9 |
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import static java.util.concurrent.TimeUnit.MILLISECONDS; |
10 |
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import static java.util.concurrent.TimeUnit.NANOSECONDS; |
11 |
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|
12 |
+ |
import java.util.ArrayList; |
13 |
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import java.util.Arrays; |
14 |
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import java.util.Collection; |
15 |
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import java.util.HashSet; |
16 |
+ |
import java.util.concurrent.atomic.AtomicBoolean; |
17 |
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import java.util.concurrent.locks.AbstractQueuedSynchronizer; |
18 |
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import java.util.concurrent.locks.AbstractQueuedSynchronizer.ConditionObject; |
19 |
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|
18 |
– |
import junit.framework.AssertionFailedError; |
20 |
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import junit.framework.Test; |
21 |
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import junit.framework.TestSuite; |
22 |
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|
23 |
+ |
@SuppressWarnings("WaitNotInLoop") // we implement spurious-wakeup freedom |
24 |
|
public class AbstractQueuedSynchronizerTest extends JSR166TestCase { |
25 |
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public static void main(String[] args) { |
26 |
< |
junit.textui.TestRunner.run(suite()); |
26 |
> |
main(suite(), args); |
27 |
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} |
28 |
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public static Test suite() { |
29 |
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return new TestSuite(AbstractQueuedSynchronizerTest.class); |
35 |
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* methods/features of AbstractQueuedSynchronizer are tested via |
36 |
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* other test classes, including those for ReentrantLock, |
37 |
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* ReentrantReadWriteLock, and Semaphore. |
38 |
+ |
* |
39 |
+ |
* Unlike the javadoc sample, we don't track owner thread via |
40 |
+ |
* AbstractOwnableSynchronizer methods. |
41 |
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*/ |
42 |
|
static class Mutex extends AbstractQueuedSynchronizer { |
43 |
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/** An eccentric value for locked synchronizer state. */ |
45 |
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|
46 |
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static final int UNLOCKED = 0; |
47 |
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|
48 |
+ |
/** Owner thread is untracked, so this is really just isLocked(). */ |
49 |
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@Override public boolean isHeldExclusively() { |
50 |
|
int state = getState(); |
51 |
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assertTrue(state == UNLOCKED || state == LOCKED); |
52 |
|
return state == LOCKED; |
53 |
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} |
54 |
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|
55 |
< |
@Override public boolean tryAcquire(int acquires) { |
55 |
> |
@Override protected boolean tryAcquire(int acquires) { |
56 |
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assertEquals(LOCKED, acquires); |
57 |
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return compareAndSetState(UNLOCKED, LOCKED); |
