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Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.13 by dl, Fri Jan 9 14:45:58 2004 UTC vs.
Revision 1.36 by jsr166, Thu Nov 19 03:35:48 2015 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3		* Expert Group and released to the public domain, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
5	<	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	<	* Pat Fisher, Mike Judd.
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5	>	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	>	* Pat Fisher, Mike Judd.
7		*/
8
9	<	import junit.framework.*;
10	<	import java.util.*;
11	<	import java.util.concurrent.*;
12	<	import java.io.*;
9	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10	>
11	>	import java.util.Collection;
12	>	import java.util.concurrent.CountDownLatch;
13	>	import java.util.concurrent.Semaphore;
14	>
15	>	import junit.framework.AssertionFailedError;
16	>	import junit.framework.Test;
17	>	import junit.framework.TestSuite;
18
19		public class SemaphoreTest extends JSR166TestCase {
20		public static void main(String[] args) {
21	<	junit.textui.TestRunner.run (suite());
21	>	main(suite(), args);
22		}
23		public static Test suite() {
24	<	return new TestSuite(SemaphoreTest.class);
24	>	return new TestSuite(SemaphoreTest.class);
25		}
26
27		/**
28		* Subclass to expose protected methods
29		*/
30		static class PublicSemaphore extends Semaphore {
31	<	PublicSemaphore(int p, boolean f) { super(p, f); }
32	<	public Collection<Thread> getQueuedThreads() {
33	<	return super.getQueuedThreads();
31	>	PublicSemaphore(int permits) { super(permits); }
32	>	PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
33	>	public Collection<Thread> getQueuedThreads() {
34	>	return super.getQueuedThreads();
35	>	}
36	>	public boolean hasQueuedThread(Thread t) {
37	>	return super.getQueuedThreads().contains(t);
38		}
39	<	public void reducePermits(int p) {
40	<	super.reducePermits(p);
39	>	public void reducePermits(int reduction) {
40	>	super.reducePermits(reduction);
41		}
42		}
43
44		/**
45		* A runnable calling acquire
46		*/
47	<	class InterruptibleLockRunnable implements Runnable {
47	>	class InterruptibleLockRunnable extends CheckedRunnable {
48		final Semaphore lock;
49	<	InterruptibleLockRunnable(Semaphore l) { lock = l; }
50	<	public void run() {
49	>	InterruptibleLockRunnable(Semaphore s) { lock = s; }
50	>	public void realRun() {
51		try {
52		lock.acquire();
53	<	} catch(InterruptedException success){}
53	>	}
54	>	catch (InterruptedException ignored) {}
55		}
56		}
57
48	–
58		/**
59	<	* A runnable calling acquire that expects to be
51	<	* interrupted
59	>	* A runnable calling acquire that expects to be interrupted
60		*/
61	<	class InterruptedLockRunnable implements Runnable {
61	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
62		final Semaphore lock;
63	<	InterruptedLockRunnable(Semaphore l) { lock = l; }
64	<	public void run() {
65	<	try {
66	<	lock.acquire();
67	<	threadShouldThrow();
68	<	} catch(InterruptedException success){}
63	>	InterruptedLockRunnable(Semaphore s) { lock = s; }
64	>	public void realRun() throws InterruptedException {
65	>	lock.acquire();
66	>	}
67	>	}
68	>
69	>	/**
70	>	* Spin-waits until s.hasQueuedThread(t) becomes true.
71	>	*/
72	>	void waitForQueuedThread(PublicSemaphore s, Thread t) {
73	>	long startTime = System.nanoTime();
74	>	while (!s.hasQueuedThread(t)) {
75	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
76	>	throw new AssertionFailedError("timed out");
77	>	Thread.yield();
78	>	}
79	>	assertTrue(s.hasQueuedThreads());
80	>	assertTrue(t.isAlive());
81	>	}
82	>
83	>	/**
84	>	* Spin-waits until s.hasQueuedThreads() becomes true.
85	>	*/
86	>	void waitForQueuedThreads(Semaphore s) {
87	>	long startTime = System.nanoTime();
88	>	while (!s.hasQueuedThreads()) {
89	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
90	>	throw new AssertionFailedError("timed out");
91	>	Thread.yield();
92	>	}
93	>	}
94	>
95	>	enum AcquireMethod {
96	>	acquire() {
97	>	void acquire(Semaphore s) throws InterruptedException {
98	>	s.acquire();
99	>	}
100	>	},
101	>	acquireN() {
102	>	void acquire(Semaphore s, int permits) throws InterruptedException {
103	>	s.acquire(permits);
104	>	}
105	>	},
106	>	acquireUninterruptibly() {
107	>	void acquire(Semaphore s) {
108	>	s.acquireUninterruptibly();
109	>	}
110	>	},
111	>	acquireUninterruptiblyN() {
112	>	void acquire(Semaphore s, int permits) {
113	>	s.acquireUninterruptibly(permits);
114	>	}
115	>	},
116	>	tryAcquire() {
117	>	void acquire(Semaphore s) {
118	>	assertTrue(s.tryAcquire());
119	>	}
120	>	},
121	>	tryAcquireN() {
122	>	void acquire(Semaphore s, int permits) {
123	>	assertTrue(s.tryAcquire(permits));
124	>	}
125	>	},
126	>	tryAcquireTimed() {
127	>	void acquire(Semaphore s) throws InterruptedException {
128	>	assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
129	>	}
130	>	},
131	>	tryAcquireTimedN {
132	>	void acquire(Semaphore s, int permits) throws InterruptedException {
133	>	assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
134	>	}
135	>	};
136	>
137	>	// Intentionally meta-circular
138	>
139	>	/** Acquires 1 permit. */
140	>	void acquire(Semaphore s) throws InterruptedException {
141	>	acquire(s, 1);
142	>	}
143	>	/** Acquires the given number of permits. */
144	>	void acquire(Semaphore s, int permits) throws InterruptedException {
145	>	for (int i = 0; i < permits; i++)
146	>	acquire(s);
147		}
148		}
149
150		/**
151		* Zero, negative, and positive initial values are allowed in constructor
152		*/
153	<	public void testConstructor() {
154	<	Semaphore s0 = new Semaphore(0, false);
