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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 1.30 by jsr166, Fri Jun 3 05:07:14 2011 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.*;
11 > import java.util.concurrent.CountDownLatch;
12 > import java.util.concurrent.Semaphore;
13 > import static java.util.concurrent.TimeUnit.MILLISECONDS;
14  
15   public class SemaphoreTest extends JSR166TestCase {
16      public static void main(String[] args) {
17 <        junit.textui.TestRunner.run (suite());  
17 >        junit.textui.TestRunner.run(suite());
18      }
19      public static Test suite() {
20 <        return new TestSuite(SemaphoreTest.class);
20 >        return new TestSuite(SemaphoreTest.class);
21      }
22  
23      /**
24       * Subclass to expose protected methods
25       */
26      static class PublicSemaphore extends Semaphore {
27 <        PublicSemaphore(int p, boolean f) { super(p, f); }
28 <        public Collection<Thread> getQueuedThreads() {
29 <            return super.getQueuedThreads();
27 >        PublicSemaphore(int permits) { super(permits); }
28 >        PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
29 >        public Collection<Thread> getQueuedThreads() {
30 >            return super.getQueuedThreads();
31          }
32 <        public void reducePermits(int p) {
33 <            super.reducePermits(p);
32 >        public boolean hasQueuedThread(Thread t) {
33 >            return super.getQueuedThreads().contains(t);
34 >        }
35 >        public void reducePermits(int reduction) {
36 >            super.reducePermits(reduction);
37          }
38      }
39  
40      /**
41       * A runnable calling acquire
42       */
43 <    class InterruptibleLockRunnable implements Runnable {
43 >    class InterruptibleLockRunnable extends CheckedRunnable {
44          final Semaphore lock;
45 <        InterruptibleLockRunnable(Semaphore l) { lock = l; }
46 <        public void run() {
45 >        InterruptibleLockRunnable(Semaphore s) { lock = s; }
46 >        public void realRun() {
47              try {
48                  lock.acquire();
49 <            } catch(InterruptedException success){}
49 >            }
50 >            catch (InterruptedException ignored) {}
51          }
52      }
53  
48
54      /**
55 <     * A runnable calling acquire that expects to be
51 <     * interrupted
55 >     * A runnable calling acquire that expects to be interrupted
56       */
57 <    class InterruptedLockRunnable implements Runnable {
57 >    class InterruptedLockRunnable extends CheckedInterruptedRunnable {
58          final Semaphore lock;
59 <        InterruptedLockRunnable(Semaphore l) { lock = l; }
60 <        public void run() {
61 <            try {
62 <                lock.acquire();
63 <                threadShouldThrow();
64 <            } catch(InterruptedException success){}
59 >        InterruptedLockRunnable(Semaphore s) { lock = s; }
60 >        public void realRun() throws InterruptedException {
61 >            lock.acquire();
62 >        }
63 >    }
64 >
65 >    /**
66 >     * Spin-waits until s.hasQueuedThread(t) becomes true.
67 >     */
68 >    void waitForQueuedThread(PublicSemaphore s, Thread t) {
69 >        long startTime = System.nanoTime();
70 >        while (!s.hasQueuedThread(t)) {
71 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
72 >                throw new AssertionFailedError("timed out");
73 >            Thread.yield();
74 >        }
75 >        assert(s.hasQueuedThreads());
76 >        assertTrue(t.isAlive());
77 >    }
78 >
79 >    /**
80 >     * Spin-waits until s.hasQueuedThreads() becomes true.
