ViewVC Help
View File | Revision Log | Show Annotations | Download File | Root Listing
root/jsr166/jsr166/src/test/tck/SemaphoreTest.java
(Generate patch)

Comparing jsr166/src/test/tck/SemaphoreTest.java (file contents):
Revision 1.11 by dl, Sun Jan 4 00:57:21 2004 UTC vs.
Revision 1.45 by jsr166, Tue Aug 13 00:46:27 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
5 < * Other contributors include Andrew Wright, Jeffrey Hayes,
6 < * Pat Fisher, Mike Judd.
4 > * http://creativecommons.org/publicdomain/zero/1.0/
5 > * Other contributors include Andrew Wright, Jeffrey Hayes,
6 > * Pat Fisher, Mike Judd.
7   */
8  
9 < import junit.framework.*;
10 < import java.util.*;
11 < import java.util.concurrent.*;
12 < import java.io.*;
9 > import static java.util.concurrent.TimeUnit.MILLISECONDS;
10 >
11 > import java.util.Collection;
12 > import java.util.concurrent.CountDownLatch;
13 > import java.util.concurrent.Semaphore;
14 >
15 > import junit.framework.Test;
16 > import junit.framework.TestSuite;
17  
18   public class SemaphoreTest extends JSR166TestCase {
19      public static void main(String[] args) {
20 <        junit.textui.TestRunner.run (suite());  
20 >        main(suite(), args);
21      }
22      public static Test suite() {
23 <        return new TestSuite(SemaphoreTest.class);
23 >        return new TestSuite(SemaphoreTest.class);
24      }
25  
26      /**
27       * Subclass to expose protected methods
28       */
29      static class PublicSemaphore extends Semaphore {
30 <        PublicSemaphore(int p, boolean f) { super(p, f); }
31 <        public Collection<Thread> getQueuedThreads() {
32 <            return super.getQueuedThreads();
30 >        PublicSemaphore(int permits) { super(permits); }
31 >        PublicSemaphore(int permits, boolean fair) { super(permits, fair); }
32 >        public Collection<Thread> getQueuedThreads() {
33 >            return super.getQueuedThreads();
34          }
35 <        public void reducePermits(int p) {
36 <            super.reducePermits(p);
35 >        public boolean hasQueuedThread(Thread t) {
36 >            return super.getQueuedThreads().contains(t);
37 >        }
38 >        public void reducePermits(int reduction) {
39 >            super.reducePermits(reduction);
40          }
41      }
42  
43      /**
44       * A runnable calling acquire
45       */
46 <    class InterruptibleLockRunnable implements Runnable {
46 >    class InterruptibleLockRunnable extends CheckedRunnable {
47          final Semaphore lock;
48 <        InterruptibleLockRunnable(Semaphore l) { lock = l; }
49 <        public void run() {
48 >        InterruptibleLockRunnable(Semaphore s) { lock = s; }
49 >        public void realRun() {
50              try {
51                  lock.acquire();
52 <            } catch(InterruptedException success){}
52 >            }
53 >            catch (InterruptedException ignored) {}
54          }
55      }
56  
48
57      /**
58 <     * A runnable calling acquire that expects to be
51 <     * interrupted
58 >     * A runnable calling acquire that expects to be interrupted
59       */
60 <    class InterruptedLockRunnable implements Runnable {
60 >    class InterruptedLockRunnable extends CheckedInterruptedRunnable {
61          final Semaphore lock;
62 <        InterruptedLockRunnable(Semaphore l) { lock = l; }
63 <        public void run() {
64 <            try {
65 <                lock.acquire();
66 <                threadShouldThrow();
67 <            } catch(InterruptedException success){}
62 >        InterruptedLockRunnable(Semaphore s) { lock = s; }
63 >        public void realRun() throws InterruptedException {
64 >            lock.acquire();
65 >        }
66 >    }
67 >
68 >    /**
69 >     * Spin-waits until s.hasQueuedThread(t) becomes true.
70 >     */
71 >    void waitForQueuedThread(PublicSemaphore s, Thread t) {
72 >        long startTime = System.nanoTime();
73 >        while (!s.hasQueuedThread(t)) {
74 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
75 >                throw new AssertionError("timed out");
76 >            Thread.yield();
77 >        }
78 >        assertTrue(s.hasQueuedThreads());
79 >        assertTrue(t.isAlive());
80 >    }
81 >
82 >    /**
83 >     * Spin-waits until s.hasQueuedThreads() becomes true.
84 >     */
85 >    void waitForQueuedThreads(Semaphore s) {
86 >        long startTime = System.nanoTime();
87 >        while (!s.hasQueuedThreads()) {
88 >            if (millisElapsedSince(startTime) > LONG_DELAY_MS)
89 >                throw new AssertionError("timed out");
90 >            Thread.yield();
91 >        }
92 >    }
93 >
94 >    enum AcquireMethod {
95 >        acquire() {
96 >            void acquire(Semaphore s) throws InterruptedException {
97 >                s.acquire();
98 >            }
99 >        },
100 >        acquireN() {
101 >            void acquire(Semaphore s, int permits) throws InterruptedException {
102 >                s.acquire(permits);
103 >            }
104 >        },
105 >        acquireUninterruptibly() {
106 >            void acquire(Semaphore s) {
107 >                s.acquireUninterruptibly();
108 >            }
109 >        },
110 >        acquireUninterruptiblyN() {
111 >            void acquire(Semaphore s, int permits) {
112 >                s.acquireUninterruptibly(permits);
113 >            }
114 >        },
115 >        tryAcquire() {
116 >            void acquire(Semaphore s) {
117 >                assertTrue(s.tryAcquire());
118 >            }
119 >        },
120 >        tryAcquireN() {
121 >            void acquire(Semaphore s, int permits) {
122 >                assertTrue(s.tryAcquire(permits));
123 >            }
124 >        },
125 >        tryAcquireTimed() {
126 >            void acquire(Semaphore s) throws InterruptedException {
127 >                assertTrue(s.tryAcquire(2 * LONG_DELAY_MS, MILLISECONDS));
128 >            }
129 >            Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
130 >        },
131 >        tryAcquireTimedN {
132 >            void acquire(Semaphore s, int permits) throws InterruptedException {
133 >                assertTrue(s.tryAcquire(permits, 2 * LONG_DELAY_MS, MILLISECONDS));
134 >            }
135 >            Thread.State parkedState() { return Thread.State.TIMED_WAITING; }
136 >        };
137 >
138 >        // Intentionally meta-circular
139 >
140 >        /** Acquires 1 permit. */
141 >        void acquire(Semaphore s) throws InterruptedException {
142 >            acquire(s, 1);
143 >        }
144 >        /** Acquires the given number of permits. */
145 >        void acquire(Semaphore s, int permits) throws InterruptedException {
146 >            for (int i = 0; i < permits; i++)
147 >                acquire(s);
148          }
149 +        Thread.State parkedState() { return Thread.State.WAITING; }
150      }
151  
152      /**
153       * Zero, negative, and positive initial values are allowed in constructor
154       */
155 <    public void testConstructor() {
156 <        Semaphore s0 = new Semaphore(0, false);
157 <        assertEquals(0, s0.availablePermits());
158 <        assertFalse(s0.isFair());
159 <        Semaphore s1 = new Semaphore(-1, false);
160 <        assertEquals(-1, s1.availablePermits());