155	<	assertEquals(0, s0.availablePermits());
156	<	assertFalse(s0.isFair());
157	<	Semaphore s1 = new Semaphore(-1, false);
158	<	assertEquals(-1, s1.availablePermits());
159	<	assertFalse(s1.isFair());
160	<	Semaphore s2 = new Semaphore(-1, false);
75	<	assertEquals(-1, s2.availablePermits());
76	<	assertFalse(s2.isFair());
153	>	public void testConstructor()      { testConstructor(false); }
154	>	public void testConstructor_fair() { testConstructor(true); }
155	>	public void testConstructor(boolean fair) {
156	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
157	>	Semaphore s = new Semaphore(permits, fair);
158	>	assertEquals(permits, s.availablePermits());
159	>	assertEquals(fair, s.isFair());
160	>	}
161		}
162
163		/**
164		* Constructor without fairness argument behaves as nonfair
165		*/
166	<	public void testConstructor2() {
167	<	Semaphore s0 = new Semaphore(0);
168	<	assertEquals(0, s0.availablePermits());
169	<	assertFalse(s0.isFair());
170	<	Semaphore s1 = new Semaphore(-1);
171	<	assertEquals(-1, s1.availablePermits());
88	<	assertFalse(s1.isFair());
89	<	Semaphore s2 = new Semaphore(-1);
90	<	assertEquals(-1, s2.availablePermits());
91	<	assertFalse(s2.isFair());
166	>	public void testConstructorDefaultsToNonFair() {
167	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
168	>	Semaphore s = new Semaphore(permits);
169	>	assertEquals(permits, s.availablePermits());
170	>	assertFalse(s.isFair());
171	>	}
172		}
173
174		/**
175		* tryAcquire succeeds when sufficient permits, else fails
176		*/
177	<	public void testTryAcquireInSameThread() {
178	<	Semaphore s = new Semaphore(2, false);
177	>	public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
178	>	public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
179	>	public void testTryAcquireInSameThread(boolean fair) {
180	>	Semaphore s = new Semaphore(2, fair);
181		assertEquals(2, s.availablePermits());
182		assertTrue(s.tryAcquire());
183		assertTrue(s.tryAcquire());
184		assertEquals(0, s.availablePermits());
185		assertFalse(s.tryAcquire());
186	+	assertFalse(s.tryAcquire());
187	+	assertEquals(0, s.availablePermits());
188		}
189
190		/**
191	<	* Acquire and release of semaphore succeed if initially available
108	<	*/
109	<	public void testAcquireReleaseInSameThread() {
110	<	Semaphore s = new Semaphore(1, false);
111	<	try {
112	<	s.acquire();
113	<	s.release();
114	<	s.acquire();
115	<	s.release();
116	<	s.acquire();
117	<	s.release();
118	<	s.acquire();
119	<	s.release();
120	<	s.acquire();
121	<	s.release();
122	<	assertEquals(1, s.availablePermits());
123	<	} catch( InterruptedException e){
124	<	unexpectedException();
125	<	}
126	<	}
127	<
128	<	/**
129	<	* Uninterruptible acquire and release of semaphore succeed if
130	<	* initially available
131	<	*/
132	<	public void testAcquireUninterruptiblyReleaseInSameThread() {
133	<	Semaphore s = new Semaphore(1, false);
134	<	try {
135	<	s.acquireUninterruptibly();
136	<	s.release();
137	<	s.acquireUninterruptibly();
138	<	s.release();
139	<	s.acquireUninterruptibly();
140	<	s.release();
141	<	s.acquireUninterruptibly();
142	<	s.release();
143	<	s.acquireUninterruptibly();
144	<	s.release();
145	<	assertEquals(1, s.availablePermits());
146	<	} finally {
147	<	}
148	<	}
149	<
150	<	/**
151	<	* Timed Acquire and release of semaphore succeed if
152	<	* initially available
153	<	*/
154	<	public void testTimedAcquireReleaseInSameThread() {
155	<	Semaphore s = new Semaphore(1, false);
156	<	try {
157	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
158	<	s.release();
159	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
160	<	s.release();
161	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
162	<	s.release();
163	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
164	<	s.release();
165	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
166	<	s.release();
167	<	assertEquals(1, s.availablePermits());
168	<	} catch( InterruptedException e){
169	<	unexpectedException();
170	<	}
171	<	}
172	<
173	<	/**
174	<	* A release in one thread enables an acquire in another thread
175	<	*/
176	<	public void testAcquireReleaseInDifferentThreads() {
177	<	final Semaphore s = new Semaphore(0, false);
178	<	Thread t = new Thread(new Runnable() {
179	<	public void run() {
180	<	try {
181	<	s.acquire();
182	<	s.release();
183	<	s.release();
184	<	s.acquire();
185	<	} catch(InterruptedException ie){
186	<	threadUnexpectedException();
187	<	}
188	<	}
189	<	});
190	<	try {
191	<	t.start();
192	<	Thread.sleep(SHORT_DELAY_MS);
193	<	s.release();
194	<	s.release();
195	<	s.acquire();
196	<	s.acquire();
197	<	s.release();
198	<	t.join();
199	<	} catch( InterruptedException e){
200	<	unexpectedException();
201	<	}
202	<	}
203	<
204	<	/**
205	<	* A release in one thread enables an uninterruptible acquire in another thread
191	>	* timed tryAcquire times out
192		*/
193	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
194	<	final Semaphore s = new Semaphore(0, false);
195	<	Thread t = new Thread(new Runnable() {
196	<	public void run() {
197	<	s.acquireUninterruptibly();
198	<	s.release();
199	<	s.release();
200	<	s.acquireUninterruptibly();
201	<	}
202	<	});
203	<	try {
204	<	t.start();
205	<	Thread.sleep(SHORT_DELAY_MS);
206	<	s.release();
207	<	s.release();
208	<	s.acquireUninterruptibly();
209	<	s.acquireUninterruptibly();
210	<	s.release();
211	<	t.join();
212	<	} catch( InterruptedException e){
213	<	unexpectedException();
214	<	}
215	<	}
193	>	public void testTryAcquire_timeout()      { testTryAcquire_timeout(false); }
194	>	public void testTryAcquire_timeout_fair() { testTryAcquire_timeout(true); }
195	>	public void testTryAcquire_timeout(boolean fair) {
