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Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.7 by dl, Sat Dec 27 19:26:43 2003 UTC vs.
Revision 1.32 by jsr166, Wed Dec 31 19:05:43 2014 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 >        junit.textui.TestRunner.run(suite());
22      }
23      public static Test suite() {
24 <        return new TestSuite(SemaphoreTest.class);
24 >        return new TestSuite(SemaphoreTest.class);
25      }
26  
27      /**
28       * Subclass to expose protected methods
29       */
30      static class PublicSemaphore extends Semaphore {
31 <        PublicSemaphore(int p, boolean f) { super(p, f); }
32 <        public Collection<Thread> getQueuedThreads() {
33 <            return super.getQueuedThreads();
31 >        PublicSemaphore(int permits) { super(permits); }
32 >        PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
33 >        public Collection<Thread> getQueuedThreads() {
34 >            return super.getQueuedThreads();
35 >        }
36 >        public boolean hasQueuedThread(Thread t) {
37 >            return super.getQueuedThreads().contains(t);
38          }
39 <        public void reducePermits(int p) {
40 <            super.reducePermits(p);
39 >        public void reducePermits(int reduction) {
40 >            super.reducePermits(reduction);
41          }
42      }
43  
44      /**
45       * A runnable calling acquire
46       */
47 <    class InterruptibleLockRunnable implements Runnable {
47 >    class InterruptibleLockRunnable extends CheckedRunnable {
48          final Semaphore lock;
49 <        InterruptibleLockRunnable(Semaphore l) { lock = l; }
50 <        public void run() {
49 >        InterruptibleLockRunnable(Semaphore s) { lock = s; }
50 >        public void realRun() {
51              try {
52                  lock.acquire();
53 <            } catch(InterruptedException success){}
53 >            }
54 >            catch (InterruptedException ignored) {}
55          }
56      }
57  
48
58      /**
59 <     * A runnable calling acquire that expects to be
51 <     * interrupted
59 >     * A runnable calling acquire that expects to be interrupted
60       */
61 <    class InterruptedLockRunnable implements Runnable {
61 >    class InterruptedLockRunnable extends CheckedInterruptedRunnable {
62          final Semaphore lock;
63 <        InterruptedLockRunnable(Semaphore l) { lock = l; }
64 <        public void run() {
65 <            try {
66 <                lock.acquire();
67 <                threadShouldThrow();
68 <            } catch(InterruptedException success){}
63 >        InterruptedLockRunnable(Semaphore s) { lock = s; }
64 >        public void realRun() throws InterruptedException {
65 >            lock.acquire();
66 >        }
67 >    }
68 >
69 >    /**
70 >     * Spin-waits until s.hasQueuedThread(t) becomes true.
71 >     */
72 >    void waitForQueuedThread(PublicSemaphore s, Thread t) {
73 >        long startTime = System.nanoTime();
74 >        while (!s.hasQueuedThread(t)) {
75 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
76 >                throw new AssertionFailedError("timed out");
77 >            Thread.yield();
78 >        }
79 >        assertTrue(s.hasQueuedThreads());
80 >        assertTrue(t.isAlive());
81 >    }
82 >
83 >    /**
84 >     * Spin-waits until s.hasQueuedThreads() becomes true.
85 >     */
86 >    void waitForQueuedThreads(Semaphore s) {
87 >        long startTime = System.nanoTime();
88 >        while (!s.hasQueuedThreads()) {
89 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
90 >                throw new AssertionFailedError("timed out");
91 >            Thread.yield();
92 >        }
93 >    }
94 >
95 >    enum AcquireMethod {
96 >        acquire() {
97 >            void acquire(Semaphore s) throws InterruptedException {
98 >                s.acquire();
99 >            }
100 >        },
101 >        acquireN() {
102 >            void acquire(Semaphore s, int permits) throws InterruptedException {
103 >                s.acquire(permits);
104 >            }
105 >        },
106 >        acquireUninterruptibly() {
107 >            void acquire(Semaphore s) {
108 >                s.acquireUninterruptibly();
109 >            }
110 >        },
111 >        acquireUninterruptiblyN() {
112 >            void acquire(Semaphore s, int permits) {
113 >                s.acquireUninterruptibly(permits);
114 >            }
115 >        },
116 >        tryAcquire() {
117 >            void acquire(Semaphore s) {
118 >                assertTrue(s.tryAcquire());
119 >            }
120 >        },
121 >        tryAcquireN() {
122 >            void acquire(Semaphore s, int permits) {
123 >                assertTrue(s.tryAcquire(permits));
124 >            }
125 >        },
126 >        tryAcquireTimed() {
127 >            void acquire(Semaphore s) throws InterruptedException {
128 >                assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
129 >            }
130 >        },
131 >        tryAcquireTimedN {
132 >            void acquire(Semaphore s, int permits) throws InterruptedException {
133 >                assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
134 >            }
135 >        };
136 >
137 >        // Intentionally meta-circular
138 >
139 >        /** Acquires 1 permit. */
140 >        void acquire(Semaphore s) throws InterruptedException {
141 >            acquire(s, 1);
142 >        }
143 >        /** Acquires the given number of permits. */
144 >        void acquire(Semaphore s, int permits) throws InterruptedException {
145 >            for (int i = 0; i < permits; i++)
146 >                acquire(s);
147          }
148      }
149  
150      /**
151       * Zero, negative, and positive initial values are allowed in constructor
152       */
153 <    public void testConstructor() {
154 <        Semaphore s0 = new Semaphore(0, false);
155 <        assertEquals(0, s0.availablePermits());
156 <        assertFalse(s0.isFair());
157 <        Semaphore s1 = new Semaphore(-1, false);
158 <        assertEquals(-1, s1.availablePermits());
159 <        Semaphore s2 = new Semaphore(-1, false);
160 <        assertEquals(-1, s2.availablePermits());
153 >    public void testConstructor()      { testConstructor(false); }
154 >    public void testConstructor_fair() { testConstructor(true); }
