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

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.3 by dl, Sun Sep 14 20:42:40 2003 UTC vs.
Revision 1.42 by jsr166, Mon May 29 19:15:03 2017 UTC

#	Line 1 | Line 1
1		/*
2	<	* Written by members of JCP JSR-166 Expert Group and released to the
3	<	* public domain. Use, modify, and redistribute this code in any way
4	<	* without acknowledgement. Other contributors include Andrew Wright,
5	<	* Jeffrey Hayes, Pat Fischer, Mike Judd.
2	>	* Written by Doug Lea with assistance from members of JCP JSR-166
3	>	* Expert Group and released to the public domain, as explained at
4	>	* http://creativecommons.org/publicdomain/zero/1.0/
5	>	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	>	* Pat Fisher, Mike Judd.
7		*/
8
9	<	import junit.framework.*;
9	<	import java.util.*;
10	<	import java.util.concurrent.*;
11	<	import java.io.*;
9	>	import static java.util.concurrent.TimeUnit.MILLISECONDS;
10
11	<	public class SemaphoreTest extends JSR166TestCase {
11	>	import java.util.Collection;
12	>	import java.util.concurrent.CountDownLatch;
13	>	import java.util.concurrent.Semaphore;
14	>	import java.util.concurrent.ThreadLocalRandom;
15	>
16	>	import junit.framework.AssertionFailedError;
17	>	import junit.framework.Test;
18	>	import junit.framework.TestSuite;
19
20	+	public class SemaphoreTest extends JSR166TestCase {
21		public static void main(String[] args) {
22	<	junit.textui.TestRunner.run (suite());
22	>	main(suite(), args);
23		}
18	–
24		public static Test suite() {
25	<	return new TestSuite(SemaphoreTest.class);
25	>	return new TestSuite(SemaphoreTest.class);
26		}
27
28	<	public void testConstructor1() {
29	<	Semaphore s = new Semaphore(0);
30	<	assertEquals(0, s.availablePermits());
28	>	/**
29	>	* Subclass to expose protected methods
30	>	*/
31	>	static class PublicSemaphore extends Semaphore {
32	>	PublicSemaphore(int permits) { super(permits); }
33	>	PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
34	>	public Collection<Thread> getQueuedThreads() {
35	>	return super.getQueuedThreads();
36	>	}
37	>	public boolean hasQueuedThread(Thread t) {
38	>	return super.getQueuedThreads().contains(t);
39	>	}
40	>	public void reducePermits(int reduction) {
41	>	super.reducePermits(reduction);
42	>	}
43		}
44
45	<	public void testConstructor2() {
46	<	Semaphore s = new Semaphore(-1);
47	<	assertEquals(-1, s.availablePermits());
45	>	/**
46	>	* A runnable calling acquire
47	>	*/
48	>	class InterruptibleLockRunnable extends CheckedRunnable {
49	>	final Semaphore lock;
50	>	InterruptibleLockRunnable(Semaphore s) { lock = s; }
51	>	public void realRun() {
52	>	try {
53	>	lock.acquire();
54	>	}
55	>	catch (InterruptedException ignored) {}
56	>	}
57	>	}
58	>
59	>	/**
60	>	* A runnable calling acquire that expects to be interrupted
61	>	*/
62	>	class InterruptedLockRunnable extends CheckedInterruptedRunnable {
63	>	final Semaphore lock;
64	>	InterruptedLockRunnable(Semaphore s) { lock = s; }
65	>	public void realRun() throws InterruptedException {
66	>	lock.acquire();
67	>	}
68	>	}
69	>
70	>	/**
71	>	* Spin-waits until s.hasQueuedThread(t) becomes true.
72	>	*/
73	>	void waitForQueuedThread(PublicSemaphore s, Thread t) {
74	>	long startTime = System.nanoTime();
75	>	while (!s.hasQueuedThread(t)) {
76	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
77	>	throw new AssertionFailedError("timed out");
78	>	Thread.yield();
79	>	}
80	>	assertTrue(s.hasQueuedThreads());
81	>	assertTrue(t.isAlive());
82	>	}
83	>
84	>	/**
85	>	* Spin-waits until s.hasQueuedThreads() becomes true.