196	>	Semaphore s = new Semaphore(0, fair);
197	>	long startTime = System.nanoTime();
198	>	try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
199	>	catch (InterruptedException e) { threadUnexpectedException(e); }
200	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
201	>	}
202	>
203	>	/**
204	>	* timed tryAcquire(N) times out
205	>	*/
206	>	public void testTryAcquireN_timeout()      { testTryAcquireN_timeout(false); }
207	>	public void testTryAcquireN_timeout_fair() { testTryAcquireN_timeout(true); }
208	>	public void testTryAcquireN_timeout(boolean fair) {
209	>	Semaphore s = new Semaphore(2, fair);
210	>	long startTime = System.nanoTime();
211	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
212	>	catch (InterruptedException e) { threadUnexpectedException(e); }
213	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
214	>	}
215	>
216	>	/**
217	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
218	>	* are interruptible
219	>	*/
220	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
221	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
222	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
223	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
224	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
225	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
226	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
227	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
228	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
229	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
230	>	final Semaphore pleaseInterrupt = new Semaphore(0, fair);
231	>	Thread t = newStartedThread(new CheckedRunnable() {
232	>	public void realRun() {
233	>	// Interrupt before acquire
234	>	Thread.currentThread().interrupt();
235	>	try {
236	>	acquirer.acquire(s);
237	>	shouldThrow();
238	>	} catch (InterruptedException success) {}
239	>
240	>	// Interrupt during acquire
241	>	try {
242	>	acquirer.acquire(s);
243	>	shouldThrow();
244	>	} catch (InterruptedException success) {}
245	>
246	>	// Interrupt before acquire(N)
247	>	Thread.currentThread().interrupt();
248	>	try {
249	>	acquirer.acquire(s, 3);
250	>	shouldThrow();
251	>	} catch (InterruptedException success) {}
252	>
253	>	pleaseInterrupt.release();
254	>
255	>	// Interrupt during acquire(N)
256	>	try {
257	>	acquirer.acquire(s, 3);
258	>	shouldThrow();
259	>	} catch (InterruptedException success) {}
260	>	}});
261	>
262	>	waitForQueuedThread(s, t);
263	>	t.interrupt();
264	>	await(pleaseInterrupt);
265	>	waitForQueuedThread(s, t);
266	>	t.interrupt();
267	>	awaitTermination(t);
268	>	}
269	>
270	>	/**
271	>	* acquireUninterruptibly(), acquireUninterruptibly(N) are
272	>	* uninterruptible
273	>	*/
274	>	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
275	>	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
276	>	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
277	>	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
278	>	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
279	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
280	>	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
281	>
282	>	Thread t1 = newStartedThread(new CheckedRunnable() {
283	>	public void realRun() throws InterruptedException {
284	>	// Interrupt before acquire
285	>	pleaseInterrupt.release();
286	>	Thread.currentThread().interrupt();
287	>	acquirer.acquire(s);
288	>	assertTrue(Thread.interrupted());
289	>	}});
290	>
291	>	Thread t2 = newStartedThread(new CheckedRunnable() {
292	>	public void realRun() throws InterruptedException {
293	>	// Interrupt during acquire
294	>	pleaseInterrupt.release();
295	>	acquirer.acquire(s);
296	>	assertTrue(Thread.interrupted());
297	>	}});
298	>
299	>	await(pleaseInterrupt);
300	>	waitForQueuedThread(s, t1);
301	>	waitForQueuedThread(s, t2);
302	>	t2.interrupt();
303
304	+	assertThreadStaysAlive(t1);
305	+	assertTrue(t2.isAlive());
306
307	<	/**
233	<	*  A release in one thread enables a timed acquire in another thread
234	<	*/
235	<	public void testTimedAcquireReleaseInDifferentThreads() {
236	<	final Semaphore s = new Semaphore(1, false);
237	<	Thread t = new Thread(new Runnable() {
238	<	public void run() {
239	<	try {
240	<	s.release();
241	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
242	<	s.release();
243	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
307	>	s.release(2);
308
309	<	} catch(InterruptedException ie){
310	<	threadUnexpectedException();
247	<	}
248	<	}
249	<	});
250	<	try {
251	<	t.start();
252	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
253	<	s.release();
254	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
255	<	s.release();
256	<	s.release();
257	<	t.join();
258	<	} catch( InterruptedException e){
259	<	unexpectedException();
260	<	}
261	<	}
262	<
263	<	/**
264	<	* A waiting acquire blocks interruptibly
265	<	*/
266	<	public void testAcquire_InterruptedException() {
267	<	final Semaphore s = new Semaphore(0, false);
268	<	Thread t = new Thread(new Runnable() {
269	<	public void run() {
270	<	try {
271	<	s.acquire();
272	<	threadShouldThrow();
273	<	} catch(InterruptedException success){}
274	<	}
275	<	});
276	<	t.start();
277	<	try {
278	<	Thread.sleep(SHORT_DELAY_MS);
279	<	t.interrupt();
280	<	t.join();
281	<	} catch(InterruptedException e){
282	<	unexpectedException();
283	<	}
284	<	}
285	<
286	<	/**
287	<	*  A waiting timed acquire blocks interruptibly
288	<	*/
289	<	public void testTryAcquire_InterruptedException() {
290	<	final Semaphore s = new Semaphore(0, false);
291	<	Thread t = new Thread(new Runnable() {
292	<	public void run() {
293	<	try {
294	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