81 >     */
82 >    void waitForQueuedThreads(Semaphore s) {
83 >        long startTime = System.nanoTime();
84 >        while (!s.hasQueuedThreads()) {
85 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
86 >                throw new AssertionFailedError("timed out");
87 >            Thread.yield();
88 >        }
89 >    }
90 >
91 >    enum AcquireMethod {
92 >        acquire() {
93 >            void acquire(Semaphore s) throws InterruptedException {
94 >                s.acquire();
95 >            }
96 >        },
97 >        acquireN() {
98 >            void acquire(Semaphore s, int permits) throws InterruptedException {
99 >                s.acquire(permits);
100 >            }
101 >        },
102 >        acquireUninterruptibly() {
103 >            void acquire(Semaphore s) {
104 >                s.acquireUninterruptibly();
105 >            }
106 >        },
107 >        acquireUninterruptiblyN() {
108 >            void acquire(Semaphore s, int permits) {
109 >                s.acquireUninterruptibly(permits);
110 >            }
111 >        },
112 >        tryAcquire() {
113 >            void acquire(Semaphore s) {
114 >                assertTrue(s.tryAcquire());
115 >            }
116 >        },
117 >        tryAcquireN() {
118 >            void acquire(Semaphore s, int permits) {
119 >                assertTrue(s.tryAcquire(permits));
120 >            }
121 >        },
122 >        tryAcquireTimed() {
123 >            void acquire(Semaphore s) throws InterruptedException {
124 >                assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
125 >            }
126 >        },
127 >        tryAcquireTimedN {
128 >            void acquire(Semaphore s, int permits) throws InterruptedException {
129 >                assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
130 >            }
131 >        };
132 >
133 >        // Intentionally meta-circular
134 >
135 >        /** Acquires 1 permit. */
136 >        void acquire(Semaphore s) throws InterruptedException {
137 >            acquire(s, 1);
138 >        }
139 >        /** Acquires the given number of permits. */
140 >        void acquire(Semaphore s, int permits) throws InterruptedException {
141 >            for (int i = 0; i < permits; i++)
142 >                acquire(s);
143          }
144      }
145  
146      /**
147       * Zero, negative, and positive initial values are allowed in constructor
148       */
149 <    public void testConstructor() {
150 <        Semaphore s0 = new Semaphore(0, false);
151 <        assertEquals(0, s0.availablePermits());
152 <        assertFalse(s0.isFair());
153 <        Semaphore s1 = new Semaphore(-1, false);
154 <        assertEquals(-1, s1.availablePermits());
155 <        Semaphore s2 = new Semaphore(-1, false);
156 <        assertEquals(-1, s2.availablePermits());
149 >    public void testConstructor()      { testConstructor(false); }
150 >    public void testConstructor_fair() { testConstructor(true); }
151 >    public void testConstructor(boolean fair) {
152 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
153 >            Semaphore s = new Semaphore(permits, fair);
154 >            assertEquals(permits, s.availablePermits());
155 >            assertEquals(fair, s.isFair());
156 >        }
157 >    }
158 >
159 >    /**
160 >     * Constructor without fairness argument behaves as nonfair
161 >     */
162 >    public void testConstructorDefaultsToNonFair() {
163 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
164 >            Semaphore s = new Semaphore(permits);
165 >            assertEquals(permits, s.availablePermits());
166 >            assertFalse(s.isFair());
167 >        }
168      }
169  
170      /**
171 <     * tryAcquire succeeds when sufficent permits, else fails
171 >     * tryAcquire succeeds when sufficient permits, else fails
172       */
173 <    public void testTryAcquireInSameThread() {
174 <        Semaphore s = new Semaphore(2, false);
173 >    public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
174 >    public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
175 >    public void testTryAcquireInSameThread(boolean fair) {
176 >        Semaphore s = new Semaphore(2, fair);
177          assertEquals(2, s.availablePermits());
178          assertTrue(s.tryAcquire());
179          assertTrue(s.tryAcquire());
180          assertEquals(0, s.availablePermits());
181          assertFalse(s.tryAcquire());
182 +        assertFalse(s.tryAcquire());
183 +        assertEquals(0, s.availablePermits());
184      }
185  
186      /**
187 <     * Acquire and release of semaphore succeed if initially available
187 >     * timed tryAcquire times out
188       */
189 <    public void testAcquireReleaseInSameThread() {
190 <        Semaphore s = new Semaphore(1, false);
191 <        try {
192 <            s.acquire();
193 <            s.release();
194 <            s.acquire();
195 <            s.release();
196 <            s.acquire();
197 <            s.release();
198 <            s.acquire();
199 <            s.release();
200 <            s.acquire();
201 <            s.release();
202 <            assertEquals(1, s.availablePermits());
203 <        } catch( InterruptedException e){
204 <            unexpectedException();
205 <        }
189 >    public void testTryAcquire_timeout()      { testTryAcquire_timeout(false); }
190 >    public void testTryAcquire_timeout_fair() { testTryAcquire_timeout(true); }
