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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.9 by dl, Mon Dec 29 19:05:40 2003 UTC vs.
Revision 1.39 by jsr166, Sun May 14 03:31:53 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	>	* Constructor without fairness argument behaves as nonfair
169	>	*/
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() {
182	<	Semaphore s = new Semaphore(2, false);
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 ThreadLocalRandom rnd = ThreadLocalRandom.current();
199	>	final boolean fair = rnd.nextBoolean();
200	>	final Semaphore s = new Semaphore(0, fair);
201	>	final long startTime = System.nanoTime();
202	>	try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
203	>	catch (InterruptedException e) { threadUnexpectedException(e); }
204	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
205	>	}
206	>
207	>	/**
208	>	* timed tryAcquire(N) times out
209	>	*/
210	>	public void testTryAcquireN_timeout() {
211	>	final ThreadLocalRandom rnd = ThreadLocalRandom.current();
212	>	final boolean fair = rnd.nextBoolean();
213	>	final Semaphore s = new Semaphore(2, fair);
214	>	final long startTime = System.nanoTime();
215	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
216	>	catch (InterruptedException e) { threadUnexpectedException(e); }
217	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
218	>	}
219	>
220	>	/**
221	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
222	>	* are interruptible
223	>	*/
224	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
225	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
226	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
227	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
228	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
229	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
230	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
231	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
232	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
233	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
234	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
235	>	= new java.util.concurrent.CyclicBarrier(2);
236	>	Thread t = newStartedThread(new CheckedRunnable() {
237	>	public void realRun() {
238	>	// Interrupt before acquire
239	>	Thread.currentThread().interrupt();
240	>	try {
241	>	acquirer.acquire(s);
242	>	shouldThrow();
243	>	} catch (InterruptedException success) {}
244	>	assertFalse(Thread.interrupted());
245	>
246	>	// Interrupt before acquire(N)
247	>	Thread.currentThread().interrupt();
248	>	try {
249	>	acquirer.acquire(s, 3);
250	>	shouldThrow();
251	>	} catch (InterruptedException success) {}
252	>	assertFalse(Thread.interrupted());
253	>
254	>	// Interrupt during acquire
255	>	await(pleaseInterrupt);
256	>	try {
257	>	acquirer.acquire(s);
258	>	shouldThrow();
259	>	} catch (InterruptedException success) {}
260	>	assertFalse(Thread.interrupted());
261	>
262	>	// Interrupt during acquire(N)
263	>	await(pleaseInterrupt);
264	>	try {
265	>	acquirer.acquire(s, 3);
266	>	shouldThrow();
267	>	} catch (InterruptedException success) {}
268	>	assertFalse(Thread.interrupted());
269	>	}});
270	>
271	>	for (int n = 2; n-->0; ) {
272	>	await(pleaseInterrupt);
273	>	assertThreadBlocks(t, acquirer.parkedState());
274	>	t.interrupt();
275		}
276	+
277	+	awaitTermination(t);
278		}
279
280		/**
281	<	* Uninterruptible acquire and release of semaphore succeed if
282	<	* initially available
281	>	* acquireUninterruptibly(), acquireUninterruptibly(N) are
282	>	* uninterruptible
283		*/
284	<	public void testAcquireUninterruptiblyReleaseInSameThread() {
285	<	Semaphore s = new Semaphore(1, false);
286	<	try {
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	<	s.acquireUninterruptibly();
296	<	s.release();
297	<	assertEquals(1, s.availablePermits());
298	<	} finally {
299	<	}
300	<	}
284	>	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
285	>	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
286	>	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
287	>	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
288	>	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
289	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
290	>	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
291	>
292	>	Thread t1 = newStartedThread(new CheckedRunnable() {
293	>	public void realRun() throws InterruptedException {
294	>	// Interrupt before acquire
295	>	pleaseInterrupt.release();
296	>	Thread.currentThread().interrupt();
