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 |
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* Other contributors include Andrew Wright, Jeffrey Hayes, |
6 |
* Pat Fisher, Mike Judd. |
7 |
*/ |
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|
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import junit.framework.*; |
10 |
import java.util.*; |
11 |
import java.util.concurrent.*; |
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import java.io.*; |
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|
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public class SemaphoreTest extends JSR166TestCase { |
15 |
public static void main(String[] args) { |
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junit.textui.TestRunner.run (suite()); |
17 |
} |
18 |
public static Test suite() { |
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return new TestSuite(SemaphoreTest.class); |
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} |
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|
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/** |
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* Subclass to expose protected methods |
24 |
*/ |
25 |
static class PublicSemaphore extends Semaphore { |
26 |
PublicSemaphore(int p, boolean f) { super(p, f); } |
27 |
public Collection<Thread> getQueuedThreads() { |
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return super.getQueuedThreads(); |
29 |
} |
30 |
public void reducePermits(int p) { |
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super.reducePermits(p); |
32 |
} |
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} |
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|
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/** |
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* A runnable calling acquire |
37 |
*/ |
38 |
class InterruptibleLockRunnable implements Runnable { |
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final Semaphore lock; |
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InterruptibleLockRunnable(Semaphore l) { lock = l; } |
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public void run() { |
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try { |
43 |
lock.acquire(); |
44 |
} catch(InterruptedException success){} |
45 |
} |
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} |
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|
48 |
|
49 |
/** |
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* A runnable calling acquire that expects to be |
51 |
* interrupted |
52 |
*/ |
53 |
class InterruptedLockRunnable implements Runnable { |
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final Semaphore lock; |
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InterruptedLockRunnable(Semaphore l) { lock = l; } |
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public void run() { |
57 |
try { |
58 |
lock.acquire(); |
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threadShouldThrow(); |
60 |
} catch(InterruptedException success){} |
61 |
} |
62 |
} |
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|
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/** |
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* Zero, negative, and positive initial values are allowed in constructor |
66 |
*/ |
67 |
public void testConstructor() { |
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Semaphore s0 = new Semaphore(0, false); |
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assertEquals(0, s0.availablePermits()); |
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assertFalse(s0.isFair()); |
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Semaphore s1 = new Semaphore(-1, false); |
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assertEquals(-1, s1.availablePermits()); |
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assertFalse(s1.isFair()); |
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Semaphore s2 = new Semaphore(-1, false); |
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assertEquals(-1, s2.availablePermits()); |
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assertFalse(s2.isFair()); |
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} |
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|
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/** |
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* Constructor without fairness argument behaves as nonfair |
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*/ |
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public void testConstructor2() { |
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Semaphore s0 = new Semaphore(0); |
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assertEquals(0, s0.availablePermits()); |
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assertFalse(s0.isFair()); |
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Semaphore s1 = new Semaphore(-1); |
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assertEquals(-1, s1.availablePermits()); |
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assertFalse(s1.isFair()); |
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Semaphore s2 = new Semaphore(-1); |
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assertEquals(-1, s2.availablePermits()); |
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assertFalse(s2.isFair()); |
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} |
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|
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/** |
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* tryAcquire succeeds when sufficient permits, else fails |
96 |
*/ |
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public void testTryAcquireInSameThread() { |
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Semaphore s = new Semaphore(2, false); |
