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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.12 by dl, Sun Jan 4 22:58:03 2004 UTC vs.
Revision 1.38 by jsr166, Sun May 14 00:38:16 2017 UTC

#	Line 1 | Line 1
1		/*
2		* Written by Doug Lea with assistance from members of JCP JSR-166
3		* Expert Group and released to the public domain, as explained at
4	<	* http://creativecommons.org/licenses/publicdomain
5	<	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	<	* Pat Fisher, Mike Judd.
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5	>	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	>	* Pat Fisher, Mike Judd.
7		*/
8
9	<	import junit.framework.*;
10	<	import java.util.*;
11	<	import java.util.concurrent.*;
12	<	import java.io.*;
9	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10	>
11	>	import java.util.Collection;
12	>	import java.util.concurrent.CountDownLatch;
13	>	import java.util.concurrent.Semaphore;
14	>
15	>	import junit.framework.AssertionFailedError;
16	>	import junit.framework.Test;
17	>	import junit.framework.TestSuite;
18
19		public class SemaphoreTest extends JSR166TestCase {
20		public static void main(String[] args) {
21	<	junit.textui.TestRunner.run (suite());
21	>	main(suite(), args);
22		}
23		public static Test suite() {
24	<	return new TestSuite(SemaphoreTest.class);
24	>	return new TestSuite(SemaphoreTest.class);
25		}
26
27		/**
28		* Subclass to expose protected methods
29		*/
30		static class PublicSemaphore extends Semaphore {
31	<	PublicSemaphore(int p, boolean f) { super(p, f); }
32	<	public Collection<Thread> getQueuedThreads() {
33	<	return super.getQueuedThreads();
31	>	PublicSemaphore(int permits) { super(permits); }
32	>	PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
33	>	public Collection<Thread> getQueuedThreads() {
34	>	return super.getQueuedThreads();
35	>	}
36	>	public boolean hasQueuedThread(Thread t) {
37	>	return super.getQueuedThreads().contains(t);
38		}
39	<	public void reducePermits(int p) {
40	<	super.reducePermits(p);
39	>	public void reducePermits(int reduction) {
40	>	super.reducePermits(reduction);
41		}
42		}
43
44		/**
45		* A runnable calling acquire
46		*/
47	<	class InterruptibleLockRunnable implements Runnable {
47	>	class InterruptibleLockRunnable extends CheckedRunnable {
48		final Semaphore lock;
49	<	InterruptibleLockRunnable(Semaphore l) { lock = l; }
50	<	public void run() {
49	>	InterruptibleLockRunnable(Semaphore s) { lock = s; }
50	>	public void realRun() {
51		try {
52		lock.acquire();
53	<	} catch(InterruptedException success){}
53	>	}
54	>	catch (InterruptedException ignored) {}
55		}
56		}
57
48	–
58		/**
59	<	* A runnable calling acquire that expects to be
51	<	* interrupted
59	>	* A runnable calling acquire that expects to be interrupted
60		*/
61	<	class InterruptedLockRunnable implements Runnable {
61	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
62		final Semaphore lock;
63	<	InterruptedLockRunnable(Semaphore l) { lock = l; }
64	<	public void run() {
65	<	try {
66	<	lock.acquire();
67	<	threadShouldThrow();
68	<	} catch(InterruptedException success){}
63	>	InterruptedLockRunnable(Semaphore s) { lock = s; }
64	>	public void realRun() throws InterruptedException {
65	>	lock.acquire();
66	>	}
67	>	}
68	>
69	>	/**
70	>	* Spin-waits until s.hasQueuedThread(t) becomes true.
71	>	*/
72	>	void waitForQueuedThread(PublicSemaphore s, Thread t) {
73	>	long startTime = System.nanoTime();
74	>	while (!s.hasQueuedThread(t)) {
75	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
76	>	throw new AssertionFailedError("timed out");
77	>	Thread.yield();
78	>	}
79	>	assertTrue(s.hasQueuedThreads());
80	>	assertTrue(t.isAlive());
81	>	}
82	>
83	>	/**
84	>	* Spin-waits until s.hasQueuedThreads() becomes true.
85	>	*/
86	>	void waitForQueuedThreads(Semaphore s) {
87	>	long startTime = System.nanoTime();
88	>	while (!s.hasQueuedThreads()) {
89	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
90	>	throw new AssertionFailedError("timed out");
91	>	Thread.yield();
92	>	}
93	>	}
94	>
95	>	enum AcquireMethod {
96	>	acquire() {
97	>	void acquire(Semaphore s) throws InterruptedException {
98	>	s.acquire();
99	>	}
100	>	},
101	>	acquireN() {
102	>	void acquire(Semaphore s, int permits) throws InterruptedException {
103	>	s.acquire(permits);
104	>	}
105	>	},
106	>	acquireUninterruptibly() {
107	>	void acquire(Semaphore s) {
108	>	s.acquireUninterruptibly();
109	>	}
110	>	},
111	>	acquireUninterruptiblyN() {
112	>	void acquire(Semaphore s, int permits) {
113	>	s.acquireUninterruptibly(permits);
114	>	}
115	>	},
116	>	tryAcquire() {
117	>	void acquire(Semaphore s) {
118	>	assertTrue(s.tryAcquire());
119	>	}
120	>	},
121	>	tryAcquireN() {
122	>	void acquire(Semaphore s, int permits) {
123	>	assertTrue(s.tryAcquire(permits));
124	>	}
125	>	},
126	>	tryAcquireTimed() {
127	>	void acquire(Semaphore s) throws InterruptedException {
128	>	assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
129	>	}
130	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
131	>	},
132	>	tryAcquireTimedN {
133	>	void acquire(Semaphore s, int permits) throws InterruptedException {
134	>	assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
135	>	}
136	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
137	>	};
138	>
139	>	// Intentionally meta-circular
140	>
141	>	/** Acquires 1 permit. */
142	>	void acquire(Semaphore s) throws InterruptedException {
143	>	acquire(s, 1);
144	>	}
145	>	/** Acquires the given number of permits. */
146	>	void acquire(Semaphore s, int permits) throws InterruptedException {
147	>	for (int i = 0; i < permits; i++)
148	>	acquire(s);
149		}
150	+	Thread.State parkedState() { return Thread.State.WAITING; }
