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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.8 by dl, Sun Dec 28 21:56:18 2003 UTC vs.
Revision 1.38 by jsr166, Sun May 14 00:38:16 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	>
15	>	import junit.framework.AssertionFailedError;
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 p, boolean f) { super(p, f); }
32	<	public Collection<Thread> getQueuedThreads() {
33	<	return super.getQueuedThreads();
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 p) {
40	<	super.reducePermits(p);
39	>	public void reducePermits(int reduction) {
40	>	super.reducePermits(reduction);
41		}
42		}
43
44		/**
45		* A runnable calling acquire
46		*/
47	<	class InterruptibleLockRunnable implements Runnable {
47	>	class InterruptibleLockRunnable extends CheckedRunnable {
48		final Semaphore lock;
49	<	InterruptibleLockRunnable(Semaphore l) { lock = l; }
50	<	public void run() {
49	>	InterruptibleLockRunnable(Semaphore s) { lock = s; }
50	>	public void realRun() {
51		try {
52		lock.acquire();
53	<	} catch(InterruptedException success){}
53	>	}
54	>	catch (InterruptedException ignored) {}
55		}
56		}
57
48	–
58		/**
59	<	* A runnable calling acquire that expects to be
51	<	* interrupted
59	>	* A runnable calling acquire that expects to be interrupted
60		*/
61	<	class InterruptedLockRunnable implements Runnable {
61	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
62		final Semaphore lock;
63	<	InterruptedLockRunnable(Semaphore l) { lock = l; }
64	<	public void run() {
65	<	try {
66	<	lock.acquire();
67	<	threadShouldThrow();
68	<	} catch(InterruptedException success){}
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 AssertionFailedError("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 AssertionFailedError("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, false);
158	<	assertEquals(0, s0.availablePermits());
159	<	assertFalse(s0.isFair());
160	<	Semaphore s1 = new Semaphore(-1, false);
161	<	assertEquals(-1, s1.availablePermits());
162	<	Semaphore s2 = new Semaphore(-1, false);
163	<	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, false);
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, false);
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()      { testTryAcquire_timeout(false); }
197	>	public void testTryAcquire_timeout_fair() { testTryAcquire_timeout(true); }
198	>	public void testTryAcquire_timeout(boolean fair) {
199	>	Semaphore s = new Semaphore(0, fair);
200	>	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()      { testTryAcquireN_timeout(false); }
210	>	public void testTryAcquireN_timeout_fair() { testTryAcquireN_timeout(true); }
211	>	public void testTryAcquireN_timeout(boolean fair) {
212	>	Semaphore s = new Semaphore(2, fair);
213	>	long startTime = System.nanoTime();
214	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
215	>	catch (InterruptedException e) { threadUnexpectedException(e); }
216	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
217	>	}
218	>
219	>	/**
220	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
221	>	* are interruptible
222	>	*/
223	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
224	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
225	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
226	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
227	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
228	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
229	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
230	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
231	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
232	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
233	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
234	>	= new java.util.concurrent.CyclicBarrier(2);
235	>	Thread t = newStartedThread(new CheckedRunnable() {
236	>	public void realRun() {
237	>	// Interrupt before acquire
238	>	Thread.currentThread().interrupt();
239	>	try {
240	>	acquirer.acquire(s);
241	>	shouldThrow();
242	>	} catch (InterruptedException success) {}
243	>	assertFalse(Thread.interrupted());
244	>
245	>	// Interrupt before acquire(N)
246	>	Thread.currentThread().interrupt();
247	>	try {
248	>	acquirer.acquire(s, 3);
249	>	shouldThrow();
250	>	} catch (InterruptedException success) {}
251	>	assertFalse(Thread.interrupted());
252	>
253	>	// Interrupt during acquire
254	>	await(pleaseInterrupt);
255	>	try {
256	>	acquirer.acquire(s);
257	>	shouldThrow();
258	>	} catch (InterruptedException success) {}
259	>	assertFalse(Thread.interrupted());
260	>