161 <        Semaphore s2 = new Semaphore(-1, false);
162 <        assertEquals(-1, s2.availablePermits());
155 >    public void testConstructor()      { testConstructor(false); }
156 >    public void testConstructor_fair() { testConstructor(true); }
157 >    public void testConstructor(boolean fair) {
158 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
159 >            Semaphore s = new Semaphore(permits, fair);
160 >            assertEquals(permits, s.availablePermits());
161 >            assertEquals(fair, s.isFair());
162 >        }
163 >    }
164 >
165 >    /**
166 >     * Constructor without fairness argument behaves as nonfair
167 >     */
168 >    public void testConstructorDefaultsToNonFair() {
169 >        for (int permits : new int[] { -42, -1, 0, 1, 42 }) {
170 >            Semaphore s = new Semaphore(permits);
171 >            assertEquals(permits, s.availablePermits());
172 >            assertFalse(s.isFair());
173 >        }
174      }
175  
176      /**
177       * tryAcquire succeeds when sufficient permits, else fails
178       */
179 <    public void testTryAcquireInSameThread() {
180 <        Semaphore s = new Semaphore(2, false);
179 >    public void testTryAcquireInSameThread()      { testTryAcquireInSameThread(false); }
180 >    public void testTryAcquireInSameThread_fair() { testTryAcquireInSameThread(true); }
181 >    public void testTryAcquireInSameThread(boolean fair) {
182 >        Semaphore s = new Semaphore(2, fair);
183          assertEquals(2, s.availablePermits());
184          assertTrue(s.tryAcquire());
185          assertTrue(s.tryAcquire());
186          assertEquals(0, s.availablePermits());
187          assertFalse(s.tryAcquire());
188 +        assertFalse(s.tryAcquire());
189 +        assertEquals(0, s.availablePermits());
190      }
191  
192      /**
193 <     * Acquire and release of semaphore succeed if initially available
193 >     * timed tryAcquire times out
194       */
195 <    public void testAcquireReleaseInSameThread() {
196 <        Semaphore s = new Semaphore(1, false);
197 <        try {
198 <            s.acquire();
199 <            s.release();
200 <            s.acquire();
201 <            s.release();
202 <            s.acquire();
203 <            s.release();
204 <            s.acquire();
205 <            s.release();
206 <            s.acquire();
207 <            s.release();
208 <            assertEquals(1, s.availablePermits());
209 <        } catch( InterruptedException e){
210 <            unexpectedException();
195 >    public void testTryAcquire_timeout() throws InterruptedException {
196 >        final boolean fair = randomBoolean();
197 >        final Semaphore s = new Semaphore(0, fair);
198 >        final long startTime = System.nanoTime();
199 >        assertFalse(s.tryAcquire(timeoutMillis(), MILLISECONDS));
200 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
201 >    }
202 >
203 >    /**
204 >     * timed tryAcquire(N) times out
205 >     */
206 >    public void testTryAcquireN_timeout() throws InterruptedException {
207 >        final boolean fair = randomBoolean();
208 >        final Semaphore s = new Semaphore(2, fair);
209 >        final long startTime = System.nanoTime();
210 >        assertFalse(s.tryAcquire(3, timeoutMillis(), MILLISECONDS));
211 >        assertTrue(millisElapsedSince(startTime) >= timeoutMillis());
212 >    }
213 >
214 >    /**
215 >     * acquire(), acquire(N), timed tryAcquired, timed tryAcquire(N)
216 >     * are interruptible
217 >     */
218 >    public void testInterruptible_acquire()               { testInterruptible(false, AcquireMethod.acquire); }
219 >    public void testInterruptible_acquire_fair()          { testInterruptible(true,  AcquireMethod.acquire); }
220 >    public void testInterruptible_acquireN()              { testInterruptible(false, AcquireMethod.acquireN); }
221 >    public void testInterruptible_acquireN_fair()         { testInterruptible(true,  AcquireMethod.acquireN); }
222 >    public void testInterruptible_tryAcquireTimed()       { testInterruptible(false, AcquireMethod.tryAcquireTimed); }
223 >    public void testInterruptible_tryAcquireTimed_fair()  { testInterruptible(true,  AcquireMethod.tryAcquireTimed); }
224 >    public void testInterruptible_tryAcquireTimedN()      { testInterruptible(false, AcquireMethod.tryAcquireTimedN); }
225 >    public void testInterruptible_tryAcquireTimedN_fair() { testInterruptible(true,  AcquireMethod.tryAcquireTimedN); }
226 >    public void testInterruptible(boolean fair, final AcquireMethod acquirer) {
227 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
228 >        final java.util.concurrent.CyclicBarrier pleaseInterrupt
229 >            = new java.util.concurrent.CyclicBarrier(2);
230 >        Thread t = newStartedThread(new CheckedRunnable() {
231 >            public void realRun() {
232 >                // Interrupt before acquire
233 >                Thread.currentThread().interrupt();
234 >                try {
235 >                    acquirer.acquire(s);
236 >                    shouldThrow();
237 >                } catch (InterruptedException success) {}
238 >                assertFalse(Thread.interrupted());
239 >
240 >                // Interrupt before acquire(N)
241 >                Thread.currentThread().interrupt();
242 >                try {
243 >                    acquirer.acquire(s, 3);
244 >                    shouldThrow();
245 >                } catch (InterruptedException success) {}
246 >                assertFalse(Thread.interrupted());
247 >
248 >                // Interrupt during acquire
249 >                await(pleaseInterrupt);
250 >                try {
251 >                    acquirer.acquire(s);
252 >                    shouldThrow();
253 >                } catch (InterruptedException success) {}
254 >                assertFalse(Thread.interrupted());
255 >
256 >                // Interrupt during acquire(N)
257 >                await(pleaseInterrupt);
258 >                try {
259 >                    acquirer.acquire(s, 3);
260 >                    shouldThrow();
261 >                } catch (InterruptedException success) {}
262 >                assertFalse(Thread.interrupted());
263 >            }});
264 >
265 >        for (int n = 2; n-->0; ) {
266 >            await(pleaseInterrupt);
267 >            assertThreadBlocks(t, acquirer.parkedState());
268 >            t.interrupt();
269          }
109    }
270  
271 <    /**
112 <     * Uninterruptible acquire and release of semaphore succeed if
113 <     * initially available
114 <     */
115 <    public void testAcquireUninterruptiblyReleaseInSameThread() {
116 <        Semaphore s = new Semaphore(1, false);
117 <        try {
118 <            s.acquireUninterruptibly();
119 <            s.release();
120 <            s.acquireUninterruptibly();
121 <            s.release();
122 <            s.acquireUninterruptibly();
123 <            s.release();
124 <            s.acquireUninterruptibly();
125 <            s.release();
126 <            s.acquireUninterruptibly();
127 <            s.release();
128 <            assertEquals(1, s.availablePermits());
129 <        } finally {
130 <        }
271 >        awaitTermination(t);
272      }
273  
274      /**
