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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.7 by dl, Sat Dec 27 19:26:43 2003 UTC vs.
Revision 1.40 by jsr166, Sun May 14 03:48:35 2017 UTC

#	Line 1 | Line 1
1		/*
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/licenses/publicdomain
5	<	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	<	* Pat Fisher, Mike Judd.
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.AssertionFailedError;
17	>	import junit.framework.Test;
18	>	import junit.framework.TestSuite;
19
20		public class SemaphoreTest extends JSR166TestCase {
21		public static void main(String[] args) {
22	<	junit.textui.TestRunner.run (suite());
22	>	main(suite(), args);
23		}
24		public static Test suite() {
25	<	return new TestSuite(SemaphoreTest.class);
25	>	return new TestSuite(SemaphoreTest.class);
26		}
27
28		/**
29		* Subclass to expose protected methods
30		*/
31		static class PublicSemaphore extends Semaphore {
32	<	PublicSemaphore(int p, boolean f) { super(p, f); }
33	<	public Collection<Thread> getQueuedThreads() {
34	<	return super.getQueuedThreads();
32	>	PublicSemaphore(int permits) { super(permits); }
33	>	PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
34	>	public Collection<Thread> getQueuedThreads() {
35	>	return super.getQueuedThreads();
36	>	}
37	>	public boolean hasQueuedThread(Thread t) {
38	>	return super.getQueuedThreads().contains(t);
39		}
40	<	public void reducePermits(int p) {
41	<	super.reducePermits(p);
40	>	public void reducePermits(int reduction) {
41	>	super.reducePermits(reduction);
42		}
43		}
44
45		/**
46		* A runnable calling acquire
47		*/
48	<	class InterruptibleLockRunnable implements Runnable {
48	>	class InterruptibleLockRunnable extends CheckedRunnable {
49		final Semaphore lock;
50	<	InterruptibleLockRunnable(Semaphore l) { lock = l; }
51	<	public void run() {
50	>	InterruptibleLockRunnable(Semaphore s) { lock = s; }
51	>	public void realRun() {
52		try {
53		lock.acquire();
54	<	} catch(InterruptedException success){}
54	>	}
55	>	catch (InterruptedException ignored) {}
56		}
57		}
58
48	–
59		/**
60	<	* A runnable calling acquire that expects to be
51	<	* interrupted
60	>	* A runnable calling acquire that expects to be interrupted
61		*/
62	<	class InterruptedLockRunnable implements Runnable {
62	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
63		final Semaphore lock;
64	<	InterruptedLockRunnable(Semaphore l) { lock = l; }
65	<	public void run() {
66	<	try {
67	<	lock.acquire();
68	<	threadShouldThrow();
69	<	} catch(InterruptedException success){}
64	>	InterruptedLockRunnable(Semaphore s) { lock = s; }
65	>	public void realRun() throws InterruptedException {
66	>	lock.acquire();
67	>	}
68	>	}
69	>
70	>	/**
71	>	* Spin-waits until s.hasQueuedThread(t) becomes true.
72	>	*/
73	>	void waitForQueuedThread(PublicSemaphore s, Thread t) {
74	>	long startTime = System.nanoTime();
75	>	while (!s.hasQueuedThread(t)) {
76	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
77	>	throw new AssertionFailedError("timed out");
78	>	Thread.yield();
79	>	}
80	>	assertTrue(s.hasQueuedThreads());
81	>	assertTrue(t.isAlive());
82	>	}
83	>
84	>	/**
85	>	* Spin-waits until s.hasQueuedThreads() becomes true.
86	>	*/
87	>	void waitForQueuedThreads(Semaphore s) {
88	>	long startTime = System.nanoTime();
89	>	while (!s.hasQueuedThreads()) {
90	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
91	>	throw new AssertionFailedError("timed out");
92	>	Thread.yield();
93	>	}
94	>	}
95	>
96	>	enum AcquireMethod {
97	>	acquire() {
98	>	void acquire(Semaphore s) throws InterruptedException {
99	>	s.acquire();
100	>	}
101	>	},
102	>	acquireN() {
103	>	void acquire(Semaphore s, int permits) throws InterruptedException {
104	>	s.acquire(permits);
105	>	}
106	>	},
107	>	acquireUninterruptibly() {
108	>	void acquire(Semaphore s) {
109	>	s.acquireUninterruptibly();
110	>	}
111	>	},
112	>	acquireUninterruptiblyN() {
113	>	void acquire(Semaphore s, int permits) {
114	>	s.acquireUninterruptibly(permits);
115	>	}
116	>	},
117	>	tryAcquire() {
118	>	void acquire(Semaphore s) {
119	>	assertTrue(s.tryAcquire());
120	>	}
121	>	},
122	>	tryAcquireN() {
123	>	void acquire(Semaphore s, int permits) {
124	>	assertTrue(s.tryAcquire(permits));
125	>	}
126	>	},
127	>	tryAcquireTimed() {
128	>	void acquire(Semaphore s) throws InterruptedException {
129	>	assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
130	>	}
131	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
132	>	},
133	>	tryAcquireTimedN {
134	>	void acquire(Semaphore s, int permits) throws InterruptedException {
135	>	assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
136	>	}
137	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
138	>	};
139	>
140	>	// Intentionally meta-circular
141	>
142	>	/** Acquires 1 permit. */
143	>	void acquire(Semaphore s) throws InterruptedException {
144	>	acquire(s, 1);
145	>	}
146	>	/** Acquires the given number of permits. */
147	>	void acquire(Semaphore s, int permits) throws InterruptedException {
148	>	for (int i = 0; i < permits; i++)
149	>	acquire(s);
150		}
151	+	Thread.State parkedState() { return Thread.State.WAITING; }
152		}
153
154		/**
155		* Zero, negative, and positive initial values are allowed in constructor
156		*/
157	<	public void testConstructor() {
158	<	Semaphore s0 = new Semaphore(0, false);
159	<	assertEquals(0, s0.availablePermits());
