ViewVC Help

View File | Revision Log | Show Annotations | Download File | Root Listing

root/jsr166/jsr166/src/test/tck/SemaphoreTest.java

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.1 by dl, Sun Aug 31 19:24:55 2003 UTC vs.
Revision 1.43 by jsr166, Tue Jan 23 20:44:11 2018 UTC

#	Line 1 | Line 1
1		/*
2	<	* Written by members of JCP JSR-166 Expert Group and released to the
3	<	* public domain. Use, modify, and redistribute this code in any way
4	<	* without acknowledgement. Other contributors include Andrew Wright,
5	<	* Jeffrey Hayes, Pat Fischer, Mike Judd.
2	>	* Written by Doug Lea with assistance from members of JCP JSR-166
3	>	* Expert Group and released to the public domain, as explained at
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5	>	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	>	* Pat Fisher, Mike Judd.
7		*/
8
9	<	import junit.framework.*;
9	<	import java.util.*;
10	<	import java.util.concurrent.*;
9	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10
11	<	public class SemaphoreTest extends TestCase{
11	>	import java.util.Collection;
12	>	import java.util.concurrent.CountDownLatch;
13	>	import java.util.concurrent.Semaphore;
14	>	import java.util.concurrent.ThreadLocalRandom;
15
16	+	import junit.framework.Test;
17	+	import junit.framework.TestSuite;
18	+
19	+	public class SemaphoreTest extends JSR166TestCase {
20		public static void main(String[] args) {
21	<	junit.textui.TestRunner.run (suite());
21	>	main(suite(), args);
22		}
17	–
23		public static Test suite() {
24	<	return new TestSuite(SemaphoreTest.class);
24	>	return new TestSuite(SemaphoreTest.class);
25		}
26
27	<	private static long SHORT_DELAY_MS = 100;
28	<	private static long MEDIUM_DELAY_MS = 1000;
29	<	private static long LONG_DELAY_MS = 10000;
27	>	/**
28	>	* Subclass to expose protected methods
29	>	*/
30	>	static class PublicSemaphore extends Semaphore {
31	>	PublicSemaphore(int permits) { super(permits); }
32	>	PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
33	>	public Collection<Thread> getQueuedThreads() {
34	>	return super.getQueuedThreads();
35	>	}
36	>	public boolean hasQueuedThread(Thread t) {
37	>	return super.getQueuedThreads().contains(t);
38	>	}
39	>	public void reducePermits(int reduction) {
40	>	super.reducePermits(reduction);
41	>	}
42	>	}
43
44	+	/**
45	+	* A runnable calling acquire
46	+	*/
47	+	class InterruptibleLockRunnable extends CheckedRunnable {
48	+	final Semaphore lock;
49	+	InterruptibleLockRunnable(Semaphore s) { lock = s; }
50	+	public void realRun() {
51	+	try {
52	+	lock.acquire();
53	+	}
54	+	catch (InterruptedException ignored) {}
55	+	}
56	+	}
57
58	<	public void testConstructor1() {
59	<	Semaphore s = new Semaphore(0);
60	<	assertEquals(0, s.availablePermits());
58	>	/**
59	>	* A runnable calling acquire that expects to be interrupted
60	>	*/
61	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
62	>	final Semaphore lock;
63	>	InterruptedLockRunnable(Semaphore s) { lock = s; }
64	>	public void realRun() throws InterruptedException {
65	>	lock.acquire();
66	>	}
67		}
68
69	<	public void testConstructor2() {
70	<	Semaphore s = new Semaphore(-1);
71	<	assertEquals(-1, s.availablePermits());
69	>	/**
70	>	* Spin-waits until s.hasQueuedThread(t) becomes true.
71	>	*/
72	>	void waitForQueuedThread(PublicSemaphore s, Thread t) {
73	>	long startTime = System.nanoTime();
74	>	while (!s.hasQueuedThread(t)) {
75	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
76	>	throw new AssertionError("timed out");
77	>	Thread.yield();
78	>	}
79	>	assertTrue(s.hasQueuedThreads());
80	>	assertTrue(t.isAlive());
81	>	}
82	>
83	>	/**
84	>	* Spin-waits until s.hasQueuedThreads() becomes true.