275 <     * Timed Acquire and release of semaphore succeed if
276 <     * initially available
275 >     * acquireUninterruptibly(), acquireUninterruptibly(N) are
276 >     * uninterruptible
277       */
278 <    public void testTimedAcquireReleaseInSameThread() {
279 <        Semaphore s = new Semaphore(1, false);
280 <        try {
281 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
282 <            s.release();
283 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
284 <            s.release();
285 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
286 <            s.release();
287 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
288 <            s.release();
289 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
290 <            s.release();
291 <            assertEquals(1, s.availablePermits());
292 <        } catch( InterruptedException e){
293 <            unexpectedException();
294 <        }
295 <    }
278 >    public void testUninterruptible_acquireUninterruptibly()       { testUninterruptible(false, AcquireMethod.acquireUninterruptibly); }
279 >    public void testUninterruptible_acquireUninterruptibly_fair()  { testUninterruptible(true,  AcquireMethod.acquireUninterruptibly); }
280 >    public void testUninterruptible_acquireUninterruptiblyN()      { testUninterruptible(false, AcquireMethod.acquireUninterruptiblyN); }
281 >    public void testUninterruptible_acquireUninterruptiblyN_fair() { testUninterruptible(true,  AcquireMethod.acquireUninterruptiblyN); }
282 >    public void testUninterruptible(boolean fair, final AcquireMethod acquirer) {
283 >        final PublicSemaphore s = new PublicSemaphore(0, fair);
284 >        final Semaphore pleaseInterrupt = new Semaphore(-1, fair);
285 >
286 >        Thread t1 = newStartedThread(new CheckedRunnable() {
287 >            public void realRun() throws InterruptedException {
288 >                // Interrupt before acquire
289 >                pleaseInterrupt.release();
290 >                Thread.currentThread().interrupt();
291 >                acquirer.acquire(s);
292 >                assertTrue(Thread.interrupted());
293 >            }});
294 >
295 >        Thread t2 = newStartedThread(new CheckedRunnable() {
296 >            public void realRun() throws InterruptedException {
297 >                // Interrupt during acquire
298 >                pleaseInterrupt.release();
299 >                acquirer.acquire(s);
300 >                assertTrue(Thread.interrupted());
301 >            }});
302 >
303 >        await(pleaseInterrupt);
304 >        waitForQueuedThread(s, t1);
305 >        waitForQueuedThread(s, t2);
306 >        t2.interrupt();
307  
308 <    /**
309 <     * A release in one thread enables an acquire in another thread
158 <     */
159 <    public void testAcquireReleaseInDifferentThreads() {
160 <        final Semaphore s = new Semaphore(0, false);
161 <        Thread t = new Thread(new Runnable() {
162 <                public void run() {
163 <                    try {
164 <                        s.acquire();
165 <                        s.release();
166 <                        s.release();
167 <                        s.acquire();
168 <                    } catch(InterruptedException ie){
169 <                        threadUnexpectedException();
170 <                    }
171 <                }
172 <            });
173 <        try {
174 <            t.start();
175 <            Thread.sleep(SHORT_DELAY_MS);
176 <            s.release();
177 <            s.release();
178 <            s.acquire();
179 <            s.acquire();
180 <            s.release();
181 <            t.join();
182 <        } catch( InterruptedException e){
183 <            unexpectedException();
184 <        }
185 <    }
186 <
187 <    /**
188 <     * A release in one thread enables an uninterruptible acquire in another thread
189 <     */
190 <    public void testUninterruptibleAcquireReleaseInDifferentThreads() {
191 <        final Semaphore s = new Semaphore(0, false);
192 <        Thread t = new Thread(new Runnable() {
193 <                public void run() {
194 <                    s.acquireUninterruptibly();
195 <                    s.release();
196 <                    s.release();
197 <                    s.acquireUninterruptibly();
198 <                }
199 <            });
200 <        try {
201 <            t.start();
202 <            Thread.sleep(SHORT_DELAY_MS);
203 <            s.release();
204 <            s.release();
205 <            s.acquireUninterruptibly();
206 <            s.acquireUninterruptibly();
207 <            s.release();
208 <            t.join();
209 <        } catch( InterruptedException e){
210 <            unexpectedException();
211 <        }
212 <    }
213 <
214 <
215 <    /**
216 <     *  A release in one thread enables a timed acquire in another thread
217 <     */
218 <    public void testTimedAcquireReleaseInDifferentThreads() {
219 <        final Semaphore s = new Semaphore(1, false);
220 <        Thread t = new Thread(new Runnable() {
221 <                public void run() {
222 <                    try {
223 <                        s.release();
224 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
225 <                        s.release();
226 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
308 >        assertThreadBlocks(t1, Thread.State.WAITING);
309 >        assertThreadBlocks(t2, Thread.State.WAITING);
310  
311 <                    } catch(InterruptedException ie){
229 <                        threadUnexpectedException();
230 <                    }
231 <                }
232 <            });
233 <        try {
234 <            t.start();
235 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
236 <            s.release();
237 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
238 <            s.release();
239 <            s.release();
240 <            t.join();
241 <        } catch( InterruptedException e){
242 <            unexpectedException();
243 <        }
244 <    }
311 >        s.release(2);
312  
313 <    /**
314 <     * A waiting acquire blocks interruptibly
248 <     */
249 <    public void testAcquire_InterruptedException() {
250 <        final Semaphore s = new Semaphore(0, false);
251 <        Thread t = new Thread(new Runnable() {
252 <                public void run() {
253 <                    try {
254 <                        s.acquire();
255 <                        threadShouldThrow();
256 <                    } catch(InterruptedException success){}
257 <                }
258 <            });
259 <        t.start();
260 <        try {
261 <            Thread.sleep(SHORT_DELAY_MS);
262 <            t.interrupt();
263 <            t.join();
264 <        } catch(InterruptedException e){
265 <            unexpectedException();
266 <        }
267 <    }
268 <    
269 <    /**
270 <     *  A waiting timed acquire blocks interruptibly
271 <     */
272 <    public void testTryAcquire_InterruptedException() {
273 <        final Semaphore s = new Semaphore(0, false);
274 <        Thread t = new Thread(new Runnable() {
275 <                public void run() {
276 <                    try {
277 <                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
278 <                        threadShouldThrow();
