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Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.15 by jsr166, Mon Nov 2 20:28:32 2009 UTC vs.
Revision 1.44 by jsr166, Mon Aug 12 06:21:11 2019 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 > import java.util.concurrent.ThreadLocalRandom;
15 >
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 AssertionError("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 AssertionError("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 >            Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
131 >        },
132 >        tryAcquireTimedN {
133 >            void acquire(Semaphore s, int permits) throws InterruptedException {
134 >                assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
135 >            }
136 >            Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
137 >        };
138 >
139 >        // Intentionally meta-circular
140 >
141 >        /** Acquires 1 permit. */
142 >        void acquire(Semaphore s) throws InterruptedException {
143 >            acquire(s, 1);
144 >        }
145 >        /** Acquires the given number of permits. */
146 >        void acquire(Semaphore s, int permits) throws InterruptedException {
147 >            for (int i = 0; i < permits; i++)
148 >                acquire(s);
149          }
150 +        Thread.State parkedState() { return Thread.State.WAITING; }
151      }
152  
153      /**
154       * Zero, negative, and positive initial values are allowed in constructor
155       */
156 <    public void testConstructor() {
157 <        Semaphore s0 = new Semaphore(0, false);
158 <        assertEquals(0, s0.availablePermits());
159 <        assertFalse(s0.isFair());
160 <        Semaphore s1 = new Semaphore(-1, false);
161 <        assertEquals(-1, s1.availablePermits());
162 <        assertFalse(s1.isFair());
163 <        Semaphore s2 = new Semaphore(-1, false);
75 <        assertEquals(-1, s2.availablePermits());
76 <        assertFalse(s2.isFair());
156 >    public void testConstructor()      { testConstructor(false); }
157 >    public void testConstructor_fair() { testConstructor(true); }
158 >    public void testConstructor(boolean fair) {
159 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
160 >            Semaphore s = new Semaphore(permits, fair);
161 >            assertEquals(permits, s.availablePermits());
162 >            assertEquals(fair, s.isFair());
163 >        }
164      }
165  
166      /**
167       * Constructor without fairness argument behaves as nonfair
168       */
169 <    public void testConstructor2() {
170 <        Semaphore s0 = new Semaphore(0);
171 <        assertEquals(0, s0.availablePermits());
172 <        assertFalse(s0.isFair());
173 <        Semaphore s1 = new Semaphore(-1);
174 <        assertEquals(-1, s1.availablePermits());
88 <        assertFalse(s1.isFair());
89 <        Semaphore s2 = new Semaphore(-1);
90 <        assertEquals(-1, s2.availablePermits());
91 <        assertFalse(s2.isFair());
169 >    public void testConstructorDefaultsToNonFair() {
170 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
171 >            Semaphore s = new Semaphore(permits);
172 >            assertEquals(permits, s.availablePermits());
173 >            assertFalse(s.isFair());
174 >        }
175      }
176  
177      /**
178       * tryAcquire succeeds when sufficient permits, else fails
179       */
180 <    public void testTryAcquireInSameThread() {
181 <        Semaphore s = new Semaphore(2, false);
180 >    public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
181 >    public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
182 >    public void testTryAcquireInSameThread(boolean fair) {
183 >        Semaphore s = new Semaphore(2, fair);
184          assertEquals(2, s.availablePermits());
185          assertTrue(s.tryAcquire());
186          assertTrue(s.tryAcquire());
187          assertEquals(0, s.availablePermits());
188          assertFalse(s.tryAcquire());
189 +        assertFalse(s.tryAcquire());
190 +        assertEquals(0, s.availablePermits());
191      }
192  
193      /**
194 <     * 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
194 >     * timed tryAcquire times out
195       */
196 <    public void testAcquireReleaseInDifferentThreads() {
197 <        final Semaphore s = new Semaphore(0, false);
198 <        Thread t = new Thread(new Runnable() {
199 <                public void run() {
200 <                    try {
201 <                        s.acquire();
202 <                        s.release();
203 <                        s.release();
204 <                        s.acquire();
205 <                    } catch(InterruptedException ie){
206 <                        threadUnexpectedException();
207 <                    }
208 <                }
209 <            });