191 >    public void testTryAcquire_timeout(boolean fair) {
192 >        Semaphore s = new Semaphore(0, fair);
193 >        long startTime = System.nanoTime();
194 >        try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
195 >        catch (InterruptedException e) { threadUnexpectedException(e); }
196 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
197 >    }
198 >
199 >    /**
200 >     * timed tryAcquire(N) times out
201 >     */
202 >    public void testTryAcquireN_timeout()      { testTryAcquireN_timeout(false); }
203 >    public void testTryAcquireN_timeout_fair() { testTryAcquireN_timeout(true); }
204 >    public void testTryAcquireN_timeout(boolean fair) {
205 >        Semaphore s = new Semaphore(2, fair);
206 >        long startTime = System.nanoTime();
207 >        try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
208 >        catch (InterruptedException e) { threadUnexpectedException(e); }
209 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
210 >    }
211 >
212 >    /**
213 >     * acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
214 >     * are interruptible
215 >     */
216 >    public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
217 >    public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
218 >    public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
219 >    public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
220 >    public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
221 >    public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
222 >    public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
223 >    public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
224 >    public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
225 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
226 >        final Semaphore pleaseInterrupt = new Semaphore(0, fair);
227 >        Thread t = newStartedThread(new CheckedRunnable() {
228 >            public void realRun() {
229 >                // Interrupt before acquire
230 >                Thread.currentThread().interrupt();
231 >                try {
232 >                    acquirer.acquire(s);
233 >                    shouldThrow();
234 >                } catch (InterruptedException success) {}
235 >
236 >                // Interrupt during acquire
237 >                try {
238 >                    acquirer.acquire(s);
239 >                    shouldThrow();
240 >                } catch (InterruptedException success) {}
241 >
242 >                // Interrupt before acquire(N)
243 >                Thread.currentThread().interrupt();
244 >                try {
245 >                    acquirer.acquire(s, 3);
246 >                    shouldThrow();
247 >                } catch (InterruptedException success) {}
248 >
249 >                pleaseInterrupt.release();
250 >
251 >                // Interrupt during acquire(N)
252 >                try {
253 >                    acquirer.acquire(s, 3);
254 >                    shouldThrow();
255 >                } catch (InterruptedException success) {}
256 >            }});
257 >
258 >        waitForQueuedThread(s, t);
259 >        t.interrupt();
260 >        await(pleaseInterrupt);
261 >        waitForQueuedThread(s, t);
262 >        t.interrupt();
263 >        awaitTermination(t);
264 >    }
265 >
266 >    /**
267 >     * acquireUninterruptibly(), acquireUninterruptibly(N) are
268 >     * uninterruptible
269 >     */
270 >    public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
271 >    public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
272 >    public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
273 >    public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
274 >    public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
275 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
276 >        final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
277 >
278 >        Thread t1 = newStartedThread(new CheckedRunnable() {
279 >            public void realRun() throws InterruptedException {
280 >                // Interrupt before acquire
281 >                pleaseInterrupt.release();
282 >                Thread.currentThread().interrupt();
283 >                acquirer.acquire(s);
284 >                assertTrue(Thread.interrupted());
285 >            }});
286 >
287 >        Thread t2 = newStartedThread(new CheckedRunnable() {
288 >            public void realRun() throws InterruptedException {
289 >                // Interrupt during acquire
290 >                pleaseInterrupt.release();
291 >                acquirer.acquire(s);
292 >                assertTrue(Thread.interrupted());
293 >            }});
294 >
295 >        await(pleaseInterrupt);
296 >        waitForQueuedThread(s, t1);
297 >        waitForQueuedThread(s, t2);
298 >        t2.interrupt();
299 >
300 >        assertThreadStaysAlive(t1);
301 >        assertTrue(t2.isAlive());
302 >
303 >        s.release(2);
304 >
305 >        awaitTermination(t1);
306 >        awaitTermination(t2);
307 >    }
308 >
309 >    /**
310 >     * hasQueuedThreads reports whether there are waiting threads
311 >     */
312 >    public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
313 >    public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
314 >    public void testHasQueuedThreads(boolean fair) {
315 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