279 <                    } catch(InterruptedException success){
280 <                    }
281 <                }
282 <            });
283 <        t.start();
284 <        try {
285 <            Thread.sleep(SHORT_DELAY_MS);
286 <            t.interrupt();
287 <            t.join();
288 <        } catch(InterruptedException e){
289 <            unexpectedException();
290 <        }
313 >        awaitTermination(t1);
314 >        awaitTermination(t2);
315      }
316  
317      /**
318       * hasQueuedThreads reports whether there are waiting threads
319       */
320 <    public void testHasQueuedThreads() {
321 <        final Semaphore lock = new Semaphore(1, false);
322 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
323 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
324 <        try {
325 <            assertFalse(lock.hasQueuedThreads());
326 <            lock.acquireUninterruptibly();
327 <            t1.start();
328 <            Thread.sleep(SHORT_DELAY_MS);
329 <            assertTrue(lock.hasQueuedThreads());
330 <            t2.start();
331 <            Thread.sleep(SHORT_DELAY_MS);
332 <            assertTrue(lock.hasQueuedThreads());
333 <            t1.interrupt();
334 <            Thread.sleep(SHORT_DELAY_MS);
335 <            assertTrue(lock.hasQueuedThreads());
336 <            lock.release();
337 <            Thread.sleep(SHORT_DELAY_MS);
338 <            assertFalse(lock.hasQueuedThreads());
315 <            t1.join();
316 <            t2.join();
317 <        } catch(Exception e){
318 <            unexpectedException();
319 <        }
320 <    }
320 >    public void testHasQueuedThreads()      { testHasQueuedThreads(false); }
321 >    public void testHasQueuedThreads_fair() { testHasQueuedThreads(true); }
322 >    public void testHasQueuedThreads(boolean fair) {
323 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
324 >        assertFalse(lock.hasQueuedThreads());
325 >        lock.acquireUninterruptibly();
326 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
327 >        waitForQueuedThread(lock, t1);
328 >        assertTrue(lock.hasQueuedThreads());
329 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
330 >        waitForQueuedThread(lock, t2);
331 >        assertTrue(lock.hasQueuedThreads());
332 >        t1.interrupt();
333 >        awaitTermination(t1);
334 >        assertTrue(lock.hasQueuedThreads());
335 >        lock.release();
336 >        awaitTermination(t2);
337 >        assertFalse(lock.hasQueuedThreads());
338 >    }
339  
340      /**
341       * getQueueLength reports number of waiting threads
342       */
343 <    public void testGetQueueLength() {
344 <        final Semaphore lock = new Semaphore(1, false);
345 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
346 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
347 <        try {
348 <            assertEquals(0, lock.getQueueLength());
349 <            lock.acquireUninterruptibly();
350 <            t1.start();
351 <            Thread.sleep(SHORT_DELAY_MS);
352 <            assertEquals(1, lock.getQueueLength());
353 <            t2.start();
354 <            Thread.sleep(SHORT_DELAY_MS);
355 <            assertEquals(2, lock.getQueueLength());
356 <            t1.interrupt();
357 <            Thread.sleep(SHORT_DELAY_MS);
358 <            assertEquals(1, lock.getQueueLength());
359 <            lock.release();
360 <            Thread.sleep(SHORT_DELAY_MS);
361 <            assertEquals(0, lock.getQueueLength());
344 <            t1.join();
345 <            t2.join();
346 <        } catch(Exception e){
347 <            unexpectedException();
348 <        }
349 <    }
343 >    public void testGetQueueLength()      { testGetQueueLength(false); }
344 >    public void testGetQueueLength_fair() { testGetQueueLength(true); }
345 >    public void testGetQueueLength(boolean fair) {
346 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
347 >        assertEquals(0, lock.getQueueLength());
348 >        lock.acquireUninterruptibly();
349 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
350 >        waitForQueuedThread(lock, t1);
351 >        assertEquals(1, lock.getQueueLength());
352 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
353 >        waitForQueuedThread(lock, t2);
354 >        assertEquals(2, lock.getQueueLength());
355 >        t1.interrupt();
356 >        awaitTermination(t1);
357 >        assertEquals(1, lock.getQueueLength());
358 >        lock.release();
359 >        awaitTermination(t2);
360 >        assertEquals(0, lock.getQueueLength());
361 >    }
362  
363      /**
364       * getQueuedThreads includes waiting threads
365       */
366 <    public void testGetQueuedThreads() {
367 <        final PublicSemaphore lock = new PublicSemaphore(1, false);
368 <        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
369 <        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
370 <        try {
371 <            assertTrue(lock.getQueuedThreads().isEmpty());
372 <            lock.acquireUninterruptibly();
373 <            assertTrue(lock.getQueuedThreads().isEmpty());
374 <            t1.start();
375 <            Thread.sleep(SHORT_DELAY_MS);
376 <            assertTrue(lock.getQueuedThreads().contains(t1));
377 <            t2.start();
378 <            Thread.sleep(SHORT_DELAY_MS);
379 <            assertTrue(lock.getQueuedThreads().contains(t1));
380 <            assertTrue(lock.getQueuedThreads().contains(t2));
381 <            t1.interrupt();
382 <            Thread.sleep(SHORT_DELAY_MS);
383 <            assertFalse(lock.getQueuedThreads().contains(t1));
384 <            assertTrue(lock.getQueuedThreads().contains(t2));
385 <            lock.release();
386 <            Thread.sleep(SHORT_DELAY_MS);
387 <            assertTrue(lock.getQueuedThreads().isEmpty());
376 <            t1.join();
377 <            t2.join();
378 <        } catch(Exception e){
379 <            unexpectedException();
380 <        }
381 <    }
366 >    public void testGetQueuedThreads()      { testGetQueuedThreads(false); }
367 >    public void testGetQueuedThreads_fair() { testGetQueuedThreads(true); }
368 >    public void testGetQueuedThreads(boolean fair) {
369 >        final PublicSemaphore lock = new PublicSemaphore(1, fair);
370 >        assertTrue(lock.getQueuedThreads().isEmpty());
371 >        lock.acquireUninterruptibly();
372 >        assertTrue(lock.getQueuedThreads().isEmpty());
373 >        Thread t1 = newStartedThread(new InterruptedLockRunnable(lock));
374 >        waitForQueuedThread(lock, t1);
375 >        assertTrue(lock.getQueuedThreads().contains(t1));
376 >        Thread t2 = newStartedThread(new InterruptibleLockRunnable(lock));
377 >        waitForQueuedThread(lock, t2);
378 >        assertTrue(lock.getQueuedThreads().contains(t1));
379 >        assertTrue(lock.getQueuedThreads().contains(t2));
380 >        t1.interrupt();
381 >        awaitTermination(t1);
382 >        assertFalse(lock.getQueuedThreads().contains(t1));
383 >        assertTrue(lock.getQueuedThreads().contains(t2));
384 >        lock.release();
385 >        awaitTermination(t2);
386 >        assertTrue(lock.getQueuedThreads().isEmpty());
387 >    }
388  
389      /**
390       * drainPermits reports and removes given number of permits
