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Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.6 by dl, Mon Nov 3 13:50:07 2003 UTC vs.
Revision 1.30 by jsr166, Fri Jun 3 05:07:14 2011 UTC

# Line 1 | Line 1
1   /*
2 < * Written by members of JCP JSR-166 Expert Group and released to the
3 < * public domain. Use, modify, and redistribute this code in any way
4 < * without acknowledgement. Other contributors include Andrew Wright,
5 < * Jeffrey Hayes, Pat Fischer, Mike Judd.
2 > * Written by Doug Lea with assistance from members of JCP JSR-166
3 > * Expert Group and released to the public domain, as explained at
4 > * http://creativecommons.org/publicdomain/zero/1.0/
5 > * Other contributors include Andrew Wright, Jeffrey Hayes,
6 > * Pat Fisher, Mike Judd.
7   */
8  
9   import junit.framework.*;
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  
47
54      /**
55 <     * A runnable calling acquire that expects to be
50 <     * 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
112 <     * 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
134 <     * 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();
169 <                    }
170 <                }
171 <            });
172 <        try {
173 <            t.start();
174 <            Thread.sleep(SHORT_DELAY_MS);
175 <            s.release();
176 <            s.release();
177 <            s.acquire();
178 <            s.acquire();
179 <            s.release();
180 <            t.join();
181 <        } catch( InterruptedException e){
182 <            unexpectedException();
183 <        }
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() {
193 <                    s.acquireUninterruptibly();
194 <                    s.release();
195 <                    s.release();
196 <                    s.acquireUninterruptibly();
197 <                }
198 <            });
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();
203 <            s.release();
204 <            s.acquireUninterruptibly();
205 <            s.acquireUninterruptibly();
206 <            s.release();
207 <            t.join();
208 <        } catch( InterruptedException e){
209 <            unexpectedException();
210 <        }
405 >            s.release(-1);
406 >            shouldThrow();
407 >        } catch (IllegalArgumentException success) {}
408      }
409  
213
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() {
221 <                    try {
222 <                        s.release();
223 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
224 <                        s.release();
225 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
226 <
227 <                    } catch(InterruptedException ie){
228 <                        threadUnexpectedException();
229 <                    }
230 <                }
231 <            });
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();
236 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
237 <            s.release();
238 <            s.release();
239 <            t.join();
240 <        } catch( InterruptedException e){
241 <            unexpectedException();
242 <        }
243 <    }
244 <
245 <    /**
246 <     * A waiting acquire blocks interruptibly
247 <     */
248 <    public void testAcquire_InterruptedException() {
249 <        final Semaphore s = new Semaphore(0, false);
250 <        Thread t = new Thread(new Runnable() {
251 <                public void run() {
252 <                    try {
253 <                        s.acquire();
254 <                        threadShouldThrow();
255 <                    } catch(InterruptedException success){}
256 <                }
257 <            });
258 <        t.start();
259 <        try {
260 <            Thread.sleep(SHORT_DELAY_MS);
261 <            t.interrupt();
262 <            t.join();
263 <        } catch(InterruptedException e){
264 <            unexpectedException();
265 <        }
266 <    }
267 <    
268 <    /**
269 <     *  A waiting timed acquire blocks interruptibly
270 <     */
271 <    public void testTryAcquire_InterruptedException() {
272 <        final Semaphore s = new Semaphore(0, false);
273 <        Thread t = new Thread(new Runnable() {
274 <                public void run() {
275 <                    try {
276 <                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
277 <                        threadShouldThrow();
278 <                    } catch(InterruptedException success){
279 <                    }
280 <                }
281 <            });
282 <        t.start();
283 <        try {
284 <            Thread.sleep(SHORT_DELAY_MS);
285 <            t.interrupt();
286 <            t.join();
287 <        } catch(InterruptedException e){