155 >    public void testConstructor(boolean fair) {
156 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
157 >            Semaphore s = new Semaphore(permits, fair);
158 >            assertEquals(permits, s.availablePermits());
159 >            assertEquals(fair, s.isFair());
160 >        }
161      }
162  
163      /**
164 <     * tryAcquire succeeds when sufficent permits, else fails
164 >     * Constructor without fairness argument behaves as nonfair
165       */
166 <    public void testTryAcquireInSameThread() {
167 <        Semaphore s = new Semaphore(2, false);
166 >    public void testConstructorDefaultsToNonFair() {
167 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
168 >            Semaphore s = new Semaphore(permits);
169 >            assertEquals(permits, s.availablePermits());
170 >            assertFalse(s.isFair());
171 >        }
172 >    }
173 >
174 >    /**
175 >     * tryAcquire succeeds when sufficient permits, else fails
176 >     */
177 >    public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
178 >    public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
179 >    public void testTryAcquireInSameThread(boolean fair) {
180 >        Semaphore s = new Semaphore(2, fair);
181          assertEquals(2, s.availablePermits());
182          assertTrue(s.tryAcquire());
183          assertTrue(s.tryAcquire());
184          assertEquals(0, s.availablePermits());
185          assertFalse(s.tryAcquire());
186 +        assertFalse(s.tryAcquire());
187 +        assertEquals(0, s.availablePermits());
188      }
189  
190      /**
191 <     * Acquire and release of semaphore succeed if initially available
191 >     * timed tryAcquire times out
192       */
193 <    public void testAcquireReleaseInSameThread() {
194 <        Semaphore s = new Semaphore(1, false);
195 <        try {
196 <            s.acquire();
197 <            s.release();
198 <            s.acquire();
199 <            s.release();
200 <            s.acquire();
201 <            s.release();
202 <            s.acquire();
203 <            s.release();
204 <            s.acquire();
205 <            s.release();
206 <            assertEquals(1, s.availablePermits());
207 <        } catch( InterruptedException e){
208 <            unexpectedException();
209 <        }
193 >    public void testTryAcquire_timeout()      { testTryAcquire_timeout(false); }
194 >    public void testTryAcquire_timeout_fair() { testTryAcquire_timeout(true); }
195 >    public void testTryAcquire_timeout(boolean fair) {
196 >        Semaphore s = new Semaphore(0, fair);
197 >        long startTime = System.nanoTime();
198 >        try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
199 >        catch (InterruptedException e) { threadUnexpectedException(e); }
200 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
201 >    }
202 >
203 >    /**
204 >     * timed tryAcquire(N) times out
205 >     */
206 >    public void testTryAcquireN_timeout()      { testTryAcquireN_timeout(false); }
207 >    public void testTryAcquireN_timeout_fair() { testTryAcquireN_timeout(true); }
208 >    public void testTryAcquireN_timeout(boolean fair) {
209 >        Semaphore s = new Semaphore(2, fair);
210 >        long startTime = System.nanoTime();
211 >        try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
212 >        catch (InterruptedException e) { threadUnexpectedException(e); }
213 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
214 >    }
215 >
216 >    /**
217 >     * acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
218 >     * are interruptible
219 >     */
220 >    public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
221 >    public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
222 >    public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
223 >    public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
224 >    public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
225 >    public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
226 >    public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
227 >    public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
228 >    public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
229 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
230 >        final Semaphore pleaseInterrupt = new Semaphore(0, fair);
231 >        Thread t = newStartedThread(new CheckedRunnable() {
232 >            public void realRun() {
233 >                // Interrupt before acquire
234 >                Thread.currentThread().interrupt();
235 >                try {
236 >                    acquirer.acquire(s);
237 >                    shouldThrow();
238 >                } catch (InterruptedException success) {}
239 >
240 >                // Interrupt during acquire
241 >                try {
242 >                    acquirer.acquire(s);
243 >                    shouldThrow();
244 >                } catch (InterruptedException success) {}
245 >
246 >                // Interrupt before acquire(N)
247 >                Thread.currentThread().interrupt();
248 >                try {
249 >                    acquirer.acquire(s, 3);
250 >                    shouldThrow();
251 >                } catch (InterruptedException success) {}
252 >
253 >                pleaseInterrupt.release();
254 >
255 >                // Interrupt during acquire(N)
256 >                try {
257 >                    acquirer.acquire(s, 3);
258 >                    shouldThrow();
259 >                } catch (InterruptedException success) {}
260 >            }});
261 >
262 >        waitForQueuedThread(s, t);
263 >        t.interrupt();
264 >        await(pleaseInterrupt);
265 >        waitForQueuedThread(s, t);
266 >        t.interrupt();
267 >        awaitTermination(t);
268 >    }
269 >
270 >    /**
271 >     * acquireUninterruptibly(), acquireUninterruptibly(N) are
272 >     * uninterruptible
273 >     */
274 >    public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
275 >    public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
276 >    public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
277 >    public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
278 >    public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
279 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