85	>	*/
86	>	void waitForQueuedThreads(Semaphore s) {
87	>	long startTime = System.nanoTime();
88	>	while (!s.hasQueuedThreads()) {
89	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
90	>	throw new AssertionError("timed out");
91	>	Thread.yield();
92	>	}
93	>	}
94	>
95	>	enum AcquireMethod {
96	>	acquire() {
97	>	void acquire(Semaphore s) throws InterruptedException {
98	>	s.acquire();
99	>	}
100	>	},
101	>	acquireN() {
102	>	void acquire(Semaphore s, int permits) throws InterruptedException {
103	>	s.acquire(permits);
104	>	}
105	>	},
106	>	acquireUninterruptibly() {
107	>	void acquire(Semaphore s) {
108	>	s.acquireUninterruptibly();
109	>	}
110	>	},
111	>	acquireUninterruptiblyN() {
112	>	void acquire(Semaphore s, int permits) {
113	>	s.acquireUninterruptibly(permits);
114	>	}
115	>	},
116	>	tryAcquire() {
117	>	void acquire(Semaphore s) {
118	>	assertTrue(s.tryAcquire());
119	>	}
120	>	},
121	>	tryAcquireN() {
122	>	void acquire(Semaphore s, int permits) {
123	>	assertTrue(s.tryAcquire(permits));
124	>	}
125	>	},
126	>	tryAcquireTimed() {
127	>	void acquire(Semaphore s) throws InterruptedException {
128	>	assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
129	>	}
130	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
131	>	},
132	>	tryAcquireTimedN {
133	>	void acquire(Semaphore s, int permits) throws InterruptedException {
134	>	assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
135	>	}
136	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
137	>	};
138	>
139	>	// Intentionally meta-circular
140	>
141	>	/** Acquires 1 permit. */
142	>	void acquire(Semaphore s) throws InterruptedException {
143	>	acquire(s, 1);
144	>	}
145	>	/** Acquires the given number of permits. */
146	>	void acquire(Semaphore s, int permits) throws InterruptedException {
147	>	for (int i = 0; i < permits; i++)
148	>	acquire(s);
149	>	}
150	>	Thread.State parkedState() { return Thread.State.WAITING; }
151		}
152
153	<	public void testTryAcquireInSameThread() {
154	<	Semaphore s = new Semaphore(2);
153	>	/**
154	>	* Zero, negative, and positive initial values are allowed in constructor
155	>	*/
156	>	public void testConstructor()      { testConstructor(false); }
157	>	public void testConstructor_fair() { testConstructor(true); }
158	>	public void testConstructor(boolean fair) {
159	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
160	>	Semaphore s = new Semaphore(permits, fair);
161	>	assertEquals(permits, s.availablePermits());
162	>	assertEquals(fair, s.isFair());
163	>	}
164	>	}
165	>
166	>	/**
167	>	* Constructor without fairness argument behaves as nonfair
168	>	*/
169	>	public void testConstructorDefaultsToNonFair() {
170	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
171	>	Semaphore s = new Semaphore(permits);
172	>	assertEquals(permits, s.availablePermits());
173	>	assertFalse(s.isFair());
174	>	}
175	>	}
176	>
177	>	/**
178	>	* tryAcquire succeeds when sufficient permits, else fails
179	>	*/
180	>	public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
181	>	public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
182	>	public void testTryAcquireInSameThread(boolean fair) {
183	>	Semaphore s = new Semaphore(2, fair);
184		assertEquals(2, s.availablePermits());
185		assertTrue(s.tryAcquire());
186		assertTrue(s.tryAcquire());
187		assertEquals(0, s.availablePermits());
188		assertFalse(s.tryAcquire());
189	+	assertFalse(s.tryAcquire());
190	+	assertEquals(0, s.availablePermits());
191		}
192
193	<	public void testAcquireReleaseInSameThread(){
194	<	Semaphore s = new Semaphore(1);
195	<	try {
196	<	s.acquire();
197	<	s.release();
198	<	s.acquire();
199	<	s.release();
200	<	s.acquire();
201	<	s.release();
202	<	s.acquire();
203	<	s.release();
204	<	s.acquire();
205	<	s.release();
206	<	assertEquals(1, s.availablePermits());
207	<	} catch( InterruptedException e){
208	<	fail("unexpected exception");
193	>	/**
194	>	* timed tryAcquire times out
195	>	*/
196	>	public void testTryAcquire_timeout() {