391       */
392 <    public void testDrainPermits() {
393 <        Semaphore s = new Semaphore(0, false);
392 >    public void testDrainPermits()      { testDrainPermits(false); }
393 >    public void testDrainPermits_fair() { testDrainPermits(true); }
394 >    public void testDrainPermits(boolean fair) {
395 >        Semaphore s = new Semaphore(0, fair);
396          assertEquals(0, s.availablePermits());
397          assertEquals(0, s.drainPermits());
398          s.release(10);
# Line 395 | Line 403 | public class SemaphoreTest extends JSR16
403      }
404  
405      /**
406 <     * reducePermits reduces number of permits
406 >     * release(-N) throws IllegalArgumentException
407       */
408 <    public void testReducePermits() {
409 <        PublicSemaphore s = new PublicSemaphore(10, false);
410 <        assertEquals(10, s.availablePermits());
411 <        s.reducePermits(1);
404 <        assertEquals(9, s.availablePermits());
405 <        s.reducePermits(10);
406 <        assertEquals(-1, s.availablePermits());
407 <    }
408 <
409 <    /**
410 <     * a deserialized serialized semaphore has same number of permits
411 <     */
412 <    public void testSerialization() {
413 <        Semaphore l = new Semaphore(3, false);
408 >    public void testReleaseIAE()      { testReleaseIAE(false); }
409 >    public void testReleaseIAE_fair() { testReleaseIAE(true); }
410 >    public void testReleaseIAE(boolean fair) {
411 >        Semaphore s = new Semaphore(10, fair);
412          try {
413 <            l.acquire();
414 <            l.release();
415 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
418 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
419 <            out.writeObject(l);
420 <            out.close();
421 <
422 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
423 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
424 <            Semaphore r = (Semaphore) in.readObject();
425 <            assertEquals(3, r.availablePermits());
426 <            assertFalse(r.isFair());
427 <            r.acquire();
428 <            r.release();
429 <        } catch(Exception e){
430 <            unexpectedException();
431 <        }
413 >            s.release(-1);
414 >            shouldThrow();
415 >        } catch (IllegalArgumentException success) {}
416      }
417  
434
418      /**
419 <     * Zero, negative, and positive initial values are allowed in constructor
419 >     * reducePermits(-N) throws IllegalArgumentException
420       */
421 <    public void testConstructor_fair() {
422 <        Semaphore s0 = new Semaphore(0, true);
423 <        assertEquals(0, s0.availablePermits());
424 <        assertTrue(s0.isFair());
425 <        Semaphore s1 = new Semaphore(-1, true);
426 <        assertEquals(-1, s1.availablePermits());
427 <        Semaphore s2 = new Semaphore(-1, true);
428 <        assertEquals(-1, s2.availablePermits());
446 <    }
447 <
448 <    /**
449 <     * tryAcquire succeeds when sufficient permits, else fails
450 <     */
451 <    public void testTryAcquireInSameThread_fair() {
452 <        Semaphore s = new Semaphore(2, true);
453 <        assertEquals(2, s.availablePermits());
454 <        assertTrue(s.tryAcquire());
455 <        assertTrue(s.tryAcquire());
456 <        assertEquals(0, s.availablePermits());
457 <        assertFalse(s.tryAcquire());
421 >    public void testReducePermitsIAE()      { testReducePermitsIAE(false); }
422 >    public void testReducePermitsIAE_fair() { testReducePermitsIAE(true); }
423 >    public void testReducePermitsIAE(boolean fair) {
424 >        PublicSemaphore s = new PublicSemaphore(10, fair);
425 >        try {
426 >            s.reducePermits(-1);
427 >            shouldThrow();
428 >        } catch (IllegalArgumentException success) {}
429      }
430  
431      /**
432 <     * tryAcquire(n) succeeds when sufficient permits, else fails
432 >     * reducePermits reduces number of permits
433       */
434 <    public void testTryAcquireNInSameThread_fair() {
435 <        Semaphore s = new Semaphore(2, true);
436 <        assertEquals(2, s.availablePermits());
437 <        assertTrue(s.tryAcquire(2));
438 <        assertEquals(0, s.availablePermits());
439 <        assertFalse(s.tryAcquire());
434 >    public void testReducePermits()      { testReducePermits(false); }
435 >    public void testReducePermits_fair() { testReducePermits(true); }
436 >    public void testReducePermits(boolean fair) {
437 >        PublicSemaphore s = new PublicSemaphore(10, fair);
438 >        assertEquals(10, s.availablePermits());
439 >        s.reducePermits(0);
440 >        assertEquals(10, s.availablePermits());
441 >        s.reducePermits(1);
442 >        assertEquals(9, s.availablePermits());
443 >        s.reducePermits(10);
444 >        assertEquals(-1, s.availablePermits());
445 >        s.reducePermits(10);
446 >        assertEquals(-11, s.availablePermits());
447 >        s.reducePermits(0);
448 >        assertEquals(-11, s.availablePermits());
449      }
450  
451      /**
452 <     * Acquire and release of semaphore succeed if initially available
452 >     * a reserialized semaphore has same number of permits and
453 >     * fairness, but no queued threads
454       */
455 <    public void testAcquireReleaseInSameThread_fair() {
456 <        Semaphore s = new Semaphore(1, true);
455 >    public void testSerialization()      { testSerialization(false); }
456 >    public void testSerialization_fair() { testSerialization(true); }
457 >    public void testSerialization(boolean fair) {
458          try {
459 +            Semaphore s = new Semaphore(3, fair);
460              s.acquire();
478            s.release();
479            s.acquire();
480            s.release();
481            s.acquire();
482            s.release();
483            s.acquire();
484            s.release();
461              s.acquire();
462              s.release();
487            assertEquals(1, s.availablePermits());
488        } catch( InterruptedException e){
489            unexpectedException();
490        }
491    }
463  
464 <    /**
465 <     * Acquire(n) and release(n) of semaphore succeed if initially available
466 <     */
467 <    public void testAcquireReleaseNInSameThread_fair() {
468 <        Semaphore s = new Semaphore(1, true);
469 <        try {
470 <            s.release(1);
471 <            s.acquire(1);
472 <            s.release(2);
473 <            s.acquire(2);
474 <            s.release(3);
475 <            s.acquire(3);
476 <            s.release(4);
477 <            s.acquire(4);
478 <            s.release(5);
479 <            s.acquire(5);
480 <            assertEquals(1, s.availablePermits());
481 <        } catch( InterruptedException e){
482 <            unexpectedException();
483 <        }
484 <    }
485 <
486 <    /**
487 <     * Acquire(n) and release(n) of semaphore succeed if initially available
488 <     */
489 <    public void testAcquireUninterruptiblyReleaseNInSameThread_fair() {
490 <        Semaphore s = new Semaphore(1, true);
491 <        try {
492 <            s.release(1);
493 <            s.acquireUninterruptibly(1);
523 <            s.release(2);
524 <            s.acquireUninterruptibly(2);
525 <            s.release(3);
526 <            s.acquireUninterruptibly(3);