295	<	threadShouldThrow();
296	<	} catch(InterruptedException success){
297	<	}
298	<	}
299	<	});
300	<	t.start();
301	<	try {
302	<	Thread.sleep(SHORT_DELAY_MS);
303	<	t.interrupt();
304	<	t.join();
305	<	} catch(InterruptedException e){
306	<	unexpectedException();
307	<	}
309	>	awaitTermination(t1);
310	>	awaitTermination(t2);
311		}
312
313		/**
314		* hasQueuedThreads reports whether there are waiting threads
315		*/
316	<	public void testHasQueuedThreads() {
317	<	final Semaphore lock = new Semaphore(1, false);
318	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
319	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
320	<	try {
321	<	assertFalse(lock.hasQueuedThreads());
322	<	lock.acquireUninterruptibly();
323	<	t1.start();
324	<	Thread.sleep(SHORT_DELAY_MS);
325	<	assertTrue(lock.hasQueuedThreads());
326	<	t2.start();
327	<	Thread.sleep(SHORT_DELAY_MS);
328	<	assertTrue(lock.hasQueuedThreads());
329	<	t1.interrupt();
330	<	Thread.sleep(SHORT_DELAY_MS);
331	<	assertTrue(lock.hasQueuedThreads());
332	<	lock.release();
333	<	Thread.sleep(SHORT_DELAY_MS);
334	<	assertFalse(lock.hasQueuedThreads());
332	<	t1.join();
333	<	t2.join();
334	<	} catch(Exception e){
335	<	unexpectedException();
336	<	}
337	<	}
316	>	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
317	>	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
318	>	public void testHasQueuedThreads(boolean fair) {
319	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
320	>	assertFalse(lock.hasQueuedThreads());
321	>	lock.acquireUninterruptibly();
322	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
323	>	waitForQueuedThread(lock, t1);
324	>	assertTrue(lock.hasQueuedThreads());
325	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
326	>	waitForQueuedThread(lock, t2);
327	>	assertTrue(lock.hasQueuedThreads());
328	>	t1.interrupt();
329	>	awaitTermination(t1);
330	>	assertTrue(lock.hasQueuedThreads());
331	>	lock.release();
332	>	awaitTermination(t2);
333	>	assertFalse(lock.hasQueuedThreads());
334	>	}
335
336		/**
337		* getQueueLength reports number of waiting threads
338		*/
339	<	public void testGetQueueLength() {
340	<	final Semaphore lock = new Semaphore(1, false);
341	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
342	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
343	<	try {
344	<	assertEquals(0, lock.getQueueLength());
345	<	lock.acquireUninterruptibly();
346	<	t1.start();
347	<	Thread.sleep(SHORT_DELAY_MS);
348	<	assertEquals(1, lock.getQueueLength());
349	<	t2.start();
350	<	Thread.sleep(SHORT_DELAY_MS);
351	<	assertEquals(2, lock.getQueueLength());
352	<	t1.interrupt();
353	<	Thread.sleep(SHORT_DELAY_MS);
354	<	assertEquals(1, lock.getQueueLength());
355	<	lock.release();
356	<	Thread.sleep(SHORT_DELAY_MS);
357	<	assertEquals(0, lock.getQueueLength());
361	<	t1.join();
362	<	t2.join();
363	<	} catch(Exception e){
364	<	unexpectedException();
365	<	}
366	<	}
339	>	public void testGetQueueLength()      { testGetQueueLength(false); }
340	>	public void testGetQueueLength_fair() { testGetQueueLength(true); }
341	>	public void testGetQueueLength(boolean fair) {
342	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
343	>	assertEquals(0, lock.getQueueLength());
344	>	lock.acquireUninterruptibly();
345	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
346	>	waitForQueuedThread(lock, t1);
347	>	assertEquals(1, lock.getQueueLength());
348	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
349	>	waitForQueuedThread(lock, t2);
350	>	assertEquals(2, lock.getQueueLength());
351	>	t1.interrupt();
352	>	awaitTermination(t1);
353	>	assertEquals(1, lock.getQueueLength());
354	>	lock.release();
355	>	awaitTermination(t2);
356	>	assertEquals(0, lock.getQueueLength());
357	>	}
358
359		/**
360		* getQueuedThreads includes waiting threads
361		*/
362	<	public void testGetQueuedThreads() {
363	<	final PublicSemaphore lock = new PublicSemaphore(1, false);
364	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
365	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
366	<	try {
367	<	assertTrue(lock.getQueuedThreads().isEmpty());
368	<	lock.acquireUninterruptibly();
369	<	assertTrue(lock.getQueuedThreads().isEmpty());
370	<	t1.start();
371	<	Thread.sleep(SHORT_DELAY_MS);
372	<	assertTrue(lock.getQueuedThreads().contains(t1));
373	<	t2.start();
374	<	Thread.sleep(SHORT_DELAY_MS);
375	<	assertTrue(lock.getQueuedThreads().contains(t1));
376	<	assertTrue(lock.getQueuedThreads().contains(t2));
377	<	t1.interrupt();
378	<	Thread.sleep(SHORT_DELAY_MS);
379	<	assertFalse(lock.getQueuedThreads().contains(t1));
380	<	assertTrue(lock.getQueuedThreads().contains(t2));
381	<	lock.release();
382	<	Thread.sleep(SHORT_DELAY_MS);
383	<	assertTrue(lock.getQueuedThreads().isEmpty());
393	<	t1.join();
394	<	t2.join();
395	<	} catch(Exception e){
396	<	unexpectedException();
397	<	}
398	<	}
362	>	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
363	>	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
364	>	public void testGetQueuedThreads(boolean fair) {
365	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
366	>	assertTrue(lock.getQueuedThreads().isEmpty());
367	>	lock.acquireUninterruptibly();
368	>	assertTrue(lock.getQueuedThreads().isEmpty());
369	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
370	>	waitForQueuedThread(lock, t1);
371	>	assertTrue(lock.getQueuedThreads().contains(t1));
372	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
373	>	waitForQueuedThread(lock, t2);
374	>	assertTrue(lock.getQueuedThreads().contains(t1));
375	>	assertTrue(lock.getQueuedThreads().contains(t2));
376	>	t1.interrupt();
377	>	awaitTermination(t1);
378	>	assertFalse(lock.getQueuedThreads().contains(t1));
