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Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.17 by jsr166, Mon Nov 16 05:30:08 2009 UTC vs.
Revision 1.36 by jsr166, Thu Nov 19 03:35:48 2015 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
4 > * http://creativecommons.org/publicdomain/zero/1.0/
5   * Other contributors include Andrew Wright, Jeffrey Hayes,
6   * Pat Fisher, Mike Judd.
7   */
8  
9 < import junit.framework.*;
10 < import java.util.*;
11 < import java.util.concurrent.*;
12 < import java.io.*;
9 > import static java.util.concurrent.TimeUnit.MILLISECONDS;
10 >
11 > import java.util.Collection;
12 > import java.util.concurrent.CountDownLatch;
13 > import java.util.concurrent.Semaphore;
14 >
15 > import junit.framework.AssertionFailedError;
16 > import junit.framework.Test;
17 > import junit.framework.TestSuite;
18  
19   public class SemaphoreTest extends JSR166TestCase {
20      public static void main(String[] args) {
21 <        junit.textui.TestRunner.run (suite());
21 >        main(suite(), args);
22      }
23      public static Test suite() {
24 <        return new TestSuite(SemaphoreTest.class);
24 >        return new TestSuite(SemaphoreTest.class);
25      }
26  
27      /**
28       * Subclass to expose protected methods
29       */
30      static class PublicSemaphore extends Semaphore {
31 <        PublicSemaphore(int p, boolean f) { super(p, f); }
31 >        PublicSemaphore(int permits) { super(permits); }
32 >        PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
33          public Collection<Thread> getQueuedThreads() {
34              return super.getQueuedThreads();
35          }
36 <        public void reducePermits(int p) {
37 <            super.reducePermits(p);
36 >        public boolean hasQueuedThread(Thread t) {
37 >            return super.getQueuedThreads().contains(t);
38 >        }
39 >        public void reducePermits(int reduction) {
40 >            super.reducePermits(reduction);
41          }
42      }
43  
44      /**
45       * A runnable calling acquire
46       */
47 <    class InterruptibleLockRunnable implements Runnable {
47 >    class InterruptibleLockRunnable extends CheckedRunnable {
48          final Semaphore lock;
49 <        InterruptibleLockRunnable(Semaphore l) { lock = l; }
50 <        public void run() {
49 >        InterruptibleLockRunnable(Semaphore s) { lock = s; }
50 >        public void realRun() {
51              try {
52                  lock.acquire();
53 <            } catch (InterruptedException success) {}
53 >            }
54 >            catch (InterruptedException ignored) {}
55          }
56      }
57  
48
58      /**
59 <     * A runnable calling acquire that expects to be
51 <     * interrupted
59 >     * A runnable calling acquire that expects to be interrupted
60       */
61 <    class InterruptedLockRunnable implements Runnable {
61 >    class InterruptedLockRunnable extends CheckedInterruptedRunnable {
62          final Semaphore lock;
63 <        InterruptedLockRunnable(Semaphore l) { lock = l; }
64 <        public void run() {
65 <            try {
66 <                lock.acquire();
67 <                threadShouldThrow();
68 <            } catch (InterruptedException success) {}
63 >        InterruptedLockRunnable(Semaphore s) { lock = s; }
64 >        public void realRun() throws InterruptedException {
65 >            lock.acquire();
66 >        }
67 >    }
68 >
69 >    /**
70 >     * Spin-waits until s.hasQueuedThread(t) becomes true.
71 >     */
72 >    void waitForQueuedThread(PublicSemaphore s, Thread t) {
73 >        long startTime = System.nanoTime();
74 >        while (!s.hasQueuedThread(t)) {
75 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
76 >                throw new AssertionFailedError("timed out");
77 >            Thread.yield();
78 >        }
79 >        assertTrue(s.hasQueuedThreads());
80 >        assertTrue(t.isAlive());
81 >    }
82 >
83 >    /**
84 >     * Spin-waits until s.hasQueuedThreads() becomes true.
85 >     */
86 >    void waitForQueuedThreads(Semaphore s) {
87 >        long startTime = System.nanoTime();
88 >        while (!s.hasQueuedThreads()) {
89 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
90 >                throw new AssertionFailedError("timed out");
91 >            Thread.yield();
92 >        }
93 >    }
94 >
95 >    enum AcquireMethod {
96 >        acquire() {
97 >            void acquire(Semaphore s) throws InterruptedException {
98 >                s.acquire();
99 >            }
100 >        },
101 >        acquireN() {
102 >            void acquire(Semaphore s, int permits) throws InterruptedException {
103 >                s.acquire(permits);
104 >            }
105 >        },
106 >        acquireUninterruptibly() {
107 >            void acquire(Semaphore s) {
108 >                s.acquireUninterruptibly();
109 >            }
110 >        },
111 >        acquireUninterruptiblyN() {
112 >            void acquire(Semaphore s, int permits) {
113 >                s.acquireUninterruptibly(permits);
114 >            }
115 >        },
116 >        tryAcquire() {
117 >            void acquire(Semaphore s) {
118 >                assertTrue(s.tryAcquire());
119 >            }
120 >        },
121 >        tryAcquireN() {
122 >            void acquire(Semaphore s, int permits) {
123 >                assertTrue(s.tryAcquire(permits));
124 >            }
125 >        },
126 >        tryAcquireTimed() {
127 >            void acquire(Semaphore s) throws InterruptedException {
128 >                assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
129 >            }
130 >        },
131 >        tryAcquireTimedN {
132 >            void acquire(Semaphore s, int permits) throws InterruptedException {
133 >                assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
134 >            }
135 >        };
136 >
137 >        // Intentionally meta-circular
138 >
139 >        /** Acquires 1 permit. */
140 >        void acquire(Semaphore s) throws InterruptedException {
141 >            acquire(s, 1);
142 >        }
143 >        /** Acquires the given number of permits. */
144 >        void acquire(Semaphore s, int permits) throws InterruptedException {
145 >            for (int i = 0; i < permits; i++)
146 >                acquire(s);
147          }
148      }
149  
150      /**
151       * Zero, negative, and positive initial values are allowed in constructor
152       */
153 <    public void testConstructor() {
154 <        Semaphore s0 = new Semaphore(0, false);
155 <        assertEquals(0, s0.availablePermits());
156 <        assertFalse(s0.isFair());
157 <        Semaphore s1 = new Semaphore(-1, false);
158 <        assertEquals(-1, s1.availablePermits());
159 <        assertFalse(s1.isFair());
160 <        Semaphore s2 = new Semaphore(-1, false);
75 <        assertEquals(-1, s2.availablePermits());
76 <        assertFalse(s2.isFair());
153 >    public void testConstructor()      { testConstructor(false); }
154 >    public void testConstructor_fair() { testConstructor(true); }
155 >    public void testConstructor(boolean fair) {