160	<	assertFalse(s0.isFair());
161	<	Semaphore s1 = new Semaphore(-1, false);
162	<	assertEquals(-1, s1.availablePermits());
163	<	Semaphore s2 = new Semaphore(-1, false);
164	<	assertEquals(-1, s2.availablePermits());
157	>	public void testConstructor()      { testConstructor(false); }
158	>	public void testConstructor_fair() { testConstructor(true); }
159	>	public void testConstructor(boolean fair) {
160	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
161	>	Semaphore s = new Semaphore(permits, fair);
162	>	assertEquals(permits, s.availablePermits());
163	>	assertEquals(fair, s.isFair());
164	>	}
165		}
166
167		/**
168	<	* tryAcquire succeeds when sufficent permits, else fails
168	>	* Constructor without fairness argument behaves as nonfair
169		*/
170	<	public void testTryAcquireInSameThread() {
171	<	Semaphore s = new Semaphore(2, false);
170	>	public void testConstructorDefaultsToNonFair() {
171	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
172	>	Semaphore s = new Semaphore(permits);
173	>	assertEquals(permits, s.availablePermits());
174	>	assertFalse(s.isFair());
175	>	}
176	>	}
177	>
178	>	/**
179	>	* tryAcquire succeeds when sufficient permits, else fails
180	>	*/
181	>	public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
182	>	public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
183	>	public void testTryAcquireInSameThread(boolean fair) {
184	>	Semaphore s = new Semaphore(2, fair);
185		assertEquals(2, s.availablePermits());
186		assertTrue(s.tryAcquire());
187		assertTrue(s.tryAcquire());
188		assertEquals(0, s.availablePermits());
189		assertFalse(s.tryAcquire());
190	+	assertFalse(s.tryAcquire());
191	+	assertEquals(0, s.availablePermits());
192		}
193
194		/**
195	<	* Acquire and release of semaphore succeed if initially available
195	>	* timed tryAcquire times out
196		*/
197	<	public void testAcquireReleaseInSameThread() {
198	<	Semaphore s = new Semaphore(1, false);
199	<	try {
200	<	s.acquire();
201	<	s.release();
202	<	s.acquire();
203	<	s.release();
204	<	s.acquire();
205	<	s.release();
206	<	s.acquire();
207	<	s.release();
208	<	s.acquire();
209	<	s.release();
210	<	assertEquals(1, s.availablePermits());
211	<	} catch( InterruptedException e){
212	<	unexpectedException();
197	>	public void testTryAcquire_timeout() {
198	>	final boolean fair = ThreadLocalRandom.current().nextBoolean();
199	>	final Semaphore s = new Semaphore(0, fair);
200	>	final long startTime = System.nanoTime();
201	>	try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
202	>	catch (InterruptedException e) { threadUnexpectedException(e); }
203	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
204	>	}
205	>
206	>	/**
207	>	* timed tryAcquire(N) times out
208	>	*/
209	>	public void testTryAcquireN_timeout() {
210	>	final boolean fair = ThreadLocalRandom.current().nextBoolean();
211	>	final Semaphore s = new Semaphore(2, fair);
212	>	final long startTime = System.nanoTime();
213	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
214	>	catch (InterruptedException e) { threadUnexpectedException(e); }
215	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
216	>	}
217	>
218	>	/**
219	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
220	>	* are interruptible
221	>	*/
222	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
223	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
224	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
225	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
226	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
227	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
228	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
229	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
230	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
231	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
232	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
233	>	= new java.util.concurrent.CyclicBarrier(2);
234	>	Thread t = newStartedThread(new CheckedRunnable() {
235	>	public void realRun() {
236	>	// Interrupt before acquire
237	>	Thread.currentThread().interrupt();
238	>	try {
239	>	acquirer.acquire(s);
240	>	shouldThrow();
241	>	} catch (InterruptedException success) {}
242	>	assertFalse(Thread.interrupted());
243	>
244	>	// Interrupt before acquire(N)
245	>	Thread.currentThread().interrupt();
246	>	try {
247	>	acquirer.acquire(s, 3);
248	>	shouldThrow();
249	>	} catch (InterruptedException success) {}
250	>	assertFalse(Thread.interrupted());
251	>
252	>	// Interrupt during acquire
253	>	await(pleaseInterrupt);
254	>	try {
255	>	acquirer.acquire(s);
256	>	shouldThrow();
257	>	} catch (InterruptedException success) {}
258	>	assertFalse(Thread.interrupted());
259	>
260	>	// Interrupt during acquire(N)
261	>	await(pleaseInterrupt);
262	>	try {
263	>	acquirer.acquire(s, 3);
264	>	shouldThrow();
265	>	} catch (InterruptedException success) {}
266	>	assertFalse(Thread.interrupted());
267	>	}});
268	>
269	>	for (int n = 2; n-->0; ) {
270	>	await(pleaseInterrupt);
271	>	assertThreadBlocks(t, acquirer.parkedState());
272	>	t.interrupt();
273		}
274	+
275	+	awaitTermination(t);
276		}
277
278		/**
279	<	* Uninterruptible acquire and release of semaphore succeed if
280	<	* initially available
279	>	* acquireUninterruptibly(), acquireUninterruptibly(N) are
280	>	* uninterruptible
281		*/