261	>	// Interrupt during acquire(N)
262	>	await(pleaseInterrupt);
263	>	try {
264	>	acquirer.acquire(s, 3);
265	>	shouldThrow();
266	>	} catch (InterruptedException success) {}
267	>	assertFalse(Thread.interrupted());
268	>	}});
269	>
270	>	for (int n = 2; n-->0; ) {
271	>	await(pleaseInterrupt);
272	>	assertThreadBlocks(t, acquirer.parkedState());
273	>	t.interrupt();
274		}
275	+
276	+	awaitTermination(t);
277		}
278
279		/**
280	<	* Uninterruptible acquire and release of semaphore succeed if
281	<	* initially available
280	>	* acquireUninterruptibly(), acquireUninterruptibly(N) are
281	>	* uninterruptible
282		*/
283	<	public void testAcquireUninterruptiblyReleaseInSameThread() {
284	<	Semaphore s = new Semaphore(1, false);
285	<	try {
286	<	s.acquireUninterruptibly();
287	<	s.release();
288	<	s.acquireUninterruptibly();
289	<	s.release();
290	<	s.acquireUninterruptibly();
291	<	s.release();
292	<	s.acquireUninterruptibly();
293	<	s.release();
294	<	s.acquireUninterruptibly();
295	<	s.release();
296	<	assertEquals(1, s.availablePermits());
297	<	} finally {
298	<	}
299	<	}
283	>	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
284	>	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
285	>	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
286	>	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
287	>	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
288	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
289	>	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
290	>
291	>	Thread t1 = newStartedThread(new CheckedRunnable() {
292	>	public void realRun() throws InterruptedException {
293	>	// Interrupt before acquire
294	>	pleaseInterrupt.release();
295	>	Thread.currentThread().interrupt();
296	>	acquirer.acquire(s);
297	>	assertTrue(Thread.interrupted());
298	>	}});
299	>
300	>	Thread t2 = newStartedThread(new CheckedRunnable() {
301	>	public void realRun() throws InterruptedException {
302	>	// Interrupt during acquire
303	>	pleaseInterrupt.release();
304	>	acquirer.acquire(s);
305	>	assertTrue(Thread.interrupted());
306	>	}});
307	>
308	>	await(pleaseInterrupt);
309	>	waitForQueuedThread(s, t1);
310	>	waitForQueuedThread(s, t2);
311	>	t2.interrupt();
312
313	<	/**
314	<	* Timed Acquire and release of semaphore succeed if
315	<	* initially available
316	<	*/
317	<	public void testTimedAcquireReleaseInSameThread() {
318	<	Semaphore s = new Semaphore(1, false);
319	<	try {
140	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
141	<	s.release();
142	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
143	<	s.release();
144	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
145	<	s.release();
146	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
147	<	s.release();
148	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
149	<	s.release();
150	<	assertEquals(1, s.availablePermits());
151	<	} catch( InterruptedException e){
152	<	unexpectedException();
153	<	}
313	>	assertThreadBlocks(t1, Thread.State.WAITING);
314	>	assertThreadBlocks(t2, Thread.State.WAITING);
315	>
316	>	s.release(2);
317	>
318	>	awaitTermination(t1);
319	>	awaitTermination(t2);
320		}
321
322		/**
323	<	* A release in one thread enables an acquire in another thread
323	>	* hasQueuedThreads reports whether there are waiting threads
324		*/
325	<	public void testAcquireReleaseInDifferentThreads() {
326	<	final Semaphore s = new Semaphore(0, false);
327	<	Thread t = new Thread(new Runnable() {
328	<	public void run() {
329	<	try {
330	<	s.acquire();
331	<	s.release();
332	<	s.release();
333	<	s.acquire();
334	<	} catch(InterruptedException ie){
335	<	threadUnexpectedException();
336	<	}
337	<	}
338	<	});
339	<	try {
340	<	t.start();
341	<	Thread.sleep(SHORT_DELAY_MS);
342	<	s.release();
177	<	s.release();
178	<	s.acquire();
179	<	s.acquire();
180	<	s.release();
181	<	t.join();
182	<	} catch( InterruptedException e){
183	<	unexpectedException();
184	<	}
325	>	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
326	>	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
327	>	public void testHasQueuedThreads(boolean fair) {
328	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
329	>	assertFalse(lock.hasQueuedThreads());
330	>	lock.acquireUninterruptibly();
331	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
332	>	waitForQueuedThread(lock, t1);
333	>	assertTrue(lock.hasQueuedThreads());
334	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
335	>	waitForQueuedThread(lock, t2);
336	>	assertTrue(lock.hasQueuedThreads());
337	>	t1.interrupt();
338	>	awaitTermination(t1);
339	>	assertTrue(lock.hasQueuedThreads());