86	>	*/
87	>	void waitForQueuedThreads(Semaphore s) {
88	>	long startTime = System.nanoTime();
89	>	while (!s.hasQueuedThreads()) {
90	>	if (millisElapsedSince(startTime) > LONG_DELAY_MS)
91	>	throw new AssertionFailedError("timed out");
92	>	Thread.yield();
93	>	}
94	>	}
95	>
96	>	enum AcquireMethod {
97	>	acquire() {
98	>	void acquire(Semaphore s) throws InterruptedException {
99	>	s.acquire();
100	>	}
101	>	},
102	>	acquireN() {
103	>	void acquire(Semaphore s, int permits) throws InterruptedException {
104	>	s.acquire(permits);
105	>	}
106	>	},
107	>	acquireUninterruptibly() {
108	>	void acquire(Semaphore s) {
109	>	s.acquireUninterruptibly();
110	>	}
111	>	},
112	>	acquireUninterruptiblyN() {
113	>	void acquire(Semaphore s, int permits) {
114	>	s.acquireUninterruptibly(permits);
115	>	}
116	>	},
117	>	tryAcquire() {
118	>	void acquire(Semaphore s) {
119	>	assertTrue(s.tryAcquire());
120	>	}
121	>	},
122	>	tryAcquireN() {
123	>	void acquire(Semaphore s, int permits) {
124	>	assertTrue(s.tryAcquire(permits));
125	>	}
126	>	},
127	>	tryAcquireTimed() {
128	>	void acquire(Semaphore s) throws InterruptedException {
129	>	assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
130	>	}
131	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
132	>	},
133	>	tryAcquireTimedN {
134	>	void acquire(Semaphore s, int permits) throws InterruptedException {
135	>	assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
136	>	}
137	>	Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
138	>	};
139	>
140	>	// Intentionally meta-circular
141	>
142	>	/** Acquires 1 permit. */
143	>	void acquire(Semaphore s) throws InterruptedException {
144	>	acquire(s, 1);
145	>	}
146	>	/** Acquires the given number of permits. */
147	>	void acquire(Semaphore s, int permits) throws InterruptedException {
148	>	for (int i = 0; i < permits; i++)
149	>	acquire(s);
150	>	}
151	>	Thread.State parkedState() { return Thread.State.WAITING; }
152		}
153
154	<	public void testTryAcquireInSameThread() {
155	<	Semaphore s = new Semaphore(2);
154	>	/**
155	>	* Zero, negative, and positive initial values are allowed in constructor
156	>	*/
157	>	public void testConstructor()      { testConstructor(false); }
158	>	public void testConstructor_fair() { testConstructor(true); }
159	>	public void testConstructor(boolean fair) {
160	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
161	>	Semaphore s = new Semaphore(permits, fair);
162	>	assertEquals(permits, s.availablePermits());
163	>	assertEquals(fair, s.isFair());
164	>	}
165	>	}
166	>
167	>	/**
168	>	* Constructor without fairness argument behaves as nonfair
169	>	*/
170	>	public void testConstructorDefaultsToNonFair() {
171	>	for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
172	>	Semaphore s = new Semaphore(permits);
173	>	assertEquals(permits, s.availablePermits());
174	>	assertFalse(s.isFair());
175	>	}
176	>	}
177	>
178	>	/**
179	>	* tryAcquire succeeds when sufficient permits, else fails
180	>	*/
181	>	public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
182	>	public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
183	>	public void testTryAcquireInSameThread(boolean fair) {
184	>	Semaphore s = new Semaphore(2, fair);
185		assertEquals(2, s.availablePermits());
186		assertTrue(s.tryAcquire());
187		assertTrue(s.tryAcquire());
188		assertEquals(0, s.availablePermits());
189		assertFalse(s.tryAcquire());
190	+	assertFalse(s.tryAcquire());
191	+	assertEquals(0, s.availablePermits());
192		}
193
194	<	public void testAcquireReleaseInSameThread(){
195	<	Semaphore s = new Semaphore(1);
196	<	try {
197	<	s.acquire();
198	<	s.release();
199	<	s.acquire();
200	<	s.release();
201	<	s.acquire();
202	<	s.release();
203	<	s.acquire();
204	<	s.release();
205	<	s.acquire();
206	<	s.release();
207	<	assertEquals(1, s.availablePermits());