527 <            s.release(4);
528 <            s.acquireUninterruptibly(4);
529 <            s.release(5);
530 <            s.acquireUninterruptibly(5);
531 <            assertEquals(1, s.availablePermits());
532 <        } finally {
464 >            Semaphore clone = serialClone(s);
465 >            assertEquals(fair, s.isFair());
466 >            assertEquals(fair, clone.isFair());
467 >            assertEquals(2, s.availablePermits());
468 >            assertEquals(2, clone.availablePermits());
469 >            clone.acquire();
470 >            clone.acquire();
471 >            clone.release();
472 >            assertEquals(2, s.availablePermits());
473 >            assertEquals(1, clone.availablePermits());
474 >            assertFalse(s.hasQueuedThreads());
475 >            assertFalse(clone.hasQueuedThreads());
476 >        } catch (InterruptedException e) { threadUnexpectedException(e); }
477 >
478 >        {
479 >            PublicSemaphore s = new PublicSemaphore(0, fair);
480 >            Thread t = newStartedThread(new InterruptibleLockRunnable(s));
481 >            // waitForQueuedThreads(s); // suffers from "flicker", so ...
482 >            waitForQueuedThread(s, t);  // ... we use this instead
483 >            PublicSemaphore clone = serialClone(s);
484 >            assertEquals(fair, s.isFair());
485 >            assertEquals(fair, clone.isFair());
486 >            assertEquals(0, s.availablePermits());
487 >            assertEquals(0, clone.availablePermits());
488 >            assertTrue(s.hasQueuedThreads());
489 >            assertFalse(clone.hasQueuedThreads());
490 >            s.release();
491 >            awaitTermination(t);
492 >            assertFalse(s.hasQueuedThreads());
493 >            assertFalse(clone.hasQueuedThreads());
494          }
495      }
496  
497      /**
498 <     * release(n) in one thread enables timed acquire(n) in another thread
498 >     * tryAcquire(n) succeeds when sufficient permits, else fails
499       */
500 <    public void testTimedAcquireReleaseNInSameThread_fair() {
501 <        Semaphore s = new Semaphore(1, true);
502 <        try {
503 <            s.release(1);
504 <            assertTrue(s.tryAcquire(1, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
505 <            s.release(2);
506 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
507 <            s.release(3);
508 <            assertTrue(s.tryAcquire(3, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
509 <            s.release(4);
510 <            assertTrue(s.tryAcquire(4, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
511 <            s.release(5);
551 <            assertTrue(s.tryAcquire(5, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
552 <            assertEquals(1, s.availablePermits());
553 <        } catch( InterruptedException e){
554 <            unexpectedException();
555 <        }
500 >    public void testTryAcquireNInSameThread()      { testTryAcquireNInSameThread(false); }
501 >    public void testTryAcquireNInSameThread_fair() { testTryAcquireNInSameThread(true); }
502 >    public void testTryAcquireNInSameThread(boolean fair) {
503 >        Semaphore s = new Semaphore(2, fair);
504 >        assertEquals(2, s.availablePermits());
505 >        assertFalse(s.tryAcquire(3));
506 >        assertEquals(2, s.availablePermits());
507 >        assertTrue(s.tryAcquire(2));
508 >        assertEquals(0, s.availablePermits());
509 >        assertFalse(s.tryAcquire(1));
510 >        assertFalse(s.tryAcquire(2));
511 >        assertEquals(0, s.availablePermits());
512      }
513  
514      /**
515 <     * release in one thread enables timed acquire in another thread
515 >     * acquire succeeds if permits available
516       */
517 <    public void testTimedAcquireReleaseInSameThread_fair() {
518 <        Semaphore s = new Semaphore(1, true);
519 <        try {
520 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
521 <            s.release();
522 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
523 <            s.release();
524 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
525 <            s.release();
526 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
527 <            s.release();
528 <            assertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
529 <            s.release();
517 >    public void testReleaseAcquireSameThread_acquire()       { testReleaseAcquireSameThread(false, AcquireMethod.acquire); }
518 >    public void testReleaseAcquireSameThread_acquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquire); }
519 >    public void testReleaseAcquireSameThread_acquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireN); }
520 >    public void testReleaseAcquireSameThread_acquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireN); }
521 >    public void testReleaseAcquireSameThread_acquireUninterruptibly()       { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
522 >    public void testReleaseAcquireSameThread_acquireUninterruptibly_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
523 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN()      { testReleaseAcquireSameThread(false, AcquireMethod.acquireUninterruptibly); }
524 >    public void testReleaseAcquireSameThread_acquireUninterruptiblyN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.acquireUninterruptibly); }
525 >    public void testReleaseAcquireSameThread_tryAcquire()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquire); }
526 >    public void testReleaseAcquireSameThread_tryAcquire_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquire); }
527 >    public void testReleaseAcquireSameThread_tryAcquireN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireN); }
528 >    public void testReleaseAcquireSameThread_tryAcquireN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireN); }
529 >    public void testReleaseAcquireSameThread_tryAcquireTimed()       { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimed); }
530 >    public void testReleaseAcquireSameThread_tryAcquireTimed_fair()  { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimed); }
531 >    public void testReleaseAcquireSameThread_tryAcquireTimedN()      { testReleaseAcquireSameThread(false, AcquireMethod.tryAcquireTimedN); }
532 >    public void testReleaseAcquireSameThread_tryAcquireTimedN_fair() { testReleaseAcquireSameThread(true, AcquireMethod.tryAcquireTimedN); }
533 >    public void testReleaseAcquireSameThread(boolean fair,
534 >                                             final AcquireMethod acquirer) {
535 >        Semaphore s = new Semaphore(1, fair);
536 >        for (int i = 1; i < 6; i++) {
537 >            s.release(i);
538 >            assertEquals(1 + i, s.availablePermits());
539 >            try {
540 >                acquirer.acquire(s, i);
541 >            } catch (InterruptedException e) { threadUnexpectedException(e); }
542              assertEquals(1, s.availablePermits());
575        } catch( InterruptedException e){
576            unexpectedException();
543          }
544      }
545  
546      /**
547 <     * A release in one thread enables an acquire in another thread
547 >     * release in one thread enables acquire in another thread
548       */