316 >        assertFalse(lock.hasQueuedThreads());
317 >        lock.acquireUninterruptibly();
318 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
319 >        waitForQueuedThread(lock, t1);
320 >        assertTrue(lock.hasQueuedThreads());
321 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
322 >        waitForQueuedThread(lock, t2);
323 >        assertTrue(lock.hasQueuedThreads());
324 >        t1.interrupt();
325 >        awaitTermination(t1);
326 >        assertTrue(lock.hasQueuedThreads());
327 >        lock.release();
328 >        awaitTermination(t2);
329 >        assertFalse(lock.hasQueuedThreads());
330      }
331  
332      /**
333 <     * Uninterruptible acquire and release of semaphore succeed if
113 <     * initially available
333 >     * getQueueLength reports number of waiting threads
334       */
335 <    public void testAcquireUninterruptiblyReleaseInSameThread() {
336 <        Semaphore s = new Semaphore(1, false);
337 <        try {
338 <            s.acquireUninterruptibly();
339 <            s.release();
340 <            s.acquireUninterruptibly();
341 <            s.release();
342 <            s.acquireUninterruptibly();
343 <            s.release();
344 <            s.acquireUninterruptibly();
345 <            s.release();
346 <            s.acquireUninterruptibly();
347 <            s.release();
348 <            assertEquals(1, s.availablePermits());
349 <        } finally {
350 <        }
335 >    public void testGetQueueLength()      { testGetQueueLength(false); }
336 >    public void testGetQueueLength_fair() { testGetQueueLength(true); }
337 >    public void testGetQueueLength(boolean fair) {
338 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
339 >        assertEquals(0, lock.getQueueLength());
340 >        lock.acquireUninterruptibly();
341 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
342 >        waitForQueuedThread(lock, t1);
343 >        assertEquals(1, lock.getQueueLength());
344 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
345 >        waitForQueuedThread(lock, t2);
346 >        assertEquals(2, lock.getQueueLength());
347 >        t1.interrupt();
348 >        awaitTermination(t1);
349 >        assertEquals(1, lock.getQueueLength());
350 >        lock.release();
351 >        awaitTermination(t2);
352 >        assertEquals(0, lock.getQueueLength());
353      }
354  
355      /**
356 <     * Timed Acquire and release of semaphore succeed if
135 <     * initially available
356 >     * getQueuedThreads includes waiting threads
357       */
358 <    public void testTimedAcquireReleaseInSameThread() {
359 <        Semaphore s = new Semaphore(1, false);
360 <        try {
361 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
362 <            s.release();
363 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
364 <            s.release();
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 <            assertEquals(1, s.availablePermits());
372 <        } catch( InterruptedException e){
373 <            unexpectedException();
374 <        }
358 >    public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
359 >    public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
360 >    public void testGetQueuedThreads(boolean fair) {
361 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
362 >        assertTrue(lock.getQueuedThreads().isEmpty());
363 >        lock.acquireUninterruptibly();
364 >        assertTrue(lock.getQueuedThreads().isEmpty());
365 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
366 >        waitForQueuedThread(lock, t1);
367 >        assertTrue(lock.getQueuedThreads().contains(t1));
368 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
369 >        waitForQueuedThread(lock, t2);
370 >        assertTrue(lock.getQueuedThreads().contains(t1));
371 >        assertTrue(lock.getQueuedThreads().contains(t2));
372 >        t1.interrupt();
373 >        awaitTermination(t1);
374 >        assertFalse(lock.getQueuedThreads().contains(t1));
375 >        assertTrue(lock.getQueuedThreads().contains(t2));
376 >        lock.release();
377 >        awaitTermination(t2);
378 >        assertTrue(lock.getQueuedThreads().isEmpty());
379      }
380  
381      /**
382 <     * A release in one thread enables an acquire in another thread
383 <     */
384 <    public void testAcquireReleaseInDifferentThreads() {
385 <        final Semaphore s = new Semaphore(0, false);
386 <        Thread t = new Thread(new Runnable() {
387 <                public void run() {
388 <                    try {
389 <                        s.acquire();
390 <                        s.release();
391 <                        s.release();
392 <                        s.acquire();
393 <                    } catch(InterruptedException ie){
394 <                        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 <        }
382 >     * drainPermits reports and removes given number of permits
383 >     */
384 >    public void testDrainPermits()      { testDrainPermits(false); }
385 >    public void testDrainPermits_fair() { testDrainPermits(true); }
386 >    public void testDrainPermits(boolean fair) {
387 >        Semaphore s = new Semaphore(0, fair);
388 >        assertEquals(0, s.availablePermits());
389 >        assertEquals(0, s.drainPermits());
390 >        s.release(10);
391 >        assertEquals(10, s.availablePermits());
392 >        assertEquals(10, s.drainPermits());