210 <        try {
211 <            t.start();
212 <            Thread.sleep(SHORT_DELAY_MS);
213 <            s.release();
214 <            s.release();
215 <            s.acquire();
216 <            s.acquire();
217 <            s.release();
218 <            t.join();
219 <        } catch( InterruptedException e){
220 <            unexpectedException();
196 >    public void testTryAcquire_timeout() throws InterruptedException {
197 >        final boolean fair = randomBoolean();
198 >        final Semaphore s = new Semaphore(0, fair);
199 >        final long startTime = System.nanoTime();
200 >        assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS));
201 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
202 >    }
203 >
204 >    /**
205 >     * timed tryAcquire(N) times out
206 >     */
207 >    public void testTryAcquireN_timeout() throws InterruptedException {
208 >        final boolean fair = randomBoolean();
209 >        final Semaphore s = new Semaphore(2, fair);
210 >        final long startTime = System.nanoTime();
211 >        assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS));
212 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
213 >    }
214 >
215 >    /**
216 >     * acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
217 >     * are interruptible
218 >     */
219 >    public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
220 >    public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
221 >    public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
222 >    public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
223 >    public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
224 >    public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
225 >    public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
226 >    public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
227 >    public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
228 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
229 >        final java.util.concurrent.CyclicBarrier pleaseInterrupt
230 >            = new java.util.concurrent.CyclicBarrier(2);
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 >                assertFalse(Thread.interrupted());
240 >
241 >                // Interrupt before acquire(N)
242 >                Thread.currentThread().interrupt();
243 >                try {
244 >                    acquirer.acquire(s, 3);
245 >                    shouldThrow();
246 >                } catch (InterruptedException success) {}
247 >                assertFalse(Thread.interrupted());
248 >
249 >                // Interrupt during acquire
250 >                await(pleaseInterrupt);
251 >                try {
252 >                    acquirer.acquire(s);
253 >                    shouldThrow();
254 >                } catch (InterruptedException success) {}
255 >                assertFalse(Thread.interrupted());
256 >
257 >                // Interrupt during acquire(N)
258 >                await(pleaseInterrupt);
259 >                try {
260 >                    acquirer.acquire(s, 3);
261 >                    shouldThrow();
262 >                } catch (InterruptedException success) {}
263 >                assertFalse(Thread.interrupted());
264 >            }});
265 >
266 >        for (int n = 2; n-->0; ) {
267 >            await(pleaseInterrupt);
268 >            assertThreadBlocks(t, acquirer.parkedState());
269 >            t.interrupt();
270          }
202    }
271  
272 <    /**
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 <        }
272 >        awaitTermination(t);
273      }
274  
231
275      /**
276 <     *  A release in one thread enables a timed acquire in another thread
276 >     * acquireUninterruptibly(), acquireUninterruptibly(N) are
277 >     * uninterruptible
278       */
279 <    public void testTimedAcquireReleaseInDifferentThreads() {
280 <        final Semaphore s = new Semaphore(1, false);
281 <        Thread t = new Thread(new Runnable() {
282 <                public void run() {
283 <                    try {
284 <                        s.release();
285 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
286 <                        s.release();
287 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
279 >    public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
280 >    public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
281 >    public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
282 >    public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
283 >    public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
284 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
285 >        final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
286 >
287 >        Thread t1 = newStartedThread(new CheckedRunnable() {
288 >            public void realRun() throws InterruptedException {