340	>	lock.release();
341	>	awaitTermination(t2);
342	>	assertFalse(lock.hasQueuedThreads());
343		}
344
345		/**
346	<	* A release in one thread enables an uninterruptible acquire in another thread
346	>	* getQueueLength reports number of waiting threads
347		*/
348	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
349	<	final Semaphore s = new Semaphore(0, false);
350	<	Thread t = new Thread(new Runnable() {
351	<	public void run() {
352	<	s.acquireUninterruptibly();
353	<	s.release();
354	<	s.release();
355	<	s.acquireUninterruptibly();
356	<	}
357	<	});
358	<	try {
359	<	t.start();
360	<	Thread.sleep(SHORT_DELAY_MS);
361	<	s.release();
362	<	s.release();
363	<	s.acquireUninterruptibly();
364	<	s.acquireUninterruptibly();
365	<	s.release();
208	<	t.join();
209	<	} catch( InterruptedException e){
210	<	unexpectedException();
211	<	}
348	>	public void testGetQueueLength()      { testGetQueueLength(false); }
349	>	public void testGetQueueLength_fair() { testGetQueueLength(true); }
350	>	public void testGetQueueLength(boolean fair) {
351	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
352	>	assertEquals(0, lock.getQueueLength());
353	>	lock.acquireUninterruptibly();
354	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
355	>	waitForQueuedThread(lock, t1);
356	>	assertEquals(1, lock.getQueueLength());
357	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
358	>	waitForQueuedThread(lock, t2);
359	>	assertEquals(2, lock.getQueueLength());
360	>	t1.interrupt();
361	>	awaitTermination(t1);
362	>	assertEquals(1, lock.getQueueLength());
363	>	lock.release();
364	>	awaitTermination(t2);
365	>	assertEquals(0, lock.getQueueLength());
366		}
367
214	–
368		/**
369	<	*  A release in one thread enables a timed acquire in another thread
369	>	* getQueuedThreads includes waiting threads
370		*/
371	<	public void testTimedAcquireReleaseInDifferentThreads() {
372	<	final Semaphore s = new Semaphore(1, false);
373	<	Thread t = new Thread(new Runnable() {
374	<	public void run() {
375	<	try {
376	<	s.release();
377	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
378	<	s.release();
379	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
380	<
381	<	} catch(InterruptedException ie){
382	<	threadUnexpectedException();
383	<	}
384	<	}
385	<	});
386	<	try {
387	<	t.start();
388	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
389	<	s.release();
390	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
391	<	s.release();
239	<	s.release();
240	<	t.join();
241	<	} catch( InterruptedException e){
242	<	unexpectedException();
243	<	}
371	>	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
372	>	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
373	>	public void testGetQueuedThreads(boolean fair) {
374	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
375	>	assertTrue(lock.getQueuedThreads().isEmpty());
376	>	lock.acquireUninterruptibly();
377	>	assertTrue(lock.getQueuedThreads().isEmpty());
378	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
379	>	waitForQueuedThread(lock, t1);
380	>	assertTrue(lock.getQueuedThreads().contains(t1));
381	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
382	>	waitForQueuedThread(lock, t2);
383	>	assertTrue(lock.getQueuedThreads().contains(t1));
384	>	assertTrue(lock.getQueuedThreads().contains(t2));
385	>	t1.interrupt();
386	>	awaitTermination(t1);
387	>	assertFalse(lock.getQueuedThreads().contains(t1));
388	>	assertTrue(lock.getQueuedThreads().contains(t2));
389	>	lock.release();
390	>	awaitTermination(t2);
391	>	assertTrue(lock.getQueuedThreads().isEmpty());
392		}
393
394		/**
395	<	* A waiting acquire blocks interruptibly
396	<	*/
397	<	public void testAcquire_InterruptedException() {
398	<	final Semaphore s = new Semaphore(0, false);
399	<	Thread t = new Thread(new Runnable() {
400	<	public void run() {
401	<	try {
402	<	s.acquire();
403	<	threadShouldThrow();
404	<	} catch(InterruptedException success){}
405	<	}
406	<	});
407	<	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	<	}
395	>	* drainPermits reports and removes given number of permits
396	>	*/
397	>	public void testDrainPermits()      { testDrainPermits(false); }
398	>	public void testDrainPermits_fair() { testDrainPermits(true); }
399	>	public void testDrainPermits(boolean fair) {
400	>	Semaphore s = new Semaphore(0, fair);
401	>	assertEquals(0, s.availablePermits());
402	>	assertEquals(0, s.drainPermits());
403	>	s.release(10);
404	>	assertEquals(10, s.availablePermits());
405	>	assertEquals(10, s.drainPermits());
406	>	assertEquals(0, s.availablePermits());