156 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
157 >            Semaphore s = new Semaphore(permits, fair);
158 >            assertEquals(permits, s.availablePermits());
159 >            assertEquals(fair, s.isFair());
160 >        }
161      }
162  
163      /**
164       * Constructor without fairness argument behaves as nonfair
165       */
166 <    public void testConstructor2() {
167 <        Semaphore s0 = new Semaphore(0);
168 <        assertEquals(0, s0.availablePermits());
169 <        assertFalse(s0.isFair());
170 <        Semaphore s1 = new Semaphore(-1);
171 <        assertEquals(-1, s1.availablePermits());
88 <        assertFalse(s1.isFair());
89 <        Semaphore s2 = new Semaphore(-1);
90 <        assertEquals(-1, s2.availablePermits());
91 <        assertFalse(s2.isFair());
166 >    public void testConstructorDefaultsToNonFair() {
167 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
168 >            Semaphore s = new Semaphore(permits);
169 >            assertEquals(permits, s.availablePermits());
170 >            assertFalse(s.isFair());
171 >        }
172      }
173  
174      /**
175       * tryAcquire succeeds when sufficient permits, else fails
176       */
177 <    public void testTryAcquireInSameThread() {
178 <        Semaphore s = new Semaphore(2, false);
177 >    public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
178 >    public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
179 >    public void testTryAcquireInSameThread(boolean fair) {
180 >        Semaphore s = new Semaphore(2, fair);
181          assertEquals(2, s.availablePermits());
182          assertTrue(s.tryAcquire());
183          assertTrue(s.tryAcquire());
184          assertEquals(0, s.availablePermits());
185          assertFalse(s.tryAcquire());
186 +        assertFalse(s.tryAcquire());
187 +        assertEquals(0, s.availablePermits());
188      }
189  
190      /**
191 <     * Acquire and release of semaphore succeed if initially available
108 <     */
109 <    public void testAcquireReleaseInSameThread() {
110 <        Semaphore s = new Semaphore(1, false);
111 <        try {
112 <            s.acquire();
113 <            s.release();
114 <            s.acquire();
115 <            s.release();
116 <            s.acquire();
117 <            s.release();
118 <            s.acquire();
119 <            s.release();
120 <            s.acquire();
121 <            s.release();
122 <            assertEquals(1, s.availablePermits());
123 <        } catch ( InterruptedException e) {
124 <            unexpectedException();
125 <        }
126 <    }
127 <
128 <    /**
129 <     * Uninterruptible acquire and release of semaphore succeed if
130 <     * initially available
131 <     */
132 <    public void testAcquireUninterruptiblyReleaseInSameThread() {
133 <        Semaphore s = new Semaphore(1, false);
134 <        try {
135 <            s.acquireUninterruptibly();
136 <            s.release();
137 <            s.acquireUninterruptibly();
138 <            s.release();
139 <            s.acquireUninterruptibly();
140 <            s.release();
141 <            s.acquireUninterruptibly();
142 <            s.release();
143 <            s.acquireUninterruptibly();
144 <            s.release();
145 <            assertEquals(1, s.availablePermits());
146 <        } finally {
147 <        }
148 <    }
149 <
150 <    /**
151 <     * Timed Acquire and release of semaphore succeed if
152 <     * initially available
153 <     */
154 <    public void testTimedAcquireReleaseInSameThread() {
155 <        Semaphore s = new Semaphore(1, false);
156 <        try {
157 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
158 <            s.release();
159 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
160 <            s.release();
161 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
162 <            s.release();
163 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
164 <            s.release();
165 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
166 <            s.release();
167 <            assertEquals(1, s.availablePermits());
168 <        } catch ( InterruptedException e) {
169 <            unexpectedException();
170 <        }
171 <    }
172 <
173 <    /**
174 <     * A release in one thread enables an acquire in another thread
175 <     */
176 <    public void testAcquireReleaseInDifferentThreads() {
177 <        final Semaphore s = new Semaphore(0, false);
178 <        Thread t = new Thread(new Runnable() {
179 <                public void run() {
180 <                    try {
181 <                        s.acquire();
182 <                        s.release();
183 <                        s.release();
184 <                        s.acquire();
185 <                    } catch (InterruptedException ie) {
186 <                        threadUnexpectedException();
187 <                    }
188 <                }
189 <            });
190 <        try {
191 <            t.start();
192 <            Thread.sleep(SHORT_DELAY_MS);
193 <            s.release();
194 <            s.release();
195 <            s.acquire();
196 <            s.acquire();
197 <            s.release();
198 <            t.join();
199 <        } catch ( InterruptedException e) {
200 <            unexpectedException();
201 <        }
202 <    }
203 <
204 <    /**
205 <     * A release in one thread enables an uninterruptible acquire in another thread
206 <     */
207 <    public void testUninterruptibleAcquireReleaseInDifferentThreads() {
208 <        final Semaphore s = new Semaphore(0, false);
209 <        Thread t = new Thread(new Runnable() {
210 <                public void run() {
211 <                    s.acquireUninterruptibly();
212 <                    s.release();
213 <                    s.release();
214 <                    s.acquireUninterruptibly();
215 <                }
216 <            });
217 <        try {
218 <            t.start();
219 <            Thread.sleep(SHORT_DELAY_MS);
220 <            s.release();
221 <            s.release();
222 <            s.acquireUninterruptibly();
223 <            s.acquireUninterruptibly();
224 <            s.release();
225 <            t.join();
226 <        } catch ( InterruptedException e) {
227 <            unexpectedException();
228 <        }
229 <    }
230 <
231 <
232 <    /**
233 <     *  A release in one thread enables a timed acquire in another thread
191 >     * timed tryAcquire times out
192       */
193 <    public void testTimedAcquireReleaseInDifferentThreads() {
194 <        final Semaphore s = new Semaphore(1, false);
195 <        Thread t = new Thread(new Runnable() {
196 <                public void run() {
197 <                    try {
198 <                        s.release();
199 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
200 <                        s.release();
201 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
193 >    public void testTryAcquire_timeout()      { testTryAcquire_timeout(false); }
194 >    public void testTryAcquire_timeout_fair() { testTryAcquire_timeout(true); }