58 |
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} |
59 |
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|
60 |
< |
@Override public boolean tryRelease(int releases) { |
60 |
> |
@Override protected boolean tryRelease(int releases) { |
61 |
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if (getState() != LOCKED) throw new IllegalMonitorStateException(); |
62 |
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assertEquals(LOCKED, releases); |
63 |
|
setState(UNLOCKED); |
88 |
|
release(LOCKED); |
89 |
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} |
90 |
|
|
91 |
+ |
/** Faux-Implements Lock.newCondition(). */ |
92 |
|
public ConditionObject newCondition() { |
93 |
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return new ConditionObject(); |
94 |
|
} |
95 |
|
} |
96 |
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|
97 |
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/** |
98 |
< |
* A simple latch class, to test shared mode. |
98 |
> |
* A minimal latch class, to test shared mode. |
99 |
|
*/ |
100 |
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static class BooleanLatch extends AbstractQueuedSynchronizer { |
101 |
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public boolean isSignalled() { return getState() != 0; } |
144 |
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long startTime = System.nanoTime(); |
145 |
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while (!sync.isQueued(t)) { |
146 |
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if (millisElapsedSince(startTime) > LONG_DELAY_MS) |
147 |
< |
throw new AssertionFailedError("timed out"); |
147 |
> |
throw new AssertionError("timed out"); |
148 |
|
Thread.yield(); |
149 |
|
} |
150 |
|
assertTrue(t.isAlive()); |
228 |
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assertTrue(c.await(timeoutMillis, MILLISECONDS)); |
229 |
|
break; |
230 |
|
case awaitNanos: |
231 |
< |
long nanosTimeout = MILLISECONDS.toNanos(timeoutMillis); |
232 |
< |
long nanosRemaining = c.awaitNanos(nanosTimeout); |
231 |
> |
long timeoutNanos = MILLISECONDS.toNanos(timeoutMillis); |
232 |
> |
long nanosRemaining = c.awaitNanos(timeoutNanos); |
233 |
|
assertTrue(nanosRemaining > 0); |
234 |
|
break; |
235 |
|
case awaitUntil: |
236 |
|
assertTrue(c.awaitUntil(delayedDate(timeoutMillis))); |
237 |
|
break; |
238 |
+ |
default: |
239 |
+ |
throw new AssertionError(); |
240 |
|
} |
241 |
|
} |
242 |
|
|
245 |
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* default timeout duration). |
246 |
|
*/ |
247 |
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void assertAwaitTimesOut(ConditionObject c, AwaitMethod awaitMethod) { |
248 |
< |
long timeoutMillis = timeoutMillis(); |
249 |
< |
long startTime = System.nanoTime(); |
248 |
> |
final long timeoutMillis = timeoutMillis(); |
249 |
> |
final long startTime; |
250 |
|
try { |
251 |
|
switch (awaitMethod) { |
252 |
|
case awaitTimed: |
253 |
+ |
startTime = System.nanoTime(); |
254 |
|
assertFalse(c.await(timeoutMillis, MILLISECONDS)); |
255 |
+ |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis); |
256 |
|
break; |
257 |
|
case awaitNanos: |
258 |
< |
long nanosTimeout = MILLISECONDS.toNanos(timeoutMillis); |
259 |
< |
long nanosRemaining = c.awaitNanos(nanosTimeout); |
258 |
> |
startTime = System.nanoTime(); |
259 |
> |
long timeoutNanos = MILLISECONDS.toNanos(timeoutMillis); |
260 |
> |
long nanosRemaining = c.awaitNanos(timeoutNanos); |
261 |
|
assertTrue(nanosRemaining <= 0); |
262 |
+ |