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assertEquals(2, s.availablePermits()); |
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assertTrue(s.tryAcquire()); |
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assertTrue(s.tryAcquire()); |
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assertEquals(0, s.availablePermits()); |
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assertFalse(s.tryAcquire()); |
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} |
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|
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/** |
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* Acquire and release of semaphore succeed if initially available |
108 |
*/ |
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public void testAcquireReleaseInSameThread() { |
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Semaphore s = new Semaphore(1, false); |
111 |
try { |
112 |
s.acquire(); |
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s.release(); |
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s.acquire(); |
115 |
s.release(); |
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s.acquire(); |
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s.release(); |
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s.acquire(); |
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s.release(); |
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s.acquire(); |
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s.release(); |
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assertEquals(1, s.availablePermits()); |
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} catch( InterruptedException e){ |
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unexpectedException(); |
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} |
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} |
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|
128 |
/** |
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* Uninterruptible acquire and release of semaphore succeed if |
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* initially available |
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*/ |
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public void testAcquireUninterruptiblyReleaseInSameThread() { |
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Semaphore s = new Semaphore(1, false); |
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try { |
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s.acquireUninterruptibly(); |
136 |
s.release(); |
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s.acquireUninterruptibly(); |
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s.release(); |
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s.acquireUninterruptibly(); |
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s.release(); |
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s.acquireUninterruptibly(); |
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s.release(); |
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s.acquireUninterruptibly(); |
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s.release(); |
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assertEquals(1, s.availablePermits()); |
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} finally { |
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} |
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} |
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|
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/** |
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* Timed Acquire and release of semaphore succeed if |
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* initially available |
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*/ |
154 |
public void testTimedAcquireReleaseInSameThread() { |
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Semaphore s = new Semaphore(1, false); |
156 |
try { |
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assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
158 |
s.release(); |
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assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
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s.release(); |
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assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
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s.release(); |
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assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
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s.release(); |
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assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
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s.release(); |
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assertEquals(1, s.availablePermits()); |
168 |
} catch( InterruptedException e){ |
169 |
unexpectedException(); |
170 |
} |
171 |
} |
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|
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/** |
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* 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 { |
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s.acquire(); |
182 |
s.release(); |
183 |
s.release(); |
184 |
s.acquire(); |
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} catch(InterruptedException ie){ |
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threadUnexpectedException(); |
187 |
} |
188 |
} |
189 |
}); |
190 |
try { |
191 |
t.start(); |
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Thread.sleep(SHORT_DELAY_MS); |
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s.release(); |
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s.release(); |