282	<	public void testAcquireUninterruptiblyReleaseInSameThread() {
283	<	Semaphore s = new Semaphore(1, false);
284	<	try {
285	<	s.acquireUninterruptibly();
286	<	s.release();
287	<	s.acquireUninterruptibly();
288	<	s.release();
289	<	s.acquireUninterruptibly();
290	<	s.release();
291	<	s.acquireUninterruptibly();
292	<	s.release();
293	<	s.acquireUninterruptibly();
294	<	s.release();
295	<	assertEquals(1, s.availablePermits());
296	<	} finally {
297	<	}
282	>	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
283	>	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
284	>	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
285	>	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
286	>	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
287	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
288	>	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
289	>
290	>	Thread t1 = newStartedThread(new CheckedRunnable() {
291	>	public void realRun() throws InterruptedException {
292	>	// Interrupt before acquire
293	>	pleaseInterrupt.release();
294	>	Thread.currentThread().interrupt();
295	>	acquirer.acquire(s);
296	>	assertTrue(Thread.interrupted());
297	>	}});
298	>
299	>	Thread t2 = newStartedThread(new CheckedRunnable() {
300	>	public void realRun() throws InterruptedException {
301	>	// Interrupt during acquire
302	>	pleaseInterrupt.release();
303	>	acquirer.acquire(s);
304	>	assertTrue(Thread.interrupted());
305	>	}});
306	>
307	>	await(pleaseInterrupt);
308	>	waitForQueuedThread(s, t1);
309	>	waitForQueuedThread(s, t2);
310	>	t2.interrupt();
311	>
312	>	assertThreadBlocks(t1, Thread.State.WAITING);
313	>	assertThreadBlocks(t2, Thread.State.WAITING);
314	>
315	>	s.release(2);
316	>
317	>	awaitTermination(t1);
318	>	awaitTermination(t2);
319	>	}
320	>
321	>	/**
322	>	* hasQueuedThreads reports whether there are waiting threads
323	>	*/
324	>	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
325	>	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
326	>	public void testHasQueuedThreads(boolean fair) {
327	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
328	>	assertFalse(lock.hasQueuedThreads());
329	>	lock.acquireUninterruptibly();
330	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
331	>	waitForQueuedThread(lock, t1);
332	>	assertTrue(lock.hasQueuedThreads());
333	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
334	>	waitForQueuedThread(lock, t2);
335	>	assertTrue(lock.hasQueuedThreads());
336	>	t1.interrupt();
337	>	awaitTermination(t1);
338	>	assertTrue(lock.hasQueuedThreads());
339	>	lock.release();
340	>	awaitTermination(t2);
341	>	assertFalse(lock.hasQueuedThreads());
342		}
343
344		/**
345	<	* Timed Acquire and release of semaphore succeed if
135	<	* initially available
345	>	* getQueueLength reports number of waiting threads
346		*/
347	<	public void testTimedAcquireReleaseInSameThread() {
348	<	Semaphore s = new Semaphore(1, false);
349	<	try {
350	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
351	<	s.release();
352	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
353	<	s.release();
354	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
355	<	s.release();
356	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
357	<	s.release();
358	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
359	<	s.release();
360	<	assertEquals(1, s.availablePermits());
361	<	} catch( InterruptedException e){
362	<	unexpectedException();
363	<	}
347	>	public void testGetQueueLength()      { testGetQueueLength(false); }
348	>	public void testGetQueueLength_fair() { testGetQueueLength(true); }
349	>	public void testGetQueueLength(boolean fair) {
350	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
351	>	assertEquals(0, lock.getQueueLength());
352	>	lock.acquireUninterruptibly();
353	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
354	>	waitForQueuedThread(lock, t1);
355	>	assertEquals(1, lock.getQueueLength());
356	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
357	>	waitForQueuedThread(lock, t2);
358	>	assertEquals(2, lock.getQueueLength());
359	>	t1.interrupt();
360	>	awaitTermination(t1);
361	>	assertEquals(1, lock.getQueueLength());
362	>	lock.release();
363	>	awaitTermination(t2);
364	>	assertEquals(0, lock.getQueueLength());
365		}
366
367		/**
368	<	* A release in one thread enables an acquire in another thread
368	>	* getQueuedThreads includes waiting threads
369		*/
370	<	public void testAcquireReleaseInDifferentThreads() {
371	<	final Semaphore s = new Semaphore(0, false);
372	<	Thread t = new Thread(new Runnable() {
373	<	public void run() {
374	<	try {
375	<	s.acquire();
376	<	s.release();
377	<	s.release();
378	<	s.acquire();
379	<	} catch(InterruptedException ie){
380	<	threadUnexpectedException();
381	<	}
382	<	}
383	<	});
384	<	try {
385	<	t.start();
386	<	Thread.sleep(SHORT_DELAY_MS);
387	<	s.release();
388	<	s.release();
389	<	s.acquire();
390	<	s.acquire();
180	<	s.release();
181	<	t.join();
182	<	} catch( InterruptedException e){
183	<	unexpectedException();
184	<	}
370	>	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
371	>	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
372	>	public void testGetQueuedThreads(boolean fair) {
373	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
374	>	assertTrue(lock.getQueuedThreads().isEmpty());
375	>	lock.acquireUninterruptibly();
376	>	assertTrue(lock.getQueuedThreads().isEmpty());