407	>	assertEquals(0, s.drainPermits());
408		}
409
410		/**
411	<	* hasQueuedThreads reports whether there are waiting threads
411	>	* release(-N) throws IllegalArgumentException
412		*/
413	<	public void testHasQueuedThreads() {
414	<	final Semaphore lock = new Semaphore(1, false);
415	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
416	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
413	>	public void testReleaseIAE()      { testReleaseIAE(false); }
414	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
415	>	public void testReleaseIAE(boolean fair) {
416	>	Semaphore s = new Semaphore(10, fair);
417		try {
418	<	assertFalse(lock.hasQueuedThreads());
419	<	lock.acquireUninterruptibly();
420	<	t1.start();
421	<	Thread.sleep(SHORT_DELAY_MS);
305	<	assertTrue(lock.hasQueuedThreads());
306	<	t2.start();
307	<	Thread.sleep(SHORT_DELAY_MS);
308	<	assertTrue(lock.hasQueuedThreads());
309	<	t1.interrupt();
310	<	Thread.sleep(SHORT_DELAY_MS);
311	<	assertTrue(lock.hasQueuedThreads());
312	<	lock.release();
313	<	Thread.sleep(SHORT_DELAY_MS);
314	<	assertFalse(lock.hasQueuedThreads());
315	<	t1.join();
316	<	t2.join();
317	<	} catch(Exception e){
318	<	unexpectedException();
319	<	}
320	<	}
321	<
322	<	/**
323	<	* getQueueLength reports number of waiting threads
324	<	*/
325	<	public void testGetQueueLength() {
326	<	final Semaphore lock = new Semaphore(1, false);
327	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
328	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
329	<	try {
330	<	assertEquals(0, lock.getQueueLength());
331	<	lock.acquireUninterruptibly();
332	<	t1.start();
333	<	Thread.sleep(SHORT_DELAY_MS);
334	<	assertEquals(1, lock.getQueueLength());
335	<	t2.start();
336	<	Thread.sleep(SHORT_DELAY_MS);
337	<	assertEquals(2, lock.getQueueLength());
338	<	t1.interrupt();
339	<	Thread.sleep(SHORT_DELAY_MS);
340	<	assertEquals(1, lock.getQueueLength());
341	<	lock.release();
342	<	Thread.sleep(SHORT_DELAY_MS);
343	<	assertEquals(0, lock.getQueueLength());
344	<	t1.join();
345	<	t2.join();
346	<	} catch(Exception e){
347	<	unexpectedException();
348	<	}
349	<	}
418	>	s.release(-1);
419	>	shouldThrow();
420	>	} catch (IllegalArgumentException success) {}
421	>	}
422
423		/**
424	<	* getQueuedThreads includes waiting threads
424	>	* reducePermits(-N) throws IllegalArgumentException
425		*/
426	<	public void testGetQueuedThreads() {
427	<	final PublicSemaphore lock = new PublicSemaphore(1, false);
428	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
429	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
426	>	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
427	>	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
428	>	public void testReducePermitsIAE(boolean fair) {
429	>	PublicSemaphore s = new PublicSemaphore(10, fair);
430		try {
431	<	assertTrue(lock.getQueuedThreads().isEmpty());
432	<	lock.acquireUninterruptibly();
433	<	assertTrue(lock.getQueuedThreads().isEmpty());
434	<	t1.start();
363	<	Thread.sleep(SHORT_DELAY_MS);
364	<	assertTrue(lock.getQueuedThreads().contains(t1));
365	<	t2.start();
366	<	Thread.sleep(SHORT_DELAY_MS);
367	<	assertTrue(lock.getQueuedThreads().contains(t1));
368	<	assertTrue(lock.getQueuedThreads().contains(t2));
369	<	t1.interrupt();
370	<	Thread.sleep(SHORT_DELAY_MS);
371	<	assertFalse(lock.getQueuedThreads().contains(t1));
372	<	assertTrue(lock.getQueuedThreads().contains(t2));
373	<	lock.release();
374	<	Thread.sleep(SHORT_DELAY_MS);
375	<	assertTrue(lock.getQueuedThreads().isEmpty());
376	<	t1.join();
377	<	t2.join();
378	<	} catch(Exception e){
379	<	unexpectedException();
380	<	}
381	<	}
382	<
431	>	s.reducePermits(-1);
432	>	shouldThrow();
433	>	} catch (IllegalArgumentException success) {}
434	>	}
435
436		/**
437		* reducePermits reduces number of permits
438		*/
439	<	public void testReducePermits() {
440	<	PublicSemaphore s = new PublicSemaphore(10, false);
439	>	public void testReducePermits()      { testReducePermits(false); }
440	>	public void testReducePermits_fair() { testReducePermits(true); }
441	>	public void testReducePermits(boolean fair) {
442	>	PublicSemaphore s = new PublicSemaphore(10, fair);
443	>	assertEquals(10, s.availablePermits());
444	>	s.reducePermits(0);
445		assertEquals(10, s.availablePermits());
446		s.reducePermits(1);
447		assertEquals(9, s.availablePermits());
448		s.reducePermits(10);
449		assertEquals(-1, s.availablePermits());
450	+	s.reducePermits(10);
451	+	assertEquals(-11, s.availablePermits());
452	+	s.reducePermits(0);
453	+	assertEquals(-11, s.availablePermits());
454		}
455
456		/**