297	>	acquirer.acquire(s);
298	>	assertTrue(Thread.interrupted());
299	>	}});
300	>
301	>	Thread t2 = newStartedThread(new CheckedRunnable() {
302	>	public void realRun() throws InterruptedException {
303	>	// Interrupt during acquire
304	>	pleaseInterrupt.release();
305	>	acquirer.acquire(s);
306	>	assertTrue(Thread.interrupted());
307	>	}});
308	>
309	>	await(pleaseInterrupt);
310	>	waitForQueuedThread(s, t1);
311	>	waitForQueuedThread(s, t2);
312	>	t2.interrupt();
313
314	<	/**
315	<	* Timed Acquire and release of semaphore succeed if
316	<	* initially available
317	<	*/
318	<	public void testTimedAcquireReleaseInSameThread() {
319	<	Semaphore s = new Semaphore(1, false);
320	<	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	<	}
314	>	assertThreadBlocks(t1, Thread.State.WAITING);
315	>	assertThreadBlocks(t2, Thread.State.WAITING);
316	>
317	>	s.release(2);
318	>
319	>	awaitTermination(t1);
320	>	awaitTermination(t2);
321		}
322
323		/**
324	<	* A release in one thread enables an acquire in another thread
324	>	* hasQueuedThreads reports whether there are waiting threads
325		*/
326	<	public void testAcquireReleaseInDifferentThreads() {
327	<	final Semaphore s = new Semaphore(0, false);
328	<	Thread t = new Thread(new Runnable() {
329	<	public void run() {
330	<	try {
331	<	s.acquire();
332	<	s.release();
333	<	s.release();
334	<	s.acquire();
335	<	} catch(InterruptedException ie){
336	<	threadUnexpectedException();
337	<	}
338	<	}
339	<	});
340	<	try {
341	<	t.start();
342	<	Thread.sleep(SHORT_DELAY_MS);
343	<	s.release();
177	<	s.release();
178	<	s.acquire();
179	<	s.acquire();
180	<	s.release();
181	<	t.join();
182	<	} catch( InterruptedException e){
183	<	unexpectedException();
184	<	}
326	>	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
327	>	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
328	>	public void testHasQueuedThreads(boolean fair) {
329	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
330	>	assertFalse(lock.hasQueuedThreads());
331	>	lock.acquireUninterruptibly();
332	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
333	>	waitForQueuedThread(lock, t1);
334	>	assertTrue(lock.hasQueuedThreads());
335	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
336	>	waitForQueuedThread(lock, t2);
337	>	assertTrue(lock.hasQueuedThreads());
338	>	t1.interrupt();
339	>	awaitTermination(t1);
340	>	assertTrue(lock.hasQueuedThreads());
341	>	lock.release();
342	>	awaitTermination(t2);
343	>	assertFalse(lock.hasQueuedThreads());
344		}
345
346		/**
347	<	* A release in one thread enables an uninterruptible acquire in another thread
347	>	* getQueueLength reports number of waiting threads
348		*/
349	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
350	<	final Semaphore s = new Semaphore(0, false);
351	<	Thread t = new Thread(new Runnable() {
352	<	public void run() {
353	<	s.acquireUninterruptibly();
354	<	s.release();
355	<	s.release();
356	<	s.acquireUninterruptibly();
357	<	}
358	<	});
359	<	try {
360	<	t.start();
361	<	Thread.sleep(SHORT_DELAY_MS);
362	<	s.release();
363	<	s.release();
364	<	s.acquireUninterruptibly();
365	<	s.acquireUninterruptibly();
366	<	s.release();
208	<	t.join();
209	<	} catch( InterruptedException e){
210	<	unexpectedException();
211	<	}
349	>	public void testGetQueueLength()      { testGetQueueLength(false); }
350	>	public void testGetQueueLength_fair() { testGetQueueLength(true); }
351	>	public void testGetQueueLength(boolean fair) {
352	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
353	>	assertEquals(0, lock.getQueueLength());
354	>	lock.acquireUninterruptibly();
355	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
356	>	waitForQueuedThread(lock, t1);
357	>	assertEquals(1, lock.getQueueLength());
358	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
359	>	waitForQueuedThread(lock, t2);
360	>	assertEquals(2, lock.getQueueLength());
361	>	t1.interrupt();
362	>	awaitTermination(t1);
363	>	assertEquals(1, lock.getQueueLength());
364	>	lock.release();
365	>	awaitTermination(t2);
366	>	assertEquals(0, lock.getQueueLength());
367		}
368
214	–
369		/**
370	<	*  A release in one thread enables a timed acquire in another thread
370	>	* getQueuedThreads includes waiting threads
371		*/
372	<	public void testTimedAcquireReleaseInDifferentThreads() {
373	<	final Semaphore s = new Semaphore(1, false);
374	<	Thread t = new Thread(new Runnable() {
375	<	public void run() {
376	<	try {
377	<	s.release();
378	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
379	<	s.release();