377	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
378	>	waitForQueuedThread(lock, t1);
379	>	assertTrue(lock.getQueuedThreads().contains(t1));
380	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
381	>	waitForQueuedThread(lock, t2);
382	>	assertTrue(lock.getQueuedThreads().contains(t1));
383	>	assertTrue(lock.getQueuedThreads().contains(t2));
384	>	t1.interrupt();
385	>	awaitTermination(t1);
386	>	assertFalse(lock.getQueuedThreads().contains(t1));
387	>	assertTrue(lock.getQueuedThreads().contains(t2));
388	>	lock.release();
389	>	awaitTermination(t2);
390	>	assertTrue(lock.getQueuedThreads().isEmpty());
391		}
392
393		/**
394	<	* A release in one thread enables an uninterruptible acquire in another thread
395	<	*/
396	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
397	<	final Semaphore s = new Semaphore(0, false);
398	<	Thread t = new Thread(new Runnable() {
399	<	public void run() {
400	<	s.acquireUninterruptibly();
401	<	s.release();
402	<	s.release();
403	<	s.acquireUninterruptibly();
404	<	}
405	<	});
406	<	try {
201	<	t.start();
202	<	Thread.sleep(SHORT_DELAY_MS);
203	<	s.release();
204	<	s.release();
205	<	s.acquireUninterruptibly();
206	<	s.acquireUninterruptibly();
207	<	s.release();
208	<	t.join();
209	<	} catch( InterruptedException e){
210	<	unexpectedException();
211	<	}
394	>	* drainPermits reports and removes given number of permits
395	>	*/
396	>	public void testDrainPermits()      { testDrainPermits(false); }
397	>	public void testDrainPermits_fair() { testDrainPermits(true); }
398	>	public void testDrainPermits(boolean fair) {
399	>	Semaphore s = new Semaphore(0, fair);
400	>	assertEquals(0, s.availablePermits());
401	>	assertEquals(0, s.drainPermits());
402	>	s.release(10);
403	>	assertEquals(10, s.availablePermits());
404	>	assertEquals(10, s.drainPermits());
405	>	assertEquals(0, s.availablePermits());
406	>	assertEquals(0, s.drainPermits());
407		}
408
214	–
409		/**
410	<	*  A release in one thread enables a timed acquire in another thread
410	>	* release(-N) throws IllegalArgumentException
411		*/
412	<	public void testTimedAcquireReleaseInDifferentThreads() {
413	<	final Semaphore s = new Semaphore(1, false);
414	<	Thread t = new Thread(new Runnable() {
415	<	public void run() {
222	<	try {
223	<	s.release();
224	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
225	<	s.release();
226	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
227	<
228	<	} catch(InterruptedException ie){
229	<	threadUnexpectedException();
230	<	}
231	<	}
232	<	});
412	>	public void testReleaseIAE()      { testReleaseIAE(false); }
413	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
414	>	public void testReleaseIAE(boolean fair) {
415	>	Semaphore s = new Semaphore(10, fair);
416		try {
417	<	t.start();
418	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
419	<	s.release();
237	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
238	<	s.release();
239	<	s.release();
240	<	t.join();
241	<	} catch( InterruptedException e){
242	<	unexpectedException();
243	<	}
244	<	}
245	<
246	<	/**
247	<	* A waiting acquire blocks interruptibly
248	<	*/
249	<	public void testAcquire_InterruptedException() {
250	<	final Semaphore s = new Semaphore(0, false);
251	<	Thread t = new Thread(new Runnable() {
252	<	public void run() {
253	<	try {
254	<	s.acquire();
255	<	threadShouldThrow();
256	<	} catch(InterruptedException success){}
257	<	}
258	<	});
259	<	t.start();
260	<	try {
261	<	Thread.sleep(SHORT_DELAY_MS);
262	<	t.interrupt();
263	<	t.join();
264	<	} catch(InterruptedException e){
265	<	unexpectedException();
266	<	}
267	<	}
268	<
269	<	/**
270	<	*  A waiting timed acquire blocks interruptibly
271	<	*/
272	<	public void testTryAcquire_InterruptedException() {
273	<	final Semaphore s = new Semaphore(0, false);
274	<	Thread t = new Thread(new Runnable() {
275	<	public void run() {
276	<	try {
277	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
278	<	threadShouldThrow();
279	<	} catch(InterruptedException success){
280	<	}
281	<	}
282	<	});
283	<	t.start();
284	<	try {
285	<	Thread.sleep(SHORT_DELAY_MS);
286	<	t.interrupt();
287	<	t.join();
288	<	} catch(InterruptedException e){
289	<	unexpectedException();
290	<	}
417	>	s.release(-1);
418	>	shouldThrow();
419	>	} catch (IllegalArgumentException success) {}
420		}
421
422		/**
423	<	* getQueueLength reports number of waiting threads
295	<	*/
296	<	public void testGetQueueLength() {
297	<	final Semaphore lock = new Semaphore(1, false);
298	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
299	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
300	<	try {
301	<	assertEquals(0, lock.getQueueLength());
302	<	lock.acquireUninterruptibly();
303	<	t1.start();
304	<	Thread.sleep(SHORT_DELAY_MS);
305	<	assertEquals(1, lock.getQueueLength());
306	<	t2.start();
307	<	Thread.sleep(SHORT_DELAY_MS);
308	<	assertEquals(2, lock.getQueueLength());
309	<	t1.interrupt();
310	<	Thread.sleep(SHORT_DELAY_MS);
311	<	assertEquals(1, lock.getQueueLength());
312	<	lock.release();
313	<	Thread.sleep(SHORT_DELAY_MS);
314	<	assertEquals(0, lock.getQueueLength());
315	<	t1.join();
316	<	t2.join();
317	<	} catch(Exception e){
318	<	unexpectedException();
319	<	}
320	<	}
321	<
322	<	/**
323	<	* getQueuedThreads includes waiting threads
423	>	* reducePermits(-N) throws IllegalArgumentException
424		*/
425	<	public void testGetQueuedThreads() {