457	<	* a deserialized serialized semaphore has same number of permits
458	<	*/
399	<	public void testSerialization() {
400	<	Semaphore l = new Semaphore(3, false);
401	<	try {
402	<	l.acquire();
403	<	l.release();
404	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
405	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
406	<	out.writeObject(l);
407	<	out.close();
408	<
409	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
410	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
411	<	Semaphore r = (Semaphore) in.readObject();
412	<	assertEquals(3, r.availablePermits());
413	<	assertFalse(r.isFair());
414	<	r.acquire();
415	<	r.release();
416	<	} catch(Exception e){
417	<	unexpectedException();
418	<	}
419	<	}
420	<
421	<
422	<	/**
423	<	* Zero, negative, and positive initial values are allowed in constructor
424	<	*/
425	<	public void testConstructor_fair() {
426	<	Semaphore s0 = new Semaphore(0, true);
427	<	assertEquals(0, s0.availablePermits());
428	<	assertTrue(s0.isFair());
429	<	Semaphore s1 = new Semaphore(-1, true);
430	<	assertEquals(-1, s1.availablePermits());
431	<	Semaphore s2 = new Semaphore(-1, true);
432	<	assertEquals(-1, s2.availablePermits());
433	<	}
434	<
435	<	/**
436	<	* tryAcquire succeeds when sufficent permits, else fails
437	<	*/
438	<	public void testTryAcquireInSameThread_fair() {
439	<	Semaphore s = new Semaphore(2, true);
440	<	assertEquals(2, s.availablePermits());
441	<	assertTrue(s.tryAcquire());
442	<	assertTrue(s.tryAcquire());
443	<	assertEquals(0, s.availablePermits());
444	<	assertFalse(s.tryAcquire());
445	<	}
446	<
447	<	/**
448	<	* tryAcquire(n) succeeds when sufficent permits, else fails
449	<	*/
450	<	public void testTryAcquireNInSameThread_fair() {
451	<	Semaphore s = new Semaphore(2, true);
452	<	assertEquals(2, s.availablePermits());
453	<	assertTrue(s.tryAcquire(2));
454	<	assertEquals(0, s.availablePermits());
455	<	assertFalse(s.tryAcquire());
456	<	}
457	<
458	<	/**
459	<	* Acquire and release of semaphore succeed if initially available
457	>	* a reserialized semaphore has same number of permits and
458	>	* fairness, but no queued threads
459		*/
460	<	public void testAcquireReleaseInSameThread_fair() {
461	<	Semaphore s = new Semaphore(1, true);
460	>	public void testSerialization()      { testSerialization(false); }
461	>	public void testSerialization_fair() { testSerialization(true); }
462	>	public void testSerialization(boolean fair) {
463		try {
464	+	Semaphore s = new Semaphore(3, fair);
465		s.acquire();
465	–	s.release();
466		s.acquire();
467		s.release();
468	–	s.acquire();
469	–	s.release();
470	–	s.acquire();
471	–	s.release();
472	–	s.acquire();
473	–	s.release();
474	–	assertEquals(1, s.availablePermits());
475	–	} catch( InterruptedException e){
476	–	unexpectedException();
477	–	}
478	–	}
468
469	<	/**
470	<	* Acquire(n) and release(n) of semaphore succeed if initially available
471	<	*/
472	<	public void testAcquireReleaseNInSameThread_fair() {
473	<	Semaphore s = new Semaphore(1, true);
474	<	try {
475	<	s.release(1);
476	<	s.acquire(1);
477	<	s.release(2);
478	<	s.acquire(2);
479	<	s.release(3);
480	<	s.acquire(3);
481	<	s.release(4);
482	<	s.acquire(4);
483	<	s.release(5);
484	<	s.acquire(5);
485	<	assertEquals(1, s.availablePermits());
486	<	} catch( InterruptedException e){
487	<	unexpectedException();
469	>	Semaphore clone = serialClone(s);
470	>	assertEquals(fair, s.isFair());
471	>	assertEquals(fair, clone.isFair());
472	>	assertEquals(2, s.availablePermits());
473	>	assertEquals(2, clone.availablePermits());
474	>	clone.acquire();
475	>	clone.acquire();
476	>	clone.release();
477	>	assertEquals(2, s.availablePermits());
478	>	assertEquals(1, clone.availablePermits());
479	>	assertFalse(s.hasQueuedThreads());
480	>	assertFalse(clone.hasQueuedThreads());
481	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
482	>
483	>	{
484	>	PublicSemaphore s = new PublicSemaphore(0, fair);
485	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
486	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
487	>	waitForQueuedThread(s, t);  // ... we use this instead
488	>	PublicSemaphore clone = serialClone(s);
489	>	assertEquals(fair, s.isFair());
490	>	assertEquals(fair, clone.isFair());
491	>	assertEquals(0, s.availablePermits());
492	>	assertEquals(0, clone.availablePermits());
493	>	assertTrue(s.hasQueuedThreads());
494	>	assertFalse(clone.hasQueuedThreads());
495	>	s.release();
496	>	awaitTermination(t);
497	>	assertFalse(s.hasQueuedThreads());
498	>	assertFalse(clone.hasQueuedThreads());
499		}
500		}
501
502		/**
503	<	* Acquire(n) and release(n) of semaphore succeed if initially available