208	<	} catch( InterruptedException e){
209	<	fail("unexpected exception");
194	>	/**
195	>	* timed tryAcquire times out
196	>	*/
197	>	public void testTryAcquire_timeout() {
198	>	final boolean fair = ThreadLocalRandom.current().nextBoolean();
199	>	final Semaphore s = new Semaphore(0, fair);
200	>	final 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() {
210	>	final boolean fair = ThreadLocalRandom.current().nextBoolean();
211	>	final Semaphore s = new Semaphore(2, fair);
212	>	final long startTime = System.nanoTime();
213	>	try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
214	>	catch (InterruptedException e) { threadUnexpectedException(e); }
215	>	assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
216	>	}
217	>
218	>	/**
219	>	* acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
220	>	* are interruptible
221	>	*/
222	>	public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
223	>	public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
224	>	public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
225	>	public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
226	>	public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
227	>	public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
228	>	public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
229	>	public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
230	>	public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
231	>	final PublicSemaphore s = new PublicSemaphore(0, fair);
232	>	final java.util.concurrent.CyclicBarrier pleaseInterrupt
233	>	= new java.util.concurrent.CyclicBarrier(2);
234	>	Thread t = newStartedThread(new CheckedRunnable() {
235	>	public void realRun() {
236	>	// Interrupt before acquire
237	>	Thread.currentThread().interrupt();
238	>	try {
239	>	acquirer.acquire(s);
240	>	shouldThrow();
241	>	} catch (InterruptedException success) {}
242	>	assertFalse(Thread.interrupted());
243	>
244	>	// Interrupt before acquire(N)
245	>	Thread.currentThread().interrupt();
246	>	try {
247	>	acquirer.acquire(s, 3);
248	>	shouldThrow();
249	>	} catch (InterruptedException success) {}
250	>	assertFalse(Thread.interrupted());
251	>
252	>	// Interrupt during acquire
253	>	await(pleaseInterrupt);
254	>	try {
255	>	acquirer.acquire(s);
256	>	shouldThrow();
257	>	} catch (InterruptedException success) {}
258	>	assertFalse(Thread.interrupted());
259	>
260	>	// Interrupt during acquire(N)
261	>	await(pleaseInterrupt);
262	>	try {
263	>	acquirer.acquire(s, 3);
264	>	shouldThrow();
265	>	} catch (InterruptedException success) {}
266	>	assertFalse(Thread.interrupted());
267	>	}});
268	>
269	>	for (int n = 2; n-->0; ) {
270	>	await(pleaseInterrupt);
271	>	assertThreadBlocks(t, acquirer.parkedState());
272	>	t.interrupt();
273		}
274	+
275	+	awaitTermination(t);
276	+	}
277	+
278	+	/**
279	+	* acquireUninterruptibly(), acquireUninterruptibly(N) are
280	+	* uninterruptible
281	+	*/
282	+	public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
283	+	public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
284	+	public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
285	+	public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
286	+	public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
287	+	final PublicSemaphore s = new PublicSemaphore(0, fair);
288	+	final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
289	+
290	+	Thread t1 = newStartedThread(new CheckedRunnable() {
291	+	public void realRun() throws InterruptedException {
292	+	// Interrupt before acquire
293	+	pleaseInterrupt.release();
294	+	Thread.currentThread().interrupt();
295	+	acquirer.acquire(s);
296	+	assertTrue(Thread.interrupted());
297	+	}});
298	+
299	+	Thread t2 = newStartedThread(new CheckedRunnable() {
300	+	public void realRun() throws InterruptedException {
301	+	// Interrupt during acquire