426	<	final PublicSemaphore lock = new PublicSemaphore(1, false);
427	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
428	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
425	>	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
426	>	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
427	>	public void testReducePermitsIAE(boolean fair) {
428	>	PublicSemaphore s = new PublicSemaphore(10, fair);
429		try {
430	<	assertTrue(lock.getQueuedThreads().isEmpty());
431	<	lock.acquireUninterruptibly();
432	<	assertTrue(lock.getQueuedThreads().isEmpty());
433	<	t1.start();
334	<	Thread.sleep(SHORT_DELAY_MS);
335	<	assertTrue(lock.getQueuedThreads().contains(t1));
336	<	t2.start();
337	<	Thread.sleep(SHORT_DELAY_MS);
338	<	assertTrue(lock.getQueuedThreads().contains(t1));
339	<	assertTrue(lock.getQueuedThreads().contains(t2));
340	<	t1.interrupt();
341	<	Thread.sleep(SHORT_DELAY_MS);
342	<	assertFalse(lock.getQueuedThreads().contains(t1));
343	<	assertTrue(lock.getQueuedThreads().contains(t2));
344	<	lock.release();
345	<	Thread.sleep(SHORT_DELAY_MS);
346	<	assertTrue(lock.getQueuedThreads().isEmpty());
347	<	t1.join();
348	<	t2.join();
349	<	} catch(Exception e){
350	<	unexpectedException();
351	<	}
352	<	}
353	<
430	>	s.reducePermits(-1);
431	>	shouldThrow();
432	>	} catch (IllegalArgumentException success) {}
433	>	}
434
435		/**
436		* reducePermits reduces number of permits
437		*/
438	<	public void testReducePermits() {
439	<	PublicSemaphore s = new PublicSemaphore(10, false);
438	>	public void testReducePermits()      { testReducePermits(false); }
439	>	public void testReducePermits_fair() { testReducePermits(true); }
440	>	public void testReducePermits(boolean fair) {
441	>	PublicSemaphore s = new PublicSemaphore(10, fair);
442	>	assertEquals(10, s.availablePermits());
443	>	s.reducePermits(0);
444		assertEquals(10, s.availablePermits());
445		s.reducePermits(1);
446		assertEquals(9, s.availablePermits());
447		s.reducePermits(10);
448		assertEquals(-1, s.availablePermits());
449	+	s.reducePermits(10);
450	+	assertEquals(-11, s.availablePermits());
451	+	s.reducePermits(0);
452	+	assertEquals(-11, s.availablePermits());
453		}
454
455		/**
456	<	* a deserialized serialized semaphore has same number of permits
457	<	*/
370	<	public void testSerialization() {
371	<	Semaphore l = new Semaphore(3, false);
372	<	try {
373	<	l.acquire();
374	<	l.release();
375	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
376	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
377	<	out.writeObject(l);
378	<	out.close();
379	<
380	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
381	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
382	<	Semaphore r = (Semaphore) in.readObject();
383	<	assertEquals(3, r.availablePermits());
384	<	assertFalse(r.isFair());
385	<	r.acquire();
386	<	r.release();
387	<	} catch(Exception e){
388	<	unexpectedException();
389	<	}
390	<	}
391	<
392	<
393	<	/**
394	<	* Zero, negative, and positive initial values are allowed in constructor
395	<	*/
396	<	public void testConstructor_fair() {
397	<	Semaphore s0 = new Semaphore(0, true);
398	<	assertEquals(0, s0.availablePermits());
399	<	assertTrue(s0.isFair());
400	<	Semaphore s1 = new Semaphore(-1, true);
401	<	assertEquals(-1, s1.availablePermits());
402	<	Semaphore s2 = new Semaphore(-1, true);
403	<	assertEquals(-1, s2.availablePermits());
404	<	}
405	<
406	<	/**
407	<	* tryAcquire succeeds when sufficent permits, else fails
408	<	*/
409	<	public void testTryAcquireInSameThread_fair() {
410	<	Semaphore s = new Semaphore(2, true);
411	<	assertEquals(2, s.availablePermits());
412	<	assertTrue(s.tryAcquire());
413	<	assertTrue(s.tryAcquire());
414	<	assertEquals(0, s.availablePermits());
415	<	assertFalse(s.tryAcquire());
416	<	}
417	<
418	<	/**
419	<	* tryAcquire(n) succeeds when sufficent permits, else fails
420	<	*/
421	<	public void testTryAcquireNInSameThread_fair() {
422	<	Semaphore s = new Semaphore(2, true);
423	<	assertEquals(2, s.availablePermits());
424	<	assertTrue(s.tryAcquire(2));
425	<	assertEquals(0, s.availablePermits());
426	<	assertFalse(s.tryAcquire());
427	<	}
428	<
429	<	/**
430	<	* Acquire and release of semaphore succeed if initially available
456	>	* a reserialized semaphore has same number of permits and
457	>	* fairness, but no queued threads
458		*/
459	<	public void testAcquireReleaseInSameThread_fair() {
460	<	Semaphore s = new Semaphore(1, true);
459	>	public void testSerialization()      { testSerialization(false); }
460	>	public void testSerialization_fair() { testSerialization(true); }
461	>	public void testSerialization(boolean fair) {
462		try {
463	+	Semaphore s = new Semaphore(3, fair);
464		s.acquire();
436	–	s.release();
437	–	s.acquire();
438	–	s.release();
439	–	s.acquire();
440	–	s.release();
441	–	s.acquire();
442	–	s.release();
465		s.acquire();
466		s.release();
445	–	assertEquals(1, s.availablePermits());
446	–	} catch( InterruptedException e){
447	–	unexpectedException();
448	–	}
449	–	}
450	–
451	–	/**
452	–	* Acquire(n) and release(n) of semaphore succeed if initially available
453	–	*/
454	–	public void testAcquireReleaseNInSameThread_fair() {
455	–	Semaphore s = new Semaphore(1, true);
456	–	try {
457	–	s.release(1);
458	–	s.acquire(1);
459	–	s.release(2);
460	–	s.acquire(2);
461	–	s.release(3);
462	–	s.acquire(3);
463	–	s.release(4);
464	–	s.acquire(4);
465	–	s.release(5);