289 >                // Interrupt before acquire
290 >                pleaseInterrupt.release();
291 >                Thread.currentThread().interrupt();
292 >                acquirer.acquire(s);
293 >                assertTrue(Thread.interrupted());
294 >            }});
295 >
296 >        Thread t2 = newStartedThread(new CheckedRunnable() {
297 >            public void realRun() throws InterruptedException {
298 >                // Interrupt during acquire
299 >                pleaseInterrupt.release();
300 >                acquirer.acquire(s);
301 >                assertTrue(Thread.interrupted());
302 >            }});
303 >
304 >        await(pleaseInterrupt);
305 >        waitForQueuedThread(s, t1);
306 >        waitForQueuedThread(s, t2);
307 >        t2.interrupt();
308  
309 <                    } catch(InterruptedException ie){
310 <                        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 <    }
309 >        assertThreadBlocks(t1, Thread.State.WAITING);
310 >        assertThreadBlocks(t2, Thread.State.WAITING);
311  
312 <    /**
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 <    }
312 >        s.release(2);
313  
314 <    /**
315 <     *  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 <        }
314 >        awaitTermination(t1);
315 >        awaitTermination(t2);
316      }
317  
318      /**
319       * hasQueuedThreads reports whether there are waiting threads
320       */
321 <    public void testHasQueuedThreads() {
322 <        final Semaphore lock = new Semaphore(1, false);
323 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
324 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
325 <        try {
326 <            assertFalse(lock.hasQueuedThreads());
327 <            lock.acquireUninterruptibly();
328 <            t1.start();
329 <            Thread.sleep(SHORT_DELAY_MS);
330 <            assertTrue(lock.hasQueuedThreads());
331 <            t2.start();
332 <            Thread.sleep(SHORT_DELAY_MS);
333 <            assertTrue(lock.hasQueuedThreads());
334 <            t1.interrupt();
335 <            Thread.sleep(SHORT_DELAY_MS);
336 <            assertTrue(lock.hasQueuedThreads());
337 <            lock.release();
338 <            Thread.sleep(SHORT_DELAY_MS);
331 <            assertFalse(lock.hasQueuedThreads());
332 <            t1.join();
333 <            t2.join();
334 <        } catch(Exception e){
335 <            unexpectedException();
336 <        }
321 >    public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
322 >    public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
323 >    public void testHasQueuedThreads(boolean fair) {
324 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
325 >        assertFalse(lock.hasQueuedThreads());
326 >        lock.acquireUninterruptibly();
327 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
328 >        waitForQueuedThread(lock, t1);
329 >        assertTrue(lock.hasQueuedThreads());
330 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
331 >        waitForQueuedThread(lock, t2);
332 >        assertTrue(lock.hasQueuedThreads());
333 >        t1.interrupt();
334 >        awaitTermination(t1);
335 >        assertTrue(lock.hasQueuedThreads());
336 >        lock.release();
337 >        awaitTermination(t2);
338 >        assertFalse(lock.hasQueuedThreads());
339      }
340  
341      /**
342       * getQueueLength reports number of waiting threads
343       */
344 <    public void testGetQueueLength() {
345 <        final Semaphore lock = new Semaphore(1, false);
346 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
347 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
348 <        try {
349 <            assertEquals(0, lock.getQueueLength());
350 <            lock.acquireUninterruptibly();
351 <            t1.start();
352 <            Thread.sleep(SHORT_DELAY_MS);
353 <            assertEquals(1, lock.getQueueLength());
354 <            t2.start();
355 <            Thread.sleep(SHORT_DELAY_MS);
356 <            assertEquals(2, lock.getQueueLength());
357 <            t1.interrupt();
358 <            Thread.sleep(SHORT_DELAY_MS);
359 <            assertEquals(1, lock.getQueueLength());
360 <            lock.release();
361 <            Thread.sleep(SHORT_DELAY_MS);
360 <            assertEquals(0, lock.getQueueLength());
361 <            t1.join();
362 <            t2.join();
363 <        } catch(Exception e){
364 <            unexpectedException();
365 <        }
344 >    public void testGetQueueLength()      { testGetQueueLength(false); }
345 >    public void testGetQueueLength_fair() { testGetQueueLength(true); }
346 >    public void testGetQueueLength(boolean fair) {
347 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
348 >        assertEquals(0, lock.getQueueLength());
349 >        lock.acquireUninterruptibly();