195 >    public void testTryAcquire_timeout(boolean fair) {
196 >        Semaphore s = new Semaphore(0, fair);
197 >        long startTime = System.nanoTime();
198 >        try { assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS)); }
199 >        catch (InterruptedException e) { threadUnexpectedException(e); }
200 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
201 >    }
202 >
203 >    /**
204 >     * timed tryAcquire(N) times out
205 >     */
206 >    public void testTryAcquireN_timeout()      { testTryAcquireN_timeout(false); }
207 >    public void testTryAcquireN_timeout_fair() { testTryAcquireN_timeout(true); }
208 >    public void testTryAcquireN_timeout(boolean fair) {
209 >        Semaphore s = new Semaphore(2, fair);
210 >        long startTime = System.nanoTime();
211 >        try { assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS)); }
212 >        catch (InterruptedException e) { threadUnexpectedException(e); }
213 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
214 >    }
215 >
216 >    /**
217 >     * acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
218 >     * are interruptible
219 >     */
220 >    public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
221 >    public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
222 >    public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
223 >    public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
224 >    public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
225 >    public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
226 >    public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
227 >    public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
228 >    public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
229 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
230 >        final Semaphore pleaseInterrupt = new Semaphore(0, fair);
231 >        Thread t = newStartedThread(new CheckedRunnable() {
232 >            public void realRun() {
233 >                // Interrupt before acquire
234 >                Thread.currentThread().interrupt();
235 >                try {
236 >                    acquirer.acquire(s);
237 >                    shouldThrow();
238 >                } catch (InterruptedException success) {}
239 >
240 >                // Interrupt during acquire
241 >                try {
242 >                    acquirer.acquire(s);
243 >                    shouldThrow();
244 >                } catch (InterruptedException success) {}
245 >
246 >                // Interrupt before acquire(N)
247 >                Thread.currentThread().interrupt();
248 >                try {
249 >                    acquirer.acquire(s, 3);
250 >                    shouldThrow();
251 >                } catch (InterruptedException success) {}
252 >
253 >                pleaseInterrupt.release();
254 >
255 >                // Interrupt during acquire(N)
256 >                try {
257 >                    acquirer.acquire(s, 3);
258 >                    shouldThrow();
259 >                } catch (InterruptedException success) {}
260 >            }});
261 >
262 >        waitForQueuedThread(s, t);
263 >        t.interrupt();
264 >        await(pleaseInterrupt);
265 >        waitForQueuedThread(s, t);
266 >        t.interrupt();
267 >        awaitTermination(t);
268 >    }
269 >
270 >    /**
271 >     * acquireUninterruptibly(), acquireUninterruptibly(N) are
272 >     * uninterruptible
273 >     */
274 >    public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
275 >    public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
276 >    public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
277 >    public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
278 >    public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
279 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
280 >        final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
281 >
282 >        Thread t1 = newStartedThread(new CheckedRunnable() {
283 >            public void realRun() throws InterruptedException {
284 >                // Interrupt before acquire
285 >                pleaseInterrupt.release();
286 >                Thread.currentThread().interrupt();
287 >                acquirer.acquire(s);
288 >                assertTrue(Thread.interrupted());
289 >            }});
290 >
291 >        Thread t2 = newStartedThread(new CheckedRunnable() {
292 >            public void realRun() throws InterruptedException {
293 >                // Interrupt during acquire
294 >                pleaseInterrupt.release();
295 >                acquirer.acquire(s);
296 >                assertTrue(Thread.interrupted());
297 >            }});
298 >
299 >        await(pleaseInterrupt);
300 >        waitForQueuedThread(s, t1);
301 >        waitForQueuedThread(s, t2);
302 >        t2.interrupt();
303  
304 <                    } catch (InterruptedException ie) {
305 <                        threadUnexpectedException();
247 <                    }
248 <                }
249 <            });
250 <        try {
251 <            t.start();
252 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
253 <            s.release();
254 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
255 <            s.release();
256 <            s.release();
257 <            t.join();
258 <        } catch ( InterruptedException e) {
259 <            unexpectedException();
260 <        }
261 <    }
304 >        assertThreadStaysAlive(t1);
305 >        assertTrue(t2.isAlive());
306  
307 <    /**
264 <     * A waiting acquire blocks interruptibly
265 <     */
266 <    public void testAcquire_InterruptedException() {
267 <        final Semaphore s = new Semaphore(0, false);
268 <        Thread t = new Thread(new Runnable() {
269 <                public void run() {
270 <                    try {
271 <                        s.acquire();
272 <                        threadShouldThrow();
273 <                    } catch (InterruptedException success) {}
274 <                }
275 <            });
276 <        t.start();
277 <        try {
278 <            Thread.sleep(SHORT_DELAY_MS);
279 <            t.interrupt();
280 <            t.join();
281 <        } catch (InterruptedException e) {
282 <            unexpectedException();
283 <        }
284 <    }
307 >        s.release(2);
308  
309 <    /**
310 <     *  A waiting timed acquire blocks interruptibly
288 <     */
289 <    public void testTryAcquire_InterruptedException() {
290 <        final Semaphore s = new Semaphore(0, false);
291 <        Thread t = new Thread(new Runnable() {
292 <                public void run() {
293 <                    try {
294 <                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
295 <                        threadShouldThrow();
296 <                    } catch (InterruptedException success) {
297 <                    }
298 <                }
299 <            });
300 <        t.start();
301 <        try {
302 <            Thread.sleep(SHORT_DELAY_MS);
303 <            t.interrupt();
304 <            t.join();
305 <        } catch (InterruptedException e) {