151		}
152
153		/**
154		* Zero, negative, and positive initial values are allowed in constructor
155		*/
156	<	public void testConstructor() {
157	<	Semaphore s0 = new Semaphore(0, false);
158	<	assertEquals(0, s0.availablePermits());
159	<	assertFalse(s0.isFair());
160	<	Semaphore s1 = new Semaphore(-1, false);
161	<	assertEquals(-1, s1.availablePermits());
162	<	Semaphore s2 = new Semaphore(-1, false);
74	<	assertEquals(-1, s2.availablePermits());
75	<	}
76	<
77	<	/**
78	<	* tryAcquire succeeds when sufficient permits, else fails
79	<	*/
80	<	public void testTryAcquireInSameThread() {
81	<	Semaphore s = new Semaphore(2, false);
82	<	assertEquals(2, s.availablePermits());
83	<	assertTrue(s.tryAcquire());
84	<	assertTrue(s.tryAcquire());
85	<	assertEquals(0, s.availablePermits());
86	<	assertFalse(s.tryAcquire());
87	<	}
88	<
89	<	/**
90	<	* Acquire and release of semaphore succeed if initially available
91	<	*/
92	<	public void testAcquireReleaseInSameThread() {
93	<	Semaphore s = new Semaphore(1, false);
94	<	try {
95	<	s.acquire();
96	<	s.release();
97	<	s.acquire();
98	<	s.release();
99	<	s.acquire();
100	<	s.release();
101	<	s.acquire();
102	<	s.release();
103	<	s.acquire();
104	<	s.release();
105	<	assertEquals(1, s.availablePermits());
106	<	} catch( InterruptedException e){
107	<	unexpectedException();
156	>	public void testConstructor()      { testConstructor(false); }
157	>	public void testConstructor_fair() { testConstructor(true); }
158	>	public void testConstructor(boolean fair) {
159	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
160	>	Semaphore s = new Semaphore(permits, fair);
161	>	assertEquals(permits, s.availablePermits());
162	>	assertEquals(fair, s.isFair());
163		}
164		}
165
166		/**
167	<	* Uninterruptible acquire and release of semaphore succeed if
113	<	* initially available
167	>	* Constructor without fairness argument behaves as nonfair
168		*/
169	<	public void testAcquireUninterruptiblyReleaseInSameThread() {
170	<	Semaphore s = new Semaphore(1, false);
171	<	try {
172	<	s.acquireUninterruptibly();
173	<	s.release();
120	<	s.acquireUninterruptibly();
121	<	s.release();
122	<	s.acquireUninterruptibly();
123	<	s.release();
124	<	s.acquireUninterruptibly();
125	<	s.release();
126	<	s.acquireUninterruptibly();
127	<	s.release();
128	<	assertEquals(1, s.availablePermits());
129	<	} finally {
169	>	public void testConstructorDefaultsToNonFair() {
170	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
171	>	Semaphore s = new Semaphore(permits);
172	>	assertEquals(permits, s.availablePermits());
173	>	assertFalse(s.isFair());
174		}
175		}
176
177		/**
178	<	* Timed Acquire and release of semaphore succeed if
135	<	* initially available
178	>	* tryAcquire succeeds when sufficient permits, else fails
179		*/
180	<	public void testTimedAcquireReleaseInSameThread() {
181	<	Semaphore s = new Semaphore(1, false);
182	<	try {
183	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
184	<	s.release();
185	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
186	<	s.release();
187	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
188	<	s.release();
189	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
190	<	s.release();
148	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
149	<	s.release();
150	<	assertEquals(1, s.availablePermits());
151	<	} catch( InterruptedException e){
152	<	unexpectedException();
153	<	}
180	>	public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
181	>	public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
182	>	public void testTryAcquireInSameThread(boolean fair) {
183	>	Semaphore s = new Semaphore(2, fair);
184	>	assertEquals(2, s.availablePermits());
185	>	assertTrue(s.tryAcquire());
186	>	assertTrue(s.tryAcquire());
187	>	assertEquals(0, s.availablePermits());
188	>	assertFalse(s.tryAcquire());
189	>	assertFalse(s.tryAcquire());
190	>	assertEquals(0, s.availablePermits());
191		}
192
193		/**
194	<	* A release in one thread enables an acquire in another thread
194	>	* timed tryAcquire times out
195		*/
196	<	public void testAcquireReleaseInDifferentThreads() {
197	<	final Semaphore s = new Semaphore(0, false);
198	<	Thread t = new Thread(new Runnable() {
199	<	public void run() {
200	<	try {
201	<	s.acquire();
202	<	s.release();
203	<	s.release();
204	<	s.acquire();
205	<	} catch(InterruptedException ie){
206	<	threadUnexpectedException();
207	<	}
208	<	}
209	<	});
210	<	try {
211	<	t.start();
212	<	Thread.sleep(SHORT_DELAY_MS);
213	<	s.release();
214	<	s.release();
215	<	s.acquire();
216	<	s.acquire();
217	<	s.release();
218	<	t.join();
219	<	} catch( InterruptedException e){
220	<	unexpectedException();
196	>	public void testTryAcquire_timeout()      { testTryAcquire_timeout(false); }
197	>	public void testTryAcquire_timeout_fair() { testTryAcquire_timeout(true); }
198	>	public void testTryAcquire_timeout(boolean fair) {
199	>	Semaphore s = new Semaphore(0, fair);
200	>	long startTime = System.nanoTime();
201	>	try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
202	>	catch (InterruptedException e) { threadUnexpectedException(e); }
203	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
204	>	}
205	>
206	>	/**
207	>	* timed tryAcquire(N) times out
208	>	*/
209	>	public void testTryAcquireN_timeout()      { testTryAcquireN_timeout(false); }
210	>	public void testTryAcquireN_timeout_fair() { testTryAcquireN_timeout(true); }
211	>	public void testTryAcquireN_timeout(boolean fair) {
212	>	Semaphore s = new Semaphore(2, fair);
213	>	long startTime = System.nanoTime();
214	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
215	>	catch (InterruptedException e) { threadUnexpectedException(e); }
