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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.6 by dl, Mon Nov 3 13:50:07 2003 UTC vs.
Revision 1.39 by jsr166, Sun May 14 03:31:53 2017 UTC

#	Line 1 | Line 1
1		/*
2	<	* Written by members of JCP JSR-166 Expert Group and released to the
3	<	* public domain. Use, modify, and redistribute this code in any way
4	<	* without acknowledgement. Other contributors include Andrew Wright,
5	<	* Jeffrey Hayes, Pat Fischer, Mike Judd.
2	>	* Written by Doug Lea with assistance from members of JCP JSR-166
3	>	* Expert Group and released to the public domain, as explained at
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5	>	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	>	* Pat Fisher, Mike Judd.
7		*/
8
9	<	import junit.framework.*;
10	<	import java.util.*;
11	<	import java.util.concurrent.*;
12	<	import java.io.*;
9	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10	>
11	>	import java.util.Collection;
12	>	import java.util.concurrent.CountDownLatch;
13	>	import java.util.concurrent.Semaphore;
14	>	import java.util.concurrent.ThreadLocalRandom;
15	>
16	>	import junit.framework.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
47	–
59		/**
60	<	* A runnable calling acquire that expects to be
50	<	* interrupted
60	>	* A runnable calling acquire that expects to be interrupted
61		*/
62	<	class InterruptedLockRunnable implements Runnable {
62	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
63		final Semaphore lock;
64	<	InterruptedLockRunnable(Semaphore l) { lock = l; }
65	<	public void run() {
66	<	try {
67	<	lock.acquire();
68	<	threadShouldThrow();
69	<	} catch(InterruptedException success){}
64	>	InterruptedLockRunnable(Semaphore s) { lock = s; }
65	>	public void realRun() throws InterruptedException {
66	>	lock.acquire();
67	>	}
68	>	}
69	>
70	>	/**
71	>	* Spin-waits until s.hasQueuedThread(t) becomes true.
72	>	*/
73	>	void waitForQueuedThread(PublicSemaphore s, Thread t) {
74	>	long startTime = System.nanoTime();
75	>	while (!s.hasQueuedThread(t)) {
76	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
77	>	throw new AssertionFailedError("timed out");
78	>	Thread.yield();
79	>	}
80	>	assertTrue(s.hasQueuedThreads());
81	>	assertTrue(t.isAlive());
82	>	}
83	>
84	>	/**
85	>	* Spin-waits until s.hasQueuedThreads() becomes true.
86	>	*/
87	>	void waitForQueuedThreads(Semaphore s) {
88	>	long startTime = System.nanoTime();
89	>	while (!s.hasQueuedThreads()) {
90	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
91	>	throw new AssertionFailedError("timed out");
92	>	Thread.yield();
93	>	}
94	>	}
95	>
96	>	enum AcquireMethod {
97	>	acquire() {
98	>	void acquire(Semaphore s) throws InterruptedException {
99	>	s.acquire();
100	>	}
101	>	},
102	>	acquireN() {
103	>	void acquire(Semaphore s, int permits) throws InterruptedException {
104	>	s.acquire(permits);
105	>	}
106	>	},
107	>	acquireUninterruptibly() {
108	>	void acquire(Semaphore s) {
109	>	s.acquireUninterruptibly();
110	>	}
111	>	},
112	>	acquireUninterruptiblyN() {
113	>	void acquire(Semaphore s, int permits) {
114	>	s.acquireUninterruptibly(permits);
115	>	}
116	>	},
117	>	tryAcquire() {
118	>	void acquire(Semaphore s) {
119	>	assertTrue(s.tryAcquire());
120	>	}
121	>	},
122	>	tryAcquireN() {
123	>	void acquire(Semaphore s, int permits) {
124	>	assertTrue(s.tryAcquire(permits));
125	>	}
126	>	},
127	>	tryAcquireTimed() {
128	>	void acquire(Semaphore s) throws InterruptedException {
129	>	assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
130	>	}
131	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
132	>	},
133	>	tryAcquireTimedN {
134	>	void acquire(Semaphore s, int permits) throws InterruptedException {