288 <            unexpectedException();
289 <        }
418 >            s.reducePermits(-1);
419 >            shouldThrow();
420 >        } catch (IllegalArgumentException success) {}
421      }
422  
423      /**
293     * getQueueLength reports number of waiting threads
294     */
295    public void testGetQueueLength() {
296        final Semaphore lock = new Semaphore(1, false);
297        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
298        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
299        try {
300            assertEquals(0, lock.getQueueLength());
301            lock.acquireUninterruptibly();
302            t1.start();
303            Thread.sleep(SHORT_DELAY_MS);
304            assertEquals(1, lock.getQueueLength());
305            t2.start();
306            Thread.sleep(SHORT_DELAY_MS);
307            assertEquals(2, lock.getQueueLength());
308            t1.interrupt();
309            Thread.sleep(SHORT_DELAY_MS);
310            assertEquals(1, lock.getQueueLength());
311            lock.release();
312            Thread.sleep(SHORT_DELAY_MS);
313            assertEquals(0, lock.getQueueLength());
314            t1.join();
315            t2.join();
316        } catch(Exception e){
317            unexpectedException();
318        }
319    }
320
321    /**
322     * getQueuedThreads includes waiting threads
323     */
324    public void testGetQueuedThreads() {
325        final PublicSemaphore lock = new PublicSemaphore(1, false);
326        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
327        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
328        try {
329            assertTrue(lock.getQueuedThreads().isEmpty());
330            lock.acquireUninterruptibly();
331            assertTrue(lock.getQueuedThreads().isEmpty());
332            t1.start();
333            Thread.sleep(SHORT_DELAY_MS);
334            assertTrue(lock.getQueuedThreads().contains(t1));
335            t2.start();
336            Thread.sleep(SHORT_DELAY_MS);
337            assertTrue(lock.getQueuedThreads().contains(t1));
338            assertTrue(lock.getQueuedThreads().contains(t2));
339            t1.interrupt();
340            Thread.sleep(SHORT_DELAY_MS);
341            assertFalse(lock.getQueuedThreads().contains(t1));
342            assertTrue(lock.getQueuedThreads().contains(t2));
343            lock.release();
344            Thread.sleep(SHORT_DELAY_MS);
345            assertTrue(lock.getQueuedThreads().isEmpty());
346            t1.join();
347            t2.join();
348        } catch(Exception e){
349            unexpectedException();
350        }
351    }
352
353
354    /**
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));
376 <            out.writeObject(l);
377 <            out.close();
378 <
379 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
380 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
381 <            Semaphore r = (Semaphore) in.readObject();
382 <            assertEquals(3, r.availablePermits());
383 <            assertFalse(r.isFair());
384 <            r.acquire();
385 <            r.release();
386 <        } catch(Exception e){
387 <            unexpectedException();
388 <        }
389 <    }
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());
412 <        assertTrue(s.tryAcquire());
413 <        assertEquals(0, s.availablePermits());
414 <        assertFalse(s.tryAcquire());
415 <    }
416 <
417 <    /**
418 <     * tryAcquire(n) succeeds when sufficent permits, else fails
419 <     */
420 <    public void testTryAcquireNInSameThread_fair() {
421 <        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 <
428 <    /**
429 <     * Acquire and release of semaphore succeed if initially available
430 <     */
431 <    public void testAcquireReleaseInSameThread_fair() {
432 <        Semaphore s = new Semaphore(1, true);
433 <        try {
434 <            s.acquire();
435 <            s.release();
436 <            s.acquire();
437 <            s.release();
438 <            s.acquire();
439 <            s.release();
440 <            s.acquire();
441 <            s.release();
442 <            s.acquire();
443 <            s.release();
444 <            assertEquals(1, s.availablePermits());
445 <        } catch( InterruptedException e){
446 <            unexpectedException();
447 <        }
448 <    }
449 <
450 <    /**
451 <     * Acquire(n) and release(n) of semaphore succeed if initially available
452 <     */
453 <    public void testAcquireReleaseNInSameThread_fair() {
454 <        Semaphore s = new Semaphore(1, true);
455 <        try {
456 <            s.release(1);
457 <            s.acquire(1);
458 <            s.release(2);
459 <            s.acquire(2);