216	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
217	>	}
218	>
219	>	/**
220	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
221	>	* are interruptible
222	>	*/
223	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
224	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
225	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
226	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
227	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
228	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
229	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
230	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
231	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
232	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
233	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
234	>	= new java.util.concurrent.CyclicBarrier(2);
235	>	Thread t = newStartedThread(new CheckedRunnable() {
236	>	public void realRun() {
237	>	// Interrupt before acquire
238	>	Thread.currentThread().interrupt();
239	>	try {
240	>	acquirer.acquire(s);
241	>	shouldThrow();
242	>	} catch (InterruptedException success) {}
243	>	assertFalse(Thread.interrupted());
244	>
245	>	// Interrupt before acquire(N)
246	>	Thread.currentThread().interrupt();
247	>	try {
248	>	acquirer.acquire(s, 3);
249	>	shouldThrow();
250	>	} catch (InterruptedException success) {}
251	>	assertFalse(Thread.interrupted());
252	>
253	>	// Interrupt during acquire
254	>	await(pleaseInterrupt);
255	>	try {
256	>	acquirer.acquire(s);
257	>	shouldThrow();
258	>	} catch (InterruptedException success) {}
259	>	assertFalse(Thread.interrupted());
260	>
261	>	// Interrupt during acquire(N)
262	>	await(pleaseInterrupt);
263	>	try {
264	>	acquirer.acquire(s, 3);
265	>	shouldThrow();
266	>	} catch (InterruptedException success) {}
267	>	assertFalse(Thread.interrupted());
268	>	}});
269	>
270	>	for (int n = 2; n-->0; ) {
271	>	await(pleaseInterrupt);
272	>	assertThreadBlocks(t, acquirer.parkedState());
273	>	t.interrupt();
274		}
275	+
276	+	awaitTermination(t);
277		}
278
279		/**
280	<	* A release in one thread enables an uninterruptible acquire in another thread
280	>	* acquireUninterruptibly(), acquireUninterruptibly(N) are
281	>	* uninterruptible
282		*/
283	<	public void testUninterruptibleAcquireReleaseInDifferentThreads() {
284	<	final Semaphore s = new Semaphore(0, false);
285	<	Thread t = new Thread(new Runnable() {
286	<	public void run() {
287	<	s.acquireUninterruptibly();
288	<	s.release();
289	<	s.release();
290	<	s.acquireUninterruptibly();
291	<	}
292	<	});
293	<	try {
294	<	t.start();
295	<	Thread.sleep(SHORT_DELAY_MS);
296	<	s.release();
297	<	s.release();
298	<	s.acquireUninterruptibly();
299	<	s.acquireUninterruptibly();
300	<	s.release();
301	<	t.join();
302	<	} catch( InterruptedException e){
303	<	unexpectedException();
304	<	}
305	<	}
283	>	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
284	>	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
285	>	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
286	>	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
287	>	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
288	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
289	>	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
290	>
291	>	Thread t1 = newStartedThread(new CheckedRunnable() {
292	>	public void realRun() throws InterruptedException {
293	>	// Interrupt before acquire
294	>	pleaseInterrupt.release();
295	>	Thread.currentThread().interrupt();
296	>	acquirer.acquire(s);
297	>	assertTrue(Thread.interrupted());
298	>	}});
299	>
300	>	Thread t2 = newStartedThread(new CheckedRunnable() {
301	>	public void realRun() throws InterruptedException {
302	>	// Interrupt during acquire
303	>	pleaseInterrupt.release();
304	>	acquirer.acquire(s);
305	>	assertTrue(Thread.interrupted());
306	>	}});
307	>
308	>	await(pleaseInterrupt);
309	>	waitForQueuedThread(s, t1);
310	>	waitForQueuedThread(s, t2);
311	>	t2.interrupt();
312
313	+	assertThreadBlocks(t1, Thread.State.WAITING);
314	+	assertThreadBlocks(t2, Thread.State.WAITING);
315
316	<	/**
216	<	*  A release in one thread enables a timed acquire in another thread
217	<	*/
218	<	public void testTimedAcquireReleaseInDifferentThreads() {
219	<	final Semaphore s = new Semaphore(1, false);
220	<	Thread t = new Thread(new Runnable() {
221	<	public void run() {
222	<	try {
223	<	s.release();
224	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
225	<	s.release();
226	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
316	>	s.release(2);
317
318	<	} catch(InterruptedException ie){
319	<	threadUnexpectedException();
230	<	}
231	<	}
232	<	});
233	<	try {
234	<	t.start();
235	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
236	<	s.release();
237	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
238	<	s.release();
239	<	s.release();
240	<	t.join();
241	<	} catch( InterruptedException e){
242	<	unexpectedException();
243	<	}
244	<	}
245	<
246	<	/**
247	<	* A waiting acquire blocks interruptibly
248	<	*/
249	<	public void testAcquire_InterruptedException() {
250	<	final Semaphore s = new Semaphore(0, false);
251	<	Thread t = new Thread(new Runnable() {
252	<	public void run() {
253	<	try {
254	<	s.acquire();
255	<	threadShouldThrow();
256	<	} catch(InterruptedException success){}
257	<	}
258	<	});
259	<	t.start();
260	<	try {
261	<	Thread.sleep(SHORT_DELAY_MS);
262	<	t.interrupt();
263	<	t.join();
264	<	} catch(InterruptedException e){
265	<	unexpectedException();
266	<	}
267	<	}
268	<
269	<	/**
270	<	*  A waiting timed acquire blocks interruptibly
271	<	*/
272	<	public void testTryAcquire_InterruptedException() {
273	<	final Semaphore s = new Semaphore(0, false);