380	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
381	<
382	<	} catch(InterruptedException ie){
383	<	threadUnexpectedException();
384	<	}
385	<	}
386	<	});
387	<	try {
388	<	t.start();
389	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
390	<	s.release();
391	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
392	<	s.release();
239	<	s.release();
240	<	t.join();
241	<	} catch( InterruptedException e){
242	<	unexpectedException();
243	<	}
372	>	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
373	>	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
374	>	public void testGetQueuedThreads(boolean fair) {
375	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
376	>	assertTrue(lock.getQueuedThreads().isEmpty());
377	>	lock.acquireUninterruptibly();
378	>	assertTrue(lock.getQueuedThreads().isEmpty());
379	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
380	>	waitForQueuedThread(lock, t1);
381	>	assertTrue(lock.getQueuedThreads().contains(t1));
382	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
383	>	waitForQueuedThread(lock, t2);
384	>	assertTrue(lock.getQueuedThreads().contains(t1));
385	>	assertTrue(lock.getQueuedThreads().contains(t2));
386	>	t1.interrupt();
387	>	awaitTermination(t1);
388	>	assertFalse(lock.getQueuedThreads().contains(t1));
389	>	assertTrue(lock.getQueuedThreads().contains(t2));
390	>	lock.release();
391	>	awaitTermination(t2);
392	>	assertTrue(lock.getQueuedThreads().isEmpty());
393		}
394
395		/**
396	<	* A waiting acquire blocks interruptibly
397	<	*/
398	<	public void testAcquire_InterruptedException() {
399	<	final Semaphore s = new Semaphore(0, false);
400	<	Thread t = new Thread(new Runnable() {
401	<	public void run() {
402	<	try {
403	<	s.acquire();
404	<	threadShouldThrow();
405	<	} catch(InterruptedException success){}
406	<	}
407	<	});
408	<	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	<	}
396	>	* drainPermits reports and removes given number of permits
397	>	*/
398	>	public void testDrainPermits()      { testDrainPermits(false); }
399	>	public void testDrainPermits_fair() { testDrainPermits(true); }
400	>	public void testDrainPermits(boolean fair) {
401	>	Semaphore s = new Semaphore(0, fair);
402	>	assertEquals(0, s.availablePermits());
403	>	assertEquals(0, s.drainPermits());
404	>	s.release(10);
405	>	assertEquals(10, s.availablePermits());
406	>	assertEquals(10, s.drainPermits());
407	>	assertEquals(0, s.availablePermits());
408	>	assertEquals(0, s.drainPermits());
409		}
410
411		/**
412	<	* hasQueuedThreads reports whether there are waiting threads
295	<	*/
296	<	public void testHasQueuedThreads() {
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	<	assertFalse(lock.hasQueuedThreads());
302	<	lock.acquireUninterruptibly();
303	<	t1.start();
304	<	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
412	>	* release(-N) throws IllegalArgumentException
413		*/
414	<	public void testGetQueueLength() {
415	<	final Semaphore lock = new Semaphore(1, false);
416	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
417	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
414	>	public void testReleaseIAE()      { testReleaseIAE(false); }
415	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
416	>	public void testReleaseIAE(boolean fair) {
417	>	Semaphore s = new Semaphore(10, fair);
418		try {
419	<	assertEquals(0, lock.getQueueLength());
420	<	lock.acquireUninterruptibly();
421	<	t1.start();
422	<	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	<	}
419	>	s.release(-1);
420	>	shouldThrow();
421	>	} catch (IllegalArgumentException success) {}
422	>	}
423
424		/**
425	<	* getQueuedThreads includes waiting threads
425	>	* reducePermits(-N) throws IllegalArgumentException
426		*/
427	<	public void testGetQueuedThreads() {
428	<	final PublicSemaphore lock = new PublicSemaphore(1, false);
429	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
430	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
427	>	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
428	>	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
429	>	public void testReducePermitsIAE(boolean fair) {
430	>	PublicSemaphore s = new PublicSemaphore(10, fair);
431		try {
432	<	assertTrue(lock.getQueuedThreads().isEmpty());
433	<	lock.acquireUninterruptibly();
434	<	assertTrue(lock.getQueuedThreads().isEmpty());
435	<	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	<
432	>	s.reducePermits(-1);
433	>	shouldThrow();
434	>	} catch (IllegalArgumentException success) {}
435	>	}
436