306 <            unexpectedException();
307 <        }
309 >        awaitTermination(t1);
310 >        awaitTermination(t2);
311      }
312  
313      /**
314       * hasQueuedThreads reports whether there are waiting threads
315       */
316 <    public void testHasQueuedThreads() {
317 <        final Semaphore lock = new Semaphore(1, false);
318 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
319 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
320 <        try {
321 <            assertFalse(lock.hasQueuedThreads());
322 <            lock.acquireUninterruptibly();
323 <            t1.start();
324 <            Thread.sleep(SHORT_DELAY_MS);
325 <            assertTrue(lock.hasQueuedThreads());
326 <            t2.start();
327 <            Thread.sleep(SHORT_DELAY_MS);
328 <            assertTrue(lock.hasQueuedThreads());
329 <            t1.interrupt();
330 <            Thread.sleep(SHORT_DELAY_MS);
331 <            assertTrue(lock.hasQueuedThreads());
332 <            lock.release();
333 <            Thread.sleep(SHORT_DELAY_MS);
331 <            assertFalse(lock.hasQueuedThreads());
332 <            t1.join();
333 <            t2.join();
334 <        } catch (Exception e) {
335 <            unexpectedException();
336 <        }
316 >    public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
317 >    public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
318 >    public void testHasQueuedThreads(boolean fair) {
319 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
320 >        assertFalse(lock.hasQueuedThreads());
321 >        lock.acquireUninterruptibly();
322 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
323 >        waitForQueuedThread(lock, t1);
324 >        assertTrue(lock.hasQueuedThreads());
325 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
326 >        waitForQueuedThread(lock, t2);
327 >        assertTrue(lock.hasQueuedThreads());
328 >        t1.interrupt();
329 >        awaitTermination(t1);
330 >        assertTrue(lock.hasQueuedThreads());
331 >        lock.release();
332 >        awaitTermination(t2);
333 >        assertFalse(lock.hasQueuedThreads());
334      }
335  
336      /**
337       * getQueueLength reports number of waiting threads
338       */
339 <    public void testGetQueueLength() {
340 <        final Semaphore lock = new Semaphore(1, false);
341 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
342 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
343 <        try {
344 <            assertEquals(0, lock.getQueueLength());
345 <            lock.acquireUninterruptibly();
346 <            t1.start();
347 <            Thread.sleep(SHORT_DELAY_MS);
348 <            assertEquals(1, lock.getQueueLength());
349 <            t2.start();
350 <            Thread.sleep(SHORT_DELAY_MS);
351 <            assertEquals(2, lock.getQueueLength());
352 <            t1.interrupt();
353 <            Thread.sleep(SHORT_DELAY_MS);
354 <            assertEquals(1, lock.getQueueLength());
355 <            lock.release();
356 <            Thread.sleep(SHORT_DELAY_MS);
360 <            assertEquals(0, lock.getQueueLength());
361 <            t1.join();
362 <            t2.join();
363 <        } catch (Exception e) {
364 <            unexpectedException();
365 <        }
339 >    public void testGetQueueLength()      { testGetQueueLength(false); }
340 >    public void testGetQueueLength_fair() { testGetQueueLength(true); }
341 >    public void testGetQueueLength(boolean fair) {
342 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
343 >        assertEquals(0, lock.getQueueLength());
344 >        lock.acquireUninterruptibly();
345 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
346 >        waitForQueuedThread(lock, t1);
347 >        assertEquals(1, lock.getQueueLength());
348 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
349 >        waitForQueuedThread(lock, t2);
350 >        assertEquals(2, lock.getQueueLength());
351 >        t1.interrupt();
352 >        awaitTermination(t1);
353 >        assertEquals(1, lock.getQueueLength());
354 >        lock.release();
355 >        awaitTermination(t2);
356 >        assertEquals(0, lock.getQueueLength());
357      }
358  
359      /**
360       * getQueuedThreads includes waiting threads
361       */
362 <    public void testGetQueuedThreads() {
363 <        final PublicSemaphore lock = new PublicSemaphore(1, false);
364 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
365 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
366 <        try {
367 <            assertTrue(lock.getQueuedThreads().isEmpty());
368 <            lock.acquireUninterruptibly();
369 <            assertTrue(lock.getQueuedThreads().isEmpty());
370 <            t1.start();
371 <            Thread.sleep(SHORT_DELAY_MS);
372 <            assertTrue(lock.getQueuedThreads().contains(t1));
373 <            t2.start();
374 <            Thread.sleep(SHORT_DELAY_MS);
375 <            assertTrue(lock.getQueuedThreads().contains(t1));
376 <            assertTrue(lock.getQueuedThreads().contains(t2));
377 <            t1.interrupt();
378 <            Thread.sleep(SHORT_DELAY_MS);
379 <            assertFalse(lock.getQueuedThreads().contains(t1));
380 <            assertTrue(lock.getQueuedThreads().contains(t2));
381 <            lock.release();
382 <            Thread.sleep(SHORT_DELAY_MS);
392 <            assertTrue(lock.getQueuedThreads().isEmpty());
393 <            t1.join();
394 <            t2.join();
395 <        } catch (Exception e) {
396 <            unexpectedException();
397 <        }
362 >    public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
363 >    public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
364 >    public void testGetQueuedThreads(boolean fair) {
365 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
366 >        assertTrue(lock.getQueuedThreads().isEmpty());
367 >        lock.acquireUninterruptibly();
368 >        assertTrue(lock.getQueuedThreads().isEmpty());
369 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
370 >        waitForQueuedThread(lock, t1);
371 >        assertTrue(lock.getQueuedThreads().contains(t1));
372 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
373 >        waitForQueuedThread(lock, t2);
374 >        assertTrue(lock.getQueuedThreads().contains(t1));
375 >        assertTrue(lock.getQueuedThreads().contains(t2));
376 >        t1.interrupt();
377 >        awaitTermination(t1);
378 >        assertFalse(lock.getQueuedThreads().contains(t1));
379 >        assertTrue(lock.getQueuedThreads().contains(t2));
380 >        lock.release();
381 >        awaitTermination(t2);
382 >        assertTrue(lock.getQueuedThreads().isEmpty());
383      }
384  
385      /**
386       * drainPermits reports and removes given number of permits
387       */
388 <    public void testDrainPermits() {
389 <        Semaphore s = new Semaphore(0, false);
388 >    public void testDrainPermits()      { testDrainPermits(false); }
389 >    public void testDrainPermits_fair() { testDrainPermits(true); }
390 >    public void testDrainPermits(boolean fair) {