302	+	pleaseInterrupt.release();
303	+	acquirer.acquire(s);
304	+	assertTrue(Thread.interrupted());
305	+	}});
306	+
307	+	await(pleaseInterrupt);
308	+	waitForQueuedThread(s, t1);
309	+	waitForQueuedThread(s, t2);
310	+	t2.interrupt();
311	+
312	+	assertThreadBlocks(t1, Thread.State.WAITING);
313	+	assertThreadBlocks(t2, Thread.State.WAITING);
314	+
315	+	s.release(2);
316	+
317	+	awaitTermination(t1);
318	+	awaitTermination(t2);
319	+	}
320	+
321	+	/**
322	+	* hasQueuedThreads reports whether there are waiting threads
323	+	*/
324	+	public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
325	+	public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
326	+	public void testHasQueuedThreads(boolean fair) {
327	+	final PublicSemaphore lock = new PublicSemaphore(1, fair);
328	+	assertFalse(lock.hasQueuedThreads());
329	+	lock.acquireUninterruptibly();
330	+	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
331	+	waitForQueuedThread(lock, t1);
332	+	assertTrue(lock.hasQueuedThreads());
333	+	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
334	+	waitForQueuedThread(lock, t2);
335	+	assertTrue(lock.hasQueuedThreads());
336	+	t1.interrupt();
337	+	awaitTermination(t1);
338	+	assertTrue(lock.hasQueuedThreads());
339	+	lock.release();
340	+	awaitTermination(t2);
341	+	assertFalse(lock.hasQueuedThreads());
342	+	}
343	+
344	+	/**
345	+	* getQueueLength reports number of waiting threads
346	+	*/
347	+	public void testGetQueueLength()      { testGetQueueLength(false); }
348	+	public void testGetQueueLength_fair() { testGetQueueLength(true); }
349	+	public void testGetQueueLength(boolean fair) {
350	+	final PublicSemaphore lock = new PublicSemaphore(1, fair);
351	+	assertEquals(0, lock.getQueueLength());
352	+	lock.acquireUninterruptibly();
353	+	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
354	+	waitForQueuedThread(lock, t1);
355	+	assertEquals(1, lock.getQueueLength());
356	+	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
357	+	waitForQueuedThread(lock, t2);
358	+	assertEquals(2, lock.getQueueLength());
359	+	t1.interrupt();
360	+	awaitTermination(t1);
361	+	assertEquals(1, lock.getQueueLength());
362	+	lock.release();
363	+	awaitTermination(t2);
364	+	assertEquals(0, lock.getQueueLength());
365	+	}
366	+
367	+	/**
368	+	* getQueuedThreads includes waiting threads
369	+	*/
370	+	public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
371	+	public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
372	+	public void testGetQueuedThreads(boolean fair) {
373	+	final PublicSemaphore lock = new PublicSemaphore(1, fair);
374	+	assertTrue(lock.getQueuedThreads().isEmpty());
375	+	lock.acquireUninterruptibly();
376	+	assertTrue(lock.getQueuedThreads().isEmpty());
377	+	Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
378	+	waitForQueuedThread(lock, t1);
379	+	assertTrue(lock.getQueuedThreads().contains(t1));
380	+	Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
381	+	waitForQueuedThread(lock, t2);
382	+	assertTrue(lock.getQueuedThreads().contains(t1));
383	+	assertTrue(lock.getQueuedThreads().contains(t2));
384	+	t1.interrupt();
385	+	awaitTermination(t1);
386	+	assertFalse(lock.getQueuedThreads().contains(t1));
387	+	assertTrue(lock.getQueuedThreads().contains(t2));
388	+	lock.release();
389	+	awaitTermination(t2);
390	+	assertTrue(lock.getQueuedThreads().isEmpty());
391	+	}
392	+
393	+	/**
394	+	* drainPermits reports and removes given number of permits
395	+	*/
396	+	public void testDrainPermits()      { testDrainPermits(false); }
397	+	public void testDrainPermits_fair() { testDrainPermits(true); }
398	+	public void testDrainPermits(boolean fair) {
399	+	Semaphore s = new Semaphore(0, fair);
400	+	assertEquals(0, s.availablePermits());
401	+	assertEquals(0, s.drainPermits());
402	+	s.release(10);
403	+	assertEquals(10, s.availablePermits());