135	>	assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
136	>	}
137	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
138	>	};
139	>
140	>	// Intentionally meta-circular
141	>
142	>	/** Acquires 1 permit. */
143	>	void acquire(Semaphore s) throws InterruptedException {
144	>	acquire(s, 1);
145	>	}
146	>	/** Acquires the given number of permits. */
147	>	void acquire(Semaphore s, int permits) throws InterruptedException {
148	>	for (int i = 0; i < permits; i++)
149	>	acquire(s);
150		}
151	+	Thread.State parkedState() { return Thread.State.WAITING; }
152		}
153
154		/**
155		* Zero, negative, and positive initial values are allowed in constructor
156		*/
157	<	public void testConstructor() {
158	<	Semaphore s0 = new Semaphore(0, false);
159	<	assertEquals(0, s0.availablePermits());
160	<	assertFalse(s0.isFair());
161	<	Semaphore s1 = new Semaphore(-1, false);
162	<	assertEquals(-1, s1.availablePermits());
163	<	Semaphore s2 = new Semaphore(-1, false);
164	<	assertEquals(-1, s2.availablePermits());
157	>	public void testConstructor()      { testConstructor(false); }
158	>	public void testConstructor_fair() { testConstructor(true); }
159	>	public void testConstructor(boolean fair) {
160	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
161	>	Semaphore s = new Semaphore(permits, fair);
162	>	assertEquals(permits, s.availablePermits());
163	>	assertEquals(fair, s.isFair());
164	>	}
165		}
166
167		/**
168	<	* tryAcquire succeeds when sufficent permits, else fails
168	>	* Constructor without fairness argument behaves as nonfair
169		*/
170	<	public void testTryAcquireInSameThread() {
171	<	Semaphore s = new Semaphore(2, false);
170	>	public void testConstructorDefaultsToNonFair() {
171	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
172	>	Semaphore s = new Semaphore(permits);
173	>	assertEquals(permits, s.availablePermits());
174	>	assertFalse(s.isFair());
175	>	}
176	>	}
177	>
178	>	/**
179	>	* tryAcquire succeeds when sufficient permits, else fails
180	>	*/
181	>	public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
182	>	public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
183	>	public void testTryAcquireInSameThread(boolean fair) {
184	>	Semaphore s = new Semaphore(2, fair);
185		assertEquals(2, s.availablePermits());
186		assertTrue(s.tryAcquire());
187		assertTrue(s.tryAcquire());
188		assertEquals(0, s.availablePermits());
189		assertFalse(s.tryAcquire());
190	+	assertFalse(s.tryAcquire());
191	+	assertEquals(0, s.availablePermits());
192		}
193
194		/**
195	<	* Acquire and release of semaphore succeed if initially available
195	>	* timed tryAcquire times out
196		*/
197	<	public void testAcquireReleaseInSameThread() {
198	<	Semaphore s = new Semaphore(1, false);
199	<	try {
200	<	s.acquire();
201	<	s.release();
202	<	s.acquire();
203	<	s.release();
204	<	s.acquire();
205	<	s.release();
206	<	s.acquire();
207	<	s.release();
208	<	s.acquire();
209	<	s.release();
210	<	assertEquals(1, s.availablePermits());
211	<	} catch( InterruptedException e){
212	<	unexpectedException();
197	>	public void testTryAcquire_timeout() {
198	>	final 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	<	}
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	>	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	>	* hasQueuedThreads reports whether there are waiting threads
325	>	*/
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	<	* Timed Acquire and release of semaphore succeed if
134	<	* initially available
347	>	* getQueueLength reports number of waiting threads
348		*/
349	<	public void testTimedAcquireReleaseInSameThread() {
350	<	Semaphore s = new Semaphore(1, false);
351	<	try {
352	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