460 <            s.release(3);
461 <            s.acquire(3);
462 <            s.release(4);
463 <            s.acquire(4);
464 <            s.release(5);
465 <            s.acquire(5);
466 <            assertEquals(1, s.availablePermits());
467 <        } catch( InterruptedException e){
468 <            unexpectedException();
469 <        }
470 <    }
471 <
472 <    /**
473 <     * Acquire(n) and release(n) of semaphore succeed if initially available
474 <     */
475 <    public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
476 <        Semaphore s = new Semaphore(1, true);
477 <        try {
478 <            s.release(1);
479 <            s.acquireUninterruptibly(1);
480 <            s.release(2);
481 <            s.acquireUninterruptibly(2);
482 <            s.release(3);
483 <            s.acquireUninterruptibly(3);
484 <            s.release(4);
485 <            s.acquireUninterruptibly(4);
486 <            s.release(5);
487 <            s.acquireUninterruptibly(5);
488 <            assertEquals(1, s.availablePermits());
489 <        } finally {
490 <        }
491 <    }
492 <
493 <    /**
494 <     * release(n) in one thread enables timed acquire(n) in another thread
495 <     */
496 <    public void testTimedAcquireReleaseNInSameThread_fair() {
497 <        Semaphore s = new Semaphore(1, true);
498 <        try {
499 <            s.release(1);
500 <            assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
501 <            s.release(2);
502 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
503 <            s.release(3);
504 <            assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
505 <            s.release(4);
506 <            assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
507 <            s.release(5);
508 <            assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
509 <            assertEquals(1, s.availablePermits());
510 <        } catch( InterruptedException e){
511 <            unexpectedException();
512 <        }
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());
532        } catch( InterruptedException e){
533            unexpectedException();
534        }
535    }
536
537    /**
538     * A release in one thread enables an acquire in another thread
539     */
540    public void testAcquireReleaseInDifferentThreads_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();
546                        s.acquire();
547                        s.acquire();
548                        s.acquire();
549                    } catch(InterruptedException ie){
550                        threadUnexpectedException();
551                    }
552                }
553            });
554        try {
555            t.start();
556            Thread.sleep(SHORT_DELAY_MS);
557            s.release();
558            s.release();
559            s.release();
560            s.release();
561            s.release();
562            s.release();
563            t.join();
564            assertEquals(2, s.availablePermits());
565        } catch( InterruptedException e){
566            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() {
608 <                    try {
609 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
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 <
615 <                    } catch(InterruptedException ie){
616 <                        threadUnexpectedException();
617 <                    }
618 <                }
619 <            });
620 <        t.start();
621 <        try {
622 <            s.release();
623 <            s.release();
624 <            s.release();
625 <            s.release();
626 <            s.release();
627 <            t.join();
628 <        } catch( InterruptedException e){
629 <            unexpectedException();
630 <        }
631 <    }
632 <
633 <    /**
634 <     * release(n) in one thread enables timed acquire(n) in another thread
635 <     */
636 <    public void testTimedAcquireReleaseNInDifferentThreads_fair() {
637 <        final Semaphore s = new Semaphore(2, true);
638 <        Thread t = new Thread(new Runnable() {
639 <                public void run() {
640 <                    try {
641 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
642 <                        s.release(2);
643 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
644 <                        s.release(2);
645 <                    } catch(InterruptedException ie){
646 <                        threadUnexpectedException();
647 <                    }
648 <                }
649 <            });
650 <        t.start();
651 <        try {
652 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
653 <            s.release(2);
654 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