404	+	assertEquals(10, s.drainPermits());
405	+	assertEquals(0, s.availablePermits());
406	+	assertEquals(0, s.drainPermits());
407		}
408
409	<	public void testAcquireUninterruptiblyReleaseInSameThread(){
410	<	Semaphore s = new Semaphore(1);
409	>	/**
410	>	* release(-N) throws IllegalArgumentException
411	>	*/
412	>	public void testReleaseIAE()      { testReleaseIAE(false); }
413	>	public void testReleaseIAE_fair() { testReleaseIAE(true); }
414	>	public void testReleaseIAE(boolean fair) {
415	>	Semaphore s = new Semaphore(10, fair);
416		try {
417	<	s.acquireUninterruptibly();
418	<	s.release();
419	<	s.acquireUninterruptibly();
67	<	s.release();
68	<	s.acquireUninterruptibly();
69	<	s.release();
70	<	s.acquireUninterruptibly();
71	<	s.release();
72	<	s.acquireUninterruptibly();
73	<	s.release();
74	<	assertEquals(1, s.availablePermits());
75	<	} finally {
76	<	}
417	>	s.release(-1);
418	>	shouldThrow();
419	>	} catch (IllegalArgumentException success) {}
420		}
421
422	+	/**
423	+	* reducePermits(-N) throws IllegalArgumentException
424	+	*/
425	+	public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
426	+	public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
427	+	public void testReducePermitsIAE(boolean fair) {
428	+	PublicSemaphore s = new PublicSemaphore(10, fair);
429	+	try {
430	+	s.reducePermits(-1);
431	+	shouldThrow();
432	+	} catch (IllegalArgumentException success) {}
433	+	}
434	+
435	+	/**
436	+	* reducePermits reduces number of permits
437	+	*/
438	+	public void testReducePermits()      { testReducePermits(false); }
439	+	public void testReducePermits_fair() { testReducePermits(true); }
440	+	public void testReducePermits(boolean fair) {
441	+	PublicSemaphore s = new PublicSemaphore(10, fair);
442	+	assertEquals(10, s.availablePermits());
443	+	s.reducePermits(0);
444	+	assertEquals(10, s.availablePermits());
445	+	s.reducePermits(1);
446	+	assertEquals(9, s.availablePermits());
447	+	s.reducePermits(10);
448	+	assertEquals(-1, s.availablePermits());
449	+	s.reducePermits(10);
450	+	assertEquals(-11, s.availablePermits());
451	+	s.reducePermits(0);
452	+	assertEquals(-11, s.availablePermits());
453	+	}
454
455	<	public void testAcquireReleaseInDifferentThreads() {
456	<	final Semaphore s = new Semaphore(1);
457	<	Thread t = new Thread(new Runnable(){
458	<	public void run(){
459	<	try{
460	<	s.acquire();
461	<	s.release();
87	<	s.release();
88	<	s.acquire();
89	<	}catch(InterruptedException ie){
90	<	threadFail("unexpected exception");
91	<	}
92	<	}
93	<	});
94	<	t.start();
455	>	/**
456	>	* a reserialized semaphore has same number of permits and
457	>	* fairness, but no queued threads
458	>	*/
459	>	public void testSerialization()      { testSerialization(false); }
460	>	public void testSerialization_fair() { testSerialization(true); }
461	>	public void testSerialization(boolean fair) {
462		try {
463	<	s.release();
97	<	s.release();
463	>	Semaphore s = new Semaphore(3, fair);
464		s.acquire();
465		s.acquire();
466	<	t.join();
467	<	} catch( InterruptedException e){
468	<	fail("unexpected exception");
466	>	s.release();
467	>
468	>	Semaphore clone = serialClone(s);
469	>	assertEquals(fair, s.isFair());
470	>	assertEquals(fair, clone.isFair());
471	>	assertEquals(2, s.availablePermits());
472	>	assertEquals(2, clone.availablePermits());
473	>	clone.acquire();
474	>	clone.acquire();
475	>	clone.release();
476	>	assertEquals(2, s.availablePermits());
477	>	assertEquals(1, clone.availablePermits());
478	>	assertFalse(s.hasQueuedThreads());
479	>	assertFalse(clone.hasQueuedThreads());
480	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
481	>
482	>	{
483	>	PublicSemaphore s = new PublicSemaphore(0, fair);
484	>	Thread t = newStartedThread(new InterruptibleLockRunnable(s));
485	>	// waitForQueuedThreads(s); // suffers from "flicker", so ...