280 >        final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
281 >
282 >        Thread t1 = newStartedThread(new CheckedRunnable() {
283 >            public void realRun() throws InterruptedException {
284 >                // Interrupt before acquire
285 >                pleaseInterrupt.release();
286 >                Thread.currentThread().interrupt();
287 >                acquirer.acquire(s);
288 >                assertTrue(Thread.interrupted());
289 >            }});
290 >
291 >        Thread t2 = newStartedThread(new CheckedRunnable() {
292 >            public void realRun() throws InterruptedException {
293 >                // Interrupt during acquire
294 >                pleaseInterrupt.release();
295 >                acquirer.acquire(s);
296 >                assertTrue(Thread.interrupted());
297 >            }});
298 >
299 >        await(pleaseInterrupt);
300 >        waitForQueuedThread(s, t1);
301 >        waitForQueuedThread(s, t2);
302 >        t2.interrupt();
303 >
304 >        assertThreadStaysAlive(t1);
305 >        assertTrue(t2.isAlive());
306 >
307 >        s.release(2);
308 >
309 >        awaitTermination(t1);
310 >        awaitTermination(t2);
311 >    }
312 >
313 >    /**
314 >     * hasQueuedThreads reports whether there are waiting threads
315 >     */
316 >    public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
317 >    public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
318 >    public void testHasQueuedThreads(boolean fair) {
319 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
320 >        assertFalse(lock.hasQueuedThreads());
321 >        lock.acquireUninterruptibly();
322 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
323 >        waitForQueuedThread(lock, t1);
324 >        assertTrue(lock.hasQueuedThreads());
325 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
326 >        waitForQueuedThread(lock, t2);
327 >        assertTrue(lock.hasQueuedThreads());
328 >        t1.interrupt();
329 >        awaitTermination(t1);
330 >        assertTrue(lock.hasQueuedThreads());
331 >        lock.release();
332 >        awaitTermination(t2);
333 >        assertFalse(lock.hasQueuedThreads());
334      }
335  
336      /**
337 <     * Uninterruptible acquire and release of semaphore succeed if
113 <     * initially available
337 >     * getQueueLength reports number of waiting threads
338       */
339 <    public void testAcquireUninterruptiblyReleaseInSameThread() {
340 <        Semaphore s = new Semaphore(1, false);
341 <        try {
342 <            s.acquireUninterruptibly();
343 <            s.release();
344 <            s.acquireUninterruptibly();
345 <            s.release();
346 <            s.acquireUninterruptibly();
347 <            s.release();
348 <            s.acquireUninterruptibly();
349 <            s.release();
350 <            s.acquireUninterruptibly();
351 <            s.release();
352 <            assertEquals(1, s.availablePermits());
353 <        } finally {
354 <        }
339 >    public void testGetQueueLength()      { testGetQueueLength(false); }
340 >    public void testGetQueueLength_fair() { testGetQueueLength(true); }
341 >    public void testGetQueueLength(boolean fair) {
342 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
343 >        assertEquals(0, lock.getQueueLength());
344 >        lock.acquireUninterruptibly();
345 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
346 >        waitForQueuedThread(lock, t1);
347 >        assertEquals(1, lock.getQueueLength());
348 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
349 >        waitForQueuedThread(lock, t2);
350 >        assertEquals(2, lock.getQueueLength());
351 >        t1.interrupt();
352 >        awaitTermination(t1);
353 >        assertEquals(1, lock.getQueueLength());
354 >        lock.release();
355 >        awaitTermination(t2);
356 >        assertEquals(0, lock.getQueueLength());
357      }
358  
359      /**
360 <     * Timed Acquire and release of semaphore succeed if
135 <     * initially available
360 >     * getQueuedThreads includes waiting threads
361       */
362 <    public void testTimedAcquireReleaseInSameThread() {
363 <        Semaphore s = new Semaphore(1, false);
364 <        try {
365 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
366 <            s.release();
367 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
368 <            s.release();
369 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
370 <            s.release();
371 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
372 <            s.release();
373 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
374 <            s.release();
375 <            assertEquals(1, s.availablePermits());
376 <        } catch( InterruptedException e){
377 <            unexpectedException();
378 <        }
362 >    public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
363 >    public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
364 >    public void testGetQueuedThreads(boolean fair) {
365 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
366 >        assertTrue(lock.getQueuedThreads().isEmpty());
367 >        lock.acquireUninterruptibly();
368 >        assertTrue(lock.getQueuedThreads().isEmpty());
369 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
370 >        waitForQueuedThread(lock, t1);
371 >        assertTrue(lock.getQueuedThreads().contains(t1));
372 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
373 >        waitForQueuedThread(lock, t2);
374 >        assertTrue(lock.getQueuedThreads().contains(t1));
375 >        assertTrue(lock.getQueuedThreads().contains(t2));
376 >        t1.interrupt();
377 >        awaitTermination(t1);
378 >        assertFalse(lock.getQueuedThreads().contains(t1));
379 >        assertTrue(lock.getQueuedThreads().contains(t2));
380 >        lock.release();
381 >        awaitTermination(t2);
382 >        assertTrue(lock.getQueuedThreads().isEmpty());
383      }
384  
385      /**
386 <     * A release in one thread enables an acquire in another thread
387 <     */
388 <    public void testAcquireReleaseInDifferentThreads() {
389 <        final Semaphore s = new Semaphore(0, false);
390 <        Thread t = new Thread(new Runnable() {
391 <                public void run() {
392 <                    try {