437		/**
438		* reducePermits reduces number of permits
439		*/
440	<	public void testReducePermits() {
441	<	PublicSemaphore s = new PublicSemaphore(10, false);
440	>	public void testReducePermits()      { testReducePermits(false); }
441	>	public void testReducePermits_fair() { testReducePermits(true); }
442	>	public void testReducePermits(boolean fair) {
443	>	PublicSemaphore s = new PublicSemaphore(10, fair);
444	>	assertEquals(10, s.availablePermits());
445	>	s.reducePermits(0);
446		assertEquals(10, s.availablePermits());
447		s.reducePermits(1);
448		assertEquals(9, s.availablePermits());
449		s.reducePermits(10);
450		assertEquals(-1, s.availablePermits());
451	+	s.reducePermits(10);
452	+	assertEquals(-11, s.availablePermits());
453	+	s.reducePermits(0);
454	+	assertEquals(-11, s.availablePermits());
455		}
456
457		/**
458	<	* a deserialized serialized semaphore has same number of permits
459	<	*/
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 sufficient 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 sufficient 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
458	>	* a reserialized semaphore has same number of permits and
459	>	* fairness, but no queued threads
460		*/
461	<	public void testAcquireReleaseInSameThread_fair() {
462	<	Semaphore s = new Semaphore(1, true);
461	>	public void testSerialization()      { testSerialization(false); }
462	>	public void testSerialization_fair() { testSerialization(true); }
463	>	public void testSerialization(boolean fair) {
464		try {
465	+	Semaphore s = new Semaphore(3, fair);
466		s.acquire();
465	–	s.release();
467		s.acquire();
468		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	–	}
479	–
480	–	/**
481	–	* Acquire(n) and release(n) of semaphore succeed if initially available
482	–	*/
483	–	public void testAcquireReleaseNInSameThread_fair() {
484	–	Semaphore s = new Semaphore(1, true);
485	–	try {
486	–	s.release(1);
487	–	s.acquire(1);
488	–	s.release(2);
489	–	s.acquire(2);
490	–	s.release(3);
491	–	s.acquire(3);
492	–	s.release(4);
493	–	s.acquire(4);
494	–	s.release(5);
495	–	s.acquire(5);
496	–	assertEquals(1, s.availablePermits());
497	–	} catch( InterruptedException e){
498	–	unexpectedException();
499	–	}
500	–	}
469
470	<	/**
471	<	* Acquire(n) and release(n) of semaphore succeed if initially available
472	<	*/
473	<	public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
474	<	Semaphore s = new Semaphore(1, true);
475	<	try {
476	<	s.release(1);
477	<	s.acquireUninterruptibly(1);
478	<	s.release(2);
479	<	s.acquireUninterruptibly(2);
480	<	s.release(3);
481	<	s.acquireUninterruptibly(3);
482	<	s.release(4);
483	<	s.acquireUninterruptibly(4);
484	<	s.release(5);
485	<	s.acquireUninterruptibly(5);
486	<	assertEquals(1, s.availablePermits());
487	<	} finally {
470	>	Semaphore clone = serialClone(s);
471	>	assertEquals(fair, s.isFair());
472	>	assertEquals(fair, clone.isFair());
473	>	assertEquals(2, s.availablePermits());
474	>	assertEquals(2, clone.availablePermits());
475	>	clone.acquire();
476	>	clone.acquire();
477	>	clone.release();
478	>	assertEquals(2, s.availablePermits());
479	>	assertEquals(1, clone.availablePermits());
480	>	assertFalse(s.hasQueuedThreads());
481	>	assertFalse(clone.hasQueuedThreads());
482	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
483	>
484	>	{
485	>	PublicSemaphore s = new PublicSemaphore(0, fair);
486	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
487	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
488	>	waitForQueuedThread(s, t);  // ... we use this instead
489	>	PublicSemaphore clone = serialClone(s);
490	>	assertEquals(fair, s.isFair());
491	>	assertEquals(fair, clone.isFair());
492	>	assertEquals(0, s.availablePermits());
493	>	assertEquals(0, clone.availablePermits());
494	>	assertTrue(s.hasQueuedThreads());
495	>	assertFalse(clone.hasQueuedThreads());
496	>	s.release();
497	>	awaitTermination(t);
498	>	assertFalse(s.hasQueuedThreads());
499	>	assertFalse(clone.hasQueuedThreads());
500		}
501		}
502
503		/**
504	<	* release(n) in one thread enables timed acquire(n) in another thread
504	>	* tryAcquire(n) succeeds when sufficient permits, else fails
505		*/
506	<	public void testTimedAcquireReleaseNInSameThread_fair() {
507	<	Semaphore s = new Semaphore(1, true);
508	<	try {
509	<	s.release(1);
510	<	assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
511	<	s.release(2);
512	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
513	<	s.release(3);
514	<	assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