486	>	waitForQueuedThread(s, t);  // ... we use this instead
487	>	PublicSemaphore clone = serialClone(s);
488	>	assertEquals(fair, s.isFair());
489	>	assertEquals(fair, clone.isFair());
490	>	assertEquals(0, s.availablePermits());
491	>	assertEquals(0, clone.availablePermits());
492	>	assertTrue(s.hasQueuedThreads());
493	>	assertFalse(clone.hasQueuedThreads());
494	>	s.release();
495	>	awaitTermination(t);
496	>	assertFalse(s.hasQueuedThreads());
497	>	assertFalse(clone.hasQueuedThreads());
498		}
499		}
500
501	<	public void testTimedAcquireReleaseInSameThread(){
502	<	Semaphore s = new Semaphore(1);
503	<	try {
504	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
505	<	s.release();
506	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
507	<	s.release();
508	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
509	<	s.release();
510	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
511	<	s.release();
512	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
513	<	s.release();
514	<	assertEquals(1, s.availablePermits());
515	<	} catch( InterruptedException e){
121	<	fail("unexpected exception");
122	<	}
501	>	/**
502	>	* tryAcquire(n) succeeds when sufficient permits, else fails
503	>	*/
504	>	public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
505	>	public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
506	>	public void testTryAcquireNInSameThread(boolean fair) {
507	>	Semaphore s = new Semaphore(2, fair);
508	>	assertEquals(2, s.availablePermits());
509	>	assertFalse(s.tryAcquire(3));
510	>	assertEquals(2, s.availablePermits());
511	>	assertTrue(s.tryAcquire(2));
512	>	assertEquals(0, s.availablePermits());
513	>	assertFalse(s.tryAcquire(1));
514	>	assertFalse(s.tryAcquire(2));
515	>	assertEquals(0, s.availablePermits());
516		}
517
518	<	public void testTimedAcquireReleaseInDifferentThreads() {
519	<	final Semaphore s = new Semaphore(1);
520	<	Thread t = new Thread(new Runnable(){
521	<	public void run(){
522	<	try{
523	<	s.release();
524	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
525	<	s.release();
526	<	threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
527	<
528	<	}catch(InterruptedException ie){
529	<	threadFail("unexpected exception");
530	<	}
531	<	}
532	<	});
533	<	t.start();
534	<	try {
535	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
536	<	s.release();
537	<	assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
538	<	s.release();
539	<	t.join();
540	<	} catch( InterruptedException e){
541	<	fail("unexpected exception");
518	>	/**
519	>	* acquire succeeds if permits available
520	>	*/
521	>	public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
522	>	public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
523	>	public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
524	>	public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
525	>	public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
526	>	public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
527	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
528	>	public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
529	>	public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
530	>	public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
531	>	public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
532	>	public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
533	>	public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
534	>	public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
535	>	public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
536	>	public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
537	>	public void testReleaseAcquireSameThread(boolean fair,
538	>	final AcquireMethod acquirer) {
539	>	Semaphore s = new Semaphore(1, fair);
540	>	for (int i = 1; i < 6; i++) {
541	>	s.release(i);
542	>	assertEquals(1 + i, s.availablePermits());
543	>	try {
544	>	acquirer.acquire(s, i);
545	>	} catch (InterruptedException e) { threadUnexpectedException(e); }
546	>	assertEquals(1, s.availablePermits());
547		}
548		}
549
550	<	public void testAcquire_InterruptedException(){
551	<	final Semaphore s = new Semaphore(0);
552	<	Thread t = new Thread(new Runnable(){
553	<	public void run(){
554	<	try{
555	<	s.acquire();
556	<	threadFail("should throw");
557	<	}catch(InterruptedException success){}
558	<	}
559	<	});
560	<	t.start();
561	<	try{
562	<	Thread.sleep(SHORT_DELAY_MS);
563	<	t.interrupt();
564	<	t.join();
565	<	} catch(InterruptedException e){
566	<	fail("unexpected exception");
567	<	}
568	<	}
569	<
570	<	public void testTryAcquire_InterruptedException(){
571	<	final Semaphore s = new Semaphore(0);
572	<	Thread t = new Thread(new Runnable(){
573	<	public void run(){