350 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
351 >        waitForQueuedThread(lock, t1);
352 >        assertEquals(1, lock.getQueueLength());
353 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
354 >        waitForQueuedThread(lock, t2);
355 >        assertEquals(2, lock.getQueueLength());
356 >        t1.interrupt();
357 >        awaitTermination(t1);
358 >        assertEquals(1, lock.getQueueLength());
359 >        lock.release();
360 >        awaitTermination(t2);
361 >        assertEquals(0, lock.getQueueLength());
362      }
363  
364      /**
365       * getQueuedThreads includes waiting threads
366       */
367 <    public void testGetQueuedThreads() {
368 <        final PublicSemaphore lock = new PublicSemaphore(1, false);
369 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
370 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
371 <        try {
372 <            assertTrue(lock.getQueuedThreads().isEmpty());
373 <            lock.acquireUninterruptibly();
374 <            assertTrue(lock.getQueuedThreads().isEmpty());
375 <            t1.start();
376 <            Thread.sleep(SHORT_DELAY_MS);
377 <            assertTrue(lock.getQueuedThreads().contains(t1));
378 <            t2.start();
379 <            Thread.sleep(SHORT_DELAY_MS);
380 <            assertTrue(lock.getQueuedThreads().contains(t1));
381 <            assertTrue(lock.getQueuedThreads().contains(t2));
382 <            t1.interrupt();
383 <            Thread.sleep(SHORT_DELAY_MS);
384 <            assertFalse(lock.getQueuedThreads().contains(t1));
385 <            assertTrue(lock.getQueuedThreads().contains(t2));
386 <            lock.release();
387 <            Thread.sleep(SHORT_DELAY_MS);
392 <            assertTrue(lock.getQueuedThreads().isEmpty());
393 <            t1.join();
394 <            t2.join();
395 <        } catch(Exception e){
396 <            unexpectedException();
397 <        }
367 >    public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
368 >    public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
369 >    public void testGetQueuedThreads(boolean fair) {
370 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
371 >        assertTrue(lock.getQueuedThreads().isEmpty());
372 >        lock.acquireUninterruptibly();
373 >        assertTrue(lock.getQueuedThreads().isEmpty());
374 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
375 >        waitForQueuedThread(lock, t1);
376 >        assertTrue(lock.getQueuedThreads().contains(t1));
377 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
378 >        waitForQueuedThread(lock, t2);
379 >        assertTrue(lock.getQueuedThreads().contains(t1));
380 >        assertTrue(lock.getQueuedThreads().contains(t2));
381 >        t1.interrupt();
382 >        awaitTermination(t1);
383 >        assertFalse(lock.getQueuedThreads().contains(t1));
384 >        assertTrue(lock.getQueuedThreads().contains(t2));
385 >        lock.release();
386 >        awaitTermination(t2);
387 >        assertTrue(lock.getQueuedThreads().isEmpty());
388      }
389  
390      /**
391       * drainPermits reports and removes given number of permits
392       */
393 <    public void testDrainPermits() {
394 <        Semaphore s = new Semaphore(0, false);
393 >    public void testDrainPermits()      { testDrainPermits(false); }
394 >    public void testDrainPermits_fair() { testDrainPermits(true); }
395 >    public void testDrainPermits(boolean fair) {
396 >        Semaphore s = new Semaphore(0, fair);
397          assertEquals(0, s.availablePermits());
398          assertEquals(0, s.drainPermits());
399          s.release(10);
# Line 412 | Line 404 | public class SemaphoreTest extends JSR16
404      }
405  
406      /**
407 <     * reducePermits reduces number of permits
407 >     * release(-N) throws IllegalArgumentException
408       */
409 <    public void testReducePermits() {
410 <        PublicSemaphore s = new PublicSemaphore(10, false);
411 <        assertEquals(10, s.availablePermits());
412 <        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);
409 >    public void testReleaseIAE()      { testReleaseIAE(false); }
410 >    public void testReleaseIAE_fair() { testReleaseIAE(true); }
411 >    public void testReleaseIAE(boolean fair) {
412 >        Semaphore s = new Semaphore(10, fair);
413          try {
414 <            l.acquire();
415 <            l.release();
416 <            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 <        }
414 >            s.release(-1);
415 >            shouldThrow();
416 >        } catch (IllegalArgumentException success) {}
417      }
418  
451
419      /**
420 <     * Zero, negative, and positive initial values are allowed in constructor
454 <     */
455 <    public void testConstructor_fair() {
456 <        Semaphore s0 = new Semaphore(0, true);