353	<	s.release();
354	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
355	<	s.release();
356	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
357	<	s.release();
358	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
359	<	s.release();
360	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
361	<	s.release();
362	<	assertEquals(1, s.availablePermits());
363	<	} catch( InterruptedException e){
364	<	unexpectedException();
365	<	}
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
369		/**
370	<	* A release in one thread enables an acquire in another thread
370	>	* getQueuedThreads includes waiting threads
371		*/
372	<	public void testAcquireReleaseInDifferentThreads() {
373	<	final Semaphore s = new Semaphore(0, false);
374	<	Thread t = new Thread(new Runnable() {
375	<	public void run() {
376	<	try {
377	<	s.acquire();
378	<	s.release();
379	<	s.release();
380	<	s.acquire();
381	<	} catch(InterruptedException ie){
382	<	threadUnexpectedException();
383	<	}
384	<	}
385	<	});
386	<	try {
387	<	t.start();
388	<	Thread.sleep(SHORT_DELAY_MS);
389	<	s.release();
390	<	s.release();
391	<	s.acquire();
392	<	s.acquire();
179	<	s.release();
180	<	t.join();
181	<	} catch( InterruptedException e){
182	<	unexpectedException();
183	<	}
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 release in one thread enables an uninterruptible acquire in another thread
397	<	*/
398	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
399	<	final Semaphore s = new Semaphore(0, false);
400	<	Thread t = new Thread(new Runnable() {
401	<	public void run() {
402	<	s.acquireUninterruptibly();
403	<	s.release();
404	<	s.release();
405	<	s.acquireUninterruptibly();
406	<	}
407	<	});
408	<	try {
200	<	t.start();
201	<	Thread.sleep(SHORT_DELAY_MS);
202	<	s.release();
203	<	s.release();
204	<	s.acquireUninterruptibly();
205	<	s.acquireUninterruptibly();
206	<	s.release();
207	<	t.join();
208	<	} catch( InterruptedException e){
209	<	unexpectedException();
210	<	}
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
213	–
411		/**
412	<	*  A release in one thread enables a timed acquire in another thread
412	>	* release(-N) throws IllegalArgumentException
413		*/
414	<	public void testTimedAcquireReleaseInDifferentThreads() {
415	<	final Semaphore s = new Semaphore(1, false);
416	<	Thread t = new Thread(new Runnable() {
417	<	public void run() {
221	<	try {
222	<	s.release();
223	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
224	<	s.release();
225	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
226	<
227	<	} catch(InterruptedException ie){
228	<	threadUnexpectedException();
229	<	}
230	<	}
231	<	});
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	<	t.start();
420	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
421	<	s.release();
236	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
237	<	s.release();
238	<	s.release();
239	<	t.join();
240	<	} catch( InterruptedException e){
241	<	unexpectedException();
242	<	}
243	<	}
244	<
245	<	/**
246	<	* A waiting acquire blocks interruptibly
247	<	*/
248	<	public void testAcquire_InterruptedException() {
249	<	final Semaphore s = new Semaphore(0, false);
250	<	Thread t = new Thread(new Runnable() {
251	<	public void run() {
252	<	try {
253	<	s.acquire();
254	<	threadShouldThrow();
255	<	} catch(InterruptedException success){}
256	<	}
257	<	});
258	<	t.start();
259	<	try {
260	<	Thread.sleep(SHORT_DELAY_MS);
261	<	t.interrupt();
262	<	t.join();
263	<	} catch(InterruptedException e){
264	<	unexpectedException();
265	<	}
266	<	}
267	<
268	<	/**
269	<	*  A waiting timed acquire blocks interruptibly
270	<	*/
271	<	public void testTryAcquire_InterruptedException() {
272	<	final Semaphore s = new Semaphore(0, false);