655 <            s.release(2);
656 <            t.join();
657 <        } catch( InterruptedException e){
658 <            unexpectedException();
659 <        }
660 <    }
661 <
662 <    /**
663 <     * A waiting acquire blocks interruptibly
664 <     */
665 <    public void testAcquire_InterruptedException_fair() {
666 <        final Semaphore s = new Semaphore(0, true);
667 <        Thread t = new Thread(new Runnable() {
668 <                public void run() {
669 <                    try {
670 <                        s.acquire();
671 <                        threadShouldThrow();
672 <                    } catch(InterruptedException success){}
673 <                }
674 <            });
675 <        t.start();
676 <        try {
677 <            Thread.sleep(SHORT_DELAY_MS);
678 <            t.interrupt();
679 <            t.join();
680 <        } catch(InterruptedException e){
681 <            unexpectedException();
682 <        }
683 <    }
684 <
685 <    /**
686 <     * A waiting acquire(n) blocks interruptibly
687 <     */
688 <    public void testAcquireN_InterruptedException_fair() {
689 <        final Semaphore s = new Semaphore(2, true);
690 <        Thread t = new Thread(new Runnable() {
691 <                public void run() {
692 <                    try {
693 <                        s.acquire(3);
694 <                        threadShouldThrow();
695 <                    } catch(InterruptedException success){}
696 <                }
697 <            });
698 <        t.start();
699 <        try {
700 <            Thread.sleep(SHORT_DELAY_MS);
701 <            t.interrupt();
702 <            t.join();
703 <        } catch(InterruptedException e){
704 <            unexpectedException();
705 <        }
706 <    }
707 <    
708 <    /**
709 <     *  A waiting tryAcquire blocks interruptibly
710 <     */
711 <    public void testTryAcquire_InterruptedException_fair() {
712 <        final Semaphore s = new Semaphore(0, true);
713 <        Thread t = new Thread(new Runnable() {
714 <                public void run() {
715 <                    try {
716 <                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
717 <                        threadShouldThrow();
718 <                    } catch(InterruptedException success){
719 <                    }
720 <                }
721 <            });
722 <        t.start();
723 <        try {
724 <            Thread.sleep(SHORT_DELAY_MS);
725 <            t.interrupt();
726 <            t.join();
727 <        } catch(InterruptedException e){
728 <            unexpectedException();
729 <        }
730 <    }
731 <
732 <    /**
733 <     *  A waiting tryAcquire(n) blocks interruptibly
734 <     */
735 <    public void testTryAcquireN_InterruptedException_fair() {
736 <        final Semaphore s = new Semaphore(1, true);
737 <        Thread t = new Thread(new Runnable() {
738 <                public void run() {
739 <                    try {
740 <                        s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
741 <                        threadShouldThrow();
742 <                    } catch(InterruptedException success){
743 <                    }
744 <                }
745 <            });
746 <        t.start();
747 <        try {
748 <            Thread.sleep(SHORT_DELAY_MS);
749 <            t.interrupt();
750 <            t.join();
751 <        } catch(InterruptedException e){
752 <            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
758 <     */
759 <    public void testGetQueueLength_fair() {
760 <        final Semaphore lock = new Semaphore(1, true);
761 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
762 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
763 <        try {
764 <            assertEquals(0, lock.getQueueLength());
765 <            lock.acquireUninterruptibly();
766 <            t1.start();
767 <            Thread.sleep(SHORT_DELAY_MS);
768 <            assertEquals(1, lock.getQueueLength());
769 <            t2.start();
770 <            Thread.sleep(SHORT_DELAY_MS);
771 <            assertEquals(2, lock.getQueueLength());
772 <            t1.interrupt();
773 <            Thread.sleep(SHORT_DELAY_MS);
774 <            assertEquals(1, lock.getQueueLength());
775 <            lock.release();
776 <            Thread.sleep(SHORT_DELAY_MS);
777 <            assertEquals(0, lock.getQueueLength());
778 <            t1.join();
779 <            t2.join();
780 <        } catch(Exception e){
781 <            unexpectedException();
782 <        }
783 <    }
784 <
785 <
786 <    /**
787 <     * 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  
812
633   }

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