457 <        assertEquals(0, s0.availablePermits());
458 <        assertTrue(s0.isFair());
459 <        Semaphore s1 = new Semaphore(-1, true);
460 <        assertEquals(-1, s1.availablePermits());
461 <        Semaphore s2 = new Semaphore(-1, true);
462 <        assertEquals(-1, s2.availablePermits());
463 <    }
464 <
465 <    /**
466 <     * tryAcquire succeeds when sufficient permits, else fails
420 >     * reducePermits(-N) throws IllegalArgumentException
421       */
422 <    public void testTryAcquireInSameThread_fair() {
423 <        Semaphore s = new Semaphore(2, true);
424 <        assertEquals(2, s.availablePermits());
425 <        assertTrue(s.tryAcquire());
426 <        assertTrue(s.tryAcquire());
427 <        assertEquals(0, s.availablePermits());
428 <        assertFalse(s.tryAcquire());
422 >    public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
423 >    public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
424 >    public void testReducePermitsIAE(boolean fair) {
425 >        PublicSemaphore s = new PublicSemaphore(10, fair);
426 >        try {
427 >            s.reducePermits(-1);
428 >            shouldThrow();
429 >        } catch (IllegalArgumentException success) {}
430      }
431  
432      /**
433 <     * tryAcquire(n) succeeds when sufficient permits, else fails
433 >     * reducePermits reduces number of permits
434       */
435 <    public void testTryAcquireNInSameThread_fair() {
436 <        Semaphore s = new Semaphore(2, true);
437 <        assertEquals(2, s.availablePermits());
438 <        assertTrue(s.tryAcquire(2));
439 <        assertEquals(0, s.availablePermits());
440 <        assertFalse(s.tryAcquire());
435 >    public void testReducePermits()      { testReducePermits(false); }
436 >    public void testReducePermits_fair() { testReducePermits(true); }
437 >    public void testReducePermits(boolean fair) {
438 >        PublicSemaphore s = new PublicSemaphore(10, fair);
439 >        assertEquals(10, s.availablePermits());
440 >        s.reducePermits(0);
441 >        assertEquals(10, s.availablePermits());
442 >        s.reducePermits(1);
443 >        assertEquals(9, s.availablePermits());
444 >        s.reducePermits(10);
445 >        assertEquals(-1, s.availablePermits());
446 >        s.reducePermits(10);
447 >        assertEquals(-11, s.availablePermits());
448 >        s.reducePermits(0);
449 >        assertEquals(-11, s.availablePermits());
450      }
451  
452      /**
453 <     * Acquire and release of semaphore succeed if initially available
453 >     * a reserialized semaphore has same number of permits and
454 >     * fairness, but no queued threads
455       */
456 <    public void testAcquireReleaseInSameThread_fair() {
457 <        Semaphore s = new Semaphore(1, true);
456 >    public void testSerialization()      { testSerialization(false); }
457 >    public void testSerialization_fair() { testSerialization(true); }
458 >    public void testSerialization(boolean fair) {
459          try {
460 +            Semaphore s = new Semaphore(3, fair);
461              s.acquire();
495            s.release();
496            s.acquire();
497            s.release();
462              s.acquire();
463              s.release();
500            s.acquire();
501            s.release();
502            s.acquire();
503            s.release();
504            assertEquals(1, s.availablePermits());
505        } catch( InterruptedException e){
506            unexpectedException();
507        }
508    }
464  
465 <    /**
466 <     * Acquire(n) and release(n) of semaphore succeed if initially available
467 <     */
468 <    public void testAcquireReleaseNInSameThread_fair() {
469 <        Semaphore s = new Semaphore(1, true);
470 <        try {
471 <            s.release(1);
472 <            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();
465 >            Semaphore clone = serialClone(s);
466 >            assertEquals(fair, s.isFair());
467 >            assertEquals(fair, clone.isFair());
468 >            assertEquals(2, s.availablePermits());
469 >            assertEquals(2, clone.availablePermits());
470 >            clone.acquire();
471 >            clone.acquire();
472 >            clone.release();
473              assertEquals(2, s.availablePermits());
474 <        } catch( InterruptedException e){
475 <            unexpectedException();
474 >            assertEquals(1, clone.availablePermits());
475 >            assertFalse(s.hasQueuedThreads());
476 >            assertFalse(clone.hasQueuedThreads());
477 >        } catch (InterruptedException e) { threadUnexpectedException(e); }
478 >
479 >        {
480 >            PublicSemaphore s = new PublicSemaphore(0, fair);
481 >            Thread t = newStartedThread(new InterruptibleLockRunnable(s));
482 >            // waitForQueuedThreads(s); // suffers from "flicker", so ...