assertTrue(nanosRemaining > -MILLISECONDS.toNanos(LONG_DELAY_MS)); |
263 |
+ |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis); |
264 |
|
break; |
265 |
|
case awaitUntil: |
266 |
+ |
// We shouldn't assume that nanoTime and currentTimeMillis |
267 |
+ |
// use the same time source, so don't use nanoTime here. |
268 |
+ |
java.util.Date delayedDate = delayedDate(timeoutMillis); |
269 |
|
assertFalse(c.awaitUntil(delayedDate(timeoutMillis))); |
270 |
+ |
assertTrue(new java.util.Date().getTime() >= delayedDate.getTime()); |
271 |
|
break; |
272 |
|
default: |
273 |
|
throw new UnsupportedOperationException(); |
274 |
|
} |
275 |
|
} catch (InterruptedException ie) { threadUnexpectedException(ie); } |
258 |
– |
assertTrue(millisElapsedSince(startTime) >= timeoutMillis); |
276 |
|
} |
277 |
|
|
278 |
|
/** |
975 |
|
*/ |
976 |
|
public void testAwaitUninterruptibly() { |
977 |
|
final Mutex sync = new Mutex(); |
978 |
< |
final ConditionObject c = sync.newCondition(); |
978 |
> |
final ConditionObject condition = sync.newCondition(); |
979 |
|
final BooleanLatch pleaseInterrupt = new BooleanLatch(); |
980 |
|
Thread t = newStartedThread(new CheckedRunnable() { |
981 |
|
public void realRun() { |
982 |
|
sync.acquire(); |
983 |
|
assertTrue(pleaseInterrupt.releaseShared(0)); |
984 |
< |
c.awaitUninterruptibly(); |
984 |
> |
condition.awaitUninterruptibly(); |
985 |
|
assertTrue(Thread.interrupted()); |
986 |
< |
assertHasWaitersLocked(sync, c, NO_THREADS); |
986 |
> |
assertHasWaitersLocked(sync, condition, NO_THREADS); |
987 |
|
sync.release(); |
988 |
|
}}); |
989 |
|
|
990 |
|
pleaseInterrupt.acquireShared(0); |
991 |
|
sync.acquire(); |
992 |
< |
assertHasWaitersLocked(sync, c, t); |
992 |
> |
assertHasWaitersLocked(sync, condition, t); |
993 |
|
sync.release(); |
994 |
|
t.interrupt(); |
995 |
< |
assertHasWaitersUnlocked(sync, c, t); |
996 |
< |
assertThreadStaysAlive(t); |
995 |
> |
assertHasWaitersUnlocked(sync, condition, t); |
996 |
> |
assertThreadBlocks(t, Thread.State.WAITING); |
997 |
|
sync.acquire(); |
998 |
< |
assertHasWaitersLocked(sync, c, t); |
998 |
> |
assertHasWaitersLocked(sync, condition, t); |
999 |
|
assertHasExclusiveQueuedThreads(sync, NO_THREADS); |
1000 |
< |
c.signal(); |
1001 |
< |
assertHasWaitersLocked(sync, c, NO_THREADS); |
1000 |
> |
condition.signal(); |
1001 |
> |
assertHasWaitersLocked(sync, condition, NO_THREADS); |
1002 |
|
assertHasExclusiveQueuedThreads(sync, t); |
1003 |
|
sync.release(); |
1004 |
|
awaitTermination(t); |
1141 |
|
|
1142 |
|
waitForQueuedThread(l, t); |
1143 |
|
assertFalse(l.isSignalled()); |
1144 |
< |
assertThreadStaysAlive(t); |
1144 |
> |
assertThreadBlocks(t, Thread.State.WAITING); |
1145 |
|
assertHasSharedQueuedThreads(l, t); |
1146 |
|
assertTrue(l.releaseShared(0)); |
1147 |
|
assertTrue(l.isSignalled()); |
1166 |
|
|
1167 |
|
waitForQueuedThread(l, t); |
1168 |
|
assertFalse(l.isSignalled()); |
1169 |
< |
assertThreadStaysAlive(t); |
1169 |
> |
assertThreadBlocks(t, Thread.State.TIMED_WAITING); |
1170 |
|
assertTrue(l.releaseShared(0)); |
1171 |
|
assertTrue(l.isSignalled()); |
1172 |
|
awaitTermination(t); |
1215 |
|
public void testTryAcquireSharedNanos_Timeout() { |
1216 |
|
final BooleanLatch l = new BooleanLatch(); |
1217 |
|
final BooleanLatch observedQueued = new BooleanLatch(); |
1201 |
– |
final long timeoutMillis = timeoutMillis(); |
1218 |
|
Thread t = newStartedThread(new CheckedRunnable() { |
1219 |
|
public void realRun() throws InterruptedException { |
1220 |
|
assertFalse(l.isSignalled()); |
1260 |
|
sync.release(); |
1261 |
|
} |
1262 |
|
|
1263 |
+ |
/** |
1264 |
+ |