504	<	*/
505	<	public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
506	<	Semaphore s = new Semaphore(1, true);
507	<	try {
508	<	s.release(1);
509	<	s.acquireUninterruptibly(1);
510	<	s.release(2);
511	<	s.acquireUninterruptibly(2);
512	<	s.release(3);
513	<	s.acquireUninterruptibly(3);
514	<	s.release(4);
515	<	s.acquireUninterruptibly(4);
516	<	s.release(5);
517	<	s.acquireUninterruptibly(5);
518	<	assertEquals(1, s.availablePermits());
519	<	} finally {
520	<	}
503	>	* tryAcquire(n) succeeds when sufficient permits, else fails
504	>	*/
505	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
506	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
507	>	public void testTryAcquireNInSameThread(boolean fair) {
508	>	Semaphore s = new Semaphore(2, fair);
509	>	assertEquals(2, s.availablePermits());
510	>	assertFalse(s.tryAcquire(3));
511	>	assertEquals(2, s.availablePermits());
512	>	assertTrue(s.tryAcquire(2));
513	>	assertEquals(0, s.availablePermits());
514	>	assertFalse(s.tryAcquire(1));
515	>	assertFalse(s.tryAcquire(2));
516	>	assertEquals(0, s.availablePermits());
517		}
518
519		/**
520	<	* release(n) in one thread enables timed acquire(n) in another thread
520	>	* acquire succeeds if permits available
521		*/
522	<	public void testTimedAcquireReleaseNInSameThread_fair() {
523	<	Semaphore s = new Semaphore(1, true);
524	<	try {
525	<	s.release(1);
526	<	assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
527	<	s.release(2);
528	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
529	<	s.release(3);
530	<	assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
531	<	s.release(4);
532	<	assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
533	<	s.release(5);
534	<	assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
522	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
523	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
524	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
525	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
526	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
527	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
528	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
529	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
530	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
531	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
532	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
533	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
534	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
535	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
536	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
537	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
538	>	public void testReleaseAcquireSameThread(boolean fair,
539	>	final AcquireMethod acquirer) {
540	>	Semaphore s = new Semaphore(1, fair);
541	>	for (int i = 1; i < 6; i++) {
542	>	s.release(i);
543	>	assertEquals(1 + i, s.availablePermits());
544	>	try {
545	>	acquirer.acquire(s, i);
546	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
547		assertEquals(1, s.availablePermits());
540	–	} catch( InterruptedException e){
541	–	unexpectedException();
548		}
549		}
550
551		/**
552	<	* release in one thread enables timed acquire in another thread
552	>	* release in one thread enables acquire in another thread
553		*/
554	<	public void testTimedAcquireReleaseInSameThread_fair() {
555	<	Semaphore s = new Semaphore(1, true);
556	<	try {
557	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
558	<	s.release();
559	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
560	<	s.release();
561	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
562	<	s.release();
563	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
564	<	s.release();
565	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
566	<	s.release();
567	<	assertEquals(1, s.availablePermits());
568	<	} catch( InterruptedException e){
569	<	unexpectedException();
570	<	}
571	<	}
572	<
573	<	/**
574	<	* A release in one thread enables an acquire in another thread
575	<	*/
576	<	public void testAcquireReleaseInDifferentThreads_fair() {
577	<	final Semaphore s = new Semaphore(0, true);
578	<	Thread t = new Thread(new Runnable() {
579	<	public void run() {
580	<	try {
581	<	s.acquire();
582	<	s.acquire();
583	<	s.acquire();
584	<	s.acquire();
585	<	} catch(InterruptedException ie){
586	<	threadUnexpectedException();
587	<	}
588	<	}
583	<	});
584	<	try {
585	<	t.start();
586	<	Thread.sleep(SHORT_DELAY_MS);
587	<	s.release();
588	<	s.release();
589	<	s.release();