197	>	final boolean fair = ThreadLocalRandom.current().nextBoolean();
198	>	final Semaphore s = new Semaphore(0, fair);
199	>	final long startTime = System.nanoTime();
200	>	try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
201	>	catch (InterruptedException e) { threadUnexpectedException(e); }
202	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
203	>	}
204	>
205	>	/**
206	>	* timed tryAcquire(N) times out
207	>	*/
208	>	public void testTryAcquireN_timeout() {
209	>	final boolean fair = ThreadLocalRandom.current().nextBoolean();
210	>	final Semaphore s = new Semaphore(2, fair);
211	>	final long startTime = System.nanoTime();
212	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
213	>	catch (InterruptedException e) { threadUnexpectedException(e); }
214	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
215	>	}
216	>
217	>	/**
218	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
219	>	* are interruptible
220	>	*/
221	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
222	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
223	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
224	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
225	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
226	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
227	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
228	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
229	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
230	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
231	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
232	>	= new java.util.concurrent.CyclicBarrier(2);
233	>	Thread t = newStartedThread(new CheckedRunnable() {
234	>	public void realRun() {
235	>	// Interrupt before acquire
236	>	Thread.currentThread().interrupt();
237	>	try {
238	>	acquirer.acquire(s);
239	>	shouldThrow();
240	>	} catch (InterruptedException success) {}
241	>	assertFalse(Thread.interrupted());
242	>
243	>	// Interrupt before acquire(N)
244	>	Thread.currentThread().interrupt();
245	>	try {
246	>	acquirer.acquire(s, 3);
247	>	shouldThrow();
248	>	} catch (InterruptedException success) {}
249	>	assertFalse(Thread.interrupted());
250	>
251	>	// Interrupt during acquire
252	>	await(pleaseInterrupt);
253	>	try {
254	>	acquirer.acquire(s);
255	>	shouldThrow();
256	>	} catch (InterruptedException success) {}
257	>	assertFalse(Thread.interrupted());
258	>
259	>	// Interrupt during acquire(N)
260	>	await(pleaseInterrupt);
261	>	try {
262	>	acquirer.acquire(s, 3);
263	>	shouldThrow();
264	>	} catch (InterruptedException success) {}
265	>	assertFalse(Thread.interrupted());
266	>	}});
267	>
268	>	for (int n = 2; n-->0; ) {
269	>	await(pleaseInterrupt);
270	>	assertThreadBlocks(t, acquirer.parkedState());
271	>	t.interrupt();
272		}
273	+
274	+	awaitTermination(t);
275	+	}
276	+
277	+	/**
278	+	* acquireUninterruptibly(), acquireUninterruptibly(N) are
279	+	* uninterruptible
280	+	*/
281	+	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
282	+	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
283	+	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
284	+	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
285	+	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
286	+	final PublicSemaphore s = new PublicSemaphore(0, fair);
287	+	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
288	+
289	+	Thread t1 = newStartedThread(new CheckedRunnable() {
290	+	public void realRun() throws InterruptedException {
291	+	// Interrupt before acquire
292	+	pleaseInterrupt.release();
293	+	Thread.currentThread().interrupt();
294	+	acquirer.acquire(s);
295	+	assertTrue(Thread.interrupted());
296	+	}});
297	+
298	+	Thread t2 = newStartedThread(new CheckedRunnable() {
299	+	public void realRun() throws InterruptedException {
300	+	// Interrupt during acquire
301	+	pleaseInterrupt.release();
302	+	acquirer.acquire(s);
303	+	assertTrue(Thread.interrupted());
304	+	}});
305	+
306	+	await(pleaseInterrupt);
307	+	waitForQueuedThread(s, t1);