* JDK-8191483: AbstractQueuedSynchronizer cancel/cancel race |
1265 |
+ |
* ant -Djsr166.tckTestClass=AbstractQueuedSynchronizerTest -Djsr166.methodFilter=testCancelCancelRace -Djsr166.runsPerTest=100 tck |
1266 |
+ |
*/ |
1267 |
+ |
public void testCancelCancelRace() throws InterruptedException { |
1268 |
+ |
class Sync extends AbstractQueuedSynchronizer { |
1269 |
+ |
protected boolean tryAcquire(int acquires) { |
1270 |
+ |
return !hasQueuedPredecessors() && compareAndSetState(0, 1); |
1271 |
+ |
} |
1272 |
+ |
protected boolean tryRelease(int releases) { |
1273 |
+ |
return compareAndSetState(1, 0); |
1274 |
+ |
} |
1275 |
+ |
} |
1276 |
+ |
|
1277 |
+ |
Sync s = new Sync(); |
1278 |
+ |
s.acquire(1); // acquire to force other threads to enqueue |
1279 |
+ |
|
1280 |
+ |
// try to trigger double cancel race with two background threads |
1281 |
+ |
ArrayList<Thread> threads = new ArrayList<>(); |
1282 |
+ |
Runnable failedAcquire = () -> { |
1283 |
+ |
try { |
1284 |
+ |
s.acquireInterruptibly(1); |
1285 |
+ |
shouldThrow(); |
1286 |
+ |
} catch (InterruptedException success) {} |
1287 |
+ |
}; |
1288 |
+ |
for (int i = 0; i < 2; i++) { |
1289 |
+ |
Thread thread = new Thread(failedAcquire); |
1290 |
+ |
thread.start(); |
1291 |
+ |
threads.add(thread); |
1292 |
+ |
} |
1293 |
+ |
Thread.sleep(100); |
1294 |
+ |
for (Thread thread : threads) thread.interrupt(); |
1295 |
+ |
for (Thread thread : threads) awaitTermination(thread); |
1296 |
+ |
|
1297 |
+ |
s.release(1); |
1298 |
+ |
|
1299 |
+ |
// no one holds lock now, we should be able to acquire |
1300 |
+ |
if (!s.tryAcquire(1)) |
1301 |
+ |
throw new RuntimeException( |
1302 |
+ |
String.format( |
1303 |
+ |
"Broken: hasQueuedPredecessors=%s hasQueuedThreads=%s queueLength=%d firstQueuedThread=%s", |
1304 |
+ |
s.hasQueuedPredecessors(), |
1305 |
+ |
s.hasQueuedThreads(), |
1306 |
+ |
s.getQueueLength(), |
1307 |
+ |
s.getFirstQueuedThread())); |
1308 |
+ |
} |
1309 |
+ |
|
1310 |
+ |
/** |
1311 |
+ |
* Tests scenario for |
1312 |
+ |
* JDK-8191937: Lost interrupt in AbstractQueuedSynchronizer when tryAcquire methods throw |
1313 |
+ |
* ant -Djsr166.tckTestClass=AbstractQueuedSynchronizerTest -Djsr166.methodFilter=testInterruptedFailingAcquire -Djsr166.runsPerTest=10000 tck |
1314 |
+ |
*/ |
1315 |
+ |
public void testInterruptedFailingAcquire() throws Throwable { |
1316 |
+ |
class PleaseThrow extends RuntimeException {} |
1317 |
+ |
final PleaseThrow ex = new PleaseThrow(); |
1318 |
+ |
final AtomicBoolean thrown = new AtomicBoolean(); |
1319 |
+ |
|
1320 |
+ |
// A synchronizer only offering a choice of failure modes |
1321 |
+ |
class Sync extends AbstractQueuedSynchronizer { |
1322 |
+ |
volatile boolean pleaseThrow; |
1323 |
+ |
void maybeThrow() { |
1324 |
+ |
if (pleaseThrow) { |
1325 |
+ |
// assert: tryAcquire methods can throw at most once |
1326 |
+ |
if (! thrown.compareAndSet(false, true)) |
1327 |
+ |
throw new AssertionError(); |
1328 |
+ |
throw ex; |
1329 |
+ |
} |
1330 |
+ |
} |
1331 |
+ |
|
1332 |
+ |
@Override protected boolean tryAcquire(int ignored) { |
1333 |
+ |
maybeThrow(); |
1334 |
+ |
return false; |
1335 |
+ |
} |
1336 |
+ |
@Override protected int tryAcquireShared(int ignored) { |
1337 |
+ |
maybeThrow(); |
1338 |
+ |
return -1; |
1339 |
+ |
} |
1340 |
+ |
@Override protected boolean tryRelease(int ignored) { |
1341 |
+ |
return true; |
1342 |
+ |
} |
1343 |
+ |
@Override protected boolean tryReleaseShared(int ignored) { |
1344 |
+ |
return true; |
1345 |
+ |
} |
1346 |
+ |
} |
1347 |
+ |
|
1348 |
+ |
final Sync s = new Sync(); |
1349 |
+ |