590	<	s.release();
591	<	s.release();
592	<	s.release();
593	<	t.join();
594	<	assertEquals(2, s.availablePermits());
595	<	} catch( InterruptedException e){
596	<	unexpectedException();
554	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
555	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
556	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
557	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
558	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
559	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
560	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
561	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
562	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
563	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
564	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
565	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
566	>	public void testReleaseAcquireDifferentThreads(boolean fair,
567	>	final AcquireMethod acquirer) {
568	>	final Semaphore s = new Semaphore(0, fair);
569	>	final int rounds = 4;
570	>	long startTime = System.nanoTime();
571	>	Thread t = newStartedThread(new CheckedRunnable() {
572	>	public void realRun() throws InterruptedException {
573	>	for (int i = 0; i < rounds; i++) {
574	>	assertFalse(s.hasQueuedThreads());
575	>	if (i % 2 == 0)
576	>	acquirer.acquire(s);
577	>	else
578	>	acquirer.acquire(s, 3);
579	>	}}});
580	>
581	>	for (int i = 0; i < rounds; i++) {
582	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
583	>	Thread.yield();
584	>	assertTrue(t.isAlive());
585	>	if (i % 2 == 0)
586	>	s.release();
587	>	else
588	>	s.release(3);
589		}
590	+	awaitTermination(t);
591	+	assertEquals(0, s.availablePermits());
592	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
593		}
594
595		/**
596	<	* release(n) in one thread enables acquire(n) in another thread
596	>	* fair locks are strictly FIFO
597		*/
598	<	public void testAcquireReleaseNInDifferentThreads_fair() {
599	<	final Semaphore s = new Semaphore(0, true);
600	<	Thread t = new Thread(new Runnable() {
601	<	public void run() {
602	<	try {
603	<	s.acquire(2);
604	<	s.acquire(2);
605	<	s.release(4);
606	<	} catch(InterruptedException ie){
607	<	threadUnexpectedException();
608	<	}
609	<	}
610	<	});
611	<	try {
612	<	t.start();
613	<	Thread.sleep(SHORT_DELAY_MS);
614	<	s.release(6);
615	<	s.acquire(2);
616	<	s.acquire(2);
617	<	s.release(2);
618	<	t.join();
619	<	} catch( InterruptedException e){
620	<	unexpectedException();
621	<	}
598	>	public void testFairLocksFifo() {
599	>	final PublicSemaphore s = new PublicSemaphore(1, true);
600	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
601	>	Thread t1 = newStartedThread(new CheckedRunnable() {
602	>	public void realRun() throws InterruptedException {
603	>	// Will block; permits are available, but not three
604	>	s.acquire(3);
605	>	}});
606	>
607	>	waitForQueuedThread(s, t1);
608	>
609	>	Thread t2 = newStartedThread(new CheckedRunnable() {
610	>	public void realRun() throws InterruptedException {
611	>	// Will fail, even though 1 permit is available
612	>	assertFalse(s.tryAcquire(0L, MILLISECONDS));
613	>	assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
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
629	–
630	–
635		/**
636	<	* release in one thread enables timed acquire in another thread
637	<	*/
638	<	public void testTimedAcquireReleaseInDifferentThreads_fair() {
639	<	final Semaphore s = new Semaphore(1, true);
640	<	Thread t = new Thread(new Runnable() {
641	<	public void run() {
642	<	try {
643	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
644	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
645	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
646	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
647	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
648	<
645	<	} catch(InterruptedException ie){
646	<	threadUnexpectedException();
647	<	}
648	<	}
649	<	});
650	<	t.start();
651	<	try {
652	<	s.release();
653	<	s.release();
654	<	s.release();
655	<	s.release();
656	<	s.release();
657	<	t.join();
658	<	} catch( InterruptedException e){
659	<	unexpectedException();
660	<	}
661	<	}
662	<
663	<	/**
664	<	* release(n) in one thread enables timed acquire(n) in another thread
665	<	*/
666	<	public void testTimedAcquireReleaseNInDifferentThreads_fair() {
667	<	final Semaphore s = new Semaphore(2, true);
668	<	Thread t = new Thread(new Runnable() {
669	<	public void run() {
670	<	try {
671	<	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
672	<	s.release(2);
673	<	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