515	<	s.release(4);
516	<	assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
517	<	s.release(5);
538	<	assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
539	<	assertEquals(1, s.availablePermits());
540	<	} catch( InterruptedException e){
541	<	unexpectedException();
542	<	}
506	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
507	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
508	>	public void testTryAcquireNInSameThread(boolean fair) {
509	>	Semaphore s = new Semaphore(2, fair);
510	>	assertEquals(2, s.availablePermits());
511	>	assertFalse(s.tryAcquire(3));
512	>	assertEquals(2, s.availablePermits());
513	>	assertTrue(s.tryAcquire(2));
514	>	assertEquals(0, s.availablePermits());
515	>	assertFalse(s.tryAcquire(1));
516	>	assertFalse(s.tryAcquire(2));
517	>	assertEquals(0, s.availablePermits());
518		}
519
520		/**
521	<	* release in one thread enables timed acquire in another thread
521	>	* acquire succeeds if permits available
522		*/
523	<	public void testTimedAcquireReleaseInSameThread_fair() {
524	<	Semaphore s = new Semaphore(1, true);
525	<	try {
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();
534	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
535	<	s.release();
523	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
524	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
525	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
526	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
527	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
528	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
529	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
530	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
531	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
532	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
533	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
534	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
535	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
536	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
537	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
538	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
539	>	public void testReleaseAcquireSameThread(boolean fair,
540	>	final AcquireMethod acquirer) {
541	>	Semaphore s = new Semaphore(1, fair);
542	>	for (int i = 1; i < 6; i++) {
543	>	s.release(i);
544	>	assertEquals(1 + i, s.availablePermits());
545	>	try {
546	>	acquirer.acquire(s, i);
547	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
548		assertEquals(1, s.availablePermits());
562	–	} catch( InterruptedException e){
563	–	unexpectedException();
549		}
550		}
551
552		/**
553	<	* A release in one thread enables an acquire in another thread
553	>	* release in one thread enables acquire in another thread
554		*/
555	<	public void testAcquireReleaseInDifferentThreads_fair() {
556	<	final Semaphore s = new Semaphore(0, true);
557	<	Thread t = new Thread(new Runnable() {
558	<	public void run() {
559	<	try {
560	<	s.acquire();
561	<	s.acquire();
562	<	s.acquire();
563	<	s.acquire();
564	<	} catch(InterruptedException ie){
565	<	threadUnexpectedException();
566	<	}
567	<	}
568	<	});
569	<	try {
570	<	t.start();
571	<	Thread.sleep(SHORT_DELAY_MS);
572	<	s.release();
573	<	s.release();
574	<	s.release();
575	<	s.release();
576	<	s.release();
577	<	s.release();
578	<	t.join();
579	<	assertEquals(2, s.availablePermits());
580	<	} catch( InterruptedException e){
581	<	unexpectedException();
555	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
556	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
557	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
558	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
559	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
560	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
561	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
562	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
563	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
564	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
565	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
566	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
567	>	public void testReleaseAcquireDifferentThreads(boolean fair,
568	>	final AcquireMethod acquirer) {
569	>	final Semaphore s = new Semaphore(0, fair);
570	>	final int rounds = 4;
571	>	long startTime = System.nanoTime();
572	>	Thread t = newStartedThread(new CheckedRunnable() {
573	>	public void realRun() throws InterruptedException {