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s.acquire(); |
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s.acquire(); |
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s.release(); |
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t.join(); |
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} catch( InterruptedException e){ |
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unexpectedException(); |
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} |
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} |
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|
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/** |
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* A release in one thread enables an uninterruptible acquire in another thread |
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*/ |
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public void testUninterruptibleAcquireReleaseInDifferentThreads() { |
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final Semaphore s = new Semaphore(0, false); |
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Thread t = new Thread(new Runnable() { |
210 |
public void run() { |
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s.acquireUninterruptibly(); |
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s.release(); |
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s.release(); |
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s.acquireUninterruptibly(); |
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} |
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}); |
217 |
try { |
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t.start(); |
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Thread.sleep(SHORT_DELAY_MS); |
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s.release(); |
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s.release(); |
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s.acquireUninterruptibly(); |
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s.acquireUninterruptibly(); |
224 |
s.release(); |
225 |
t.join(); |
226 |
} catch( InterruptedException e){ |
227 |
unexpectedException(); |
228 |
} |
229 |
} |
230 |
|
231 |
|
232 |
/** |
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)); |
244 |
|
245 |
} catch(InterruptedException ie){ |
246 |
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 |
} |
308 |
} |
309 |
|
310 |
/** |
311 |
* hasQueuedThreads reports whether there are waiting threads |
312 |
*/ |
313 |
public void testHasQueuedThreads() { |
314 |
final Semaphore lock = new Semaphore(1, false); |
315 |
Thread t1 = new Thread(new InterruptedLockRunnable(lock)); |
316 |
Thread t2 = new Thread(new InterruptibleLockRunnable(lock)); |
317 |
try { |
318 |
assertFalse(lock.hasQueuedThreads()); |
319 |
lock.acquireUninterruptibly(); |
320 |
t1.start(); |
321 |
Thread.sleep(SHORT_DELAY_MS); |
322 |
assertTrue(lock.hasQueuedThreads()); |
323 |
t2.start(); |
324 |
Thread.sleep(SHORT_DELAY_MS); |
325 |
assertTrue(lock.hasQueuedThreads()); |
326 |
t1.interrupt(); |
327 |
Thread.sleep(SHORT_DELAY_MS); |
328 |
assertTrue(lock.hasQueuedThreads()); |
329 |
lock.release(); |
330 |
Thread.sleep(SHORT_DELAY_MS); |
331 |
assertFalse(lock.hasQueuedThreads()); |
332 |
t1.join(); |
333 |
t2.join(); |
334 |
} catch(Exception e){ |
335 |
unexpectedException(); |
336 |
} |
337 |
} |
338 |
|
339 |
/** |
340 |
* getQueueLength reports number of waiting threads |
341 |
*/ |
342 |
public void testGetQueueLength() { |
343 |
final Semaphore lock = new Semaphore(1, false); |
344 |
Thread t1 = new Thread(new InterruptedLockRunnable(lock)); |
345 |
Thread t2 = new Thread(new InterruptibleLockRunnable(lock)); |
346 |
try { |
347 |
assertEquals(0, lock.getQueueLength()); |
348 |
lock.acquireUninterruptibly(); |
349 |
t1.start(); |
350 |
Thread.sleep(SHORT_DELAY_MS); |
351 |
assertEquals(1, lock.getQueueLength()); |
352 |
t2.start(); |
353 |
Thread.sleep(SHORT_DELAY_MS); |
354 |
assertEquals(2, lock.getQueueLength()); |
355 |
t1.interrupt(); |
356 |
Thread.sleep(SHORT_DELAY_MS); |
357 |
assertEquals(1, lock.getQueueLength()); |
358 |
lock.release(); |
359 |
Thread.sleep(SHORT_DELAY_MS); |
360 |
assertEquals(0, lock.getQueueLength()); |
361 |
t1.join(); |
362 |
t2.join(); |
363 |
} catch(Exception e){ |
364 |
unexpectedException(); |
365 |
} |
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()); |
393 |
t1.join(); |
394 |
t2.join(); |
395 |
} catch(Exception e){ |
396 |
unexpectedException(); |
397 |
} |
398 |
} |
399 |
|
400 |
/** |
401 |
* drainPermits reports and removes given number of permits |
402 |
*/ |
403 |
public void testDrainPermits() { |
404 |
Semaphore s = new Semaphore(0, false); |
405 |
assertEquals(0, s.availablePermits()); |
406 |
assertEquals(0, s.drainPermits()); |
407 |
s.release(10); |
408 |
assertEquals(10, s.availablePermits()); |
409 |
assertEquals(10, s.drainPermits()); |
410 |
assertEquals(0, s.availablePermits()); |
411 |
assertEquals(0, s.drainPermits()); |
412 |
} |
413 |
|
414 |
/** |
415 |
* 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 |
428 |
*/ |
429 |
public void testSerialization() { |
430 |
Semaphore l = new Semaphore(3, false); |
431 |
try { |
432 |
l.acquire(); |
433 |
l.release(); |
434 |
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 |
} |
449 |
} |
450 |
|
451 |
|
452 |
/** |
453 |
* Zero, negative, and positive initial values are allowed in constructor |
454 |
*/ |
455 |
public void testConstructor_fair() { |
456 |
Semaphore s0 = new Semaphore(0, true); |
457 |
assertEquals(0, s0.availablePermits()); |
458 |
assertTrue(s0.isFair()); |
459 |
Semaphore s1 = new Semaphore(-1, true); |
460 |
assertEquals(-1, s1.availablePermits()); |
461 |
Semaphore s2 = new Semaphore(-1, true); |
462 |
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()); |