273	<	Thread t = new Thread(new Runnable() {
274	<	public void run() {
275	<	try {
276	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
277	<	threadShouldThrow();
278	<	} catch(InterruptedException success){
279	<	}
280	<	}
281	<	});
282	<	t.start();
283	<	try {
284	<	Thread.sleep(SHORT_DELAY_MS);
285	<	t.interrupt();
286	<	t.join();
287	<	} catch(InterruptedException e){
288	<	unexpectedException();
289	<	}
419	>	s.release(-1);
420	>	shouldThrow();
421	>	} catch (IllegalArgumentException success) {}
422		}
423
424		/**
425	<	* getQueueLength reports number of waiting threads
294	<	*/
295	<	public void testGetQueueLength() {
296	<	final Semaphore lock = new Semaphore(1, false);
297	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
298	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
299	<	try {
300	<	assertEquals(0, lock.getQueueLength());
301	<	lock.acquireUninterruptibly();
302	<	t1.start();
303	<	Thread.sleep(SHORT_DELAY_MS);
304	<	assertEquals(1, lock.getQueueLength());
305	<	t2.start();
306	<	Thread.sleep(SHORT_DELAY_MS);
307	<	assertEquals(2, lock.getQueueLength());
308	<	t1.interrupt();
309	<	Thread.sleep(SHORT_DELAY_MS);
310	<	assertEquals(1, lock.getQueueLength());
311	<	lock.release();
312	<	Thread.sleep(SHORT_DELAY_MS);
313	<	assertEquals(0, lock.getQueueLength());
314	<	t1.join();
315	<	t2.join();
316	<	} catch(Exception e){
317	<	unexpectedException();
318	<	}
319	<	}
320	<
321	<	/**
322	<	* 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();
333	<	Thread.sleep(SHORT_DELAY_MS);
334	<	assertTrue(lock.getQueuedThreads().contains(t1));
335	<	t2.start();
336	<	Thread.sleep(SHORT_DELAY_MS);
337	<	assertTrue(lock.getQueuedThreads().contains(t1));
338	<	assertTrue(lock.getQueuedThreads().contains(t2));
339	<	t1.interrupt();
340	<	Thread.sleep(SHORT_DELAY_MS);
341	<	assertFalse(lock.getQueuedThreads().contains(t1));
342	<	assertTrue(lock.getQueuedThreads().contains(t2));
343	<	lock.release();
344	<	Thread.sleep(SHORT_DELAY_MS);
345	<	assertTrue(lock.getQueuedThreads().isEmpty());
346	<	t1.join();
347	<	t2.join();
348	<	} catch(Exception e){
349	<	unexpectedException();
350	<	}
351	<	}
352	<
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	<	*/
369	<	public void testSerialization() {
370	<	Semaphore l = new Semaphore(3, false);
371	<	try {
372	<	l.acquire();
373	<	l.release();
374	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
375	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
376	<	out.writeObject(l);
377	<	out.close();
378	<
379	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
380	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
381	<	Semaphore r = (Semaphore) in.readObject();
382	<	assertEquals(3, r.availablePermits());
383	<	assertFalse(r.isFair());
384	<	r.acquire();
385	<	r.release();
386	<	} catch(Exception e){
387	<	unexpectedException();
388	<	}
389	<	}
390	<
391	<
392	<	/**
393	<	* Zero, negative, and positive initial values are allowed in constructor
394	<	*/
395	<	public void testConstructor_fair() {
396	<	Semaphore s0 = new Semaphore(0, true);
397	<	assertEquals(0, s0.availablePermits());
398	<	assertTrue(s0.isFair());
399	<	Semaphore s1 = new Semaphore(-1, true);
400	<	assertEquals(-1, s1.availablePermits());
401	<	Semaphore s2 = new Semaphore(-1, true);
402	<	assertEquals(-1, s2.availablePermits());
403	<	}
404	<
405	<	/**
406	<	* tryAcquire succeeds when sufficent permits, else fails
407	<	*/
408	<	public void testTryAcquireInSameThread_fair() {
409	<	Semaphore s = new Semaphore(2, true);
410	<	assertEquals(2, s.availablePermits());
411	<	assertTrue(s.tryAcquire());
412	<	assertTrue(s.tryAcquire());
413	<	assertEquals(0, s.availablePermits());
414	<	assertFalse(s.tryAcquire());
415	<	}
416	<
417	<	/**