393 <                        s.acquire();
394 <                        s.release();
395 <                        s.release();
396 <                        s.acquire();
397 <                    } catch(InterruptedException ie){
398 <                        threadUnexpectedException();
170 <                    }
171 <                }
172 <            });
173 <        try {
174 <            t.start();
175 <            Thread.sleep(SHORT_DELAY_MS);
176 <            s.release();
177 <            s.release();
178 <            s.acquire();
179 <            s.acquire();
180 <            s.release();
181 <            t.join();
182 <        } catch( InterruptedException e){
183 <            unexpectedException();
184 <        }
386 >     * drainPermits reports and removes given number of permits
387 >     */
388 >    public void testDrainPermits()      { testDrainPermits(false); }
389 >    public void testDrainPermits_fair() { testDrainPermits(true); }
390 >    public void testDrainPermits(boolean fair) {
391 >        Semaphore s = new Semaphore(0, fair);
392 >        assertEquals(0, s.availablePermits());
393 >        assertEquals(0, s.drainPermits());
394 >        s.release(10);
395 >        assertEquals(10, s.availablePermits());
396 >        assertEquals(10, s.drainPermits());
397 >        assertEquals(0, s.availablePermits());
398 >        assertEquals(0, s.drainPermits());
399      }
400  
401      /**
402 <     * A release in one thread enables an uninterruptible acquire in another thread
402 >     * release(-N) throws IllegalArgumentException
403       */
404 <    public void testUninterruptibleAcquireReleaseInDifferentThreads() {
405 <        final Semaphore s = new Semaphore(0, false);
406 <        Thread t = new Thread(new Runnable() {
407 <                public void run() {
194 <                    s.acquireUninterruptibly();
195 <                    s.release();
196 <                    s.release();
197 <                    s.acquireUninterruptibly();
198 <                }
199 <            });
404 >    public void testReleaseIAE()      { testReleaseIAE(false); }
405 >    public void testReleaseIAE_fair() { testReleaseIAE(true); }
406 >    public void testReleaseIAE(boolean fair) {
407 >        Semaphore s = new Semaphore(10, fair);
408          try {
409 <            t.start();
410 <            Thread.sleep(SHORT_DELAY_MS);
411 <            s.release();
204 <            s.release();
205 <            s.acquireUninterruptibly();
206 <            s.acquireUninterruptibly();
207 <            s.release();
208 <            t.join();
209 <        } catch( InterruptedException e){
210 <            unexpectedException();
211 <        }
409 >            s.release(-1);
410 >            shouldThrow();
411 >        } catch (IllegalArgumentException success) {}
412      }
413  
214
414      /**
415 <     *  A release in one thread enables a timed acquire in another thread
415 >     * reducePermits(-N) throws IllegalArgumentException
416       */
417 <    public void testTimedAcquireReleaseInDifferentThreads() {
418 <        final Semaphore s = new Semaphore(1, false);
419 <        Thread t = new Thread(new Runnable() {
420 <                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));
227 <
228 <                    } catch(InterruptedException ie){
229 <                        threadUnexpectedException();
230 <                    }
231 <                }
232 <            });
417 >    public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
418 >    public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
419 >    public void testReducePermitsIAE(boolean fair) {
420 >        PublicSemaphore s = new PublicSemaphore(10, fair);
421          try {
422 <            t.start();
423 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
424 <            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 <        }
422 >            s.reducePermits(-1);
423 >            shouldThrow();
424 >        } catch (IllegalArgumentException success) {}
425      }
426  
427      /**
294     * getQueueLength reports number of waiting threads
295     */
296    public void testGetQueueLength() {
297        final Semaphore lock = new Semaphore(1, false);
298        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
299        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
300        try {
301            assertEquals(0, lock.getQueueLength());
302            lock.acquireUninterruptibly();
303            t1.start();
304            Thread.sleep(SHORT_DELAY_MS);
305            assertEquals(1, lock.getQueueLength());
306            t2.start();
307            Thread.sleep(SHORT_DELAY_MS);
308            assertEquals(2, lock.getQueueLength());
309            t1.interrupt();
310            Thread.sleep(SHORT_DELAY_MS);
311            assertEquals(1, lock.getQueueLength());
312            lock.release();
313            Thread.sleep(SHORT_DELAY_MS);
314            assertEquals(0, lock.getQueueLength());
315            t1.join();
316            t2.join();
317        } catch(Exception e){
318            unexpectedException();
319        }
320    }
321
322    /**
323     * getQueuedThreads includes waiting threads
324     */
325    public void testGetQueuedThreads() {
326        final PublicSemaphore lock = new PublicSemaphore(1, false);
327        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
328        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
329        try {
330            assertTrue(lock.getQueuedThreads().isEmpty());
331            lock.acquireUninterruptibly();
332            assertTrue(lock.getQueuedThreads().isEmpty());
333            t1.start();
334            Thread.sleep(SHORT_DELAY_MS);
335            assertTrue(lock.getQueuedThreads().contains(t1));
336            t2.start();
337            Thread.sleep(SHORT_DELAY_MS);
338            assertTrue(lock.getQueuedThreads().contains(t1));
339            assertTrue(lock.getQueuedThreads().contains(t2));
340            t1.interrupt();
341            Thread.sleep(SHORT_DELAY_MS);
342            assertFalse(lock.getQueuedThreads().contains(t1));
343            assertTrue(lock.getQueuedThreads().contains(t2));
344            lock.release();
345            Thread.sleep(SHORT_DELAY_MS);
346            assertTrue(lock.getQueuedThreads().isEmpty());
347            t1.join();