379	>	assertTrue(lock.getQueuedThreads().contains(t2));
380	>	lock.release();
381	>	awaitTermination(t2);
382	>	assertTrue(lock.getQueuedThreads().isEmpty());
383	>	}
384
385		/**
386		* drainPermits reports and removes given number of permits
387		*/
388	<	public void testDrainPermits() {
389	<	Semaphore s = new Semaphore(0, false);
388	>	public void testDrainPermits()      { testDrainPermits(false); }
389	>	public void testDrainPermits_fair() { testDrainPermits(true); }
390	>	public void testDrainPermits(boolean fair) {
391	>	Semaphore s = new Semaphore(0, fair);
392		assertEquals(0, s.availablePermits());
393		assertEquals(0, s.drainPermits());
394		s.release(10);
#	Line 412 | Line 399 | public class SemaphoreTest extends JSR16
399		}
400
401		/**
402	<	* reducePermits reduces number of permits
416	<	*/
417	<	public void testReducePermits() {
418	<	PublicSemaphore s = new PublicSemaphore(10, false);
419	<	assertEquals(10, s.availablePermits());
420	<	s.reducePermits(1);
421	<	assertEquals(9, s.availablePermits());
422	<	s.reducePermits(10);
423	<	assertEquals(-1, s.availablePermits());
424	<	}
425	<
426	<	/**
427	<	* a deserialized serialized semaphore has same number of permits
402	>	* release(-N) throws IllegalArgumentException
403		*/
404	<	public void testSerialization() {
405	<	Semaphore l = new Semaphore(3, false);
404	>	public void testReleaseIAE()      { testReleaseIAE(false); }
405	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
406	>	public void testReleaseIAE(boolean fair) {
407	>	Semaphore s = new Semaphore(10, fair);
408		try {
409	<	l.acquire();
410	<	l.release();
411	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
435	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
436	<	out.writeObject(l);
437	<	out.close();
438	<
439	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
440	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
441	<	Semaphore r = (Semaphore) in.readObject();
442	<	assertEquals(3, r.availablePermits());
443	<	assertFalse(r.isFair());
444	<	r.acquire();
445	<	r.release();
446	<	} catch(Exception e){
447	<	unexpectedException();
448	<	}
409	>	s.release(-1);
410	>	shouldThrow();
411	>	} catch (IllegalArgumentException success) {}
412		}
413
451	–
414		/**
415	<	* Zero, negative, and positive initial values are allowed in constructor
415	>	* reducePermits(-N) throws IllegalArgumentException
416		*/
417	<	public void testConstructor_fair() {
418	<	Semaphore s0 = new Semaphore(0, true);
419	<	assertEquals(0, s0.availablePermits());
420	<	assertTrue(s0.isFair());
421	<	Semaphore s1 = new Semaphore(-1, true);
422	<	assertEquals(-1, s1.availablePermits());
423	<	Semaphore s2 = new Semaphore(-1, true);
424	<	assertEquals(-1, s2.availablePermits());
463	<	}
464	<
465	<	/**
466	<	* tryAcquire succeeds when sufficient permits, else fails
467	<	*/
468	<	public void testTryAcquireInSameThread_fair() {
469	<	Semaphore s = new Semaphore(2, true);
470	<	assertEquals(2, s.availablePermits());
471	<	assertTrue(s.tryAcquire());
472	<	assertTrue(s.tryAcquire());
473	<	assertEquals(0, s.availablePermits());
474	<	assertFalse(s.tryAcquire());
417	>	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
418	>	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
419	>	public void testReducePermitsIAE(boolean fair) {
420	>	PublicSemaphore s = new PublicSemaphore(10, fair);
421	>	try {
422	>	s.reducePermits(-1);
423	>	shouldThrow();
424	>	} catch (IllegalArgumentException success) {}
425		}
426
427		/**
428	<	* tryAcquire(n) succeeds when sufficient permits, else fails
428	>	* reducePermits reduces number of permits
429		*/
430	<	public void testTryAcquireNInSameThread_fair() {
431	<	Semaphore s = new Semaphore(2, true);
432	<	assertEquals(2, s.availablePermits());
433	<	assertTrue(s.tryAcquire(2));
434	<	assertEquals(0, s.availablePermits());
435	<	assertFalse(s.tryAcquire());
430	>	public void testReducePermits()      { testReducePermits(false); }
431	>	public void testReducePermits_fair() { testReducePermits(true); }
432	>	public void testReducePermits(boolean fair) {
433	>	PublicSemaphore s = new PublicSemaphore(10, fair);
434	>	assertEquals(10, s.availablePermits());
435	>	s.reducePermits(0);
436	>	assertEquals(10, s.availablePermits());
437	>	s.reducePermits(1);
438	>	assertEquals(9, s.availablePermits());
439	>	s.reducePermits(10);
440	>	assertEquals(-1, s.availablePermits());
441	>	s.reducePermits(10);
442	>	assertEquals(-11, s.availablePermits());
443	>	s.reducePermits(0);
444	>	assertEquals(-11, s.availablePermits());
445		}
446
447		/**
448	<	* Acquire and release of semaphore succeed if initially available
448	>	* a reserialized semaphore has same number of permits and
449	>	* fairness, but no queued threads
450		*/
451	<	public void testAcquireReleaseInSameThread_fair() {
452	<	Semaphore s = new Semaphore(1, true);
451	>	public void testSerialization()      { testSerialization(false); }
452	>	public void testSerialization_fair() { testSerialization(true); }
453	>	public void testSerialization(boolean fair) {
454		try {
455	+	Semaphore s = new Semaphore(3, fair);
456		s.acquire();
495	–	s.release();
496	–	s.acquire();
497	–	s.release();
457		s.acquire();
458		s.release();
500	–	s.acquire();
501	–	s.release();
502	–	s.acquire();
503	–	s.release();
504	–	assertEquals(1, s.availablePermits());
505	–	} catch( InterruptedException e){
506	–	unexpectedException();
507	–	}
508	–	}
459
460	<	/**
461	<	* Acquire(n) and release(n) of semaphore succeed if initially available
462	<	*/
463	<	public void testAcquireReleaseNInSameThread_fair() {
464	<	Semaphore s = new Semaphore(1, true);
465	<	try {
466	<	s.release(1);