674	<	s.release(2);
675	<	} catch(InterruptedException ie){
676	<	threadUnexpectedException();
677	<	}
678	<	}
679	<	});
680	<	t.start();
681	<	try {
682	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
683	<	s.release(2);
684	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
685	<	s.release(2);
686	<	t.join();
687	<	} catch( InterruptedException e){
688	<	unexpectedException();
689	<	}
690	<	}
691	<
692	<	/**
693	<	* A waiting acquire blocks interruptibly
694	<	*/
695	<	public void testAcquire_InterruptedException_fair() {
696	<	final Semaphore s = new Semaphore(0, true);
697	<	Thread t = new Thread(new Runnable() {
698	<	public void run() {
699	<	try {
700	<	s.acquire();
701	<	threadShouldThrow();
702	<	} catch(InterruptedException success){}
703	<	}
704	<	});
705	<	t.start();
706	<	try {
707	<	Thread.sleep(SHORT_DELAY_MS);
708	<	t.interrupt();
709	<	t.join();
710	<	} catch(InterruptedException e){
711	<	unexpectedException();
712	<	}
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
715	–	/**
716	–	* A waiting acquire(n) blocks interruptibly
717	–	*/
718	–	public void testAcquireN_InterruptedException_fair() {
719	–	final Semaphore s = new Semaphore(2, true);
720	–	Thread t = new Thread(new Runnable() {
721	–	public void run() {
722	–	try {
723	–	s.acquire(3);
724	–	threadShouldThrow();
725	–	} catch(InterruptedException success){}
726	–	}
727	–	});
728	–	t.start();
729	–	try {
730	–	Thread.sleep(SHORT_DELAY_MS);
731	–	t.interrupt();
732	–	t.join();
733	–	} catch(InterruptedException e){
734	–	unexpectedException();
735	–	}
736	–	}
737	–
738	–	/**
739	–	*  A waiting tryAcquire blocks interruptibly
740	–	*/
741	–	public void testTryAcquire_InterruptedException_fair() {
742	–	final Semaphore s = new Semaphore(0, true);
743	–	Thread t = new Thread(new Runnable() {
744	–	public void run() {
745	–	try {
746	–	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
747	–	threadShouldThrow();
748	–	} catch(InterruptedException success){
749	–	}
750	–	}
751	–	});
752	–	t.start();
753	–	try {
754	–	Thread.sleep(SHORT_DELAY_MS);
755	–	t.interrupt();
756	–	t.join();
757	–	} catch(InterruptedException e){
758	–	unexpectedException();
759	–	}
760	–	}
761	–
762	–	/**
763	–	*  A waiting tryAcquire(n) blocks interruptibly
764	–	*/
765	–	public void testTryAcquireN_InterruptedException_fair() {
766	–	final Semaphore s = new Semaphore(1, true);
767	–	Thread t = new Thread(new Runnable() {
768	–	public void run() {
769	–	try {
770	–	s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
771	–	threadShouldThrow();
772	–	} catch(InterruptedException success){
773	–	}
774	–	}
775	–	});
776	–	t.start();
777	–	try {
778	–	Thread.sleep(SHORT_DELAY_MS);
779	–	t.interrupt();
780	–	t.join();
781	–	} catch(InterruptedException e){
782	–	unexpectedException();
783	–	}
784	–	}
785	–
786	–	/**
787	–	* getQueueLength reports number of waiting threads
788	–	*/
789	–	public void testGetQueueLength_fair() {
790	–	final Semaphore lock = new Semaphore(1, true);
791	–	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
792	–	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
793	–	try {
794	–	assertEquals(0, lock.getQueueLength());
795	–	lock.acquireUninterruptibly();
796	–	t1.start();
797	–	Thread.sleep(SHORT_DELAY_MS);
798	–	assertEquals(1, lock.getQueueLength());
799	–	t2.start();
800	–	Thread.sleep(SHORT_DELAY_MS);
801	–	assertEquals(2, lock.getQueueLength());
802	–	t1.interrupt();
803	–	Thread.sleep(SHORT_DELAY_MS);
804	–	assertEquals(1, lock.getQueueLength());
805	–	lock.release();
806	–	Thread.sleep(SHORT_DELAY_MS);
807	–	assertEquals(0, lock.getQueueLength());
808	–	t1.join();
809	–	t2.join();
810	–	} catch(Exception e){
811	–	unexpectedException();
812	–	}
813	–	}
814	–
815	–
816	–	/**
817	–	* a deserialized serialized semaphore has same number of permits
818	–	*/
819	–	public void testSerialization_fair() {
820	–	Semaphore l = new Semaphore(3, true);
821	–
822	–	try {
823	–	l.acquire();
824	–	l.release();
825	–	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
826	–	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
827	–	out.writeObject(l);
828	–	out.close();
829	–
830	–	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
831	–	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
832	–	Semaphore r = (Semaphore) in.readObject();
833	–	assertEquals(3, r.availablePermits());
834	–	assertTrue(r.isFair());
835	–	r.acquire();
836	–	r.release();
837	–	} catch(Exception e){
838	–	unexpectedException();
839	–	}
840	–	}
841	–
842	–
651		}

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