483 >            waitForQueuedThread(s, t);  // ... we use this instead
484 >            PublicSemaphore clone = serialClone(s);
485 >            assertEquals(fair, s.isFair());
486 >            assertEquals(fair, clone.isFair());
487 >            assertEquals(0, s.availablePermits());
488 >            assertEquals(0, clone.availablePermits());
489 >            assertTrue(s.hasQueuedThreads());
490 >            assertFalse(clone.hasQueuedThreads());
491 >            s.release();
492 >            awaitTermination(t);
493 >            assertFalse(s.hasQueuedThreads());
494 >            assertFalse(clone.hasQueuedThreads());
495          }
496      }
497  
498      /**
499 <     * release(n) in one thread enables acquire(n) in another thread
499 >     * tryAcquire(n) succeeds when sufficient permits, else fails
500       */
501 <    public void testAcquireReleaseNInDifferentThreads_fair() {
502 <        final Semaphore s = new Semaphore(0, true);
503 <        Thread t = new Thread(new Runnable() {
504 <                public void run() {
505 <                    try {
506 <                        s.acquire();
507 <                        s.release(2);
508 <                        s.acquire();
509 <                    } catch(InterruptedException ie){
510 <                        threadUnexpectedException();
511 <                    }
512 <                }
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 <        }
501 >    public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
502 >    public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
503 >    public void testTryAcquireNInSameThread(boolean fair) {
504 >        Semaphore s = new Semaphore(2, fair);
505 >        assertEquals(2, s.availablePermits());
506 >        assertFalse(s.tryAcquire(3));
507 >        assertEquals(2, s.availablePermits());
508 >        assertTrue(s.tryAcquire(2));
509 >        assertEquals(0, s.availablePermits());
510 >        assertFalse(s.tryAcquire(1));
511 >        assertFalse(s.tryAcquire(2));
512 >        assertEquals(0, s.availablePermits());
513      }
514  
687
688
689
690
515      /**
516 <     * release in one thread enables timed acquire in another thread
516 >     * acquire succeeds if permits available
517       */
518 <    public void testTimedAcquireReleaseInDifferentThreads_fair() {
519 <        final Semaphore s = new Semaphore(1, true);
520 <        Thread t = new Thread(new Runnable() {
521 <                public void run() {
522 <                    try {
523 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
524 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
525 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
526 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
527 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
528 <
529 <                    } catch(InterruptedException ie){
530 <                        threadUnexpectedException();
531 <                    }
532 <                }
533 <            });
534 <        t.start();
535 <        try {
536 <            s.release();
537 <            s.release();
538 <            s.release();
539 <            s.release();
540 <            s.release();
541 <            t.join();
542 <        } catch( InterruptedException e){
543 <            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();
518 >    public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
519 >    public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
520 >    public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
521 >    public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
522 >    public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
523 >    public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
524 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
525 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
526 >    public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
527 >    public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
528 >    public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
529 >    public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
530 >    public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
531 >    public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
532 >    public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
533 >    public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
534 >    public void testReleaseAcquireSameThread(boolean fair,
535 >                                             final AcquireMethod acquirer) {
536 >        Semaphore s = new Semaphore(1, fair);
537 >        for (int i = 1; i < 6; i++) {
538 >            s.release(i);
539 >            assertEquals(1 + i, s.availablePermits());
540 >            try {
541 >                acquirer.acquire(s, i);
542 >            } catch (InterruptedException e) { threadUnexpectedException(e); }
543 >            assertEquals(1, s.availablePermits());
544          }
545      }
546  
547      /**
548 <     * getQueueLength reports number of waiting threads
548 >     * release in one thread enables acquire in another thread
549       */
550 <    public void testGetQueueLength_fair() {
551 <        final Semaphore lock = new Semaphore(1, true);
552 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
553 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
554 <        try {
555 <            assertEquals(0, lock.getQueueLength());
556 <            lock.acquireUninterruptibly();
557 <            t1.start();
558 <            Thread.sleep(SHORT_DELAY_MS);
559 <            assertEquals(1, lock.getQueueLength());
560 <            t2.start();
561 <            Thread.sleep(SHORT_DELAY_MS);
562 <            assertEquals(2, lock.getQueueLength());
563 <            t1.interrupt();
564 <            Thread.sleep(SHORT_DELAY_MS);
565 <            assertEquals(1, lock.getQueueLength());
566 <            lock.release();