475 |
} |
476 |
|
477 |
/** |
478 |
* tryAcquire(n) succeeds when sufficient permits, else fails |
479 |
*/ |
480 |
public void testTryAcquireNInSameThread_fair() { |
481 |
Semaphore s = new Semaphore(2, true); |
482 |
assertEquals(2, s.availablePermits()); |
483 |
assertTrue(s.tryAcquire(2)); |
484 |
assertEquals(0, s.availablePermits()); |
485 |
assertFalse(s.tryAcquire()); |
486 |
} |
487 |
|
488 |
/** |
489 |
* Acquire and release of semaphore succeed if initially available |
490 |
*/ |
491 |
public void testAcquireReleaseInSameThread_fair() { |
492 |
Semaphore s = new Semaphore(1, true); |
493 |
try { |
494 |
s.acquire(); |
495 |
s.release(); |
496 |
s.acquire(); |
497 |
s.release(); |
498 |
s.acquire(); |
499 |
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 |
} |
509 |
|
510 |
/** |
511 |
* Acquire(n) and release(n) of semaphore succeed if initially available |
512 |
*/ |
513 |
public void testAcquireReleaseNInSameThread_fair() { |
514 |
Semaphore s = new Semaphore(1, true); |
515 |
try { |
516 |
s.release(1); |
517 |
s.acquire(1); |
518 |
s.release(2); |
519 |
s.acquire(2); |
520 |
s.release(3); |
521 |
s.acquire(3); |
522 |
s.release(4); |
523 |
s.acquire(4); |
524 |
s.release(5); |
525 |
s.acquire(5); |
526 |
assertEquals(1, s.availablePermits()); |
527 |
} catch( InterruptedException e){ |
528 |
unexpectedException(); |
529 |
} |
530 |
} |
531 |
|
532 |
/** |
533 |
* Acquire(n) and release(n) of semaphore succeed if initially available |
534 |
*/ |
535 |
public void testAcquireUninterruptiblyReleaseNInSameThread_fair() { |
536 |
Semaphore s = new Semaphore(1, true); |
537 |
try { |
538 |
s.release(1); |
539 |
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 { |
550 |
} |
551 |
} |
552 |
|
553 |
/** |
554 |
* release(n) in one thread enables timed acquire(n) in another thread |
555 |
*/ |
556 |
public void testTimedAcquireReleaseNInSameThread_fair() { |
557 |
Semaphore s = new Semaphore(1, true); |
558 |
try { |
559 |
s.release(1); |
560 |
assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
561 |
s.release(2); |
562 |
assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
563 |
s.release(3); |
564 |
assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
565 |
s.release(4); |
566 |
assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
567 |
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 |
} |
573 |
} |
574 |
|
575 |
/** |
576 |
* release in one thread enables timed acquire in another thread |
577 |
*/ |
578 |
public void testTimedAcquireReleaseInSameThread_fair() { |
579 |
Semaphore s = new Semaphore(1, true); |
580 |
try { |
581 |
assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
582 |
s.release(); |
583 |
assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
584 |
s.release(); |
585 |
assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
586 |
s.release(); |
587 |
assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
588 |
s.release(); |
589 |
assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS)); |
590 |
s.release(); |
591 |
assertEquals(1, s.availablePermits()); |
592 |
} catch( InterruptedException e){ |
593 |
unexpectedException(); |
594 |
} |
595 |
} |
596 |
|
597 |
/** |
598 |
* A release in one thread enables an acquire in another thread |
599 |
*/ |
600 |
public void testAcquireReleaseInDifferentThreads_fair() { |
601 |
final Semaphore s = new Semaphore(0, true); |
602 |
Thread t = new Thread(new Runnable() { |
603 |
public void run() { |
604 |
try { |
605 |
s.acquire(); |
606 |
s.acquire(); |
607 |
s.acquire(); |
608 |
s.acquire(); |
609 |
} catch(InterruptedException ie){ |
610 |
threadUnexpectedException(); |
611 |
} |
612 |
} |
613 |
}); |
614 |
try { |
615 |
t.start(); |
616 |
Thread.sleep(SHORT_DELAY_MS); |
617 |
s.release(); |
618 |
s.release(); |
619 |
s.release(); |
620 |
s.release(); |
621 |
s.release(); |
622 |
s.release(); |
623 |
t.join(); |
624 |
assertEquals(2, s.availablePermits()); |
625 |
} catch( InterruptedException e){ |
626 |
unexpectedException(); |
627 |
} |
628 |
} |
629 |
|
630 |
/** |
631 |
* release(n) in one thread enables acquire(n) in another thread |
632 |
*/ |
633 |
public void testAcquireReleaseNInDifferentThreads_fair() { |
634 |
final Semaphore s = new Semaphore(0, true); |
635 |
Thread t = new Thread(new Runnable() { |
636 |
public void run() { |
637 |
try { |
638 |
s.acquire(); |
639 |
s.release(2); |
640 |
s.acquire(); |
641 |
} catch(InterruptedException ie){ |
642 |
threadUnexpectedException(); |
643 |
} |
644 |
} |
645 |
}); |
646 |
try { |
647 |
t.start(); |
648 |
Thread.sleep(SHORT_DELAY_MS); |
649 |
s.release(2); |
650 |
s.acquire(2); |
651 |
s.release(1); |
652 |
t.join(); |
653 |
} catch( InterruptedException e){ |
654 |
unexpectedException(); |
655 |
} |
656 |
} |
657 |
|
658 |
/** |
659 |
* release(n) in one thread enables acquire(n) in another thread |
660 |
*/ |
661 |
public void testAcquireReleaseNInDifferentThreads_fair2() { |
662 |
final Semaphore s = new Semaphore(0, true); |
663 |
Thread t = new Thread(new Runnable() { |
664 |
public void run() { |
665 |
try { |
666 |
s.acquire(2); |
667 |
s.acquire(2); |
668 |
s.release(4); |
669 |
} catch(InterruptedException ie){ |
670 |
threadUnexpectedException(); |
671 |
} |
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 |
} |
685 |
} |
686 |
|
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 |
/** |
903 |
* toString indicates current number of permits |
904 |
*/ |
905 |
public void testToString() { |
906 |
Semaphore s = new Semaphore(0); |
907 |
String us = s.toString(); |
908 |
assertTrue(us.indexOf("Permits = 0") >= 0); |
909 |
s.release(); |
910 |
String s1 = s.toString(); |
911 |
assertTrue(s1.indexOf("Permits = 1") >= 0); |
912 |
s.release(); |
913 |
String s2 = s.toString(); |
914 |
assertTrue(s2.indexOf("Permits = 2") >= 0); |
915 |
} |
916 |
|
917 |
} |