574	<	try{
575	<	s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
576	<	threadFail("should throw");
577	<	}catch(InterruptedException success){
578	<	}
579	<	}
580	<	});
581	<	t.start();
582	<	try{
583	<	Thread.sleep(SHORT_DELAY_MS);
584	<	t.interrupt();
585	<	t.join();
586	<	} catch(InterruptedException e){
587	<	fail("unexpected exception");
550	>	/**
551	>	* release in one thread enables acquire in another thread
552	>	*/
553	>	public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
554	>	public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
555	>	public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
556	>	public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
557	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
558	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
559	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
560	>	public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
561	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
562	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
563	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
564	>	public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
565	>	public void testReleaseAcquireDifferentThreads(boolean fair,
566	>	final AcquireMethod acquirer) {
567	>	final Semaphore s = new Semaphore(0, fair);
568	>	final int rounds = 4;
569	>	long startTime = System.nanoTime();
570	>	Thread t = newStartedThread(new CheckedRunnable() {
571	>	public void realRun() throws InterruptedException {
572	>	for (int i = 0; i < rounds; i++) {
573	>	assertFalse(s.hasQueuedThreads());
574	>	if (i % 2 == 0)
575	>	acquirer.acquire(s);
576	>	else
577	>	acquirer.acquire(s, 3);
578	>	}}});
579	>
580	>	for (int i = 0; i < rounds; i++) {
581	>	while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
582	>	Thread.yield();
583	>	assertTrue(t.isAlive());
584	>	if (i % 2 == 0)
585	>	s.release();
586	>	else
587	>	s.release(3);
588		}
589	+	awaitTermination(t);
590	+	assertEquals(0, s.availablePermits());
591	+	assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
592		}
593
594	<	public void testSerialization() {
595	<	Semaphore l = new Semaphore(3);
596	<	try {
597	<	l.acquire();
598	<	l.release();
599	<	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
600	<	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
601	<	out.writeObject(l);
602	<	out.close();
603	<
604	<	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
605	<	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
606	<	Semaphore r = (Semaphore) in.readObject();
607	<	assertEquals(3, r.availablePermits());
608	<	r.acquire();
609	<	r.release();
610	<	} catch(Exception e){
611	<	e.printStackTrace();
612	<	fail("unexpected exception");
613	<	}
594	>	/**
595	>	* fair locks are strictly FIFO
596	>	*/
597	>	public void testFairLocksFifo() {
598	>	final PublicSemaphore s = new PublicSemaphore(1, true);
599	>	final CountDownLatch pleaseRelease = new CountDownLatch(1);
600	>	Thread t1 = newStartedThread(new CheckedRunnable() {
601	>	public void realRun() throws InterruptedException {
602	>	// Will block; permits are available, but not three
603	>	s.acquire(3);
604	>	}});
605	>
606	>	waitForQueuedThread(s, t1);
607	>
608	>	Thread t2 = newStartedThread(new CheckedRunnable() {
609	>	public void realRun() throws InterruptedException {
610	>	// Will fail, even though 1 permit is available
611	>	assertFalse(
612	>	s.tryAcquire(randomExpiredTimeout(), randomTimeUnit()));
613	>	assertFalse(
614	>	s.tryAcquire(1, randomExpiredTimeout(), randomTimeUnit()));
615	>
616	>	// untimed tryAcquire will barge and succeed
617	>	assertTrue(s.tryAcquire());
618	>	s.release(2);
619	>	assertTrue(s.tryAcquire(2));
620	>	s.release();
621	>
622	>	pleaseRelease.countDown();
623	>	// Will queue up behind t1, even though 1 permit is available
624	>	s.acquire();
625	>	}});
626	>
627	>	await(pleaseRelease);
628	>	waitForQueuedThread(s, t2);
629	>	s.release(2);
630	>	awaitTermination(t1);
631	>	assertTrue(t2.isAlive());
632	>	s.release();
633	>	awaitTermination(t2);
634	>	}
635	>
636	>	/**
637	>	* toString indicates current number of permits
638	>	*/
639	>	public void testToString()      { testToString(false); }
640	>	public void testToString_fair() { testToString(true); }
641	>	public void testToString(boolean fair) {
642	>	PublicSemaphore s = new PublicSemaphore(0, fair);
643	>	assertTrue(s.toString().contains("Permits = 0"));
644	>	s.release();
645	>	assertTrue(s.toString().contains("Permits = 1"));
646	>	s.release(2);
647	>	assertTrue(s.toString().contains("Permits = 3"));
648	>	s.reducePermits(5);
649	>	assertTrue(s.toString().contains("Permits = -2"));
650		}
651
652		}

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