274	<	Thread t = new Thread(new Runnable() {
275	<	public void run() {
276	<	try {
277	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
278	<	threadShouldThrow();
279	<	} catch(InterruptedException success){
280	<	}
281	<	}
282	<	});
283	<	t.start();
284	<	try {
285	<	Thread.sleep(SHORT_DELAY_MS);
286	<	t.interrupt();
287	<	t.join();
288	<	} catch(InterruptedException e){
289	<	unexpectedException();
290	<	}
318	>	awaitTermination(t1);
319	>	awaitTermination(t2);
320		}
321
322		/**
323		* hasQueuedThreads reports whether there are waiting threads
324		*/
325	<	public void testHasQueuedThreads() {
326	<	final Semaphore lock = new Semaphore(1, false);
327	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
328	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
329	<	try {
330	<	assertFalse(lock.hasQueuedThreads());
331	<	lock.acquireUninterruptibly();
332	<	t1.start();
333	<	Thread.sleep(SHORT_DELAY_MS);
334	<	assertTrue(lock.hasQueuedThreads());
335	<	t2.start();
336	<	Thread.sleep(SHORT_DELAY_MS);
337	<	assertTrue(lock.hasQueuedThreads());
338	<	t1.interrupt();
339	<	Thread.sleep(SHORT_DELAY_MS);
340	<	assertTrue(lock.hasQueuedThreads());
341	<	lock.release();
342	<	Thread.sleep(SHORT_DELAY_MS);
343	<	assertFalse(lock.hasQueuedThreads());
315	<	t1.join();
316	<	t2.join();
317	<	} catch(Exception e){
318	<	unexpectedException();
319	<	}
320	<	}
325	>	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
326	>	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
327	>	public void testHasQueuedThreads(boolean fair) {
328	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
329	>	assertFalse(lock.hasQueuedThreads());
330	>	lock.acquireUninterruptibly();
331	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
332	>	waitForQueuedThread(lock, t1);
333	>	assertTrue(lock.hasQueuedThreads());
334	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
335	>	waitForQueuedThread(lock, t2);
336	>	assertTrue(lock.hasQueuedThreads());
337	>	t1.interrupt();
338	>	awaitTermination(t1);
339	>	assertTrue(lock.hasQueuedThreads());
340	>	lock.release();
341	>	awaitTermination(t2);
342	>	assertFalse(lock.hasQueuedThreads());
343	>	}
344
345		/**
346		* getQueueLength reports number of waiting threads
347		*/
348	<	public void testGetQueueLength() {
349	<	final Semaphore lock = new Semaphore(1, false);
350	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
351	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
352	<	try {
353	<	assertEquals(0, lock.getQueueLength());
354	<	lock.acquireUninterruptibly();
355	<	t1.start();
356	<	Thread.sleep(SHORT_DELAY_MS);
357	<	assertEquals(1, lock.getQueueLength());
358	<	t2.start();
359	<	Thread.sleep(SHORT_DELAY_MS);
360	<	assertEquals(2, lock.getQueueLength());
361	<	t1.interrupt();
362	<	Thread.sleep(SHORT_DELAY_MS);
363	<	assertEquals(1, lock.getQueueLength());
364	<	lock.release();
365	<	Thread.sleep(SHORT_DELAY_MS);
366	<	assertEquals(0, lock.getQueueLength());
344	<	t1.join();
345	<	t2.join();
346	<	} catch(Exception e){
347	<	unexpectedException();
348	<	}
349	<	}
348	>	public void testGetQueueLength()      { testGetQueueLength(false); }
349	>	public void testGetQueueLength_fair() { testGetQueueLength(true); }
350	>	public void testGetQueueLength(boolean fair) {
351	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
352	>	assertEquals(0, lock.getQueueLength());
353	>	lock.acquireUninterruptibly();
354	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
355	>	waitForQueuedThread(lock, t1);
356	>	assertEquals(1, lock.getQueueLength());
357	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
358	>	waitForQueuedThread(lock, t2);
359	>	assertEquals(2, lock.getQueueLength());
360	>	t1.interrupt();
361	>	awaitTermination(t1);
362	>	assertEquals(1, lock.getQueueLength());
363	>	lock.release();
364	>	awaitTermination(t2);
365	>	assertEquals(0, lock.getQueueLength());
366	>	}
367
368		/**
369		* getQueuedThreads includes waiting threads
370		*/
371	<	public void testGetQueuedThreads() {
372	<	final PublicSemaphore lock = new PublicSemaphore(1, false);
373	<	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
374	<	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
375	<	try {
376	<	assertTrue(lock.getQueuedThreads().isEmpty());
377	<	lock.acquireUninterruptibly();
378	<	assertTrue(lock.getQueuedThreads().isEmpty());
379	<	t1.start();
380	<	Thread.sleep(SHORT_DELAY_MS);
381	<	assertTrue(lock.getQueuedThreads().contains(t1));
382	<	t2.start();
383	<	Thread.sleep(SHORT_DELAY_MS);
384	<	assertTrue(lock.getQueuedThreads().contains(t1));
385	<	assertTrue(lock.getQueuedThreads().contains(t2));
386	<	t1.interrupt();
387	<	Thread.sleep(SHORT_DELAY_MS);
388	<	assertFalse(lock.getQueuedThreads().contains(t1));
389	<	assertTrue(lock.getQueuedThreads().contains(t2));
390	<	lock.release();
391	<	Thread.sleep(SHORT_DELAY_MS);
392	<	assertTrue(lock.getQueuedThreads().isEmpty());
376	<	t1.join();
377	<	t2.join();
378	<	} catch(Exception e){
379	<	unexpectedException();
380	<	}
381	<	}
371	>	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
372	>	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
373	>	public void testGetQueuedThreads(boolean fair) {
374	>	final PublicSemaphore lock = new PublicSemaphore(1, fair);
375	>	assertTrue(lock.getQueuedThreads().isEmpty());
376	>	lock.acquireUninterruptibly();
377	>	assertTrue(lock.getQueuedThreads().isEmpty());
378	>	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
379	>	waitForQueuedThread(lock, t1);
380	>	assertTrue(lock.getQueuedThreads().contains(t1));
381	>	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
382	>	waitForQueuedThread(lock, t2);
383	>	assertTrue(lock.getQueuedThreads().contains(t1));