466	–	s.acquire(5);
467	–	assertEquals(1, s.availablePermits());
468	–	} catch( InterruptedException e){
469	–	unexpectedException();
470	–	}
471	–	}
467
468	<	/**
469	<	* Acquire(n) and release(n) of semaphore succeed if initially available
470	<	*/
471	<	public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
472	<	Semaphore s = new Semaphore(1, true);
473	<	try {
474	<	s.release(1);
475	<	s.acquireUninterruptibly(1);
476	<	s.release(2);
477	<	s.acquireUninterruptibly(2);
478	<	s.release(3);
479	<	s.acquireUninterruptibly(3);
480	<	s.release(4);
481	<	s.acquireUninterruptibly(4);
482	<	s.release(5);
483	<	s.acquireUninterruptibly(5);
484	<	assertEquals(1, s.availablePermits());
485	<	} finally {
468	>	Semaphore clone = serialClone(s);
469	>	assertEquals(fair, s.isFair());
470	>	assertEquals(fair, clone.isFair());
471	>	assertEquals(2, s.availablePermits());
472	>	assertEquals(2, clone.availablePermits());
473	>	clone.acquire();
474	>	clone.acquire();
475	>	clone.release();
476	>	assertEquals(2, s.availablePermits());
477	>	assertEquals(1, clone.availablePermits());
478	>	assertFalse(s.hasQueuedThreads());
479	>	assertFalse(clone.hasQueuedThreads());
480	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
481	>
482	>	{
483	>	PublicSemaphore s = new PublicSemaphore(0, fair);
484	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
485	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
486	>	waitForQueuedThread(s, t);  // ... we use this instead
487	>	PublicSemaphore clone = serialClone(s);
488	>	assertEquals(fair, s.isFair());
489	>	assertEquals(fair, clone.isFair());
490	>	assertEquals(0, s.availablePermits());
491	>	assertEquals(0, clone.availablePermits());
492	>	assertTrue(s.hasQueuedThreads());
493	>	assertFalse(clone.hasQueuedThreads());
494	>	s.release();
495	>	awaitTermination(t);
496	>	assertFalse(s.hasQueuedThreads());
497	>	assertFalse(clone.hasQueuedThreads());
498		}
499		}
500
501		/**
502	<	* release(n) in one thread enables timed acquire(n) in another thread
503	<	*/
504	<	public void testTimedAcquireReleaseNInSameThread_fair() {
505	<	Semaphore s = new Semaphore(1, true);
506	<	try {
507	<	s.release(1);
508	<	assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
509	<	s.release(2);
510	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
511	<	s.release(3);
512	<	assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
513	<	s.release(4);
514	<	assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
515	<	s.release(5);
509	<	assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
510	<	assertEquals(1, s.availablePermits());
511	<	} catch( InterruptedException e){
512	<	unexpectedException();
513	<	}
502	>	* tryAcquire(n) succeeds when sufficient permits, else fails
503	>	*/
504	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
505	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
506	>	public void testTryAcquireNInSameThread(boolean fair) {
507	>	Semaphore s = new Semaphore(2, fair);
508	>	assertEquals(2, s.availablePermits());
509	>	assertFalse(s.tryAcquire(3));
510	>	assertEquals(2, s.availablePermits());
511	>	assertTrue(s.tryAcquire(2));
512	>	assertEquals(0, s.availablePermits());
513	>	assertFalse(s.tryAcquire(1));
514	>	assertFalse(s.tryAcquire(2));
515	>	assertEquals(0, s.availablePermits());
516		}
517
518		/**
519	<	* release in one thread enables timed acquire in another thread
519	>	* acquire succeeds if permits available
520		*/
521	<	public void testTimedAcquireReleaseInSameThread_fair() {
522	<	Semaphore s = new Semaphore(1, true);
523	<	try {
524	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
525	<	s.release();
526	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
527	<	s.release();
528	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
529	<	s.release();
530	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
531	<	s.release();
532	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
533	<	s.release();
521	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
522	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
523	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
524	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
525	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
526	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
527	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
528	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
529	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
530	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
531	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
532	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
533	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
534	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
535	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
536	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
537	>	public void testReleaseAcquireSameThread(boolean fair,
538	>	final AcquireMethod acquirer) {
539	>	Semaphore s = new Semaphore(1, fair);
540	>	for (int i = 1; i < 6; i++) {
541	>	s.release(i);
542	>	assertEquals(1 + i, s.availablePermits());
543	>	try {
544	>	acquirer.acquire(s, i);
545	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
546		assertEquals(1, s.availablePermits());
533	–	} catch( InterruptedException e){
534	–	unexpectedException();
547		}
548		}
549
550		/**