308	+	waitForQueuedThread(s, t2);
309	+	t2.interrupt();
310	+
311	+	assertThreadBlocks(t1, Thread.State.WAITING);
312	+	assertThreadBlocks(t2, Thread.State.WAITING);
313	+
314	+	s.release(2);
315	+
316	+	awaitTermination(t1);
317	+	awaitTermination(t2);
318	+	}
319	+
320	+	/**
321	+	* hasQueuedThreads reports whether there are waiting threads
322	+	*/
323	+	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
324	+	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
325	+	public void testHasQueuedThreads(boolean fair) {
326	+	final PublicSemaphore lock = new PublicSemaphore(1, fair);
327	+	assertFalse(lock.hasQueuedThreads());
328	+	lock.acquireUninterruptibly();
329	+	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
330	+	waitForQueuedThread(lock, t1);
331	+	assertTrue(lock.hasQueuedThreads());
332	+	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
333	+	waitForQueuedThread(lock, t2);
334	+	assertTrue(lock.hasQueuedThreads());
335	+	t1.interrupt();
336	+	awaitTermination(t1);
337	+	assertTrue(lock.hasQueuedThreads());
338	+	lock.release();
339	+	awaitTermination(t2);
340	+	assertFalse(lock.hasQueuedThreads());
341	+	}
342	+
343	+	/**
344	+	* getQueueLength reports number of waiting threads
345	+	*/
346	+	public void testGetQueueLength()      { testGetQueueLength(false); }
347	+	public void testGetQueueLength_fair() { testGetQueueLength(true); }
348	+	public void testGetQueueLength(boolean fair) {
349	+	final PublicSemaphore lock = new PublicSemaphore(1, fair);
350	+	assertEquals(0, lock.getQueueLength());
351	+	lock.acquireUninterruptibly();
352	+	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
353	+	waitForQueuedThread(lock, t1);
354	+	assertEquals(1, lock.getQueueLength());
355	+	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
356	+	waitForQueuedThread(lock, t2);
357	+	assertEquals(2, lock.getQueueLength());
358	+	t1.interrupt();
359	+	awaitTermination(t1);
360	+	assertEquals(1, lock.getQueueLength());
361	+	lock.release();
362	+	awaitTermination(t2);
363	+	assertEquals(0, lock.getQueueLength());
364	+	}
365	+
366	+	/**
367	+	* getQueuedThreads includes waiting threads
368	+	*/
369	+	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
370	+	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
371	+	public void testGetQueuedThreads(boolean fair) {
372	+	final PublicSemaphore lock = new PublicSemaphore(1, fair);
373	+	assertTrue(lock.getQueuedThreads().isEmpty());
374	+	lock.acquireUninterruptibly();
375	+	assertTrue(lock.getQueuedThreads().isEmpty());
376	+	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
377	+	waitForQueuedThread(lock, t1);
378	+	assertTrue(lock.getQueuedThreads().contains(t1));
379	+	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
380	+	waitForQueuedThread(lock, t2);
381	+	assertTrue(lock.getQueuedThreads().contains(t1));
382	+	assertTrue(lock.getQueuedThreads().contains(t2));
383	+	t1.interrupt();
384	+	awaitTermination(t1);
385	+	assertFalse(lock.getQueuedThreads().contains(t1));
386	+	assertTrue(lock.getQueuedThreads().contains(t2));
387	+	lock.release();
388	+	awaitTermination(t2);
389	+	assertTrue(lock.getQueuedThreads().isEmpty());
390	+	}
391	+
392	+	/**
393	+	* drainPermits reports and removes given number of permits
394	+	*/
395	+	public void testDrainPermits()      { testDrainPermits(false); }
396	+	public void testDrainPermits_fair() { testDrainPermits(true); }
397	+	public void testDrainPermits(boolean fair) {
398	+	Semaphore s = new Semaphore(0, fair);
399	+	assertEquals(0, s.availablePermits());
400	+	assertEquals(0, s.drainPermits());
401	+	s.release(10);
402	+	assertEquals(10, s.availablePermits());
403	+	assertEquals(10, s.drainPermits());
404	+	assertEquals(0, s.availablePermits());
405	+	assertEquals(0, s.drainPermits());
406		}
407
408	<	public void testAcquireUninterruptiblyReleaseInSameThread(){
409	<	Semaphore s = new Semaphore(1);
408	>	/**
409	>	* release(-N) throws IllegalArgumentException
410	>	*/