348            t2.join();
349        } catch(Exception e){
350            unexpectedException();
351        }
352    }
353
354
355    /**
428       * reducePermits reduces number of permits
429       */
430 <    public void testReducePermits() {
431 <        PublicSemaphore s = new PublicSemaphore(10, false);
430 >    public void testReducePermits()      { testReducePermits(false); }
431 >    public void testReducePermits_fair() { testReducePermits(true); }
432 >    public void testReducePermits(boolean fair) {
433 >        PublicSemaphore s = new PublicSemaphore(10, fair);
434 >        assertEquals(10, s.availablePermits());
435 >        s.reducePermits(0);
436          assertEquals(10, s.availablePermits());
437          s.reducePermits(1);
438          assertEquals(9, s.availablePermits());
439          s.reducePermits(10);
440          assertEquals(-1, s.availablePermits());
441 +        s.reducePermits(10);
442 +        assertEquals(-11, s.availablePermits());
443 +        s.reducePermits(0);
444 +        assertEquals(-11, s.availablePermits());
445      }
446  
447      /**
448 <     * a deserialized serialized semaphore has same number of permits
448 >     * a reserialized semaphore has same number of permits and
449 >     * fairness, but no queued threads
450       */
451 <    public void testSerialization() {
452 <        Semaphore l = new Semaphore(3, false);
451 >    public void testSerialization()      { testSerialization(false); }
452 >    public void testSerialization_fair() { testSerialization(true); }
453 >    public void testSerialization(boolean fair) {
454          try {
455 <            l.acquire();
456 <            l.release();
457 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
458 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
377 <            out.writeObject(l);
378 <            out.close();
379 <
380 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
381 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
382 <            Semaphore r = (Semaphore) in.readObject();
383 <            assertEquals(3, r.availablePermits());
384 <            assertFalse(r.isFair());
385 <            r.acquire();
386 <            r.release();
387 <        } catch(Exception e){
388 <            unexpectedException();
389 <        }
390 <    }
455 >            Semaphore s = new Semaphore(3, fair);
456 >            s.acquire();
457 >            s.acquire();
458 >            s.release();
459  
460 +            Semaphore clone = serialClone(s);
461 +            assertEquals(fair, s.isFair());
462 +            assertEquals(fair, clone.isFair());
463 +            assertEquals(2, s.availablePermits());
464 +            assertEquals(2, clone.availablePermits());
465 +            clone.acquire();
466 +            clone.acquire();
467 +            clone.release();
468 +            assertEquals(2, s.availablePermits());
469 +            assertEquals(1, clone.availablePermits());
470  
471 <    /**
472 <     * Zero, negative, and positive initial values are allowed in constructor
473 <     */
474 <    public void testConstructor_fair() {
475 <        Semaphore s0 = new Semaphore(0, true);
476 <        assertEquals(0, s0.availablePermits());
477 <        assertTrue(s0.isFair());
478 <        Semaphore s1 = new Semaphore(-1, true);
479 <        assertEquals(-1, s1.availablePermits());
480 <        Semaphore s2 = new Semaphore(-1, true);
481 <        assertEquals(-1, s2.availablePermits());
471 >            s = new Semaphore(0, fair);
472 >            Thread t = newStartedThread(new InterruptibleLockRunnable(s));
473 >            waitForQueuedThreads(s);
474 >            clone = serialClone(s);
475 >            assertEquals(fair, s.isFair());
476 >            assertEquals(fair, clone.isFair());
477 >            assertEquals(0, s.availablePermits());
478 >            assertEquals(0, clone.availablePermits());
479 >            assertTrue(s.hasQueuedThreads());
480 >            assertFalse(clone.hasQueuedThreads());
481 >            s.release();
482 >            awaitTermination(t);
483 >            assertFalse(s.hasQueuedThreads());
484 >            assertFalse(clone.hasQueuedThreads());
485 >        } catch (InterruptedException e) { threadUnexpectedException(e); }
486      }
487  
488      /**
489 <     * tryAcquire succeeds when sufficent permits, else fails
490 <     */
491 <    public void testTryAcquireInSameThread_fair() {
492 <        Semaphore s = new Semaphore(2, true);
489 >     * tryAcquire(n) succeeds when sufficient permits, else fails
490 >     */
491 >    public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
492 >    public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
493 >    public void testTryAcquireNInSameThread(boolean fair) {
494 >        Semaphore s = new Semaphore(2, fair);
495          assertEquals(2, s.availablePermits());
496 <        assertTrue(s.tryAcquire());
413 <        assertTrue(s.tryAcquire());
414 <        assertEquals(0, s.availablePermits());
415 <        assertFalse(s.tryAcquire());
416 <    }
417 <
418 <    /**
419 <     * tryAcquire(n) succeeds when sufficent permits, else fails
420 <     */
421 <    public void testTryAcquireNInSameThread_fair() {
422 <        Semaphore s = new Semaphore(2, true);
496 >        assertFalse(s.tryAcquire(3));
497          assertEquals(2, s.availablePermits());
498          assertTrue(s.tryAcquire(2));
499          assertEquals(0, s.availablePermits());
500 <        assertFalse(s.tryAcquire());
501 <    }
502 <
429 <    /**
430 <     * Acquire and release of semaphore succeed if initially available
431 <     */
432 <    public void testAcquireReleaseInSameThread_fair() {
433 <        Semaphore s = new Semaphore(1, true);
434 <        try {
435 <            s.acquire();
436 <            s.release();
437 <            s.acquire();
438 <            s.release();
439 <            s.acquire();
440 <            s.release();
441 <            s.acquire();
442 <            s.release();
443 <            s.acquire();
444 <            s.release();
445 <            assertEquals(1, s.availablePermits());
446 <        } catch( InterruptedException e){
447 <            unexpectedException();
448 <        }
449 <    }
450 <
451 <    /**
452 <     * Acquire(n) and release(n) of semaphore succeed if initially available
453 <     */