467	<	s.acquire(1);
468	<	s.release(2);
469	<	s.acquire(2);
470	<	s.release(3);
471	<	s.acquire(3);
472	<	s.release(4);
473	<	s.acquire(4);
474	<	s.release(5);
475	<	s.acquire(5);
476	<	assertEquals(1, s.availablePermits());
477	<	} catch( InterruptedException e){
478	<	unexpectedException();
479	<	}
480	<	}
481	<
482	<	/**
483	<	* Acquire(n) and release(n) of semaphore succeed if initially available
484	<	*/
485	<	public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
486	<	Semaphore s = new Semaphore(1, true);
487	<	try {
488	<	s.release(1);
489	<	s.acquireUninterruptibly(1);
540	<	s.release(2);
541	<	s.acquireUninterruptibly(2);
542	<	s.release(3);
543	<	s.acquireUninterruptibly(3);
544	<	s.release(4);
545	<	s.acquireUninterruptibly(4);
546	<	s.release(5);
547	<	s.acquireUninterruptibly(5);
548	<	assertEquals(1, s.availablePermits());
549	<	} finally {
460	>	Semaphore clone = serialClone(s);
461	>	assertEquals(fair, s.isFair());
462	>	assertEquals(fair, clone.isFair());
463	>	assertEquals(2, s.availablePermits());
464	>	assertEquals(2, clone.availablePermits());
465	>	clone.acquire();
466	>	clone.acquire();
467	>	clone.release();
468	>	assertEquals(2, s.availablePermits());
469	>	assertEquals(1, clone.availablePermits());
470	>	assertFalse(s.hasQueuedThreads());
471	>	assertFalse(clone.hasQueuedThreads());
472	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
473	>
474	>	{
475	>	PublicSemaphore s = new PublicSemaphore(0, fair);
476	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
477	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
478	>	waitForQueuedThread(s, t);  // ... we use this instead
479	>	PublicSemaphore clone = serialClone(s);
480	>	assertEquals(fair, s.isFair());
481	>	assertEquals(fair, clone.isFair());
482	>	assertEquals(0, s.availablePermits());
483	>	assertEquals(0, clone.availablePermits());
484	>	assertTrue(s.hasQueuedThreads());
485	>	assertFalse(clone.hasQueuedThreads());
486	>	s.release();
487	>	awaitTermination(t);
488	>	assertFalse(s.hasQueuedThreads());
489	>	assertFalse(clone.hasQueuedThreads());
490		}
491		}
492
493		/**
494	<	* release(n) in one thread enables timed acquire(n) in another thread
494	>	* tryAcquire(n) succeeds when sufficient permits, else fails
495		*/
496	<	public void testTimedAcquireReleaseNInSameThread_fair() {
497	<	Semaphore s = new Semaphore(1, true);
498	<	try {
499	<	s.release(1);
500	<	assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
501	<	s.release(2);
502	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
503	<	s.release(3);
504	<	assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
505	<	s.release(4);
506	<	assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
507	<	s.release(5);
568	<	assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
569	<	assertEquals(1, s.availablePermits());
570	<	} catch( InterruptedException e){
571	<	unexpectedException();
572	<	}
496	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
497	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
498	>	public void testTryAcquireNInSameThread(boolean fair) {
499	>	Semaphore s = new Semaphore(2, fair);
500	>	assertEquals(2, s.availablePermits());
501	>	assertFalse(s.tryAcquire(3));
502	>	assertEquals(2, s.availablePermits());
503	>	assertTrue(s.tryAcquire(2));
504	>	assertEquals(0, s.availablePermits());
505	>	assertFalse(s.tryAcquire(1));
506	>	assertFalse(s.tryAcquire(2));
507	>	assertEquals(0, s.availablePermits());
508		}
509
510		/**
511	<	* release in one thread enables timed acquire in another thread
511	>	* acquire succeeds if permits available
512		*/
513	<	public void testTimedAcquireReleaseInSameThread_fair() {
514	<	Semaphore s = new Semaphore(1, true);
515	<	try {
516	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
517	<	s.release();
518	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
519	<	s.release();
520	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
521	<	s.release();
522	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
523	<	s.release();
524	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
525	<	s.release();
513	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
514	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
515	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
516	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
517	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
518	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
519	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
520	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
521	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
522	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
523	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
524	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
525	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
526	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
527	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
528	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
529	>	public void testReleaseAcquireSameThread(boolean fair,
530	>	final AcquireMethod acquirer) {
531	>	Semaphore s = new Semaphore(1, fair);
532	>	for (int i = 1; i < 6; i++) {
533	>	s.release(i);
534	>	assertEquals(1 + i, s.availablePermits());
535	>	try {
536	>	acquirer.acquire(s, i);
537	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
538		assertEquals(1, s.availablePermits());
592	–	} catch( InterruptedException e){
593	–	unexpectedException();
539		}
540		}
541
542		/**
543	<	* A release in one thread enables an acquire in another thread
543	>	* release in one thread enables acquire in another thread
544		*/