411	>	public void testReleaseIAE()      { testReleaseIAE(false); }
412	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
413	>	public void testReleaseIAE(boolean fair) {
414	>	Semaphore s = new Semaphore(10, fair);
415		try {
416	<	s.acquireUninterruptibly();
417	<	s.release();
418	<	s.acquireUninterruptibly();
71	<	s.release();
72	<	s.acquireUninterruptibly();
73	<	s.release();
74	<	s.acquireUninterruptibly();
75	<	s.release();
76	<	s.acquireUninterruptibly();
77	<	s.release();
78	<	assertEquals(1, s.availablePermits());
79	<	} finally {
80	<	}
416	>	s.release(-1);
417	>	shouldThrow();
418	>	} catch (IllegalArgumentException success) {}
419		}
420
421	+	/**
422	+	* reducePermits(-N) throws IllegalArgumentException
423	+	*/
424	+	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
425	+	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
426	+	public void testReducePermitsIAE(boolean fair) {
427	+	PublicSemaphore s = new PublicSemaphore(10, fair);
428	+	try {
429	+	s.reducePermits(-1);
430	+	shouldThrow();
431	+	} catch (IllegalArgumentException success) {}
432	+	}
433	+
434	+	/**
435	+	* reducePermits reduces number of permits
436	+	*/
437	+	public void testReducePermits()      { testReducePermits(false); }
438	+	public void testReducePermits_fair() { testReducePermits(true); }
439	+	public void testReducePermits(boolean fair) {
440	+	PublicSemaphore s = new PublicSemaphore(10, fair);
441	+	assertEquals(10, s.availablePermits());
442	+	s.reducePermits(0);
443	+	assertEquals(10, s.availablePermits());
444	+	s.reducePermits(1);
445	+	assertEquals(9, s.availablePermits());
446	+	s.reducePermits(10);
447	+	assertEquals(-1, s.availablePermits());
448	+	s.reducePermits(10);
449	+	assertEquals(-11, s.availablePermits());
450	+	s.reducePermits(0);
451	+	assertEquals(-11, s.availablePermits());
452	+	}
453
454	<	public void testAcquireReleaseInDifferentThreads() {
455	<	final Semaphore s = new Semaphore(1);
456	<	Thread t = new Thread(new Runnable(){
457	<	public void run(){
458	<	try{
459	<	s.acquire();
460	<	s.release();
91	<	s.release();
92	<	s.acquire();
93	<	}catch(InterruptedException ie){
94	<	fail("unexpected exception");
95	<	}
96	<	}
97	<	});
98	<	t.start();
454	>	/**
455	>	* a reserialized semaphore has same number of permits and
456	>	* fairness, but no queued threads
457	>	*/
458	>	public void testSerialization()      { testSerialization(false); }
459	>	public void testSerialization_fair() { testSerialization(true); }
460	>	public void testSerialization(boolean fair) {
461		try {
462	<	s.release();
101	<	s.release();
462	>	Semaphore s = new Semaphore(3, fair);
463		s.acquire();
464		s.acquire();
465	<	t.join();
466	<	} catch( InterruptedException e){
467	<	fail("unexpected exception");
465	>	s.release();
466	>
467	>	Semaphore clone = serialClone(s);
468	>	assertEquals(fair, s.isFair());
469	>	assertEquals(fair, clone.isFair());
470	>	assertEquals(2, s.availablePermits());
471	>	assertEquals(2, clone.availablePermits());
472	>	clone.acquire();
473	>	clone.acquire();
474	>	clone.release();
475	>	assertEquals(2, s.availablePermits());
476	>	assertEquals(1, clone.availablePermits());
477	>	assertFalse(s.hasQueuedThreads());
478	>	assertFalse(clone.hasQueuedThreads());
479	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
480	>
481	>	{
482	>	PublicSemaphore s = new PublicSemaphore(0, fair);
483	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
484	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
485	>	waitForQueuedThread(s, t);  // ... we use this instead
486	>	PublicSemaphore clone = serialClone(s);
487	>	assertEquals(fair, s.isFair());
488	>	assertEquals(fair, clone.isFair());
489	>	assertEquals(0, s.availablePermits());
490	>	assertEquals(0, clone.availablePermits());
491	>	assertTrue(s.hasQueuedThreads());
492	>	assertFalse(clone.hasQueuedThreads());
493	>	s.release();
494	>	awaitTermination(t);
495	>	assertFalse(s.hasQueuedThreads());
496	>	assertFalse(clone.hasQueuedThreads());
497		}
498		}
499