393 >        assertEquals(0, s.availablePermits());
394 >        assertEquals(0, s.drainPermits());
395      }
396  
397      /**
398 <     * A release in one thread enables an uninterruptible acquire in another thread
398 >     * release(-N) throws IllegalArgumentException
399       */
400 <    public void testUninterruptibleAcquireReleaseInDifferentThreads() {
401 <        final Semaphore s = new Semaphore(0, false);
402 <        Thread t = new Thread(new Runnable() {
403 <                public void run() {
194 <                    s.acquireUninterruptibly();
195 <                    s.release();
196 <                    s.release();
197 <                    s.acquireUninterruptibly();
198 <                }
199 <            });
400 >    public void testReleaseIAE()      { testReleaseIAE(false); }
401 >    public void testReleaseIAE_fair() { testReleaseIAE(true); }
402 >    public void testReleaseIAE(boolean fair) {
403 >        Semaphore s = new Semaphore(10, fair);
404          try {
405 <            t.start();
406 <            Thread.sleep(SHORT_DELAY_MS);
407 <            s.release();
204 <            s.release();
205 <            s.acquireUninterruptibly();
206 <            s.acquireUninterruptibly();
207 <            s.release();
208 <            t.join();
209 <        } catch( InterruptedException e){
210 <            unexpectedException();
211 <        }
405 >            s.release(-1);
406 >            shouldThrow();
407 >        } catch (IllegalArgumentException success) {}
408      }
409  
214
410      /**
411 <     *  A release in one thread enables a timed acquire in another thread
411 >     * reducePermits(-N) throws IllegalArgumentException
412       */
413 <    public void testTimedAcquireReleaseInDifferentThreads() {
414 <        final Semaphore s = new Semaphore(1, false);
415 <        Thread t = new Thread(new Runnable() {
416 <                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 <            });
413 >    public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
414 >    public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
415 >    public void testReducePermitsIAE(boolean fair) {
416 >        PublicSemaphore s = new PublicSemaphore(10, fair);
417          try {
418 <            t.start();
419 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
420 <            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 <        }
418 >            s.reducePermits(-1);
419 >            shouldThrow();
420 >        } catch (IllegalArgumentException success) {}
421      }
422  
423      /**
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    /**
424       * reducePermits reduces number of permits
425       */
426 <    public void testReducePermits() {
427 <        PublicSemaphore s = new PublicSemaphore(10, false);
426 >    public void testReducePermits()      { testReducePermits(false); }
427 >    public void testReducePermits_fair() { testReducePermits(true); }
428 >    public void testReducePermits(boolean fair) {
429 >        PublicSemaphore s = new PublicSemaphore(10, fair);
430 >        assertEquals(10, s.availablePermits());
431 >        s.reducePermits(0);
432          assertEquals(10, s.availablePermits());
433          s.reducePermits(1);
434          assertEquals(9, s.availablePermits());
435          s.reducePermits(10);
436          assertEquals(-1, s.availablePermits());
437 +        s.reducePermits(10);
438 +        assertEquals(-11, s.availablePermits());
439 +        s.reducePermits(0);
440 +        assertEquals(-11, s.availablePermits());
441      }
442  
443      /**
444 <     * a deserialized serialized semaphore has same number of permits
444 >     * a reserialized semaphore has same number of permits and
445 >     * fairness, but no queued threads
446       */
447 <    public void testSerialization() {
448 <        Semaphore l = new Semaphore(3, false);
447 >    public void testSerialization()      { testSerialization(false); }
448 >    public void testSerialization_fair() { testSerialization(true); }
449 >    public void testSerialization(boolean fair) {
450          try {
451 <            l.acquire();
452 <            l.release();
453 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
454 <            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 <    }
451 >            Semaphore s = new Semaphore(3, fair);
452 >            s.acquire();
453 >            s.acquire();
454 >            s.release();
455  
456 +            Semaphore clone = serialClone(s);
457 +            assertEquals(fair, s.isFair());
458 +            assertEquals(fair, clone.isFair());
459 +            assertEquals(2, s.availablePermits());
460 +            assertEquals(2, clone.availablePermits());
461 +            clone.acquire();
462 +            clone.acquire();
463 +            clone.release();
464 +            assertEquals(2, s.availablePermits());
465 +            assertEquals(1, clone.availablePermits());
466  
467 <    /**
468 <     * Zero, negative, and positive initial values are allowed in constructor
469 <     */
470 <    public void testConstructor_fair() {
471 <        Semaphore s0 = new Semaphore(0, true);
472 <        assertEquals(0, s0.availablePermits());
473 <        assertTrue(s0.isFair());
474 <        Semaphore s1 = new Semaphore(-1, true);
475 <        assertEquals(-1, s1.availablePermits());
476 <        Semaphore s2 = new Semaphore(-1, true);