384	>	assertTrue(lock.getQueuedThreads().contains(t2));
385	>	t1.interrupt();
386	>	awaitTermination(t1);
387	>	assertFalse(lock.getQueuedThreads().contains(t1));
388	>	assertTrue(lock.getQueuedThreads().contains(t2));
389	>	lock.release();
390	>	awaitTermination(t2);
391	>	assertTrue(lock.getQueuedThreads().isEmpty());
392	>	}
393
394		/**
395		* drainPermits reports and removes given number of permits
396		*/
397	<	public void testDrainPermits() {
398	<	Semaphore s = new Semaphore(0, false);
397	>	public void testDrainPermits()      { testDrainPermits(false); }
398	>	public void testDrainPermits_fair() { testDrainPermits(true); }
399	>	public void testDrainPermits(boolean fair) {
400	>	Semaphore s = new Semaphore(0, fair);
401		assertEquals(0, s.availablePermits());
402		assertEquals(0, s.drainPermits());
403		s.release(10);
#	Line 395 | Line 408 | public class SemaphoreTest extends JSR16
408		}
409
410		/**
411	<	* reducePermits reduces number of permits
399	<	*/
400	<	public void testReducePermits() {
401	<	PublicSemaphore s = new PublicSemaphore(10, false);
402	<	assertEquals(10, s.availablePermits());
403	<	s.reducePermits(1);
404	<	assertEquals(9, s.availablePermits());
405	<	s.reducePermits(10);
406	<	assertEquals(-1, s.availablePermits());
407	<	}
408	<
409	<	/**
410	<	* a deserialized serialized semaphore has same number of permits
411	>	* release(-N) throws IllegalArgumentException
412		*/
413	<	public void testSerialization() {
414	<	Semaphore l = new Semaphore(3, false);
413	>	public void testReleaseIAE()      { testReleaseIAE(false); }
414	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
415	>	public void testReleaseIAE(boolean fair) {
416	>	Semaphore s = new Semaphore(10, fair);
417		try {
418	<	l.acquire();
419	<	l.release();
420	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
418	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
419	<	out.writeObject(l);
420	<	out.close();
421	<
422	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
423	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
424	<	Semaphore r = (Semaphore) in.readObject();
425	<	assertEquals(3, r.availablePermits());
426	<	assertFalse(r.isFair());
427	<	r.acquire();
428	<	r.release();
429	<	} catch(Exception e){
430	<	unexpectedException();
431	<	}
432	<	}
433	<
434	<
435	<	/**
436	<	* Zero, negative, and positive initial values are allowed in constructor
437	<	*/
438	<	public void testConstructor_fair() {
439	<	Semaphore s0 = new Semaphore(0, true);
440	<	assertEquals(0, s0.availablePermits());
441	<	assertTrue(s0.isFair());
442	<	Semaphore s1 = new Semaphore(-1, true);
443	<	assertEquals(-1, s1.availablePermits());
444	<	Semaphore s2 = new Semaphore(-1, true);
445	<	assertEquals(-1, s2.availablePermits());
418	>	s.release(-1);
419	>	shouldThrow();
420	>	} catch (IllegalArgumentException success) {}
421		}
422
423		/**
424	<	* tryAcquire succeeds when sufficient permits, else fails
424	>	* reducePermits(-N) throws IllegalArgumentException
425		*/
426	<	public void testTryAcquireInSameThread_fair() {
427	<	Semaphore s = new Semaphore(2, true);
428	<	assertEquals(2, s.availablePermits());
429	<	assertTrue(s.tryAcquire());
430	<	assertTrue(s.tryAcquire());
431	<	assertEquals(0, s.availablePermits());
432	<	assertFalse(s.tryAcquire());
426	>	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
427	>	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
428	>	public void testReducePermitsIAE(boolean fair) {
429	>	PublicSemaphore s = new PublicSemaphore(10, fair);
430	>	try {
431	>	s.reducePermits(-1);
432	>	shouldThrow();
433	>	} catch (IllegalArgumentException success) {}
434		}
435
436		/**
437	<	* tryAcquire(n) succeeds when sufficient permits, else fails
437	>	* reducePermits reduces number of permits
438		*/
439	<	public void testTryAcquireNInSameThread_fair() {
440	<	Semaphore s = new Semaphore(2, true);
441	<	assertEquals(2, s.availablePermits());
442	<	assertTrue(s.tryAcquire(2));
443	<	assertEquals(0, s.availablePermits());
444	<	assertFalse(s.tryAcquire());
439	>	public void testReducePermits()      { testReducePermits(false); }
440	>	public void testReducePermits_fair() { testReducePermits(true); }
441	>	public void testReducePermits(boolean fair) {
442	>	PublicSemaphore s = new PublicSemaphore(10, fair);
443	>	assertEquals(10, s.availablePermits());
444	>	s.reducePermits(0);
445	>	assertEquals(10, s.availablePermits());
446	>	s.reducePermits(1);
447	>	assertEquals(9, s.availablePermits());
448	>	s.reducePermits(10);
449	>	assertEquals(-1, s.availablePermits());
450	>	s.reducePermits(10);
451	>	assertEquals(-11, s.availablePermits());
452	>	s.reducePermits(0);
453	>	assertEquals(-11, s.availablePermits());
454		}
455
456		/**
457	<	* Acquire and release of semaphore succeed if initially available
457	>	* a reserialized semaphore has same number of permits and
458	>	* fairness, but no queued threads
459		*/
460	<	public void testAcquireReleaseInSameThread_fair() {
461	<	Semaphore s = new Semaphore(1, true);
460	>	public void testSerialization()      { testSerialization(false); }
461	>	public void testSerialization_fair() { testSerialization(true); }
462	>	public void testSerialization(boolean fair) {
463		try {
464	+	Semaphore s = new Semaphore(3, fair);
465		s.acquire();
478	–	s.release();
466		s.acquire();
467		s.release();
481	–	s.acquire();
482	–	s.release();
483	–	s.acquire();
484	–	s.release();
485	–	s.acquire();
486	–	s.release();
487	–	assertEquals(1, s.availablePermits());
488	–	} catch( InterruptedException e){
489	–	unexpectedException();
490	–	}
491	–	}
492	–
493	–	/**
494	–	* Acquire(n) and release(n) of semaphore succeed if initially available
495	–	*/
496	–	public void testAcquireReleaseNInSameThread_fair() {
