 |
assertTrue(found.contains(x)); |
| 370 |
assertTrue(found.contains(y)); |
| 371 |
found.clear(); |
| 372 |
|
| 373 |
c.clear(); |
| 374 |
c.forEach(spy); |
| 375 |
assertTrue(found.isEmpty()); |
| 376 |
} |
| 377 |
|
| 378 |
public void testForEachConcurrentStressTest() throws Throwable { |
| 379 |
if (!impl.isConcurrent()) return; |
| 380 |
final Collection c = impl.emptyCollection(); |
| 381 |
final long testDurationMillis = timeoutMillis(); |
| 382 |
final AtomicBoolean done = new AtomicBoolean(false); |
| 383 |
final Object elt = impl.makeElement(1); |
| 384 |
final Future<?> f1, f2; |
| 385 |
final ExecutorService pool = Executors.newCachedThreadPool(); |
| 386 |
try (PoolCleaner cleaner = cleaner(pool, done)) { |
| 387 |
final CountDownLatch threadsStarted = new CountDownLatch(2); |
| 388 |
Runnable checkElt = () -> { |
| 389 |
threadsStarted.countDown(); |
| 390 |
while (!done.get()) |
| 391 |
c.forEach((x) -> { assertSame(x, elt); }); }; |
| 392 |
Runnable addRemove = () -> { |
| 393 |
threadsStarted.countDown(); |
| 394 |
while (!done.get()) { |
| 395 |
assertTrue(c.add(elt)); |
| 396 |
assertTrue(c.remove(elt)); |
| 397 |
}}; |
| 398 |
f1 = pool.submit(checkElt); |
| 399 |
f2 = pool.submit(addRemove); |
| 400 |
Thread.sleep(testDurationMillis); |
| 401 |
} |
| 402 |
assertNull(f1.get(0L, MILLISECONDS)); |
| 403 |
assertNull(f2.get(0L, MILLISECONDS)); |
| 404 |
} |
| 405 |
|
| 406 |
// public void testCollection8DebugFail() { |
| 407 |
// fail(impl.klazz().getSimpleName()); |
| 408 |
// } |
| 409 |
} |