500	<	public void testTimedAcquireReleaseInSameThread(){
501	<	Semaphore s = new Semaphore(1);
502	<	try {
503	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
504	<	s.release();
505	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
506	<	s.release();
507	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
508	<	s.release();
509	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
510	<	s.release();
511	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
512	<	s.release();
500	>	/**
501	>	* tryAcquire(n) succeeds when sufficient permits, else fails
502	>	*/
503	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
504	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
505	>	public void testTryAcquireNInSameThread(boolean fair) {
506	>	Semaphore s = new Semaphore(2, fair);
507	>	assertEquals(2, s.availablePermits());
508	>	assertFalse(s.tryAcquire(3));
509	>	assertEquals(2, s.availablePermits());
510	>	assertTrue(s.tryAcquire(2));
511	>	assertEquals(0, s.availablePermits());
512	>	assertFalse(s.tryAcquire(1));
513	>	assertFalse(s.tryAcquire(2));
514	>	assertEquals(0, s.availablePermits());
515	>	}
516	>
517	>	/**
518	>	* acquire succeeds if permits available
519	>	*/
520	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
521	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
522	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
523	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
524	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
525	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
526	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
527	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
528	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
529	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
530	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
531	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
532	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
533	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
534	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
535	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
536	>	public void testReleaseAcquireSameThread(boolean fair,
537	>	final AcquireMethod acquirer) {
538	>	Semaphore s = new Semaphore(1, fair);
539	>	for (int i = 1; i < 6; i++) {
540	>	s.release(i);
541	>	assertEquals(1 + i, s.availablePermits());
542	>	try {
543	>	acquirer.acquire(s, i);
544	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
545		assertEquals(1, s.availablePermits());
124	–	} catch( InterruptedException e){
125	–	fail("unexpected exception");
546		}
547		}
548
549	<	public void testTimedAcquireReleaseInDifferentThreads() {
550	<	final Semaphore s = new Semaphore(1);
551	<	Thread t = new Thread(new Runnable(){
552	<	public void run(){
553	<	try{
554	<	s.release();
555	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
556	<	s.release();
557	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
558	<
559	<	}catch(InterruptedException ie){
560	<	fail("unexpected exception");
561	<	}
562	<	}
563	<	});
564	<	t.start();
565	<	try {
566	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
567	<	s.release();
568	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
569	<	s.release();
570	<	t.join();
571	<	} catch( InterruptedException e){
572	<	fail("unexpected exception");
549	>	/**
550	>	* release in one thread enables acquire in another thread
551	>	*/
552	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
553	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
554	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
555	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
556	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
557	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
558	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
559	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
560	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
561	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