497	–	Semaphore s = new Semaphore(1, true);
498	–	try {
499	–	s.release(1);
500	–	s.acquire(1);
501	–	s.release(2);
502	–	s.acquire(2);
503	–	s.release(3);
504	–	s.acquire(3);
505	–	s.release(4);
506	–	s.acquire(4);
507	–	s.release(5);
508	–	s.acquire(5);
509	–	assertEquals(1, s.availablePermits());
510	–	} catch( InterruptedException e){
511	–	unexpectedException();
512	–	}
513	–	}
468
469	<	/**
470	<	* Acquire(n) and release(n) of semaphore succeed if initially available
471	<	*/
472	<	public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
473	<	Semaphore s = new Semaphore(1, true);
474	<	try {
475	<	s.release(1);
476	<	s.acquireUninterruptibly(1);
477	<	s.release(2);
478	<	s.acquireUninterruptibly(2);
479	<	s.release(3);
480	<	s.acquireUninterruptibly(3);
481	<	s.release(4);
482	<	s.acquireUninterruptibly(4);
483	<	s.release(5);
484	<	s.acquireUninterruptibly(5);
485	<	assertEquals(1, s.availablePermits());
486	<	} finally {
469	>	Semaphore clone = serialClone(s);
470	>	assertEquals(fair, s.isFair());
471	>	assertEquals(fair, clone.isFair());
472	>	assertEquals(2, s.availablePermits());
473	>	assertEquals(2, clone.availablePermits());
474	>	clone.acquire();
475	>	clone.acquire();
476	>	clone.release();
477	>	assertEquals(2, s.availablePermits());
478	>	assertEquals(1, clone.availablePermits());
479	>	assertFalse(s.hasQueuedThreads());
480	>	assertFalse(clone.hasQueuedThreads());
481	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
482	>
483	>	{
484	>	PublicSemaphore s = new PublicSemaphore(0, fair);
485	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
486	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
487	>	waitForQueuedThread(s, t);  // ... we use this instead
488	>	PublicSemaphore clone = serialClone(s);
489	>	assertEquals(fair, s.isFair());
490	>	assertEquals(fair, clone.isFair());
491	>	assertEquals(0, s.availablePermits());
492	>	assertEquals(0, clone.availablePermits());
493	>	assertTrue(s.hasQueuedThreads());
494	>	assertFalse(clone.hasQueuedThreads());
495	>	s.release();
496	>	awaitTermination(t);
497	>	assertFalse(s.hasQueuedThreads());
498	>	assertFalse(clone.hasQueuedThreads());
499		}
500		}
501
502		/**
503	<	* release(n) in one thread enables timed acquire(n) in another thread
503	>	* tryAcquire(n) succeeds when sufficient permits, else fails
504		*/
505	<	public void testTimedAcquireReleaseNInSameThread_fair() {
506	<	Semaphore s = new Semaphore(1, true);
507	<	try {
508	<	s.release(1);
509	<	assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
510	<	s.release(2);
511	<	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
512	<	s.release(3);
513	<	assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
514	<	s.release(4);
515	<	assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
516	<	s.release(5);
551	<	assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
552	<	assertEquals(1, s.availablePermits());
553	<	} catch( InterruptedException e){
554	<	unexpectedException();
555	<	}
505	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
506	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
507	>	public void testTryAcquireNInSameThread(boolean fair) {
508	>	Semaphore s = new Semaphore(2, fair);
509	>	assertEquals(2, s.availablePermits());
510	>	assertFalse(s.tryAcquire(3));
511	>	assertEquals(2, s.availablePermits());
512	>	assertTrue(s.tryAcquire(2));
513	>	assertEquals(0, s.availablePermits());
514	>	assertFalse(s.tryAcquire(1));
515	>	assertFalse(s.tryAcquire(2));
516	>	assertEquals(0, s.availablePermits());
517		}
518
519		/**
520	<	* release in one thread enables timed acquire in another thread
520	>	* acquire succeeds if permits available
521		*/
522	<	public void testTimedAcquireReleaseInSameThread_fair() {
523	<	Semaphore s = new Semaphore(1, true);
524	<	try {
525	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
526	<	s.release();
527	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
528	<	s.release();
529	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
530	<	s.release();
531	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
532	<	s.release();
533	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
534	<	s.release();
522	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
523	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
524	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
525	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
526	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
527	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
528	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
529	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
530	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
531	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
532	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
533	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
534	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
535	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
536	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
537	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
538	>	public void testReleaseAcquireSameThread(boolean fair,
539	>	final AcquireMethod acquirer) {
540	>	Semaphore s = new Semaphore(1, fair);
541	>	for (int i = 1; i < 6; i++) {
542	>	s.release(i);
543	>	assertEquals(1 + i, s.availablePermits());
544	>	try {
545	>	acquirer.acquire(s, i);
546	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
547		assertEquals(1, s.availablePermits());
575	–	} catch( InterruptedException e){
576	–	unexpectedException();
548		}
549		}
550
551		/**
552	<	* A release in one thread enables an acquire in another thread
552	>	* release in one thread enables acquire in another thread