454 <    public void testAcquireReleaseNInSameThread_fair() {
455 <        Semaphore s = new Semaphore(1, true);
456 <        try {
457 <            s.release(1);
458 <            s.acquire(1);
459 <            s.release(2);
460 <            s.acquire(2);
461 <            s.release(3);
462 <            s.acquire(3);
463 <            s.release(4);
464 <            s.acquire(4);
465 <            s.release(5);
466 <            s.acquire(5);
467 <            assertEquals(1, s.availablePermits());
468 <        } catch( InterruptedException e){
469 <            unexpectedException();
470 <        }
471 <    }
472 <
473 <    /**
474 <     * Acquire(n) and release(n) of semaphore succeed if initially available
475 <     */
476 <    public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
477 <        Semaphore s = new Semaphore(1, true);
478 <        try {
479 <            s.release(1);
480 <            s.acquireUninterruptibly(1);
481 <            s.release(2);
482 <            s.acquireUninterruptibly(2);
483 <            s.release(3);
484 <            s.acquireUninterruptibly(3);
485 <            s.release(4);
486 <            s.acquireUninterruptibly(4);
487 <            s.release(5);
488 <            s.acquireUninterruptibly(5);
489 <            assertEquals(1, s.availablePermits());
490 <        } finally {
491 <        }
492 <    }
493 <
494 <    /**
495 <     * release(n) in one thread enables timed acquire(n) in another thread
496 <     */
497 <    public void testTimedAcquireReleaseNInSameThread_fair() {
498 <        Semaphore s = new Semaphore(1, true);
499 <        try {
500 <            s.release(1);
501 <            assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
502 <            s.release(2);
503 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
504 <            s.release(3);
505 <            assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
506 <            s.release(4);
507 <            assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
508 <            s.release(5);
509 <            assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
510 <            assertEquals(1, s.availablePermits());
511 <        } catch( InterruptedException e){
512 <            unexpectedException();
513 <        }
500 >        assertFalse(s.tryAcquire(1));
501 >        assertFalse(s.tryAcquire(2));
502 >        assertEquals(0, s.availablePermits());
503      }
504  
505      /**
506 <     * release in one thread enables timed acquire in another thread
506 >     * acquire succeeds if permits available
507       */
508 <    public void testTimedAcquireReleaseInSameThread_fair() {
509 <        Semaphore s = new Semaphore(1, true);
510 <        try {
511 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
512 <            s.release();
513 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
514 <            s.release();
515 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
516 <            s.release();
517 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
518 <            s.release();
519 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
520 <            s.release();
508 >    public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
509 >    public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
510 >    public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
511 >    public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
512 >    public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
513 >    public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
514 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
515 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
516 >    public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
517 >    public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
518 >    public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
519 >    public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
520 >    public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
521 >    public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
522 >    public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
523 >    public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
524 >    public void testReleaseAcquireSameThread(boolean fair,
525 >                                             final AcquireMethod acquirer) {
526 >        Semaphore s = new Semaphore(1, fair);
527 >        for (int i = 1; i < 6; i++) {
528 >            s.release(i);
529 >            assertEquals(1 + i, s.availablePermits());
530 >            try {
531 >                acquirer.acquire(s, i);
532 >            } catch (InterruptedException e) { threadUnexpectedException(e); }
533              assertEquals(1, s.availablePermits());
533        } catch( InterruptedException e){
534            unexpectedException();
535        }
536    }
537
538    /**
539     * A release in one thread enables an acquire in another thread
540     */
541    public void testAcquireReleaseInDifferentThreads_fair() {
542        final Semaphore s = new Semaphore(0, true);
543        Thread t = new Thread(new Runnable() {
544                public void run() {
545                    try {
546                        s.acquire();
547                        s.acquire();
548                        s.acquire();
549                        s.acquire();
550                    } catch(InterruptedException ie){
551                        threadUnexpectedException();
552                    }
553                }
554            });
555        try {
556            t.start();
557            Thread.sleep(SHORT_DELAY_MS);
558            s.release();
559            s.release();
560            s.release();
561            s.release();
562            s.release();
563            s.release();
564            t.join();
565            assertEquals(2, s.availablePermits());
566        } catch( InterruptedException e){
567            unexpectedException();
534          }
535      }
536  
537      /**
538 <     * release(n) in one thread enables acquire(n) in another thread
538 >     * release in one thread enables acquire in another thread
539       */
540 <    public void testAcquireReleaseNInDifferentThreads_fair() {
541 <        final Semaphore s = new Semaphore(0, true);
542 <        Thread t = new Thread(new Runnable() {
543 <                public void run() {