549 <    public void testAcquireReleaseInDifferentThreads_fair() {
550 <        final Semaphore s = new Semaphore(0, true);
551 <        Thread t = new Thread(new Runnable() {
552 <                public void run() {
553 <                    try {
554 <                        s.acquire();
555 <                        s.acquire();
556 <                        s.acquire();
557 <                        s.acquire();
558 <                    } catch(InterruptedException ie){
559 <                        threadUnexpectedException();
560 <                    }
561 <                }
562 <            });
563 <        try {
564 <            t.start();
565 <            Thread.sleep(SHORT_DELAY_MS);
566 <            s.release();
567 <            s.release();
568 <            s.release();
569 <            s.release();
570 <            s.release();
571 <            s.release();
572 <            t.join();
573 <            assertEquals(2, s.availablePermits());
574 <        } catch( InterruptedException e){
575 <            unexpectedException();
549 >    public void testReleaseAcquireDifferentThreads_acquire()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquire); }
550 >    public void testReleaseAcquireDifferentThreads_acquire_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquire); }
551 >    public void testReleaseAcquireDifferentThreads_acquireN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireN); }
552 >    public void testReleaseAcquireDifferentThreads_acquireN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireN); }
553 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
554 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptibly_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
555 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.acquireUninterruptibly); }
556 >    public void testReleaseAcquireDifferentThreads_acquireUninterruptiblyN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.acquireUninterruptibly); }
557 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed()       { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimed); }
558 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimed_fair()  { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimed); }
559 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN()      { testReleaseAcquireDifferentThreads(false, AcquireMethod.tryAcquireTimedN); }
560 >    public void testReleaseAcquireDifferentThreads_tryAcquireTimedN_fair() { testReleaseAcquireDifferentThreads(true, AcquireMethod.tryAcquireTimedN); }
561 >    public void testReleaseAcquireDifferentThreads(boolean fair,
562 >                                                   final AcquireMethod acquirer) {
563 >        final Semaphore s = new Semaphore(0, fair);
564 >        final int rounds = 4;
565 >        long startTime = System.nanoTime();
566 >        Thread t = newStartedThread(new CheckedRunnable() {
567 >            public void realRun() throws InterruptedException {
568 >                for (int i = 0; i < rounds; i++) {
569 >                    assertFalse(s.hasQueuedThreads());
570 >                    if (i % 2 == 0)
571 >                        acquirer.acquire(s);
572 >                    else
573 >                        acquirer.acquire(s, 3);
574 >                }}});
575 >
576 >        for (int i = 0; i < rounds; i++) {
577 >            while (! (s.availablePermits() == 0 && s.hasQueuedThreads()))
578 >                Thread.yield();
579 >            assertTrue(t.isAlive());
580 >            if (i % 2 == 0)
581 >                s.release();
582 >            else
583 >                s.release(3);
584          }
585 +        awaitTermination(t);
586 +        assertEquals(0, s.availablePermits());
587 +        assertTrue(millisElapsedSince(startTime) < LONG_DELAY_MS);
588      }
589  
590      /**
591 <     * release(n) in one thread enables acquire(n) in another thread
591 >     * fair locks are strictly FIFO
592       */
593 <    public void testAcquireReleaseNInDifferentThreads_fair() {
594 <        final Semaphore s = new Semaphore(0, true);
595 <        Thread t = new Thread(new Runnable() {
596 <                public void run() {
597 <                    try {
598 <                        s.acquire();
599 <                        s.release(2);
600 <                        s.acquire();
601 <                    } catch(InterruptedException ie){
602 <                        threadUnexpectedException();
603 <                    }
604 <                }
605 <            });
606 <        try {
607 <            t.start();
608 <            Thread.sleep(SHORT_DELAY_MS);
609 <            s.release(2);
610 <            s.acquire(2);
611 <            s.release(1);
612 <            t.join();
613 <        } catch( InterruptedException e){
614 <            unexpectedException();
615 <        }
616 <    }
617 <
618 <
619 <
620 <    /**
621 <     * release in one thread enables timed acquire in another thread
622 <     */
623 <    public void testTimedAcquireReleaseInDifferentThreads_fair() {
624 <        final Semaphore s = new Semaphore(1, true);
625 <        Thread t = new Thread(new Runnable() {
626 <                public void run() {
627 <                    try {
628 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
629 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
653 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
654 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
655 <                        threadAssertTrue(s.tryAcquire(SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
656 <
657 <                    } catch(InterruptedException ie){
658 <                        threadUnexpectedException();
659 <                    }
660 <                }
661 <            });
662 <        t.start();
663 <        try {
664 <            s.release();
665 <            s.release();
666 <            s.release();
667 <            s.release();
668 <            s.release();
669 <            t.join();
670 <        } catch( InterruptedException e){
671 <            unexpectedException();
672 <        }
593 >    public void testFairLocksFifo() {
594 >        final PublicSemaphore s = new PublicSemaphore(1, true);
595 >        final CountDownLatch pleaseRelease = new CountDownLatch(1);
596 >        Thread t1 = newStartedThread(new CheckedRunnable() {
597 >            public void realRun() throws InterruptedException {
598 >                // Will block; permits are available, but not three
599 >                s.acquire(3);
600 >            }});
601 >
602 >        waitForQueuedThread(s, t1);
603 >
604 >        Thread t2 = newStartedThread(new CheckedRunnable() {
605 >            public void realRun() throws InterruptedException {
606 >                // Will fail, even though 1 permit is available
607 >                assertFalse(
608 >                    s.tryAcquire(randomExpiredTimeout(), randomTimeUnit()));
609 >                assertFalse(
610 >                    s.tryAcquire(1, randomExpiredTimeout(), randomTimeUnit()));
611 >
612 >                // untimed tryAcquire will barge and succeed
613 >                assertTrue(s.tryAcquire());
614 >                s.release(2);
615 >                assertTrue(s.tryAcquire(2));
616 >                s.release();
617 >