553		*/
554	<	public void testAcquireReleaseInDifferentThreads_fair() {
555	<	final Semaphore s = new Semaphore(0, true);
556	<	Thread t = new Thread(new Runnable() {
557	<	public void run() {
558	<	try {
559	<	s.acquire();
560	<	s.acquire();
561	<	s.acquire();
562	<	s.acquire();
563	<	} catch(InterruptedException ie){
564	<	threadUnexpectedException();
565	<	}
566	<	}
567	<	});
568	<	try {
569	<	t.start();
570	<	Thread.sleep(SHORT_DELAY_MS);
571	<	s.release();
572	<	s.release();
573	<	s.release();
574	<	s.release();
575	<	s.release();
576	<	s.release();
577	<	t.join();
578	<	assertEquals(2, s.availablePermits());
579	<	} catch( InterruptedException e){
580	<	unexpectedException();
554	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
555	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
556	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
557	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
558	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
559	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
560	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
561	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
562	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
563	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
564	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
565	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
566	>	public void testReleaseAcquireDifferentThreads(boolean fair,
567	>	final AcquireMethod acquirer) {
568	>	final Semaphore s = new Semaphore(0, fair);
569	>	final int rounds = 4;
570	>	long startTime = System.nanoTime();
571	>	Thread t = newStartedThread(new CheckedRunnable() {
572	>	public void realRun() throws InterruptedException {
573	>	for (int i = 0; i < rounds; i++) {
574	>	assertFalse(s.hasQueuedThreads());
575	>	if (i % 2 == 0)
576	>	acquirer.acquire(s);
577	>	else
578	>	acquirer.acquire(s, 3);
579	>	}}});
580	>
581	>	for (int i = 0; i < rounds; i++) {
582	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
583	>	Thread.yield();
584	>	assertTrue(t.isAlive());
585	>	if (i % 2 == 0)
586	>	s.release();
587	>	else
588	>	s.release(3);
589		}
590	+	awaitTermination(t);
591	+	assertEquals(0, s.availablePermits());
592	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
593		}
594
595		/**
596	<	* release(n) in one thread enables acquire(n) in another thread
596	>	* fair locks are strictly FIFO
597		*/
598	<	public void testAcquireReleaseNInDifferentThreads_fair() {
599	<	final Semaphore s = new Semaphore(0, true);
600	<	Thread t = new Thread(new Runnable() {
601	<	public void run() {
602	<	try {
603	<	s.acquire();
604	<	s.release(2);
605	<	s.acquire();
606	<	} catch(InterruptedException ie){
607	<	threadUnexpectedException();
608	<	}
609	<	}
610	<	});
611	<	try {
612	<	t.start();
613	<	Thread.sleep(SHORT_DELAY_MS);
614	<	s.release(2);
615	<	s.acquire(2);
616	<	s.release(1);
617	<	t.join();
618	<	} catch( InterruptedException e){
619	<	unexpectedException();
620	<	}
598	>	public void testFairLocksFifo() {
599	>	final PublicSemaphore s = new PublicSemaphore(1, true);
600	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
601	>	Thread t1 = newStartedThread(new CheckedRunnable() {
602	>	public void realRun() throws InterruptedException {
603	>	// Will block; permits are available, but not three
604	>	s.acquire(3);
605	>	}});
606	>
607	>	waitForQueuedThread(s, t1);
608	>
609	>	Thread t2 = newStartedThread(new CheckedRunnable() {
610	>	public void realRun() throws InterruptedException {
611	>	// Will fail, even though 1 permit is available
612	>	assertFalse(s.tryAcquire(0L, MILLISECONDS));
613	>	assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
614	>
615	>	// untimed tryAcquire will barge and succeed
616	>	assertTrue(s.tryAcquire());
617	>	s.release(2);
618	>	assertTrue(s.tryAcquire(2));
619	>	s.release();
620	>
621	>	pleaseRelease.countDown();
622	>	// Will queue up behind t1, even though 1 permit is available
623	>	s.acquire();
624	>	}});
625	>
626	>	await(pleaseRelease);
627	>	waitForQueuedThread(s, t2);
628	>	s.release(2);
629	>	awaitTermination(t1);
630	>	assertTrue(t2.isAlive());
631	>	s.release();
632	>	awaitTermination(t2);
633		}
634
635		/**
636	<	* release(n) in one thread enables acquire(n) in another thread
637	<	*/
638	<	public void testAcquireReleaseNInDifferentThreads_fair2() {
639	<	final Semaphore s = new Semaphore(0, true);
640	<	Thread t = new Thread(new Runnable() {
641	<	public void run() {
642	<	try {
643	<	s.acquire(2);
644	<	s.acquire(2);
645	<	s.release(4);
646	<	} catch(InterruptedException ie){
647	<	threadUnexpectedException();
648	<	}
655	<	}
656	<	});
657	<	try {
658	<	t.start();
659	<	Thread.sleep(SHORT_DELAY_MS);
660	<	s.release(6);
661	<	s.acquire(2);
662	<	s.acquire(2);
663	<	s.release(2);
664	<	t.join();
665	<	} catch( InterruptedException e){
666	<	unexpectedException();
667	<	}
636	>	* toString indicates current number of permits
637	>	*/
638	>	public void testToString()      { testToString(false); }
639	>	public void testToString_fair() { testToString(true); }
640	>	public void testToString(boolean fair) {
641	>	PublicSemaphore s = new PublicSemaphore(0, fair);
642	>	assertTrue(s.toString().contains("Permits = 0"));
643	>	s.release();
644	>	assertTrue(s.toString().contains("Permits = 1"));
645	>	s.release(2);
646	>	assertTrue(s.toString().contains("Permits = 3"));
647	>	s.reducePermits(5);
648	>	assertTrue(s.toString().contains("Permits = -2"));
649		}
650
670	–
671	–
672	–
673	–
674	–	/**
675	–	* release in one thread enables timed acquire in another thread
676	–	*/
677	–	public void testTimedAcquireReleaseInDifferentThreads_fair() {
678	–	final Semaphore s = new Semaphore(1, true);