418	<	* tryAcquire(n) succeeds when sufficent permits, else fails
419	<	*/
420	<	public void testTryAcquireNInSameThread_fair() {
421	<	Semaphore s = new Semaphore(2, true);
422	<	assertEquals(2, s.availablePermits());
423	<	assertTrue(s.tryAcquire(2));
424	<	assertEquals(0, s.availablePermits());
425	<	assertFalse(s.tryAcquire());
426	<	}
427	<
428	<	/**
429	<	* 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();
435	–	s.release();
436	–	s.acquire();
437	–	s.release();
438	–	s.acquire();
439	–	s.release();
440	–	s.acquire();
441	–	s.release();
467		s.acquire();
468		s.release();
444	–	assertEquals(1, s.availablePermits());
445	–	} catch( InterruptedException e){
446	–	unexpectedException();
447	–	}
448	–	}
449	–
450	–	/**
451	–	* Acquire(n) and release(n) of semaphore succeed if initially available
452	–	*/
453	–	public void testAcquireReleaseNInSameThread_fair() {
454	–	Semaphore s = new Semaphore(1, true);
455	–	try {
456	–	s.release(1);
457	–	s.acquire(1);
458	–	s.release(2);
459	–	s.acquire(2);
460	–	s.release(3);
461	–	s.acquire(3);
462	–	s.release(4);
463	–	s.acquire(4);
464	–	s.release(5);
465	–	s.acquire(5);
466	–	assertEquals(1, s.availablePermits());
467	–	} catch( InterruptedException e){
468	–	unexpectedException();
469	–	}
470	–	}
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
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);
508	<	assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
509	<	assertEquals(1, s.availablePermits());
510	<	} catch( InterruptedException e){
511	<	unexpectedException();
512	<	}
504	>	* tryAcquire(n) succeeds when sufficient permits, else fails
505	>	*/
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());
532	–	} catch( InterruptedException e){
533	–	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() {
608	<	try {
609	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
610	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
611	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
612	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
613	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
614	<
615	<	} catch(InterruptedException ie){
616	<	threadUnexpectedException();
617	<	}
618	<	}
619	<	});
620	<	t.start();
621	<	try {
622	<	s.release();
623	<	s.release();
624	<	s.release();
625	<	s.release();
626	<	s.release();
627	<	t.join();
628	<	} catch( InterruptedException e){
629	<	unexpectedException();
630	<	}
631	<	}
632	<
633	<	/**
634	<	* release(n) in one thread enables timed acquire(n) in another thread
635	<	*/
636	<	public void testTimedAcquireReleaseNInDifferentThreads_fair() {
637	<	final Semaphore s = new Semaphore(2, true);
638	<	Thread t = new Thread(new Runnable() {
639	<	public void run() {
640	<	try {
641	<	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
642	<	s.release(2);
643	<	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
644	<	s.release(2);
645	<	} catch(InterruptedException ie){
646	<	threadUnexpectedException();
647	<	}
648	<	}
649	<	});
650	<	t.start();
651	<	try {
652	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
653	<	s.release(2);
654	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
655	<	s.release(2);
656	<	t.join();
657	<	} catch( InterruptedException e){
658	<	unexpectedException();
659	<	}
660	<	}
661	<
662	<	/**
663	<	* A waiting acquire blocks interruptibly
664	<	*/
665	<	public void testAcquire_InterruptedException_fair() {
666	<	final Semaphore s = new Semaphore(0, true);
667	<	Thread t = new Thread(new Runnable() {
668	<	public void run() {
669	<	try {
670	<	s.acquire();
671	<	threadShouldThrow();
672	<	} catch(InterruptedException success){}
673	<	}
674	<	});
675	<	t.start();
676	<	try {
677	<	Thread.sleep(SHORT_DELAY_MS);