477 <        assertEquals(-1, s2.availablePermits());
467 >            s = new Semaphore(0, fair);
468 >            Thread t = newStartedThread(new InterruptibleLockRunnable(s));
469 >            waitForQueuedThreads(s);
470 >            clone = serialClone(s);
471 >            assertEquals(fair, s.isFair());
472 >            assertEquals(fair, clone.isFair());
473 >            assertEquals(0, s.availablePermits());
474 >            assertEquals(0, clone.availablePermits());
475 >            assertTrue(s.hasQueuedThreads());
476 >            assertFalse(clone.hasQueuedThreads());
477 >            s.release();
478 >            awaitTermination(t);
479 >            assertFalse(s.hasQueuedThreads());
480 >            assertFalse(clone.hasQueuedThreads());
481 >        } catch (InterruptedException e) { threadUnexpectedException(e); }
482      }
483  
484      /**
485 <     * tryAcquire succeeds when sufficent permits, else fails
486 <     */
487 <    public void testTryAcquireInSameThread_fair() {
488 <        Semaphore s = new Semaphore(2, true);
485 >     * tryAcquire(n) succeeds when sufficient permits, else fails
486 >     */
487 >    public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
488 >    public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
489 >    public void testTryAcquireNInSameThread(boolean fair) {
490 >        Semaphore s = new Semaphore(2, fair);
491          assertEquals(2, s.availablePermits());
492 <        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);
492 >        assertFalse(s.tryAcquire(3));
493          assertEquals(2, s.availablePermits());
494          assertTrue(s.tryAcquire(2));
495          assertEquals(0, s.availablePermits());
496 <        assertFalse(s.tryAcquire());
497 <    }
498 <
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 <        }
496 >        assertFalse(s.tryAcquire(1));
497 >        assertFalse(s.tryAcquire(2));
498 >        assertEquals(0, s.availablePermits());
499      }
500  
501      /**
502 <     * release in one thread enables timed acquire in another thread
502 >     * acquire succeeds if permits available
503       */
504 <    public void testTimedAcquireReleaseInSameThread_fair() {
505 <        Semaphore s = new Semaphore(1, true);
506 <        try {
507 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
508 <            s.release();
509 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
510 <            s.release();
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();
504 >    public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
505 >    public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
506 >    public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
507 >    public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
508 >    public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
509 >    public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
510 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
511 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
512 >    public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
513 >    public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
514 >    public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
515 >    public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
516 >    public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
517 >    public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
518 >    public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
519 >    public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
520 >    public void testReleaseAcquireSameThread(boolean fair,
521 >                                             final AcquireMethod acquirer) {
522 >        Semaphore s = new Semaphore(1, fair);
523 >        for (int i = 1; i < 6; i++) {
524 >            s.release(i);
525 >            assertEquals(1 + i, s.availablePermits());
526 >            try {
527 >                acquirer.acquire(s, i);
528 >            } catch (InterruptedException e) { threadUnexpectedException(e); }
529              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();
530          }
531      }
532  
533      /**
534 <     * release(n) in one thread enables acquire(n) in another thread
534 >     * release in one thread enables acquire in another thread
535       */
536 <    public void testAcquireReleaseNInDifferentThreads_fair() {
537 <        final Semaphore s = new Semaphore(0, true);
538 <        Thread t = new Thread(new Runnable() {
539 <                public void run() {
540 <                    try {
541 <                        s.acquire(2);
542 <                        s.acquire(2);
543 <                        s.release(4);
544 <                    } catch(InterruptedException ie){
545 <                        threadUnexpectedException();
546 <                    }
547 <                }
548 <            });
549 <        try {
550 <            t.start();
551 <            Thread.sleep(SHORT_DELAY_MS);
552 <            s.release(6);
553 <            s.acquire(2);
554 <            s.acquire(2);
555 <            s.release(2);
556 <            t.join();
557 <        } catch( InterruptedException e){
558 <            unexpectedException();
559 <        }
560 <    }
561 <
562 <
563 <
564 <    /**
565 <     * release in one thread enables timed acquire in another thread
566 <     */
567 <    public void testTimedAcquireReleaseInDifferentThreads_fair() {