679	–	Thread t = new Thread(new Runnable() {
680	–	public void run() {
681	–	try {
682	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
683	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
684	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
685	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
686	–	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
687	–
688	–	} catch(InterruptedException ie){
689	–	threadUnexpectedException();
690	–	}
691	–	}
692	–	});
693	–	t.start();
694	–	try {
695	–	s.release();
696	–	s.release();
697	–	s.release();
698	–	s.release();
699	–	s.release();
700	–	t.join();
701	–	} catch( InterruptedException e){
702	–	unexpectedException();
703	–	}
704	–	}
705	–
706	–	/**
707	–	* release(n) in one thread enables timed acquire(n) in another thread
708	–	*/
709	–	public void testTimedAcquireReleaseNInDifferentThreads_fair() {
710	–	final Semaphore s = new Semaphore(2, true);
711	–	Thread t = new Thread(new Runnable() {
712	–	public void run() {
713	–	try {
714	–	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
715	–	s.release(2);
716	–	threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
717	–	s.release(2);
718	–	} catch(InterruptedException ie){
719	–	threadUnexpectedException();
720	–	}
721	–	}
722	–	});
723	–	t.start();
724	–	try {
725	–	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
726	–	s.release(2);
727	–	assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
728	–	s.release(2);
729	–	t.join();
730	–	} catch( InterruptedException e){
731	–	unexpectedException();
732	–	}
733	–	}
734	–
735	–	/**
736	–	* A waiting acquire blocks interruptibly
737	–	*/
738	–	public void testAcquire_InterruptedException_fair() {
739	–	final Semaphore s = new Semaphore(0, true);
740	–	Thread t = new Thread(new Runnable() {
741	–	public void run() {
742	–	try {
743	–	s.acquire();
744	–	threadShouldThrow();
745	–	} catch(InterruptedException success){}
746	–	}
747	–	});
748	–	t.start();
749	–	try {
750	–	Thread.sleep(SHORT_DELAY_MS);
751	–	t.interrupt();
752	–	t.join();
753	–	} catch(InterruptedException e){
754	–	unexpectedException();
755	–	}
756	–	}
757	–
758	–	/**
759	–	* A waiting acquire(n) blocks interruptibly
760	–	*/
761	–	public void testAcquireN_InterruptedException_fair() {
762	–	final Semaphore s = new Semaphore(2, true);
763	–	Thread t = new Thread(new Runnable() {
764	–	public void run() {
765	–	try {
766	–	s.acquire(3);
767	–	threadShouldThrow();
768	–	} catch(InterruptedException success){}
769	–	}
770	–	});
771	–	t.start();
772	–	try {
773	–	Thread.sleep(SHORT_DELAY_MS);
774	–	t.interrupt();
775	–	t.join();
776	–	} catch(InterruptedException e){
777	–	unexpectedException();
778	–	}
779	–	}
780	–
781	–	/**
782	–	*  A waiting tryAcquire blocks interruptibly
783	–	*/
784	–	public void testTryAcquire_InterruptedException_fair() {
785	–	final Semaphore s = new Semaphore(0, true);
786	–	Thread t = new Thread(new Runnable() {
787	–	public void run() {
788	–	try {
789	–	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
790	–	threadShouldThrow();
791	–	} catch(InterruptedException success){
792	–	}
793	–	}
794	–	});
795	–	t.start();
796	–	try {
797	–	Thread.sleep(SHORT_DELAY_MS);
798	–	t.interrupt();
799	–	t.join();
800	–	} catch(InterruptedException e){
801	–	unexpectedException();
802	–	}
803	–	}
804	–
805	–	/**
806	–	*  A waiting tryAcquire(n) blocks interruptibly
807	–	*/
808	–	public void testTryAcquireN_InterruptedException_fair() {
809	–	final Semaphore s = new Semaphore(1, true);
810	–	Thread t = new Thread(new Runnable() {
811	–	public void run() {
812	–	try {
813	–	s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
814	–	threadShouldThrow();
815	–	} catch(InterruptedException success){
816	–	}
817	–	}
818	–	});
819	–	t.start();
820	–	try {
821	–	Thread.sleep(SHORT_DELAY_MS);
822	–	t.interrupt();
823	–	t.join();
824	–	} catch(InterruptedException e){
825	–	unexpectedException();
826	–	}
827	–	}
828	–
829	–	/**
830	–	* getQueueLength reports number of waiting threads
831	–	*/
832	–	public void testGetQueueLength_fair() {
833	–	final Semaphore lock = new Semaphore(1, true);
834	–	Thread t1 = new Thread(new InterruptedLockRunnable(lock));
835	–	Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
836	–	try {
837	–	assertEquals(0, lock.getQueueLength());
838	–	lock.acquireUninterruptibly();
839	–	t1.start();
840	–	Thread.sleep(SHORT_DELAY_MS);
841	–	assertEquals(1, lock.getQueueLength());
842	–	t2.start();
843	–	Thread.sleep(SHORT_DELAY_MS);
844	–	assertEquals(2, lock.getQueueLength());
845	–	t1.interrupt();
846	–	Thread.sleep(SHORT_DELAY_MS);
847	–	assertEquals(1, lock.getQueueLength());
848	–	lock.release();
849	–	Thread.sleep(SHORT_DELAY_MS);
850	–	assertEquals(0, lock.getQueueLength());
851	–	t1.join();
852	–	t2.join();
853	–	} catch(Exception e){
854	–	unexpectedException();
855	–	}
856	–	}
857	–
858	–
859	–	/**
860	–	* a deserialized serialized semaphore has same number of permits
861	–	*/
862	–	public void testSerialization_fair() {
863	–	Semaphore l = new Semaphore(3, true);
864	–
865	–	try {
866	–	l.acquire();
867	–	l.release();
868	–	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
869	–	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
870	–	out.writeObject(l);
871	–	out.close();
872	–
873	–	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
874	–	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
875	–	Semaphore r = (Semaphore) in.readObject();
876	–	assertEquals(3, r.availablePermits());
877	–	assertTrue(r.isFair());
878	–	r.acquire();
879	–	r.release();
880	–	} catch(Exception e){
881	–	unexpectedException();
882	–	}
883	–	}
884	–
885	–
651		}

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