574	>	for (int i = 0; i < rounds; i++) {
575	>	assertFalse(s.hasQueuedThreads());
576	>	if (i % 2 == 0)
577	>	acquirer.acquire(s);
578	>	else
579	>	acquirer.acquire(s, 3);
580	>	}}});
581	>
582	>	for (int i = 0; i < rounds; i++) {
583	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
584	>	Thread.yield();
585	>	assertTrue(t.isAlive());
586	>	if (i % 2 == 0)
587	>	s.release();
588	>	else
589	>	s.release(3);
590		}
591	+	awaitTermination(t);
592	+	assertEquals(0, s.availablePermits());
593	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
594		}
595
596		/**
597	<	* release(n) in one thread enables acquire(n) in another thread
597	>	* fair locks are strictly FIFO
598		*/
599	<	public void testAcquireReleaseNInDifferentThreads_fair() {
600	<	final Semaphore s = new Semaphore(0, true);
601	<	Thread t = new Thread(new Runnable() {
602	<	public void run() {
603	<	try {
604	<	s.acquire(2);
605	<	s.acquire(2);
606	<	s.release(4);
607	<	} catch(InterruptedException ie){
608	<	threadUnexpectedException();
609	<	}
610	<	}
611	<	});
612	<	try {
613	<	t.start();
614	<	Thread.sleep(SHORT_DELAY_MS);
615	<	s.release(6);
616	<	s.acquire(2);
617	<	s.acquire(2);
618	<	s.release(2);
619	<	t.join();
620	<	} catch( InterruptedException e){
621	<	unexpectedException();
622	<	}
623	<	}
624	<
625	<
626	<
627	<	/**
628	<	* release in one thread enables timed acquire in another thread
629	<	*/
630	<	public void testTimedAcquireReleaseInDifferentThreads_fair() {
631	<	final Semaphore s = new Semaphore(1, true);
632	<	Thread t = new Thread(new Runnable() {
633	<	public void run() {
638	<	try {
639	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
640	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
641	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
642	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
643	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
644	<
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	<	}
713	<	}
714	<
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	<	}
599	>	public void testFairLocksFifo() {
600	>	final PublicSemaphore s = new PublicSemaphore(1, true);
601	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
602	>	Thread t1 = newStartedThread(new CheckedRunnable() {
603	>	public void realRun() throws InterruptedException {
604	>	// Will block; permits are available, but not three
605	>	s.acquire(3);
606	>	}});
607	>
608	>	waitForQueuedThread(s, t1);
609	>
610	>	Thread t2 = newStartedThread(new CheckedRunnable() {
611	>	public void realRun() throws InterruptedException {
612	>	// Will fail, even though 1 permit is available
613	>	assertFalse(s.tryAcquire(0L, MILLISECONDS));
614	>	assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
615	>
616	>	// untimed tryAcquire will barge and succeed
617	>	assertTrue(s.tryAcquire());
618	>	s.release(2);
619	>	assertTrue(s.tryAcquire(2));
620	>	s.release();
621	>
622	>	pleaseRelease.countDown();
623	>	// Will queue up behind t1, even though 1 permit is available
624	>	s.acquire();
625	>	}});
626	>
627	>	await(pleaseRelease);
628	>	waitForQueuedThread(s, t2);
629	>	s.release(2);
630	>	awaitTermination(t1);
631	>	assertTrue(t2.isAlive());
632	>	s.release();
633	>	awaitTermination(t2);
634		}
635
636		/**
637	<	*  A waiting tryAcquire(n) blocks interruptibly
638	<	*/
639	<	public void testTryAcquireN_InterruptedException_fair() {
640	<	final Semaphore s = new Semaphore(1, true);
641	<	Thread t = new Thread(new Runnable() {
642	<	public void run() {
643	<	try {
644	<	s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
645	<	threadShouldThrow();
646	<	} catch(InterruptedException success){
647	<	}
648	<	}
649	<	});
776	<	t.start();
777	<	try {
778	<	Thread.sleep(SHORT_DELAY_MS);
779	<	t.interrupt();
780	<	t.join();
781	<	} catch(InterruptedException e){
782	<	unexpectedException();
783	<	}
637	>	* toString indicates current number of permits
638	>	*/
639	>	public void testToString()      { testToString(false); }
640	>	public void testToString_fair() { testToString(true); }
641	>	public void testToString(boolean fair) {
642	>	PublicSemaphore s = new PublicSemaphore(0, fair);
643	>	assertTrue(s.toString().contains("Permits = 0"));
644	>	s.release();
645	>	assertTrue(s.toString().contains("Permits = 1"));
646	>	s.release(2);
647	>	assertTrue(s.toString().contains("Permits = 3"));
648	>	s.reducePermits(5);
649	>	assertTrue(s.toString().contains("Permits = -2"));
650		}
651
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	–
652		}

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