545	<	public void testAcquireReleaseInDifferentThreads_fair() {
546	<	final Semaphore s = new Semaphore(0, true);
547	<	Thread t = new Thread(new Runnable() {
548	<	public void run() {
549	<	try {
550	<	s.acquire();
551	<	s.acquire();
552	<	s.acquire();
553	<	s.acquire();
554	<	} catch(InterruptedException ie){
555	<	threadUnexpectedException();
556	<	}
557	<	}
558	<	});
559	<	try {
560	<	t.start();
561	<	Thread.sleep(SHORT_DELAY_MS);
562	<	s.release();
563	<	s.release();
564	<	s.release();
565	<	s.release();
566	<	s.release();
567	<	s.release();
568	<	t.join();
569	<	assertEquals(2, s.availablePermits());
570	<	} catch( InterruptedException e){
571	<	unexpectedException();
545	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
546	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
547	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
548	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
549	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
550	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
551	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
552	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
553	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
554	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
555	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
556	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
557	>	public void testReleaseAcquireDifferentThreads(boolean fair,
558	>	final AcquireMethod acquirer) {
559	>	final Semaphore s = new Semaphore(0, fair);
560	>	final int rounds = 4;
561	>	long startTime = System.nanoTime();
562	>	Thread t = newStartedThread(new CheckedRunnable() {
563	>	public void realRun() throws InterruptedException {
564	>	for (int i = 0; i < rounds; i++) {
565	>	assertFalse(s.hasQueuedThreads());
566	>	if (i % 2 == 0)
567	>	acquirer.acquire(s);
568	>	else
569	>	acquirer.acquire(s, 3);
570	>	}}});
571	>
572	>	for (int i = 0; i < rounds; i++) {
573	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
574	>	Thread.yield();
575	>	assertTrue(t.isAlive());
576	>	if (i % 2 == 0)
577	>	s.release();
578	>	else
579	>	s.release(3);
580		}
581	+	awaitTermination(t);
582	+	assertEquals(0, s.availablePermits());
583	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
584		}
585
586		/**
587	<	* release(n) in one thread enables acquire(n) in another thread
587	>	* fair locks are strictly FIFO
588		*/
589	<	public void testAcquireReleaseNInDifferentThreads_fair() {
590	<	final Semaphore s = new Semaphore(0, true);
591	<	Thread t = new Thread(new Runnable() {
592	<	public void run() {
593	<	try {
594	<	s.acquire();
595	<	s.release(2);
596	<	s.acquire();
597	<	} catch(InterruptedException ie){
598	<	threadUnexpectedException();
599	<	}
600	<	}
601	<	});
602	<	try {
603	<	t.start();
604	<	Thread.sleep(SHORT_DELAY_MS);
605	<	s.release(2);
606	<	s.acquire(2);
607	<	s.release(1);
608	<	t.join();
609	<	} catch( InterruptedException e){
610	<	unexpectedException();
611	<	}
589	>	public void testFairLocksFifo() {
590	>	final PublicSemaphore s = new PublicSemaphore(1, true);
591	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
592	>	Thread t1 = newStartedThread(new CheckedRunnable() {
593	>	public void realRun() throws InterruptedException {
594	>	// Will block; permits are available, but not three
595	>	s.acquire(3);
596	>	}});
597	>
598	>	waitForQueuedThread(s, t1);
599	>
600	>	Thread t2 = newStartedThread(new CheckedRunnable() {
601	>	public void realRun() throws InterruptedException {
602	>	// Will fail, even though 1 permit is available
603	>	assertFalse(s.tryAcquire(0L, MILLISECONDS));
604	>	assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
605	>
606	>	// untimed tryAcquire will barge and succeed
607	>	assertTrue(s.tryAcquire());
608	>	s.release(2);
609	>	assertTrue(s.tryAcquire(2));
610	>	s.release();
611	>
612	>	pleaseRelease.countDown();
613	>	// Will queue up behind t1, even though 1 permit is available
614	>	s.acquire();
615	>	}});
616	>
617	>	await(pleaseRelease);
618	>	waitForQueuedThread(s, t2);
619	>	s.release(2);
620	>	awaitTermination(t1);
621	>	assertTrue(t2.isAlive());
622	>	s.release();
623	>	awaitTermination(t2);
624		}
625
626		/**
627	<	* release(n) in one thread enables acquire(n) in another thread
628	<	*/
629	<	public void testAcquireReleaseNInDifferentThreads_fair2() {
630	<	final Semaphore s = new Semaphore(0, true);
631	<	Thread t = new Thread(new Runnable() {
632	<	public void run() {
633	<	try {
634	<	s.acquire(2);
635	<	s.acquire(2);
636	<	s.release(4);
637	<	} catch(InterruptedException ie){
638	<	threadUnexpectedException();
639	<	}
672	<	}
673	<	});
674	<	try {
675	<	t.start();
676	<	Thread.sleep(SHORT_DELAY_MS);
677	<	s.release(6);
678	<	s.acquire(2);
679	<	s.acquire(2);
680	<	s.release(2);
681	<	t.join();
682	<	} catch( InterruptedException e){
683	<	unexpectedException();
684	<	}
627	>	* toString indicates current number of permits
628	>	*/
629	>	public void testToString()      { testToString(false); }
630	>	public void testToString_fair() { testToString(true); }
631	>	public void testToString(boolean fair) {
632	>	PublicSemaphore s = new PublicSemaphore(0, fair);
633	>	assertTrue(s.toString().contains("Permits = 0"));
634	>	s.release();
635	>	assertTrue(s.toString().contains("Permits = 1"));
636	>	s.release(2);
637	>	assertTrue(s.toString().contains("Permits = 3"));
638	>	s.reducePermits(5);
639	>	assertTrue(s.toString().contains("Permits = -2"));
640		}
641
687	–
688	–
689	–
690	–
691	–	/**
692	–	* release in one thread enables timed acquire in another thread
693	–	*/
694	–	public void testTimedAcquireReleaseInDifferentThreads_fair() {
695	–	final Semaphore s = new Semaphore(1, true);