544 <                    try {
545 <                        s.acquire(2);
546 <                        s.acquire(2);
547 <                        s.release(4);
548 <                    } catch(InterruptedException ie){
549 <                        threadUnexpectedException();
550 <                    }
551 <                }
552 <            });
553 <        try {
554 <            t.start();
555 <            Thread.sleep(SHORT_DELAY_MS);
556 <            s.release(6);
557 <            s.acquire(2);
558 <            s.acquire(2);
559 <            s.release(2);
560 <            t.join();
561 <        } catch( InterruptedException e){
562 <            unexpectedException();
563 <        }
564 <    }
565 <
566 <
567 <
568 <    /**
569 <     * release in one thread enables timed acquire in another thread
570 <     */
571 <    public void testTimedAcquireReleaseInDifferentThreads_fair() {
572 <        final Semaphore s = new Semaphore(1, true);
573 <        Thread t = new Thread(new Runnable() {
574 <                public void run() {
609 <                    try {
610 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
611 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
612 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
613 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
614 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
615 <
616 <                    } catch(InterruptedException ie){
617 <                        threadUnexpectedException();
618 <                    }
619 <                }
620 <            });
621 <        t.start();
622 <        try {
623 <            s.release();
624 <            s.release();
625 <            s.release();
626 <            s.release();
627 <            s.release();
628 <            t.join();
629 <        } catch( InterruptedException e){
630 <            unexpectedException();
631 <        }
632 <    }
633 <
634 <    /**
635 <     * release(n) in one thread enables timed acquire(n) in another thread
636 <     */
637 <    public void testTimedAcquireReleaseNInDifferentThreads_fair() {
638 <        final Semaphore s = new Semaphore(2, true);
639 <        Thread t = new Thread(new Runnable() {
640 <                public void run() {
641 <                    try {
642 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
643 <                        s.release(2);
644 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
645 <                        s.release(2);
646 <                    } catch(InterruptedException ie){
647 <                        threadUnexpectedException();
648 <                    }
649 <                }
650 <            });
651 <        t.start();
652 <        try {
653 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
654 <            s.release(2);
655 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
656 <            s.release(2);
657 <            t.join();
658 <        } catch( InterruptedException e){
659 <            unexpectedException();
660 <        }
661 <    }
662 <
663 <    /**
664 <     * A waiting acquire blocks interruptibly
665 <     */
666 <    public void testAcquire_InterruptedException_fair() {
667 <        final Semaphore s = new Semaphore(0, true);
668 <        Thread t = new Thread(new Runnable() {
669 <                public void run() {
670 <                    try {
671 <                        s.acquire();
672 <                        threadShouldThrow();
673 <                    } catch(InterruptedException success){}
674 <                }
675 <            });
676 <        t.start();
677 <        try {
678 <            Thread.sleep(SHORT_DELAY_MS);
679 <            t.interrupt();
680 <            t.join();
681 <        } catch(InterruptedException e){
682 <            unexpectedException();
683 <        }
684 <    }
685 <
686 <    /**
687 <     * A waiting acquire(n) blocks interruptibly
688 <     */
689 <    public void testAcquireN_InterruptedException_fair() {
690 <        final Semaphore s = new Semaphore(2, true);
691 <        Thread t = new Thread(new Runnable() {
692 <                public void run() {
693 <                    try {
694 <                        s.acquire(3);
695 <                        threadShouldThrow();
696 <                    } catch(InterruptedException success){}
697 <                }
698 <            });
699 <        t.start();
700 <        try {
701 <            Thread.sleep(SHORT_DELAY_MS);
702 <            t.interrupt();
703 <            t.join();
704 <        } catch(InterruptedException e){
705 <            unexpectedException();
706 <        }
707 <    }
708 <    
709 <    /**
710 <     *  A waiting tryAcquire blocks interruptibly
711 <     */
712 <    public void testTryAcquire_InterruptedException_fair() {
713 <        final Semaphore s = new Semaphore(0, true);
714 <        Thread t = new Thread(new Runnable() {
715 <                public void run() {
716 <                    try {
717 <                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
718 <                        threadShouldThrow();
719 <                    } catch(InterruptedException success){
720 <                    }
721 <                }
722 <            });
723 <        t.start();
724 <        try {
725 <            Thread.sleep(SHORT_DELAY_MS);
726 <            t.interrupt();
727 <            t.join();
728 <        } catch(InterruptedException e){
729 <            unexpectedException();
730 <        }
731 <    }
732 <
733 <    /**
734 <     *  A waiting tryAcquire(n) blocks interruptibly
735 <     */
736 <    public void testTryAcquireN_InterruptedException_fair() {
737 <        final Semaphore s = new Semaphore(1, true);
738 <        Thread t = new Thread(new Runnable() {
739 <                public void run() {
740 <                    try {
741 <                        s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
742 <                        threadShouldThrow();
743 <                    } catch(InterruptedException success){
744 <                    }
745 <                }
746 <            });
747 <        t.start();
748 <        try {
749 <            Thread.sleep(SHORT_DELAY_MS);
750 <            t.interrupt();
751 <            t.join();
752 <        } catch(InterruptedException e){
753 <            unexpectedException();