567 <            Thread.sleep(SHORT_DELAY_MS);
568 <            assertEquals(0, lock.getQueueLength());
569 <            t1.join();
570 <            t2.join();
571 <        } catch(Exception e){
572 <            unexpectedException();
550 >    public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
551 >    public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
552 >    public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
553 >    public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
554 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
555 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
556 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
557 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
558 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
559 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
560 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
561 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
562 >    public void testReleaseAcquireDifferentThreads(boolean fair,
563 >                                                   final AcquireMethod acquirer) {
564 >        final Semaphore s = new Semaphore(0, fair);
565 >        final int rounds = 4;
566 >        long startTime = System.nanoTime();
567 >        Thread t = newStartedThread(new CheckedRunnable() {
568 >            public void realRun() throws InterruptedException {
569 >                for (int i = 0; i < rounds; i++) {
570 >                    assertFalse(s.hasQueuedThreads());
571 >                    if (i % 2 == 0)
572 >                        acquirer.acquire(s);
573 >                    else
574 >                        acquirer.acquire(s, 3);
575 >                }}});
576 >
577 >        for (int i = 0; i < rounds; i++) {
578 >            while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
579 >                Thread.yield();
580 >            assertTrue(t.isAlive());
581 >            if (i % 2 == 0)
582 >                s.release();
583 >            else
584 >                s.release(3);
585          }
586 +        awaitTermination(t);
587 +        assertEquals(0, s.availablePermits());
588 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
589      }
590  
875
591      /**
592 <     * a deserialized serialized semaphore has same number of permits
592 >     * fair locks are strictly FIFO
593       */
594 <    public void testSerialization_fair() {
595 <        Semaphore l = new Semaphore(3, true);
596 <
597 <        try {
598 <            l.acquire();
599 <            l.release();
600 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
601 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
602 <            out.writeObject(l);
603 <            out.close();
604 <
605 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
606 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
607 <            Semaphore r = (Semaphore) in.readObject();
608 <            assertEquals(3, r.availablePermits());
609 <            assertTrue(r.isFair());
610 <            r.acquire();
611 <            r.release();
612 <        } catch(Exception e){
613 <            unexpectedException();
614 <        }
594 >    public void testFairLocksFifo() {
595 >        final PublicSemaphore s = new PublicSemaphore(1, true);
596 >        final CountDownLatch pleaseRelease = new CountDownLatch(1);
597 >        Thread t1 = newStartedThread(new CheckedRunnable() {
598 >            public void realRun() throws InterruptedException {
599 >                // Will block; permits are available, but not three
600 >                s.acquire(3);
601 >            }});
602 >
603 >        waitForQueuedThread(s, t1);
604 >
605 >        Thread t2 = newStartedThread(new CheckedRunnable() {
606 >            public void realRun() throws InterruptedException {
607 >                // Will fail, even though 1 permit is available
608 >                assertFalse(
609 >                    s.tryAcquire(randomExpiredTimeout(), randomTimeUnit()));
610 >                assertFalse(
611 >                    s.tryAcquire(1, randomExpiredTimeout(), randomTimeUnit()));
612 >
613 >                // untimed tryAcquire will barge and succeed
614 >                assertTrue(s.tryAcquire());
615 >                s.release(2);
616 >                assertTrue(s.tryAcquire(2));
617 >                s.release();
618 >
619 >                pleaseRelease.countDown();
620 >                // Will queue up behind t1, even though 1 permit is available
621 >                s.acquire();
622 >            }});
623 >
624 >        await(pleaseRelease);
625 >        waitForQueuedThread(s, t2);
626 >        s.release(2);
627 >        awaitTermination(t1);
628 >        assertTrue(t2.isAlive());
629 >        s.release();
630 >        awaitTermination(t2);
631      }
632  
633      /**
634       * toString indicates current number of permits
635       */
636 <    public void testToString() {
637 <        Semaphore s = new Semaphore(0);
638 <        String us = s.toString();
639 <        assertTrue(us.indexOf("Permits = 0") >= 0);
640 <        s.release();
910 <        String s1 = s.toString();
911 <        assertTrue(s1.indexOf("Permits = 1") >= 0);
636 >    public void testToString()      { testToString(false); }
637 >    public void testToString_fair() { testToString(true); }
638 >    public void testToString(boolean fair) {
639 >        PublicSemaphore s = new PublicSemaphore(0, fair);
640 >        assertTrue(s.toString().contains("Permits = 0"));
641          s.release();
642 <        String s2 = s.toString();
643 <        assertTrue(s2.indexOf("Permits = 2") >= 0);
642 >        assertTrue(s.toString().contains("Permits = 1"));
643 >        s.release(2);
644 >        assertTrue(s.toString().contains("Permits = 3"));
645 >        s.reducePermits(5);
646 >        assertTrue(s.toString().contains("Permits = -2"));
647      }
648  
649   }

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