391 >        Semaphore s = new Semaphore(0, fair);
392          assertEquals(0, s.availablePermits());
393          assertEquals(0, s.drainPermits());
394          s.release(10);
# Line 412 | Line 399 | public class SemaphoreTest extends JSR16
399      }
400  
401      /**
402 <     * reducePermits reduces number of permits
402 >     * release(-N) throws IllegalArgumentException
403       */
404 <    public void testReducePermits() {
405 <        PublicSemaphore s = new PublicSemaphore(10, false);
406 <        assertEquals(10, s.availablePermits());
407 <        s.reducePermits(1);
421 <        assertEquals(9, s.availablePermits());
422 <        s.reducePermits(10);
423 <        assertEquals(-1, s.availablePermits());
424 <    }
425 <
426 <    /**
427 <     * a deserialized serialized semaphore has same number of permits
428 <     */
429 <    public void testSerialization() {
430 <        Semaphore l = new Semaphore(3, false);
404 >    public void testReleaseIAE()      { testReleaseIAE(false); }
405 >    public void testReleaseIAE_fair() { testReleaseIAE(true); }
406 >    public void testReleaseIAE(boolean fair) {
407 >        Semaphore s = new Semaphore(10, fair);
408          try {
409 <            l.acquire();
410 <            l.release();
411 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
435 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
436 <            out.writeObject(l);
437 <            out.close();
438 <
439 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
440 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
441 <            Semaphore r = (Semaphore) in.readObject();
442 <            assertEquals(3, r.availablePermits());
443 <            assertFalse(r.isFair());
444 <            r.acquire();
445 <            r.release();
446 <        } catch (Exception e) {
447 <            unexpectedException();
448 <        }
409 >            s.release(-1);
410 >            shouldThrow();
411 >        } catch (IllegalArgumentException success) {}
412      }
413  
451
414      /**
415 <     * Zero, negative, and positive initial values are allowed in constructor
415 >     * reducePermits(-N) throws IllegalArgumentException
416       */
417 <    public void testConstructor_fair() {
418 <        Semaphore s0 = new Semaphore(0, true);
419 <        assertEquals(0, s0.availablePermits());
420 <        assertTrue(s0.isFair());
421 <        Semaphore s1 = new Semaphore(-1, true);
422 <        assertEquals(-1, s1.availablePermits());
423 <        Semaphore s2 = new Semaphore(-1, true);
424 <        assertEquals(-1, s2.availablePermits());
463 <    }
464 <
465 <    /**
466 <     * tryAcquire succeeds when sufficient permits, else fails
467 <     */
468 <    public void testTryAcquireInSameThread_fair() {
469 <        Semaphore s = new Semaphore(2, true);
470 <        assertEquals(2, s.availablePermits());
471 <        assertTrue(s.tryAcquire());
472 <        assertTrue(s.tryAcquire());
473 <        assertEquals(0, s.availablePermits());
474 <        assertFalse(s.tryAcquire());
417 >    public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
418 >    public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
419 >    public void testReducePermitsIAE(boolean fair) {
420 >        PublicSemaphore s = new PublicSemaphore(10, fair);
421 >        try {
422 >            s.reducePermits(-1);
423 >            shouldThrow();
424 >        } catch (IllegalArgumentException success) {}
425      }
426  
427      /**
428 <     * tryAcquire(n) succeeds when sufficient permits, else fails
428 >     * reducePermits reduces number of permits
429       */
430 <    public void testTryAcquireNInSameThread_fair() {
431 <        Semaphore s = new Semaphore(2, true);
432 <        assertEquals(2, s.availablePermits());
433 <        assertTrue(s.tryAcquire(2));
434 <        assertEquals(0, s.availablePermits());
435 <        assertFalse(s.tryAcquire());
430 >    public void testReducePermits()      { testReducePermits(false); }
431 >    public void testReducePermits_fair() { testReducePermits(true); }
432 >    public void testReducePermits(boolean fair) {
433 >        PublicSemaphore s = new PublicSemaphore(10, fair);
434 >        assertEquals(10, s.availablePermits());
435 >        s.reducePermits(0);
436 >        assertEquals(10, s.availablePermits());
437 >        s.reducePermits(1);
438 >        assertEquals(9, s.availablePermits());
439 >        s.reducePermits(10);
440 >        assertEquals(-1, s.availablePermits());
441 >        s.reducePermits(10);
442 >        assertEquals(-11, s.availablePermits());
443 >        s.reducePermits(0);
444 >        assertEquals(-11, s.availablePermits());
445      }
446  
447      /**
448 <     * Acquire and release of semaphore succeed if initially available
448 >     * a reserialized semaphore has same number of permits and
449 >     * fairness, but no queued threads
450       */
451 <    public void testAcquireReleaseInSameThread_fair() {
452 <        Semaphore s = new Semaphore(1, true);
451 >    public void testSerialization()      { testSerialization(false); }
452 >    public void testSerialization_fair() { testSerialization(true); }
453 >    public void testSerialization(boolean fair) {
454          try {
455 +            Semaphore s = new Semaphore(3, fair);
456              s.acquire();
495            s.release();
496            s.acquire();
497            s.release();
498            s.acquire();
499            s.release();
500            s.acquire();
501            s.release();
457              s.acquire();
458              s.release();
504            assertEquals(1, s.availablePermits());
505        } catch (InterruptedException e) {
506            unexpectedException();
507        }
508    }
459  
460 <    /**
461 <     * Acquire(n) and release(n) of semaphore succeed if initially available
462 <     */
463 <    public void testAcquireReleaseNInSameThread_fair() {
464 <        Semaphore s = new Semaphore(1, true);
465 <        try {
466 <            s.release(1);
467 <            s.acquire(1);
518 <            s.release(2);
519 <            s.acquire(2);
520 <            s.release(3);
521 <            s.acquire(3);
522 <            s.release(4);
523 <            s.acquire(4);
524 <            s.release(5);
525 <            s.acquire(5);
526 <            assertEquals(1, s.availablePermits());
527 <        } catch ( InterruptedException e) {
528 <            unexpectedException();
529 <        }
530 <    }
531 <
532 <    /**
533 <     * Acquire(n) and release(n) of semaphore succeed if initially available
534 <     */
535 <    public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
536 <        Semaphore s = new Semaphore(1, true);
537 <        try {
538 <            s.release(1);
539 <            s.acquireUninterruptibly(1);
540 <            s.release(2);
541 <            s.acquireUninterruptibly(2);
542 <            s.release(3);
543 <            s.acquireUninterruptibly(3);
544 <            s.release(4);
545 <            s.acquireUninterruptibly(4);
546 <            s.release(5);
547 <            s.acquireUninterruptibly(5);
548 <            assertEquals(1, s.availablePermits());