final boolean acquireInterruptibly = randomBoolean(); |
1350 |
+ |
final Action[] uninterruptibleAcquireActions = { |
1351 |
+ |
() -> s.acquire(1), |
1352 |
+ |
() -> s.acquireShared(1), |
1353 |
+ |
}; |
1354 |
+ |
final long nanosTimeout = MILLISECONDS.toNanos(2 * LONG_DELAY_MS); |
1355 |
+ |
final Action[] interruptibleAcquireActions = { |
1356 |
+ |
() -> s.acquireInterruptibly(1), |
1357 |
+ |
() -> s.acquireSharedInterruptibly(1), |
1358 |
+ |
() -> s.tryAcquireNanos(1, nanosTimeout), |
1359 |
+ |
() -> s.tryAcquireSharedNanos(1, nanosTimeout), |
1360 |
+ |
}; |
1361 |
+ |
final Action[] releaseActions = { |
1362 |
+ |
() -> s.release(1), |
1363 |
+ |
() -> s.releaseShared(1), |
1364 |
+ |
}; |
1365 |
+ |
final Action acquireAction = acquireInterruptibly |
1366 |
+ |
? chooseRandomly(interruptibleAcquireActions) |
1367 |
+ |
: chooseRandomly(uninterruptibleAcquireActions); |
1368 |
+ |
final Action releaseAction |
1369 |
+ |
= chooseRandomly(releaseActions); |
1370 |
+ |
|
1371 |
+ |
// From os_posix.cpp: |
1372 |
+ |
// |
1373 |
+ |
// NOTE that since there is no "lock" around the interrupt and |
1374 |
+ |
// is_interrupted operations, there is the possibility that the |
1375 |
+ |
// interrupted flag (in osThread) will be "false" but that the |
1376 |
+ |
// low-level events will be in the signaled state. This is |
1377 |
+ |
// intentional. The effect of this is that Object.wait() and |
1378 |
+ |
// LockSupport.park() will appear to have a spurious wakeup, which |
1379 |
+ |
// is allowed and not harmful, and the possibility is so rare that |
1380 |
+ |
// it is not worth the added complexity to add yet another lock. |
1381 |
+ |
final Thread thread = newStartedThread(new CheckedRunnable() { |
1382 |
+ |
public void realRun() throws Throwable { |
1383 |
+ |
try { |
1384 |
+ |
acquireAction.run(); |
1385 |
+ |
shouldThrow(); |
1386 |
+ |
} catch (InterruptedException possible) { |
1387 |
+ |
assertTrue(acquireInterruptibly); |
1388 |
+ |
assertFalse(Thread.interrupted()); |
1389 |
+ |
} catch (PleaseThrow possible) { |
1390 |
+ |
awaitInterrupted(); |
1391 |
+ |
} |
1392 |
+ |
}}); |
1393 |
+ |
for (long startTime = 0L;; ) { |
1394 |
+ |
waitForThreadToEnterWaitState(thread); |
1395 |
+ |
if (s.getFirstQueuedThread() == thread |
1396 |
+ |
&& s.hasQueuedPredecessors() |
1397 |
+ |
&& s.hasQueuedThreads() |
1398 |
+ |
&& s.getQueueLength() == 1 |
1399 |
+ |
&& s.hasContended()) |
1400 |
+ |
break; |
1401 |
+ |
if (startTime == 0L) |
1402 |
+ |
startTime = System.nanoTime(); |
1403 |
+ |
else if (millisElapsedSince(startTime) > LONG_DELAY_MS) |
1404 |
+ |
fail("timed out waiting for AQS state: " |
1405 |
+ |
+ "thread state=" + thread.getState() |
1406 |
+ |
+ ", queued threads=" + s.getQueuedThreads()); |
1407 |
+ |
Thread.yield(); |
1408 |
+ |
} |
1409 |
+ |
|
1410 |
+ |
s.pleaseThrow = true; |
1411 |
+ |
// release and interrupt, in random order |
1412 |
+ |
if (randomBoolean()) { |
1413 |
+ |
thread.interrupt(); |
1414 |
+ |
releaseAction.run(); |
1415 |
+ |
} else { |
1416 |
+ |
releaseAction.run(); |
1417 |
+ |
thread.interrupt(); |
1418 |
+ |
} |
1419 |
+ |
awaitTermination(thread); |
1420 |
+ |
|
1421 |
+ |
if (! acquireInterruptibly) |
1422 |
+ |
assertTrue(thrown.get()); |
1423 |
+ |
|
1424 |
+ |
assertNull(s.getFirstQueuedThread()); |
1425 |
+ |
assertFalse(s.hasQueuedPredecessors()); |
1426 |
+ |
assertFalse(s.hasQueuedThreads()); |
1427 |
+ |
assertEquals(0, s.getQueueLength()); |
1428 |
+ |
assertTrue(s.getQueuedThreads().isEmpty()); |
1429 |
+ |
assertTrue(s.hasContended()); |
1430 |
+ |
} |
1431 |
+ |
|
1432 |
|
} |