568 <        final Semaphore s = new Semaphore(1, true);
569 <        Thread t = new Thread(new Runnable() {
570 <                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();
536 >    public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
537 >    public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
538 >    public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
539 >    public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
540 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
541 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
542 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
543 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
544 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
545 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
546 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
547 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
548 >    public void testReleaseAcquireDifferentThreads(boolean fair,
549 >                                                   final AcquireMethod acquirer) {
550 >        final Semaphore s = new Semaphore(0, fair);
551 >        final int rounds = 4;
552 >        long startTime = System.nanoTime();
553 >        Thread t = newStartedThread(new CheckedRunnable() {
554 >            public void realRun() throws InterruptedException {
555 >                for (int i = 0; i < rounds; i++) {
556 >                    assertFalse(s.hasQueuedThreads());
557 >                    if (i % 2 == 0)
558 >                        acquirer.acquire(s);
559 >                    else
560 >                        acquirer.acquire(s, 3);
561 >                }}});
562 >
563 >        for (int i = 0; i < rounds; i++) {
564 >            while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
565 >                Thread.yield();
566 >            assertTrue(t.isAlive());
567 >            if (i % 2 == 0)
568 >                s.release();
569 >            else
570 >                s.release(3);
571          }
572 +        awaitTermination(t);
573 +        assertEquals(0, s.availablePermits());
574 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
575      }
576  
577      /**
578 <     * 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
578 >     * fair locks are strictly FIFO
579       */
580 <    public void testSerialization_fair() {
581 <        Semaphore l = new Semaphore(3, true);
582 <
583 <        try {
584 <            l.acquire();
585 <            l.release();
586 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
587 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
588 <            out.writeObject(l);
589 <            out.close();
590 <
591 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
592 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
593 <            Semaphore r = (Semaphore) in.readObject();
594 <            assertEquals(3, r.availablePermits());
595 <            assertTrue(r.isFair());
596 <            r.acquire();
597 <            r.release();
598 <        } catch(Exception e){
599 <            unexpectedException();
600 <        }
580 >    public void testFairLocksFifo() {
581 >        final PublicSemaphore s = new PublicSemaphore(1, true);
582 >        final CountDownLatch pleaseRelease = new CountDownLatch(1);
583 >        Thread t1 = newStartedThread(new CheckedRunnable() {
584 >            public void realRun() throws InterruptedException {
585 >                // Will block; permits are available, but not three
586 >                s.acquire(3);
587 >            }});
588 >
589 >        waitForQueuedThreads(s);
590 >
591 >        Thread t2 = newStartedThread(new CheckedRunnable() {
592 >            public void realRun() throws InterruptedException {
593 >                // Will fail, even though 1 permit is available
594 >                assertFalse(s.tryAcquire(0L, MILLISECONDS));
595 >                assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
596 >
597 >                // untimed tryAcquire will barge and succeed
598 >                assertTrue(s.tryAcquire());
599 >                s.release(2);
600 >                assertTrue(s.tryAcquire(2));
601 >                s.release();
602 >
603 >                pleaseRelease.countDown();
604 >                // Will queue up behind t1, even though 1 permit is available
605 >                s.acquire();
606 >            }});
607 >
608 >        await(pleaseRelease);
609 >        waitForQueuedThread(s, t2);
610 >        s.release(2);
611 >        awaitTermination(t1);
612 >        assertTrue(t2.isAlive());
613 >        s.release();
614 >        awaitTermination(t2);
615 >   }
616 >
617 >    /**
618 >     * toString indicates current number of permits
619 >     */
620 >    public void testToString()      { testToString(false); }
621 >    public void testToString_fair() { testToString(true); }
622 >    public void testToString(boolean fair) {
623 >        PublicSemaphore s = new PublicSemaphore(0, fair);
624 >        assertTrue(s.toString().contains("Permits = 0"));
625 >        s.release();
626 >        assertTrue(s.toString().contains("Permits = 1"));
627 >        s.release(2);
628 >        assertTrue(s.toString().contains("Permits = 3"));
629 >        s.reducePermits(5);
630 >        assertTrue(s.toString().contains("Permits = -2"));
631      }
632  
813
633   }

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