549 <        } finally {
550 <        }
551 <    }
552 <
553 <    /**
554 <     * release(n) in one thread enables timed acquire(n) in another thread
555 <     */
556 <    public void testTimedAcquireReleaseNInSameThread_fair() {
557 <        Semaphore s = new Semaphore(1, true);
558 <        try {
559 <            s.release(1);
560 <            assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
561 <            s.release(2);
562 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
563 <            s.release(3);
564 <            assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
565 <            s.release(4);
566 <            assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
567 <            s.release(5);
568 <            assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
569 <            assertEquals(1, s.availablePermits());
570 <        } catch ( InterruptedException e) {
571 <            unexpectedException();
572 <        }
573 <    }
574 <
575 <    /**
576 <     * release in one thread enables timed acquire in another thread
577 <     */
578 <    public void testTimedAcquireReleaseInSameThread_fair() {
579 <        Semaphore s = new Semaphore(1, true);
580 <        try {
581 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
582 <            s.release();
583 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
584 <            s.release();
585 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
586 <            s.release();
587 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
588 <            s.release();
589 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
590 <            s.release();
591 <            assertEquals(1, s.availablePermits());
592 <        } catch ( InterruptedException e) {
593 <            unexpectedException();
594 <        }
595 <    }
596 <
597 <    /**
598 <     * A release in one thread enables an acquire in another thread
599 <     */
600 <    public void testAcquireReleaseInDifferentThreads_fair() {
601 <        final Semaphore s = new Semaphore(0, true);
602 <        Thread t = new Thread(new Runnable() {
603 <                public void run() {
604 <                    try {
605 <                        s.acquire();
606 <                        s.acquire();
607 <                        s.acquire();
608 <                        s.acquire();
609 <                    } catch (InterruptedException ie) {
610 <                        threadUnexpectedException();
611 <                    }
612 <                }
613 <            });
614 <        try {
615 <            t.start();
616 <            Thread.sleep(SHORT_DELAY_MS);
617 <            s.release();
618 <            s.release();
619 <            s.release();
620 <            s.release();
621 <            s.release();
622 <            s.release();
623 <            t.join();
460 >            Semaphore clone = serialClone(s);
461 >            assertEquals(fair, s.isFair());
462 >            assertEquals(fair, clone.isFair());
463 >            assertEquals(2, s.availablePermits());
464 >            assertEquals(2, clone.availablePermits());
465 >            clone.acquire();
466 >            clone.acquire();
467 >            clone.release();
468              assertEquals(2, s.availablePermits());
469 <        } catch ( InterruptedException e) {
470 <            unexpectedException();
469 >            assertEquals(1, clone.availablePermits());
470 >            assertFalse(s.hasQueuedThreads());
471 >            assertFalse(clone.hasQueuedThreads());
472 >        } catch (InterruptedException e) { threadUnexpectedException(e); }
473 >
474 >        {
475 >            PublicSemaphore s = new PublicSemaphore(0, fair);
476 >            Thread t = newStartedThread(new InterruptibleLockRunnable(s));
477 >            // waitForQueuedThreads(s); // suffers from "flicker", so ...
478 >            waitForQueuedThread(s, t);  // ... we use this instead
479 >            PublicSemaphore clone = serialClone(s);
480 >            assertEquals(fair, s.isFair());
481 >            assertEquals(fair, clone.isFair());
482 >            assertEquals(0, s.availablePermits());
483 >            assertEquals(0, clone.availablePermits());
484 >            assertTrue(s.hasQueuedThreads());
485 >            assertFalse(clone.hasQueuedThreads());
486 >            s.release();
487 >            awaitTermination(t);
488 >            assertFalse(s.hasQueuedThreads());
489 >            assertFalse(clone.hasQueuedThreads());
490          }
491      }
492  
493      /**
494 <     * release(n) in one thread enables acquire(n) in another thread
494 >     * tryAcquire(n) succeeds when sufficient permits, else fails
495       */
496 <    public void testAcquireReleaseNInDifferentThreads_fair() {
497 <        final Semaphore s = new Semaphore(0, true);
498 <        Thread t = new Thread(new Runnable() {
499 <                public void run() {
500 <                    try {
501 <                        s.acquire();
502 <                        s.release(2);
503 <                        s.acquire();
504 <                    } catch (InterruptedException ie) {
505 <                        threadUnexpectedException();
506 <                    }
507 <                }
645 <            });
646 <        try {
647 <            t.start();
648 <            Thread.sleep(SHORT_DELAY_MS);
649 <            s.release(2);
650 <            s.acquire(2);
651 <            s.release(1);
652 <            t.join();
653 <        } catch ( InterruptedException e) {
654 <            unexpectedException();
655 <        }
656 <    }
657 <
658 <    /**
659 <     * release(n) in one thread enables acquire(n) in another thread
660 <     */
661 <    public void testAcquireReleaseNInDifferentThreads_fair2() {
662 <        final Semaphore s = new Semaphore(0, true);
663 <        Thread t = new Thread(new Runnable() {
664 <                public void run() {
665 <                    try {
666 <                        s.acquire(2);
667 <                        s.acquire(2);
668 <                        s.release(4);
669 <                    } catch (InterruptedException ie) {
670 <                        threadUnexpectedException();
671 <                    }
672 <                }
673 <            });
674 <        try {
675 <            t.start();
676 <            Thread.sleep(SHORT_DELAY_MS);
677 <            s.release(6);
678 <            s.acquire(2);
679 <            s.acquire(2);
680 <            s.release(2);
681 <            t.join();
682 <        } catch ( InterruptedException e) {
683 <            unexpectedException();
684 <        }
496 >    public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
497 >    public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
498 >    public void testTryAcquireNInSameThread(boolean fair) {
499 >        Semaphore s = new Semaphore(2, fair);
500 >        assertEquals(2, s.availablePermits());
501 >        assertFalse(s.tryAcquire(3));
502 >        assertEquals(2, s.availablePermits());
503 >        assertTrue(s.tryAcquire(2));
504 >        assertEquals(0, s.availablePermits());