551	<	* A release in one thread enables an acquire in another thread
551	>	* release in one thread enables acquire in another thread
552		*/
553	<	public void testAcquireReleaseInDifferentThreads_fair() {
554	<	final Semaphore s = new Semaphore(0, true);
555	<	Thread t = new Thread(new Runnable() {
556	<	public void run() {
557	<	try {
558	<	s.acquire();
559	<	s.acquire();
560	<	s.acquire();
561	<	s.acquire();
562	<	} catch(InterruptedException ie){
563	<	threadUnexpectedException();
564	<	}
565	<	}
566	<	});
567	<	try {
568	<	t.start();
569	<	Thread.sleep(SHORT_DELAY_MS);
570	<	s.release();
571	<	s.release();
572	<	s.release();
573	<	s.release();
574	<	s.release();
575	<	s.release();
576	<	t.join();
577	<	assertEquals(2, s.availablePermits());
578	<	} catch( InterruptedException e){
579	<	unexpectedException();
553	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
554	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
555	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
556	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
557	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
558	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
559	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
560	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
561	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
562	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
563	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
564	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
565	>	public void testReleaseAcquireDifferentThreads(boolean fair,
566	>	final AcquireMethod acquirer) {
567	>	final Semaphore s = new Semaphore(0, fair);
568	>	final int rounds = 4;
569	>	long startTime = System.nanoTime();
570	>	Thread t = newStartedThread(new CheckedRunnable() {
571	>	public void realRun() throws InterruptedException {
572	>	for (int i = 0; i < rounds; i++) {
573	>	assertFalse(s.hasQueuedThreads());
574	>	if (i % 2 == 0)
575	>	acquirer.acquire(s);
576	>	else
577	>	acquirer.acquire(s, 3);
578	>	}}});
579	>
580	>	for (int i = 0; i < rounds; i++) {
581	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
582	>	Thread.yield();
583	>	assertTrue(t.isAlive());
584	>	if (i % 2 == 0)
585	>	s.release();
586	>	else
587	>	s.release(3);
588		}
589	+	awaitTermination(t);
590	+	assertEquals(0, s.availablePermits());
591	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
592		}
593
594		/**
595	<	* release(n) in one thread enables acquire(n) in another thread
595	>	* fair locks are strictly FIFO
596		*/
597	<	public void testAcquireReleaseNInDifferentThreads_fair() {
598	<	final Semaphore s = new Semaphore(0, true);
599	<	Thread t = new Thread(new Runnable() {
600	<	public void run() {
601	<	try {
602	<	s.acquire(2);
603	<	s.acquire(2);
604	<	s.release(4);
605	<	} catch(InterruptedException ie){
606	<	threadUnexpectedException();
607	<	}
608	<	}
609	<	});
610	<	try {
611	<	t.start();
612	<	Thread.sleep(SHORT_DELAY_MS);
613	<	s.release(6);
614	<	s.acquire(2);
615	<	s.acquire(2);
616	<	s.release(2);
617	<	t.join();
618	<	} catch( InterruptedException e){
619	<	unexpectedException();
620	<	}
621	<	}
622	<
623	<
624	<
625	<	/**
626	<	* release in one thread enables timed acquire in another thread
627	<	*/
628	<	public void testTimedAcquireReleaseInDifferentThreads_fair() {
629	<	final Semaphore s = new Semaphore(1, true);
630	<	Thread t = new Thread(new Runnable() {
631	<	public void run() {
609	<	try {
610	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
611	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
612	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
613	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
614	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
615	<
616	<	} catch(InterruptedException ie){
617	<	threadUnexpectedException();
618	<	}
619	<	}
620	<	});
621	<	t.start();
622	<	try {
623	<	s.release();
624	<	s.release();
625	<	s.release();
626	<	s.release();
627	<	s.release();
628	<	t.join();
629	<	} catch( InterruptedException e){
630	<	unexpectedException();
631	<	}
632	<	}
633	<
634	<	/**
635	<	* release(n) in one thread enables timed acquire(n) in another thread
636	<	*/
637	<	public void testTimedAcquireReleaseNInDifferentThreads_fair() {
638	<	final Semaphore s = new Semaphore(2, true);
639	<	Thread t = new Thread(new Runnable() {
640	<	public void run() {
641	<	try {
642	<	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
643	<	s.release(2);
644	<	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
645	<	s.release(2);
646	<	} catch(InterruptedException ie){
647	<	threadUnexpectedException();
648	<	}
649	<	}
650	<	});
651	<	t.start();
652	<	try {
653	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
654	<	s.release(2);
655	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
656	<	s.release(2);
657	<	t.join();
658	<	} catch( InterruptedException e){
659	<	unexpectedException();
660	<	}
661	<	}
662	<
663	<	/**
664	<	* A waiting acquire blocks interruptibly
665	<	*/
666	<	public void testAcquire_InterruptedException_fair() {
667	<	final Semaphore s = new Semaphore(0, true);
668	<	Thread t = new Thread(new Runnable() {
669	<	public void run() {
670	<	try {
671	<	s.acquire();
672	<	threadShouldThrow();
673	<	} catch(InterruptedException success){}
674	<	}
675	<	});
676	<	t.start();
677	<	try {
678	<	Thread.sleep(SHORT_DELAY_MS);
679	<	t.interrupt();
680	<	t.join();