562	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
563	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
564	>	public void testReleaseAcquireDifferentThreads(boolean fair,
565	>	final AcquireMethod acquirer) {
566	>	final Semaphore s = new Semaphore(0, fair);
567	>	final int rounds = 4;
568	>	long startTime = System.nanoTime();
569	>	Thread t = newStartedThread(new CheckedRunnable() {
570	>	public void realRun() throws InterruptedException {
571	>	for (int i = 0; i < rounds; i++) {
572	>	assertFalse(s.hasQueuedThreads());
573	>	if (i % 2 == 0)
574	>	acquirer.acquire(s);
575	>	else
576	>	acquirer.acquire(s, 3);
577	>	}}});
578	>
579	>	for (int i = 0; i < rounds; i++) {
580	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
581	>	Thread.yield();
582	>	assertTrue(t.isAlive());
583	>	if (i % 2 == 0)
584	>	s.release();
585	>	else
586	>	s.release(3);
587		}
588	+	awaitTermination(t);
589	+	assertEquals(0, s.availablePermits());
590	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
591		}
592
593	<	public void testAcquire_InterruptedException(){
594	<	final Semaphore s = new Semaphore(0);
595	<	Thread t = new Thread(new Runnable(){
596	<	public void run(){
597	<	try{
598	<	s.acquire();
599	<	fail("should throw");
600	<	}catch(InterruptedException success){}
601	<	}
602	<	});
603	<	t.start();
604	<	try{
605	<	Thread.sleep(SHORT_DELAY_MS);
606	<	t.interrupt();
607	<	t.join();
608	<	} catch(InterruptedException e){
609	<	fail("unexpected exception");
610	<	}
611	<	}
612	<
613	<	public void testTryAcquire_InterruptedException(){
614	<	final Semaphore s = new Semaphore(0);
615	<	Thread t = new Thread(new Runnable(){
616	<	public void run(){
617	<	try{
618	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
619	<	fail("should throw");
620	<	}catch(InterruptedException success){
621	<	}
622	<	}
623	<	});
624	<	t.start();
625	<	try{
626	<	Thread.sleep(SHORT_DELAY_MS);
627	<	t.interrupt();
628	<	t.join();
629	<	} catch(InterruptedException e){
630	<	fail("unexpected exception");
631	<	}
593	>	/**
594	>	* fair locks are strictly FIFO
595	>	*/
596	>	public void testFairLocksFifo() {
597	>	final PublicSemaphore s = new PublicSemaphore(1, true);
598	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
599	>	Thread t1 = newStartedThread(new CheckedRunnable() {
600	>	public void realRun() throws InterruptedException {
601	>	// Will block; permits are available, but not three
602	>	s.acquire(3);
603	>	}});
604	>
605	>	waitForQueuedThread(s, t1);
606	>
607	>	Thread t2 = newStartedThread(new CheckedRunnable() {
608	>	public void realRun() throws InterruptedException {
609	>	// Will fail, even though 1 permit is available
610	>	assertFalse(
611	>	s.tryAcquire(randomExpiredTimeout(), randomTimeUnit()));
612	>	assertFalse(
613	>	s.tryAcquire(1, randomExpiredTimeout(), randomTimeUnit()));
614	>
615	>	// untimed tryAcquire will barge and succeed
616	>	assertTrue(s.tryAcquire());
617	>	s.release(2);
618	>	assertTrue(s.tryAcquire(2));
619	>	s.release();
620	>
621	>	pleaseRelease.countDown();
622	>	// Will queue up behind t1, even though 1 permit is available
623	>	s.acquire();
624	>	}});
625	>
626	>	await(pleaseRelease);
627	>	waitForQueuedThread(s, t2);
628	>	s.release(2);
629	>	awaitTermination(t1);
630	>	assertTrue(t2.isAlive());
631	>	s.release();
632	>	awaitTermination(t2);
633	>	}
634	>
635	>	/**
636	>	* toString indicates current number of permits
637	>	*/
638	>	public void testToString()      { testToString(false); }
639	>	public void testToString_fair() { testToString(true); }
640	>	public void testToString(boolean fair) {
641	>	PublicSemaphore s = new PublicSemaphore(0, fair);
642	>	assertTrue(s.toString().contains("Permits = 0"));
643	>	s.release();
644	>	assertTrue(s.toString().contains("Permits = 1"));
645	>	s.release(2);
646	>	assertTrue(s.toString().contains("Permits = 3"));
647	>	s.reducePermits(5);
648	>	assertTrue(s.toString().contains("Permits = -2"));
649		}
650	+
651		}

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines