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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.5 by dl, Thu Sep 25 11:02:41 2003 UTC vs.
Revision 1.44 by jsr166, Mon Aug 12 06:21:11 2019 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.*;
10	<	import java.util.*;
11	<	import java.util.concurrent.*;
12	<	import java.io.*;
9	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10	>
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		}
23		public static Test suite() {
24	<	return new TestSuite(SemaphoreTest.class);
24	>	return new TestSuite(SemaphoreTest.class);
25	>	}
26	>
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	>	/**
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	>	/**
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		/**
154		* Zero, negative, and positive initial values are allowed in constructor
155		*/
156	<	public void testConstructor() {
157	<	Semaphore s0 = new Semaphore(0);
158	<	assertEquals(0, s0.availablePermits());
159	<	Semaphore s1 = new Semaphore(-1);
160	<	assertEquals(-1, s1.availablePermits());
161	<	Semaphore s2 = new Semaphore(-1);
162	<	assertEquals(-1, s2.availablePermits());
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 sufficent permits, else fails
178	>	* tryAcquire succeeds when sufficient permits, else fails
179		*/
180	<	public void testTryAcquireInSameThread() {
181	<	Semaphore s = new Semaphore(2);
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		/**
194	<	* Acquire and release of semaphore succeed if initially available
194	>	* timed tryAcquire times out
195		*/
196	<	public void testAcquireReleaseInSameThread() {
197	<	Semaphore s = new Semaphore(1);
198	<	try {
199	<	s.acquire();
200	<	s.release();
201	<	s.acquire();
202	<	s.release();
203	<	s.acquire();
204	<	s.release();
205	<	s.acquire();
206	<	s.release();
207	<	s.acquire();
208	<	s.release();
209	<	assertEquals(1, s.availablePermits());
210	<	} catch( InterruptedException e){
211	<	unexpectedException();
196	>	public void testTryAcquire_timeout() throws InterruptedException {
197	>	final boolean fair = randomBoolean();
198	>	final Semaphore s = new Semaphore(0, fair);
199	>	final long startTime = System.nanoTime();
200	>	assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS));
201	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
202	>	}
203	>
204	>	/**
205	>	* timed tryAcquire(N) times out
206	>	*/
207	>	public void testTryAcquireN_timeout() throws InterruptedException {
208	>	final boolean fair = randomBoolean();
209	>	final Semaphore s = new Semaphore(2, fair);
210	>	final long startTime = System.nanoTime();
211	>	assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS));
212	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
213	>	}
214	>
215	>	/**
216	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
217	>	* are interruptible
218	>	*/
219	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
220	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
221	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
222	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
223	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
224	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
225	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
226	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
227	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
228	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
229	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
230	>	= new java.util.concurrent.CyclicBarrier(2);
231	>	Thread t = newStartedThread(new CheckedRunnable() {
232	>	public void realRun() {
233	>	// Interrupt before acquire
234	>	Thread.currentThread().interrupt();
235	>	try {
236	>	acquirer.acquire(s);
237	>	shouldThrow();
238	>	} catch (InterruptedException success) {}
239	>	assertFalse(Thread.interrupted());
240	>
241	>	// Interrupt before acquire(N)
242	>	Thread.currentThread().interrupt();
243	>	try {
244	>	acquirer.acquire(s, 3);
245	>	shouldThrow();
246	>	} catch (InterruptedException success) {}
247	>	assertFalse(Thread.interrupted());
248	>
249	>	// Interrupt during acquire
250	>	await(pleaseInterrupt);
251	>	try {
252	>	acquirer.acquire(s);
253	>	shouldThrow();
254	>	} catch (InterruptedException success) {}
255	>	assertFalse(Thread.interrupted());
256	>
257	>	// Interrupt during acquire(N)
258	>	await(pleaseInterrupt);
259	>	try {
260	>	acquirer.acquire(s, 3);
261	>	shouldThrow();
262	>	} catch (InterruptedException success) {}
263	>	assertFalse(Thread.interrupted());
264	>	}});
265	>
266	>	for (int n = 2; n-->0; ) {
267	>	await(pleaseInterrupt);
268	>	assertThreadBlocks(t, acquirer.parkedState());
269	>	t.interrupt();
270		}
271	+
272	+	awaitTermination(t);
273		}
274
275		/**
276	<	* Uninterruptible acquire and release of semaphore succeed if
277	<	* initially available
276	>	* acquireUninterruptibly(), acquireUninterruptibly(N) are
277	>	* uninterruptible
278		*/
279	<	public void testAcquireUninterruptiblyReleaseInSameThread() {
280	<	Semaphore s = new Semaphore(1);
281	<	try {
282	<	s.acquireUninterruptibly();
283	<	s.release();
284	<	s.acquireUninterruptibly();
285	<	s.release();
286	<	s.acquireUninterruptibly();
287	<	s.release();
288	<	s.acquireUninterruptibly();
289	<	s.release();
290	<	s.acquireUninterruptibly();
291	<	s.release();
292	<	assertEquals(1, s.availablePermits());
293	<	} finally {
294	<	}
279	>	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
280	>	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
281	>	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
282	>	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
283	>	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
284	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
285	>	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
286	>
287	>	Thread t1 = newStartedThread(new CheckedRunnable() {
288	>	public void realRun() throws InterruptedException {
289	>	// Interrupt before acquire
290	>	pleaseInterrupt.release();
291	>	Thread.currentThread().interrupt();
292	>	acquirer.acquire(s);
293	>	assertTrue(Thread.interrupted());
294	>	}});
295	>
296	>	Thread t2 = newStartedThread(new CheckedRunnable() {
297	>	public void realRun() throws InterruptedException {
298	>	// Interrupt during acquire
299	>	pleaseInterrupt.release();
300	>	acquirer.acquire(s);
301	>	assertTrue(Thread.interrupted());
302	>	}});
303	>
304	>	await(pleaseInterrupt);
305	>	waitForQueuedThread(s, t1);
306	>	waitForQueuedThread(s, t2);
307	>	t2.interrupt();
308	>
309	>	assertThreadBlocks(t1, Thread.State.WAITING);
310	>	assertThreadBlocks(t2, Thread.State.WAITING);
311	>
312	>	s.release(2);
313	>
314	>	awaitTermination(t1);
315	>	awaitTermination(t2);
316	>	}
317	>
318	>	/**
319	>	* hasQueuedThreads reports whether there are waiting threads
320	>	*/
321	>	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
322	>	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
323	>	public void testHasQueuedThreads(boolean fair) {
324	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
325	>	assertFalse(lock.hasQueuedThreads());
326	>	lock.acquireUninterruptibly();
327	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
328	>	waitForQueuedThread(lock, t1);
329	>	assertTrue(lock.hasQueuedThreads());
330	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
331	>	waitForQueuedThread(lock, t2);
332	>	assertTrue(lock.hasQueuedThreads());
333	>	t1.interrupt();
334	>	awaitTermination(t1);
335	>	assertTrue(lock.hasQueuedThreads());
336	>	lock.release();
337	>	awaitTermination(t2);
338	>	assertFalse(lock.hasQueuedThreads());
339	>	}
340	>
341	>	/**
342	>	* getQueueLength reports number of waiting threads
343	>	*/
344	>	public void testGetQueueLength()      { testGetQueueLength(false); }
345	>	public void testGetQueueLength_fair() { testGetQueueLength(true); }
346	>	public void testGetQueueLength(boolean fair) {
347	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
348	>	assertEquals(0, lock.getQueueLength());
349	>	lock.acquireUninterruptibly();
350	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
351	>	waitForQueuedThread(lock, t1);
352	>	assertEquals(1, lock.getQueueLength());
353	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
354	>	waitForQueuedThread(lock, t2);
355	>	assertEquals(2, lock.getQueueLength());
356	>	t1.interrupt();
357	>	awaitTermination(t1);
358	>	assertEquals(1, lock.getQueueLength());
359	>	lock.release();
360	>	awaitTermination(t2);
361	>	assertEquals(0, lock.getQueueLength());
362	>	}
363	>
364	>	/**
365	>	* getQueuedThreads includes waiting threads
366	>	*/
367	>	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
368	>	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
369	>	public void testGetQueuedThreads(boolean fair) {
370	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
371	>	assertTrue(lock.getQueuedThreads().isEmpty());
372	>	lock.acquireUninterruptibly();
373	>	assertTrue(lock.getQueuedThreads().isEmpty());
374	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
375	>	waitForQueuedThread(lock, t1);
376	>	assertTrue(lock.getQueuedThreads().contains(t1));
377	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
378	>	waitForQueuedThread(lock, t2);
379	>	assertTrue(lock.getQueuedThreads().contains(t1));
380	>	assertTrue(lock.getQueuedThreads().contains(t2));
381	>	t1.interrupt();
382	>	awaitTermination(t1);
383	>	assertFalse(lock.getQueuedThreads().contains(t1));
384	>	assertTrue(lock.getQueuedThreads().contains(t2));
385	>	lock.release();
386	>	awaitTermination(t2);
387	>	assertTrue(lock.getQueuedThreads().isEmpty());
388	>	}
389	>
390	>	/**
391	>	* drainPermits reports and removes given number of permits
392	>	*/
393	>	public void testDrainPermits()      { testDrainPermits(false); }
394	>	public void testDrainPermits_fair() { testDrainPermits(true); }
395	>	public void testDrainPermits(boolean fair) {
396	>	Semaphore s = new Semaphore(0, fair);
397	>	assertEquals(0, s.availablePermits());
398	>	assertEquals(0, s.drainPermits());
399	>	s.release(10);
400	>	assertEquals(10, s.availablePermits());
401	>	assertEquals(10, s.drainPermits());
402	>	assertEquals(0, s.availablePermits());
403	>	assertEquals(0, s.drainPermits());
404		}
405
406		/**
407	<	* Timed Acquire and release of semaphore succeed if
91	<	* initially available
407	>	* release(-N) throws IllegalArgumentException
408		*/
409	<	public void testTimedAcquireReleaseInSameThread() {
410	<	Semaphore s = new Semaphore(1);
409	>	public void testReleaseIAE()      { testReleaseIAE(false); }
410	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
411	>	public void testReleaseIAE(boolean fair) {
412	>	Semaphore s = new Semaphore(10, fair);
413		try {
414	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
415	<	s.release();
416	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
99	<	s.release();
100	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
101	<	s.release();
102	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
103	<	s.release();
104	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
105	<	s.release();
106	<	assertEquals(1, s.availablePermits());
107	<	} catch( InterruptedException e){
108	<	unexpectedException();
109	<	}
414	>	s.release(-1);
415	>	shouldThrow();
416	>	} catch (IllegalArgumentException success) {}
417		}
418
419		/**
420	<	* A release in one thread enables an acquire in another thread
420	>	* reducePermits(-N) throws IllegalArgumentException
421		*/
422	<	public void testAcquireReleaseInDifferentThreads() {
423	<	final Semaphore s = new Semaphore(0);
424	<	Thread t = new Thread(new Runnable() {
425	<	public void run() {
119	<	try {
120	<	s.acquire();
121	<	s.release();
122	<	s.release();
123	<	s.acquire();
124	<	} catch(InterruptedException ie){
125	<	threadUnexpectedException();
126	<	}
127	<	}
128	<	});
422	>	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
423	>	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
424	>	public void testReducePermitsIAE(boolean fair) {
425	>	PublicSemaphore s = new PublicSemaphore(10, fair);
426		try {
427	<	t.start();
428	<	Thread.sleep(SHORT_DELAY_MS);
429	<	s.release();
430	<	s.release();
427	>	s.reducePermits(-1);
428	>	shouldThrow();
429	>	} catch (IllegalArgumentException success) {}
430	>	}
431	>
432	>	/**
433	>	* reducePermits reduces number of permits
434	>	*/
435	>	public void testReducePermits()      { testReducePermits(false); }
436	>	public void testReducePermits_fair() { testReducePermits(true); }
437	>	public void testReducePermits(boolean fair) {
438	>	PublicSemaphore s = new PublicSemaphore(10, fair);
439	>	assertEquals(10, s.availablePermits());
440	>	s.reducePermits(0);
441	>	assertEquals(10, s.availablePermits());
442	>	s.reducePermits(1);
443	>	assertEquals(9, s.availablePermits());
444	>	s.reducePermits(10);
445	>	assertEquals(-1, s.availablePermits());
446	>	s.reducePermits(10);
447	>	assertEquals(-11, s.availablePermits());
448	>	s.reducePermits(0);
449	>	assertEquals(-11, s.availablePermits());
450	>	}
451	>
452	>	/**
453	>	* a reserialized semaphore has same number of permits and
454	>	* fairness, but no queued threads
455	>	*/
456	>	public void testSerialization()      { testSerialization(false); }
457	>	public void testSerialization_fair() { testSerialization(true); }
458	>	public void testSerialization(boolean fair) {
459	>	try {
460	>	Semaphore s = new Semaphore(3, fair);
461		s.acquire();
462		s.acquire();
463		s.release();
464	<	t.join();
465	<	} catch( InterruptedException e){
466	<	unexpectedException();
464	>
465	>	Semaphore clone = serialClone(s);
466	>	assertEquals(fair, s.isFair());
467	>	assertEquals(fair, clone.isFair());
468	>	assertEquals(2, s.availablePermits());
469	>	assertEquals(2, clone.availablePermits());
470	>	clone.acquire();
471	>	clone.acquire();
472	>	clone.release();
473	>	assertEquals(2, s.availablePermits());
474	>	assertEquals(1, clone.availablePermits());
475	>	assertFalse(s.hasQueuedThreads());
476	>	assertFalse(clone.hasQueuedThreads());
477	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
478	>
479	>	{
480	>	PublicSemaphore s = new PublicSemaphore(0, fair);
481	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
482	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
483	>	waitForQueuedThread(s, t);  // ... we use this instead
484	>	PublicSemaphore clone = serialClone(s);
485	>	assertEquals(fair, s.isFair());
486	>	assertEquals(fair, clone.isFair());
487	>	assertEquals(0, s.availablePermits());
488	>	assertEquals(0, clone.availablePermits());
489	>	assertTrue(s.hasQueuedThreads());
490	>	assertFalse(clone.hasQueuedThreads());
491	>	s.release();
492	>	awaitTermination(t);
493	>	assertFalse(s.hasQueuedThreads());
494	>	assertFalse(clone.hasQueuedThreads());
495		}
496		}
497
498		/**
499	<	* A release in one thread enables an uninterruptible acquire in another thread
499	>	* tryAcquire(n) succeeds when sufficient permits, else fails
500		*/
501	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
502	<	final Semaphore s = new Semaphore(0);
503	<	Thread t = new Thread(new Runnable() {
504	<	public void run() {
505	<	s.acquireUninterruptibly();
506	<	s.release();
507	<	s.release();
508	<	s.acquireUninterruptibly();
509	<	}
510	<	});
511	<	try {
512	<	t.start();
158	<	Thread.sleep(SHORT_DELAY_MS);
159	<	s.release();
160	<	s.release();
161	<	s.acquireUninterruptibly();
162	<	s.acquireUninterruptibly();
163	<	s.release();
164	<	t.join();
165	<	} catch( InterruptedException e){
166	<	unexpectedException();
167	<	}
501	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
502	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
503	>	public void testTryAcquireNInSameThread(boolean fair) {
504	>	Semaphore s = new Semaphore(2, fair);
505	>	assertEquals(2, s.availablePermits());
506	>	assertFalse(s.tryAcquire(3));
507	>	assertEquals(2, s.availablePermits());
508	>	assertTrue(s.tryAcquire(2));
509	>	assertEquals(0, s.availablePermits());
510	>	assertFalse(s.tryAcquire(1));
511	>	assertFalse(s.tryAcquire(2));
512	>	assertEquals(0, s.availablePermits());
513		}
514
170	–
515		/**
516	<	*  A release in one thread enables a timed acquire in another thread
516	>	* acquire succeeds if permits available
517		*/
518	<	public void testTimedAcquireReleaseInDifferentThreads() {
519	<	final Semaphore s = new Semaphore(1);
520	<	Thread t = new Thread(new Runnable() {
521	<	public void run() {
522	<	try {
523	<	s.release();
524	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
525	<	s.release();
526	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
527	<
528	<	} catch(InterruptedException ie){
529	<	threadUnexpectedException();
530	<	}
531	<	}
532	<	});
533	<	try {
534	<	t.start();
535	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
536	<	s.release();
537	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
538	<	s.release();
539	<	s.release();
540	<	t.join();
541	<	} catch( InterruptedException e){
542	<	unexpectedException();
518	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
519	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
520	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
521	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
522	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
523	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
524	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
525	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
526	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
527	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
528	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
529	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
530	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
531	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
532	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
533	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
534	>	public void testReleaseAcquireSameThread(boolean fair,
535	>	final AcquireMethod acquirer) {
536	>	Semaphore s = new Semaphore(1, fair);
537	>	for (int i = 1; i < 6; i++) {
538	>	s.release(i);
539	>	assertEquals(1 + i, s.availablePermits());
540	>	try {
541	>	acquirer.acquire(s, i);
542	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
543	>	assertEquals(1, s.availablePermits());
544		}
545		}
546
547		/**
548	<	* A waiting acquire blocks interruptibly
549	<	*/
550	<	public void testAcquire_InterruptedException() {
551	<	final Semaphore s = new Semaphore(0);
552	<	Thread t = new Thread(new Runnable() {
553	<	public void run() {
554	<	try {
555	<	s.acquire();
556	<	threadShouldThrow();
557	<	} catch(InterruptedException success){}
558	<	}
559	<	});
560	<	t.start();
561	<	try {
562	<	Thread.sleep(SHORT_DELAY_MS);
563	<	t.interrupt();
564	<	t.join();
565	<	} catch(InterruptedException e){
566	<	unexpectedException();
567	<	}
568	<	}
569	<
570	<	/**
571	<	*  A waiting timed acquire blocks interruptibly
572	<	*/
573	<	public void testTryAcquire_InterruptedException() {
574	<	final Semaphore s = new Semaphore(0);
575	<	Thread t = new Thread(new Runnable() {
576	<	public void run() {
577	<	try {
578	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
579	<	threadShouldThrow();
580	<	} catch(InterruptedException success){
581	<	}
582	<	}
583	<	});
584	<	t.start();
240	<	try {
241	<	Thread.sleep(SHORT_DELAY_MS);
242	<	t.interrupt();
243	<	t.join();
244	<	} catch(InterruptedException e){
245	<	unexpectedException();
548	>	* release in one thread enables acquire in another thread
549	>	*/
550	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
551	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
552	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
553	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
554	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
555	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
556	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
557	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
558	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
559	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
560	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
561	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
562	>	public void testReleaseAcquireDifferentThreads(boolean fair,
563	>	final AcquireMethod acquirer) {
564	>	final Semaphore s = new Semaphore(0, fair);
565	>	final int rounds = 4;
566	>	long startTime = System.nanoTime();
567	>	Thread t = newStartedThread(new CheckedRunnable() {
568	>	public void realRun() throws InterruptedException {
569	>	for (int i = 0; i < rounds; i++) {
570	>	assertFalse(s.hasQueuedThreads());
571	>	if (i % 2 == 0)
572	>	acquirer.acquire(s);
573	>	else
574	>	acquirer.acquire(s, 3);
575	>	}}});
576	>
577	>	for (int i = 0; i < rounds; i++) {
578	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
579	>	Thread.yield();
580	>	assertTrue(t.isAlive());
581	>	if (i % 2 == 0)
582	>	s.release();
583	>	else
584	>	s.release(3);
585		}
586	+	awaitTermination(t);
587	+	assertEquals(0, s.availablePermits());
588	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
589		}
590
591		/**
592	<	* a deserialized serialized semaphore has same number of permits
592	>	* fair locks are strictly FIFO
593		*/
594	<	public void testSerialization() {
595	<	Semaphore l = new Semaphore(3);
596	<	try {
597	<	l.acquire();
598	<	l.release();
599	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
600	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
601	<	out.writeObject(l);
602	<	out.close();
603	<
604	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
605	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
606	<	Semaphore r = (Semaphore) in.readObject();
607	<	assertEquals(3, r.availablePermits());
608	<	r.acquire();
609	<	r.release();
610	<	} catch(Exception e){
611	<	unexpectedException();
612	<	}
594	>	public void testFairLocksFifo() {
595	>	final PublicSemaphore s = new PublicSemaphore(1, true);
596	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
597	>	Thread t1 = newStartedThread(new CheckedRunnable() {
598	>	public void realRun() throws InterruptedException {
599	>	// Will block; permits are available, but not three
600	>	s.acquire(3);
601	>	}});
602	>
603	>	waitForQueuedThread(s, t1);
604	>
605	>	Thread t2 = newStartedThread(new CheckedRunnable() {
606	>	public void realRun() throws InterruptedException {
607	>	// Will fail, even though 1 permit is available
608	>	assertFalse(
609	>	s.tryAcquire(randomExpiredTimeout(), randomTimeUnit()));
610	>	assertFalse(
611	>	s.tryAcquire(1, randomExpiredTimeout(), randomTimeUnit()));
612	>
613	>	// untimed tryAcquire will barge and succeed
614	>	assertTrue(s.tryAcquire());
615	>	s.release(2);
616	>	assertTrue(s.tryAcquire(2));
617	>	s.release();
618	>
619	>	pleaseRelease.countDown();
620	>	// Will queue up behind t1, even though 1 permit is available
621	>	s.acquire();
622	>	}});
623	>
624	>	await(pleaseRelease);
625	>	waitForQueuedThread(s, t2);
626	>	s.release(2);
627	>	awaitTermination(t1);
628	>	assertTrue(t2.isAlive());
629	>	s.release();
630	>	awaitTermination(t2);
631	>	}
632	>
633	>	/**
634	>	* toString indicates current number of permits
635	>	*/
636	>	public void testToString()      { testToString(false); }
637	>	public void testToString_fair() { testToString(true); }
638	>	public void testToString(boolean fair) {
639	>	PublicSemaphore s = new PublicSemaphore(0, fair);
640	>	assertTrue(s.toString().contains("Permits = 0"));
641	>	s.release();
642	>	assertTrue(s.toString().contains("Permits = 1"));
643	>	s.release(2);
644	>	assertTrue(s.toString().contains("Permits = 3"));
645	>	s.reducePermits(5);
646	>	assertTrue(s.toString().contains("Permits = -2"));
647		}
648
649		}

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