696	–	Thread t = new Thread(new Runnable() {
697	–	public void run() {
698	–	try {
699	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
700	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
701	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
702	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
703	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
704	–
705	–	} catch(InterruptedException ie){
706	–	threadUnexpectedException();
707	–	}
708	–	}
709	–	});
710	–	t.start();
711	–	try {
712	–	s.release();
713	–	s.release();
714	–	s.release();
715	–	s.release();
716	–	s.release();
717	–	t.join();
718	–	} catch( InterruptedException e){
719	–	unexpectedException();
720	–	}
721	–	}
722	–
723	–	/**
724	–	* release(n) in one thread enables timed acquire(n) in another thread
725	–	*/
726	–	public void testTimedAcquireReleaseNInDifferentThreads_fair() {
727	–	final Semaphore s = new Semaphore(2, true);
728	–	Thread t = new Thread(new Runnable() {
729	–	public void run() {
730	–	try {
731	–	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
732	–	s.release(2);
733	–	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
734	–	s.release(2);
735	–	} catch(InterruptedException ie){
736	–	threadUnexpectedException();
737	–	}
738	–	}
739	–	});
740	–	t.start();
741	–	try {
742	–	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
743	–	s.release(2);
744	–	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
745	–	s.release(2);
746	–	t.join();
747	–	} catch( InterruptedException e){
748	–	unexpectedException();
749	–	}
750	–	}
751	–
752	–	/**
753	–	* A waiting acquire blocks interruptibly
754	–	*/
755	–	public void testAcquire_InterruptedException_fair() {
756	–	final Semaphore s = new Semaphore(0, true);
757	–	Thread t = new Thread(new Runnable() {
758	–	public void run() {
759	–	try {
760	–	s.acquire();
761	–	threadShouldThrow();
762	–	} catch(InterruptedException success){}
763	–	}
764	–	});
765	–	t.start();
766	–	try {
767	–	Thread.sleep(SHORT_DELAY_MS);
768	–	t.interrupt();
769	–	t.join();
770	–	} catch(InterruptedException e){
771	–	unexpectedException();
772	–	}
773	–	}
774	–
775	–	/**
776	–	* A waiting acquire(n) blocks interruptibly
777	–	*/
778	–	public void testAcquireN_InterruptedException_fair() {
779	–	final Semaphore s = new Semaphore(2, true);
780	–	Thread t = new Thread(new Runnable() {
781	–	public void run() {
782	–	try {
783	–	s.acquire(3);
784	–	threadShouldThrow();
785	–	} catch(InterruptedException success){}
786	–	}
787	–	});
788	–	t.start();
789	–	try {
790	–	Thread.sleep(SHORT_DELAY_MS);
791	–	t.interrupt();
792	–	t.join();
793	–	} catch(InterruptedException e){
794	–	unexpectedException();
795	–	}
796	–	}
797	–
798	–	/**
799	–	*  A waiting tryAcquire blocks interruptibly
800	–	*/
801	–	public void testTryAcquire_InterruptedException_fair() {
802	–	final Semaphore s = new Semaphore(0, true);
803	–	Thread t = new Thread(new Runnable() {
804	–	public void run() {
805	–	try {
806	–	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
807	–	threadShouldThrow();
808	–	} catch(InterruptedException success){
809	–	}
810	–	}
811	–	});
812	–	t.start();
813	–	try {
814	–	Thread.sleep(SHORT_DELAY_MS);
815	–	t.interrupt();
816	–	t.join();
817	–	} catch(InterruptedException e){
818	–	unexpectedException();
819	–	}
820	–	}
821	–
822	–	/**
823	–	*  A waiting tryAcquire(n) blocks interruptibly
824	–	*/
825	–	public void testTryAcquireN_InterruptedException_fair() {
826	–	final Semaphore s = new Semaphore(1, true);
827	–	Thread t = new Thread(new Runnable() {
828	–	public void run() {
829	–	try {
830	–	s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
831	–	threadShouldThrow();
832	–	} catch(InterruptedException success){
833	–	}
834	–	}
835	–	});
836	–	t.start();
837	–	try {
838	–	Thread.sleep(SHORT_DELAY_MS);
839	–	t.interrupt();
840	–	t.join();
841	–	} catch(InterruptedException e){
842	–	unexpectedException();
843	–	}
844	–	}
845	–
846	–	/**
847	–	* getQueueLength reports number of waiting threads
848	–	*/
849	–	public void testGetQueueLength_fair() {
850	–	final Semaphore lock = new Semaphore(1, true);
851	–	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
852	–	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
853	–	try {
854	–	assertEquals(0, lock.getQueueLength());
855	–	lock.acquireUninterruptibly();
856	–	t1.start();
857	–	Thread.sleep(SHORT_DELAY_MS);
858	–	assertEquals(1, lock.getQueueLength());
859	–	t2.start();
860	–	Thread.sleep(SHORT_DELAY_MS);
861	–	assertEquals(2, lock.getQueueLength());
862	–	t1.interrupt();
863	–	Thread.sleep(SHORT_DELAY_MS);
864	–	assertEquals(1, lock.getQueueLength());
865	–	lock.release();
866	–	Thread.sleep(SHORT_DELAY_MS);
867	–	assertEquals(0, lock.getQueueLength());
868	–	t1.join();
869	–	t2.join();
870	–	} catch(Exception e){
871	–	unexpectedException();
872	–	}
873	–	}
874	–
875	–
876	–	/**
877	–	* a deserialized serialized semaphore has same number of permits
878	–	*/
879	–	public void testSerialization_fair() {
880	–	Semaphore l = new Semaphore(3, true);
881	–
882	–	try {
883	–	l.acquire();
884	–	l.release();
885	–	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
886	–	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
887	–	out.writeObject(l);
888	–	out.close();
889	–
890	–	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
891	–	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
892	–	Semaphore r = (Semaphore) in.readObject();
893	–	assertEquals(3, r.availablePermits());
894	–	assertTrue(r.isFair());
895	–	r.acquire();
896	–	r.release();
897	–	} catch(Exception e){
898	–	unexpectedException();
899	–	}
900	–	}
901	–
902	–
642		}

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