505 >        assertFalse(s.tryAcquire(1));
506 >        assertFalse(s.tryAcquire(2));
507 >        assertEquals(0, s.availablePermits());
508      }
509  
687
688
689
690
510      /**
511 <     * release in one thread enables timed acquire in another thread
511 >     * acquire succeeds if permits available
512       */
513 <    public void testTimedAcquireReleaseInDifferentThreads_fair() {
514 <        final Semaphore s = new Semaphore(1, true);
515 <        Thread t = new Thread(new Runnable() {
516 <                public void run() {
517 <                    try {
518 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
519 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
520 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
521 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
522 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
523 <
524 <                    } catch (InterruptedException ie) {
525 <                        threadUnexpectedException();
526 <                    }
527 <                }
528 <            });
529 <        t.start();
530 <        try {
531 <            s.release();
532 <            s.release();
533 <            s.release();
534 <            s.release();
535 <            s.release();
536 <            t.join();
537 <        } catch ( InterruptedException e) {
538 <            unexpectedException();
720 <        }
721 <    }
722 <
723 <    /**
724 <     * release(n) in one thread enables timed acquire(n) in another thread
725 <     */
726 <    public void testTimedAcquireReleaseNInDifferentThreads_fair() {
727 <        final Semaphore s = new Semaphore(2, true);
728 <        Thread t = new Thread(new Runnable() {
729 <                public void run() {
730 <                    try {
731 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
732 <                        s.release(2);
733 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
734 <                        s.release(2);
735 <                    } catch (InterruptedException ie) {
736 <                        threadUnexpectedException();
737 <                    }
738 <                }
739 <            });
740 <        t.start();
741 <        try {
742 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
743 <            s.release(2);
744 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
745 <            s.release(2);
746 <            t.join();
747 <        } catch ( InterruptedException e) {
748 <            unexpectedException();
749 <        }
750 <    }
751 <
752 <    /**
753 <     * A waiting acquire blocks interruptibly
754 <     */
755 <    public void testAcquire_InterruptedException_fair() {
756 <        final Semaphore s = new Semaphore(0, true);
757 <        Thread t = new Thread(new Runnable() {
758 <                public void run() {
759 <                    try {
760 <                        s.acquire();
761 <                        threadShouldThrow();
762 <                    } catch (InterruptedException success) {}
763 <                }
764 <            });
765 <        t.start();
766 <        try {
767 <            Thread.sleep(SHORT_DELAY_MS);
768 <            t.interrupt();
769 <            t.join();
770 <        } catch (InterruptedException e) {
771 <            unexpectedException();
772 <        }
773 <    }
774 <
775 <    /**
776 <     * A waiting acquire(n) blocks interruptibly
777 <     */
778 <    public void testAcquireN_InterruptedException_fair() {
779 <        final Semaphore s = new Semaphore(2, true);
780 <        Thread t = new Thread(new Runnable() {
781 <                public void run() {
782 <                    try {
783 <                        s.acquire(3);
784 <                        threadShouldThrow();
785 <                    } catch (InterruptedException success) {}
786 <                }
787 <            });
788 <        t.start();
789 <        try {
790 <            Thread.sleep(SHORT_DELAY_MS);
791 <            t.interrupt();
792 <            t.join();
793 <        } catch (InterruptedException e) {
794 <            unexpectedException();
795 <        }
796 <    }
797 <
798 <    /**
799 <     *  A waiting tryAcquire blocks interruptibly
800 <     */
801 <    public void testTryAcquire_InterruptedException_fair() {
802 <        final Semaphore s = new Semaphore(0, true);
803 <        Thread t = new Thread(new Runnable() {
804 <                public void run() {
805 <                    try {
806 <                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
807 <                        threadShouldThrow();
808 <                    } catch (InterruptedException success) {
809 <                    }
810 <                }
811 <            });
812 <        t.start();
813 <        try {
814 <            Thread.sleep(SHORT_DELAY_MS);
815 <            t.interrupt();
816 <            t.join();
817 <        } catch (InterruptedException e) {
818 <            unexpectedException();
819 <        }
820 <    }
821 <
822 <    /**
823 <     *  A waiting tryAcquire(n) blocks interruptibly
824 <     */
825 <    public void testTryAcquireN_InterruptedException_fair() {
826 <        final Semaphore s = new Semaphore(1, true);
827 <        Thread t = new Thread(new Runnable() {
828 <                public void run() {
829 <                    try {
830 <                        s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
831 <                        threadShouldThrow();
832 <                    } catch (InterruptedException success) {
833 <                    }
834 <                }
835 <            });
836 <        t.start();
837 <        try {
838 <            Thread.sleep(SHORT_DELAY_MS);
839 <            t.interrupt();
840 <            t.join();
841 <        } catch (InterruptedException e) {
842 <            unexpectedException();
513 >    public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
514 >    public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
515 >    public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
516 >    public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
517 >    public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
518 >    public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
519 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
520 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
521 >    public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
522 >    public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
523 >    public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
524 >    public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
525 >    public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
526 >    public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
527 >    public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
528 >    public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
529 >    public void testReleaseAcquireSameThread(boolean fair,
530 >                                             final AcquireMethod acquirer) {
531 >        Semaphore s = new Semaphore(1, fair);
532 >        for (int i = 1; i < 6; i++) {