540 >    public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
541 >    public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
542 >    public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
543 >    public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
544 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
545 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
546 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
547 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
548 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
549 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
550 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
551 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
552 >    public void testReleaseAcquireDifferentThreads(boolean fair,
553 >                                                   final AcquireMethod acquirer) {
554 >        final Semaphore s = new Semaphore(0, fair);
555 >        final int rounds = 4;
556 >        long startTime = System.nanoTime();
557 >        Thread t = newStartedThread(new CheckedRunnable() {
558 >            public void realRun() throws InterruptedException {
559 >                for (int i = 0; i < rounds; i++) {
560 >                    assertFalse(s.hasQueuedThreads());
561 >                    if (i % 2 == 0)
562 >                        acquirer.acquire(s);
563 >                    else
564 >                        acquirer.acquire(s, 3);
565 >                }}});
566 >
567 >        for (int i = 0; i < rounds; i++) {
568 >            while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
569 >                Thread.yield();
570 >            assertTrue(t.isAlive());
571 >            if (i % 2 == 0)
572 >                s.release();
573 >            else
574 >                s.release(3);
575          }
576 +        awaitTermination(t);
577 +        assertEquals(0, s.availablePermits());
578 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
579      }
580  
581      /**
582 <     * getQueueLength reports number of waiting threads
759 <     */
760 <    public void testGetQueueLength_fair() {
761 <        final Semaphore lock = new Semaphore(1, true);
762 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
763 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
764 <        try {
765 <            assertEquals(0, lock.getQueueLength());
766 <            lock.acquireUninterruptibly();
767 <            t1.start();
768 <            Thread.sleep(SHORT_DELAY_MS);
769 <            assertEquals(1, lock.getQueueLength());
770 <            t2.start();
771 <            Thread.sleep(SHORT_DELAY_MS);
772 <            assertEquals(2, lock.getQueueLength());
773 <            t1.interrupt();
774 <            Thread.sleep(SHORT_DELAY_MS);
775 <            assertEquals(1, lock.getQueueLength());
776 <            lock.release();
777 <            Thread.sleep(SHORT_DELAY_MS);
778 <            assertEquals(0, lock.getQueueLength());
779 <            t1.join();
780 <            t2.join();
781 <        } catch(Exception e){
782 <            unexpectedException();
783 <        }
784 <    }
785 <
786 <
787 <    /**
788 <     * a deserialized serialized semaphore has same number of permits
582 >     * fair locks are strictly FIFO
583       */
584 <    public void testSerialization_fair() {
585 <        Semaphore l = new Semaphore(3, true);
586 <
587 <        try {
588 <            l.acquire();
589 <            l.release();
590 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
591 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
592 <            out.writeObject(l);
593 <            out.close();
594 <
595 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
596 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
597 <            Semaphore r = (Semaphore) in.readObject();
598 <            assertEquals(3, r.availablePermits());
599 <            assertTrue(r.isFair());
600 <            r.acquire();
601 <            r.release();
602 <        } catch(Exception e){
603 <            unexpectedException();
604 <        }
584 >    public void testFairLocksFifo() {
585 >        final PublicSemaphore s = new PublicSemaphore(1, true);
586 >        final CountDownLatch pleaseRelease = new CountDownLatch(1);
587 >        Thread t1 = newStartedThread(new CheckedRunnable() {
588 >            public void realRun() throws InterruptedException {
589 >                // Will block; permits are available, but not three
590 >                s.acquire(3);
591 >            }});
592 >
593 >        waitForQueuedThreads(s);
594 >
595 >        Thread t2 = newStartedThread(new CheckedRunnable() {
596 >            public void realRun() throws InterruptedException {
597 >                // Will fail, even though 1 permit is available
598 >                assertFalse(s.tryAcquire(0L, MILLISECONDS));
599 >                assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
600 >
601 >                // untimed tryAcquire will barge and succeed
602 >                assertTrue(s.tryAcquire());
603 >                s.release(2);
604 >                assertTrue(s.tryAcquire(2));
605 >                s.release();
606 >
607 >                pleaseRelease.countDown();
608 >                // Will queue up behind t1, even though 1 permit is available
609 >                s.acquire();
610 >            }});
611 >
612 >        await(pleaseRelease);
613 >        waitForQueuedThread(s, t2);
614 >        s.release(2);
615 >        awaitTermination(t1);
616 >        assertTrue(t2.isAlive());
617 >        s.release();
618 >        awaitTermination(t2);
619 >   }
620 >
621 >    /**
622 >     * toString indicates current number of permits
623 >     */
624 >    public void testToString()      { testToString(false); }
625 >    public void testToString_fair() { testToString(true); }
626 >    public void testToString(boolean fair) {
627 >        PublicSemaphore s = new PublicSemaphore(0, fair);
628 >        assertTrue(s.toString().contains("Permits = 0"));
629 >        s.release();
630 >        assertTrue(s.toString().contains("Permits = 1"));
631 >        s.release(2);
632 >        assertTrue(s.toString().contains("Permits = 3"));
633 >        s.reducePermits(5);
634 >        assertTrue(s.toString().contains("Permits = -2"));
635      }
636  
813
637   }

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