678	<	t.interrupt();
679	<	t.join();
680	<	} catch(InterruptedException e){
681	<	unexpectedException();
682	<	}
683	<	}
684	<
685	<	/**
686	<	* A waiting acquire(n) blocks interruptibly
687	<	*/
688	<	public void testAcquireN_InterruptedException_fair() {
689	<	final Semaphore s = new Semaphore(2, true);
690	<	Thread t = new Thread(new Runnable() {
691	<	public void run() {
692	<	try {
693	<	s.acquire(3);
694	<	threadShouldThrow();
695	<	} catch(InterruptedException success){}
696	<	}
697	<	});
698	<	t.start();
699	<	try {
700	<	Thread.sleep(SHORT_DELAY_MS);
701	<	t.interrupt();
702	<	t.join();
703	<	} catch(InterruptedException e){
704	<	unexpectedException();
705	<	}
706	<	}
707	<
708	<	/**
709	<	*  A waiting tryAcquire blocks interruptibly
710	<	*/
711	<	public void testTryAcquire_InterruptedException_fair() {
712	<	final Semaphore s = new Semaphore(0, true);
713	<	Thread t = new Thread(new Runnable() {
714	<	public void run() {
715	<	try {
716	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
717	<	threadShouldThrow();
718	<	} catch(InterruptedException success){
719	<	}
720	<	}
721	<	});
722	<	t.start();
723	<	try {
724	<	Thread.sleep(SHORT_DELAY_MS);
725	<	t.interrupt();
726	<	t.join();
727	<	} catch(InterruptedException e){
728	<	unexpectedException();
729	<	}
730	<	}
731	<
732	<	/**
733	<	*  A waiting tryAcquire(n) blocks interruptibly
734	<	*/
735	<	public void testTryAcquireN_InterruptedException_fair() {
736	<	final Semaphore s = new Semaphore(1, true);
737	<	Thread t = new Thread(new Runnable() {
738	<	public void run() {
739	<	try {
740	<	s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
741	<	threadShouldThrow();
742	<	} catch(InterruptedException success){
743	<	}
744	<	}
745	<	});
746	<	t.start();
747	<	try {
748	<	Thread.sleep(SHORT_DELAY_MS);
749	<	t.interrupt();
750	<	t.join();
751	<	} catch(InterruptedException e){
752	<	unexpectedException();
753	<	}
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	<	* getQueueLength reports number of waiting threads
638	<	*/
639	<	public void testGetQueueLength_fair() {
640	<	final Semaphore lock = new Semaphore(1, true);
641	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
642	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
643	<	try {
644	<	assertEquals(0, lock.getQueueLength());
645	<	lock.acquireUninterruptibly();
646	<	t1.start();
647	<	Thread.sleep(SHORT_DELAY_MS);
648	<	assertEquals(1, lock.getQueueLength());
649	<	t2.start();
770	<	Thread.sleep(SHORT_DELAY_MS);
771	<	assertEquals(2, lock.getQueueLength());
772	<	t1.interrupt();
773	<	Thread.sleep(SHORT_DELAY_MS);
774	<	assertEquals(1, lock.getQueueLength());
775	<	lock.release();
776	<	Thread.sleep(SHORT_DELAY_MS);
777	<	assertEquals(0, lock.getQueueLength());
778	<	t1.join();
779	<	t2.join();
780	<	} catch(Exception e){
781	<	unexpectedException();
782	<	}
783	<	}
784	<
785	<
786	<	/**
787	<	* a deserialized serialized semaphore has same number of permits
788	<	*/
789	<	public void testSerialization_fair() {
790	<	Semaphore l = new Semaphore(3, true);
791	<
792	<	try {
793	<	l.acquire();
794	<	l.release();
795	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
796	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
797	<	out.writeObject(l);
798	<	out.close();
799	<
800	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
801	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
802	<	Semaphore r = (Semaphore) in.readObject();
803	<	assertEquals(3, r.availablePermits());
804	<	assertTrue(r.isFair());
805	<	r.acquire();
806	<	r.release();
807	<	} catch(Exception e){
808	<	unexpectedException();
809	<	}
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
812	–
652		}

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