533 >            s.release(i);
534 >            assertEquals(1 + i, s.availablePermits());
535 >            try {
536 >                acquirer.acquire(s, i);
537 >            } catch (InterruptedException e) { threadUnexpectedException(e); }
538 >            assertEquals(1, s.availablePermits());
539          }
540      }
541  
542      /**
543 <     * getQueueLength reports number of waiting threads
543 >     * release in one thread enables acquire in another thread
544       */
545 <    public void testGetQueueLength_fair() {
546 <        final Semaphore lock = new Semaphore(1, true);
547 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
548 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
549 <        try {
550 <            assertEquals(0, lock.getQueueLength());
551 <            lock.acquireUninterruptibly();
552 <            t1.start();
553 <            Thread.sleep(SHORT_DELAY_MS);
554 <            assertEquals(1, lock.getQueueLength());
555 <            t2.start();
556 <            Thread.sleep(SHORT_DELAY_MS);
557 <            assertEquals(2, lock.getQueueLength());
558 <            t1.interrupt();
559 <            Thread.sleep(SHORT_DELAY_MS);
560 <            assertEquals(1, lock.getQueueLength());
561 <            lock.release();
562 <            Thread.sleep(SHORT_DELAY_MS);
563 <            assertEquals(0, lock.getQueueLength());
564 <            t1.join();
565 <            t2.join();
566 <        } catch (Exception e) {
567 <            unexpectedException();
545 >    public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
546 >    public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
547 >    public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
548 >    public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
549 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
550 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
551 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
552 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
553 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
554 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
555 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
556 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
557 >    public void testReleaseAcquireDifferentThreads(boolean fair,
558 >                                                   final AcquireMethod acquirer) {
559 >        final Semaphore s = new Semaphore(0, fair);
560 >        final int rounds = 4;
561 >        long startTime = System.nanoTime();
562 >        Thread t = newStartedThread(new CheckedRunnable() {
563 >            public void realRun() throws InterruptedException {
564 >                for (int i = 0; i < rounds; i++) {
565 >                    assertFalse(s.hasQueuedThreads());
566 >                    if (i % 2 == 0)
567 >                        acquirer.acquire(s);
568 >                    else
569 >                        acquirer.acquire(s, 3);
570 >                }}});
571 >
572 >        for (int i = 0; i < rounds; i++) {
573 >            while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
574 >                Thread.yield();
575 >            assertTrue(t.isAlive());
576 >            if (i % 2 == 0)
577 >                s.release();
578 >            else
579 >                s.release(3);
580          }
581 +        awaitTermination(t);
582 +        assertEquals(0, s.availablePermits());
583 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
584      }
585  
875
586      /**
587 <     * a deserialized serialized semaphore has same number of permits
587 >     * fair locks are strictly FIFO
588       */
589 <    public void testSerialization_fair() {
590 <        Semaphore l = new Semaphore(3, true);
591 <
592 <        try {
593 <            l.acquire();
594 <            l.release();
595 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
596 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
597 <            out.writeObject(l);
598 <            out.close();
599 <
600 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
601 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
602 <            Semaphore r = (Semaphore) in.readObject();
603 <            assertEquals(3, r.availablePermits());
604 <            assertTrue(r.isFair());
605 <            r.acquire();
606 <            r.release();
607 <        } catch (Exception e) {
608 <            unexpectedException();
609 <        }
589 >    public void testFairLocksFifo() {
590 >        final PublicSemaphore s = new PublicSemaphore(1, true);
591 >        final CountDownLatch pleaseRelease = new CountDownLatch(1);
592 >        Thread t1 = newStartedThread(new CheckedRunnable() {
593 >            public void realRun() throws InterruptedException {
594 >                // Will block; permits are available, but not three
595 >                s.acquire(3);
596 >            }});
597 >
598 >        waitForQueuedThread(s, t1);
599 >
600 >        Thread t2 = newStartedThread(new CheckedRunnable() {
601 >            public void realRun() throws InterruptedException {
602 >                // Will fail, even though 1 permit is available
603 >                assertFalse(s.tryAcquire(0L, MILLISECONDS));
604 >                assertFalse(s.tryAcquire(1, 0L, MILLISECONDS));
605 >
606 >                // untimed tryAcquire will barge and succeed
607 >                assertTrue(s.tryAcquire());
608 >                s.release(2);
609 >                assertTrue(s.tryAcquire(2));
610 >                s.release();
611 >
612 >                pleaseRelease.countDown();
613 >                // Will queue up behind t1, even though 1 permit is available
614 >                s.acquire();
615 >            }});
616 >
617 >        await(pleaseRelease);
618 >        waitForQueuedThread(s, t2);
619 >        s.release(2);
620 >        awaitTermination(t1);
621 >        assertTrue(t2.isAlive());
622 >        s.release();
623 >        awaitTermination(t2);
624      }
625  
626      /**
627       * toString indicates current number of permits
628       */
629 <    public void testToString() {
630 <        Semaphore s = new Semaphore(0);
631 <        String us = s.toString();
632 <        assertTrue(us.indexOf("Permits = 0") >= 0);
633 <        s.release();
910 <        String s1 = s.toString();
911 <        assertTrue(s1.indexOf("Permits = 1") >= 0);
629 >    public void testToString()      { testToString(false); }
630 >    public void testToString_fair() { testToString(true); }
631 >    public void testToString(boolean fair) {
632 >        PublicSemaphore s = new PublicSemaphore(0, fair);
633 >        assertTrue(s.toString().contains("Permits = 0"));
634          s.release();
635 <        String s2 = s.toString();
636 <        assertTrue(s2.indexOf("Permits = 2") >= 0);
635 >        assertTrue(s.toString().contains("Permits = 1"));
636 >        s.release(2);
637 >        assertTrue(s.toString().contains("Permits = 3"));
638 >        s.reducePermits(5);
639 >        assertTrue(s.toString().contains("Permits = -2"));
640      }
641  
642   }

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