681	<	} catch(InterruptedException e){
682	<	unexpectedException();
683	<	}
684	<	}
685	<
686	<	/**
687	<	* A waiting acquire(n) blocks interruptibly
688	<	*/
689	<	public void testAcquireN_InterruptedException_fair() {
690	<	final Semaphore s = new Semaphore(2, true);
691	<	Thread t = new Thread(new Runnable() {
692	<	public void run() {
693	<	try {
694	<	s.acquire(3);
695	<	threadShouldThrow();
696	<	} catch(InterruptedException success){}
697	<	}
698	<	});
699	<	t.start();
700	<	try {
701	<	Thread.sleep(SHORT_DELAY_MS);
702	<	t.interrupt();
703	<	t.join();
704	<	} catch(InterruptedException e){
705	<	unexpectedException();
706	<	}
707	<	}
708	<
709	<	/**
710	<	*  A waiting tryAcquire blocks interruptibly
711	<	*/
712	<	public void testTryAcquire_InterruptedException_fair() {
713	<	final Semaphore s = new Semaphore(0, true);
714	<	Thread t = new Thread(new Runnable() {
715	<	public void run() {
716	<	try {
717	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
718	<	threadShouldThrow();
719	<	} catch(InterruptedException success){
720	<	}
721	<	}
722	<	});
723	<	t.start();
724	<	try {
725	<	Thread.sleep(SHORT_DELAY_MS);
726	<	t.interrupt();
727	<	t.join();
728	<	} catch(InterruptedException e){
729	<	unexpectedException();
730	<	}
731	<	}
732	<
733	<	/**
734	<	*  A waiting tryAcquire(n) blocks interruptibly
735	<	*/
736	<	public void testTryAcquireN_InterruptedException_fair() {
737	<	final Semaphore s = new Semaphore(1, true);
738	<	Thread t = new Thread(new Runnable() {
739	<	public void run() {
740	<	try {
741	<	s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
742	<	threadShouldThrow();
743	<	} catch(InterruptedException success){
744	<	}
745	<	}
746	<	});
747	<	t.start();
748	<	try {
749	<	Thread.sleep(SHORT_DELAY_MS);
750	<	t.interrupt();
751	<	t.join();
752	<	} catch(InterruptedException e){
753	<	unexpectedException();
754	<	}
597	>	public void testFairLocksFifo() {
598	>	final PublicSemaphore s = new PublicSemaphore(1, true);
599	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
600	>	Thread t1 = newStartedThread(new CheckedRunnable() {
601	>	public void realRun() throws InterruptedException {
602	>	// Will block; permits are available, but not three
603	>	s.acquire(3);
604	>	}});
605	>
606	>	waitForQueuedThread(s, t1);
607	>
608	>	Thread t2 = newStartedThread(new CheckedRunnable() {
609	>	public void realRun() throws InterruptedException {
610	>	// Will fail, even though 1 permit is available
611	>	assertFalse(s.tryAcquire(0L, MILLISECONDS));
612	>	assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
613	>
614	>	// untimed tryAcquire will barge and succeed
615	>	assertTrue(s.tryAcquire());
616	>	s.release(2);
617	>	assertTrue(s.tryAcquire(2));
618	>	s.release();
619	>
620	>	pleaseRelease.countDown();
621	>	// Will queue up behind t1, even though 1 permit is available
622	>	s.acquire();
623	>	}});
624	>
625	>	await(pleaseRelease);
626	>	waitForQueuedThread(s, t2);
627	>	s.release(2);
628	>	awaitTermination(t1);
629	>	assertTrue(t2.isAlive());
630	>	s.release();
631	>	awaitTermination(t2);
632		}
633
634		/**
635	<	* getQueueLength reports number of waiting threads
636	<	*/
637	<	public void testGetQueueLength_fair() {
638	<	final Semaphore lock = new Semaphore(1, true);
639	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
640	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
641	<	try {
642	<	assertEquals(0, lock.getQueueLength());
643	<	lock.acquireUninterruptibly();
644	<	t1.start();
645	<	Thread.sleep(SHORT_DELAY_MS);
646	<	assertEquals(1, lock.getQueueLength());
647	<	t2.start();
771	<	Thread.sleep(SHORT_DELAY_MS);
772	<	assertEquals(2, lock.getQueueLength());
773	<	t1.interrupt();
774	<	Thread.sleep(SHORT_DELAY_MS);
775	<	assertEquals(1, lock.getQueueLength());
776	<	lock.release();
777	<	Thread.sleep(SHORT_DELAY_MS);
778	<	assertEquals(0, lock.getQueueLength());
779	<	t1.join();
780	<	t2.join();
781	<	} catch(Exception e){
782	<	unexpectedException();
783	<	}
784	<	}
785	<
786	<
787	<	/**
788	<	* a deserialized serialized semaphore has same number of permits
789	<	*/
790	<	public void testSerialization_fair() {
791	<	Semaphore l = new Semaphore(3, true);
792	<
793	<	try {
794	<	l.acquire();
795	<	l.release();
796	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
797	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
798	<	out.writeObject(l);
799	<	out.close();
800	<
801	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
802	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
803	<	Semaphore r = (Semaphore) in.readObject();
804	<	assertEquals(3, r.availablePermits());
805	<	assertTrue(r.isFair());
806	<	r.acquire();
807	<	r.release();
808	<	} catch(Exception e){
809	<	unexpectedException();
810	<	}
635	>	* toString indicates current number of permits
636	>	*/
637	>	public void testToString()      { testToString(false); }
638	>	public void testToString_fair() { testToString(true); }
639	>	public void testToString(boolean fair) {
640	>	PublicSemaphore s = new PublicSemaphore(0, fair);
641	>	assertTrue(s.toString().contains("Permits = 0"));
642	>	s.release();
643	>	assertTrue(s.toString().contains("Permits = 1"));
644	>	s.release(2);
645	>	assertTrue(s.toString().contains("Permits = 3"));
646	>	s.reducePermits(5);
647	>	assertTrue(s.toString().contains("Permits = -2"));
648		}
649
813	–
650		}

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