618 >                pleaseRelease.countDown();
619 >                // Will queue up behind t1, even though 1 permit is available
620 >                s.acquire();
621 >            }});
622 >
623 >        await(pleaseRelease);
624 >        waitForQueuedThread(s, t2);
625 >        s.release(2);
626 >        awaitTermination(t1);
627 >        assertTrue(t2.isAlive());
628 >        s.release();
629 >        awaitTermination(t2);
630      }
631  
632      /**
633 <     * release(n) in one thread enables timed acquire(n) in another thread
634 <     */
635 <    public void testTimedAcquireReleaseNInDifferentThreads_fair() {
636 <        final Semaphore s = new Semaphore(2, true);
637 <        Thread t = new Thread(new Runnable() {
638 <                public void run() {
639 <                    try {
640 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
641 <                        s.release(2);
642 <                        threadAssertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
643 <                        s.release(2);
644 <                    } catch(InterruptedException ie){
645 <                        threadUnexpectedException();
689 <                    }
690 <                }
691 <            });
692 <        t.start();
693 <        try {
694 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
695 <            s.release(2);
696 <            assertTrue(s.tryAcquire(2, SHORT_DELAY_MS, TimeUnit.MILLISECONDS));
697 <            s.release(2);
698 <            t.join();
699 <        } catch( InterruptedException e){
700 <            unexpectedException();
701 <        }
633 >     * toString indicates current number of permits
634 >     */
635 >    public void testToString()      { testToString(false); }
636 >    public void testToString_fair() { testToString(true); }
637 >    public void testToString(boolean fair) {
638 >        PublicSemaphore s = new PublicSemaphore(0, fair);
639 >        assertTrue(s.toString().contains("Permits = 0"));
640 >        s.release();
641 >        assertTrue(s.toString().contains("Permits = 1"));
642 >        s.release(2);
643 >        assertTrue(s.toString().contains("Permits = 3"));
644 >        s.reducePermits(5);
645 >        assertTrue(s.toString().contains("Permits = -2"));
646      }
647  
704    /**
705     * A waiting acquire blocks interruptibly
706     */
707    public void testAcquire_InterruptedException_fair() {
708        final Semaphore s = new Semaphore(0, true);
709        Thread t = new Thread(new Runnable() {
710                public void run() {
711                    try {
712                        s.acquire();
713                        threadShouldThrow();
714                    } catch(InterruptedException success){}
715                }
716            });
717        t.start();
718        try {
719            Thread.sleep(SHORT_DELAY_MS);
720            t.interrupt();
721            t.join();
722        } catch(InterruptedException e){
723            unexpectedException();
724        }
725    }
726
727    /**
728     * A waiting acquire(n) blocks interruptibly
729     */
730    public void testAcquireN_InterruptedException_fair() {
731        final Semaphore s = new Semaphore(2, true);
732        Thread t = new Thread(new Runnable() {
733                public void run() {
734                    try {
735                        s.acquire(3);
736                        threadShouldThrow();
737                    } catch(InterruptedException success){}
738                }
739            });
740        t.start();
741        try {
742            Thread.sleep(SHORT_DELAY_MS);
743            t.interrupt();
744            t.join();
745        } catch(InterruptedException e){
746            unexpectedException();
747        }
748    }
749    
750    /**
751     *  A waiting tryAcquire blocks interruptibly
752     */
753    public void testTryAcquire_InterruptedException_fair() {
754        final Semaphore s = new Semaphore(0, true);
755        Thread t = new Thread(new Runnable() {
756                public void run() {
757                    try {
758                        s.tryAcquire(MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
759                        threadShouldThrow();
760                    } catch(InterruptedException success){
761                    }
762                }
763            });
764        t.start();
765        try {
766            Thread.sleep(SHORT_DELAY_MS);
767            t.interrupt();
768            t.join();
769        } catch(InterruptedException e){
770            unexpectedException();
771        }
772    }
773
774    /**
775     *  A waiting tryAcquire(n) blocks interruptibly
776     */
777    public void testTryAcquireN_InterruptedException_fair() {
778        final Semaphore s = new Semaphore(1, true);
779        Thread t = new Thread(new Runnable() {
780                public void run() {
781                    try {
782                        s.tryAcquire(4, MEDIUM_DELAY_MS, TimeUnit.MILLISECONDS);
783                        threadShouldThrow();
784                    } catch(InterruptedException success){
785                    }
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     * getQueueLength reports number of waiting threads
800     */
801    public void testGetQueueLength_fair() {
802        final Semaphore lock = new Semaphore(1, true);
803        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
804        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
805        try {
806            assertEquals(0, lock.getQueueLength());
807            lock.acquireUninterruptibly();
808            t1.start();
809            Thread.sleep(SHORT_DELAY_MS);
810            assertEquals(1, lock.getQueueLength());
811            t2.start();
812            Thread.sleep(SHORT_DELAY_MS);
813            assertEquals(2, lock.getQueueLength());
814            t1.interrupt();
815            Thread.sleep(SHORT_DELAY_MS);
816            assertEquals(1, lock.getQueueLength());
817            lock.release();
818            Thread.sleep(SHORT_DELAY_MS);
819            assertEquals(0, lock.getQueueLength());
820            t1.join();
821            t2.join();
822        } catch(Exception e){
823            unexpectedException();
824        }
825    }
826
827
828    /**
829     * a deserialized serialized semaphore has same number of permits
830     */
831    public void testSerialization_fair() {
832        Semaphore l = new Semaphore(3, true);
833
834        try {
835            l.acquire();
836            l.release();
837            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
838            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
839            out.writeObject(l);
840            out.close();
841
842            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
843            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
844            Semaphore r = (Semaphore) in.readObject();
845            assertEquals(3, r.availablePermits());
846            assertTrue(r.isFair());
847            r.acquire();
848            r.release();
849        } catch(Exception e){
850            unexpectedException();
851        }
852    }
853
854
648   }

Diff Legend

Removed lines
+ Added lines
< Changed lines
> Changed lines