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Comparing jsr166/src/test/tck/ReentrantReadWriteLockTest.java (file contents):
Revision 1.2 by dl, Sun Sep 7 20:39:11 2003 UTC vs.
Revision 1.52 by jsr166, Mon May 2 00:34:12 2011 UTC

# Line 1 | Line 1
1   /*
2 < * Written by members of JCP JSR-166 Expert Group and released to the
3 < * public domain. Use, modify, and redistribute this code in any way
4 < * without acknowledgement. Other contributors include Andrew Wright,
5 < * Jeffrey Hayes, Pat Fischer, Mike Judd.
2 > * Written by Doug Lea with assistance from members of JCP JSR-166
3 > * Expert Group and released to the public domain, as explained at
4 > * http://creativecommons.org/publicdomain/zero/1.0/
5 > * Other contributors include Andrew Wright, Jeffrey Hayes,
6 > * Pat Fisher, Mike Judd.
7   */
8  
9   import junit.framework.*;
10   import java.util.concurrent.locks.*;
11   import java.util.concurrent.*;
12 + import static java.util.concurrent.TimeUnit.MILLISECONDS;
13   import java.io.*;
14 + import java.util.*;
15  
16 < public class ReentrantReadWriteLockTest extends TestCase {
14 <    static int HOLD_COUNT_TEST_LIMIT = 20;
15 <    
16 > public class ReentrantReadWriteLockTest extends JSR166TestCase {
17      public static void main(String[] args) {
18 <        junit.textui.TestRunner.run (suite());  
18 >        junit.textui.TestRunner.run(suite());
19      }
19    
20      public static Test suite() {
21 <        return new TestSuite(ReentrantReadWriteLockTest.class);
21 >        return new TestSuite(ReentrantReadWriteLockTest.class);
22      }
23  
24 +    /**
25 +     * A runnable calling lockInterruptibly
26 +     */
27 +    class InterruptibleLockRunnable extends CheckedRunnable {
28 +        final ReentrantReadWriteLock lock;
29 +        InterruptibleLockRunnable(ReentrantReadWriteLock l) { lock = l; }
30 +        public void realRun() throws InterruptedException {
31 +            lock.writeLock().lockInterruptibly();
32 +        }
33 +    }
34  
25    private static long SHORT_DELAY_MS = 100;
26    private static long MEDIUM_DELAY_MS = 1000;
27    private static long LONG_DELAY_MS = 10000;
35  
36 <    /*
37 <     * Unlocks an unlocked lock, throws Illegal Monitor State
38 <     *
36 >    /**
37 >     * A runnable calling lockInterruptibly that expects to be
38 >     * interrupted
39       */
40 <    
41 <    public void testIllegalMonitorStateException(){
42 <        ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
43 <        try{
44 <            rl.writeLock().unlock();
45 <            fail("Should of thown Illegal Monitor State Exception");
40 >    class InterruptedLockRunnable extends CheckedInterruptedRunnable {
41 >        final ReentrantReadWriteLock lock;
42 >        InterruptedLockRunnable(ReentrantReadWriteLock l) { lock = l; }
43 >        public void realRun() throws InterruptedException {
44 >            lock.writeLock().lockInterruptibly();
45 >        }
46 >    }
47  
48 <        }catch(IllegalMonitorStateException success){}
48 >    /**
49 >     * Subclass to expose protected methods
50 >     */
51 >    static class PublicReentrantReadWriteLock extends ReentrantReadWriteLock {
52 >        PublicReentrantReadWriteLock() { super(); }
53 >        public Collection<Thread> getQueuedThreads() {
54 >            return super.getQueuedThreads();
55 >        }
56 >        public Collection<Thread> getWaitingThreads(Condition c) {
57 >            return super.getWaitingThreads(c);
58 >        }
59      }
60  
61 +    /**
62 +     * Releases lock, checking that it had a hold count of 1.
63 +     */
64 +    void releaseLock(ReentrantReadWriteLock.WriteLock lock) {
65 +        assertTrue(lock.isHeldByCurrentThread());
66 +        lock.unlock();
67 +        assertFalse(lock.isHeldByCurrentThread());
68 +    }
69  
70 +    /**
71 +     * Constructor sets given fairness, and is in unlocked state
72 +     */
73 +    public void testConstructor() {
74 +        ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
75 +        assertFalse(rl.isFair());
76 +        assertFalse(rl.isWriteLocked());
77 +        assertEquals(0, rl.getReadLockCount());
78 +        ReentrantReadWriteLock r2 = new ReentrantReadWriteLock(true);
79 +        assertTrue(r2.isFair());
80 +        assertFalse(r2.isWriteLocked());
81 +        assertEquals(0, r2.getReadLockCount());
82 +        ReentrantReadWriteLock r3 = new ReentrantReadWriteLock(false);
83 +        assertFalse(r3.isFair());
84 +        assertFalse(r3.isWriteLocked());
85 +        assertEquals(0, r3.getReadLockCount());
86 +    }
87  
88 <    public void testInterruptedException(){
89 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
90 <        lock.writeLock().lock();
91 <        Thread t = new Thread(new Runnable() {
92 <                public void run(){
93 <                    try{
94 <                        lock.writeLock().lockInterruptibly();
95 <                        fail("should throw");
96 <                    }catch(InterruptedException success){}
97 <                }
98 <            });
99 <        try {
100 <            t.start();
101 <            t.interrupt();
102 <            lock.writeLock().unlock();
103 <            t.join();
104 <        } catch(Exception e){
105 <            fail("unexpected exception");
106 <        }
107 <    }
108 <
109 <    public void testInterruptedException2(){
110 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
68 <        lock.writeLock().lock();
69 <        Thread t = new Thread(new Runnable() {
70 <                public void run(){
71 <                    try{
72 <                        lock.writeLock().tryLock(1000,TimeUnit.MILLISECONDS);
73 <                        fail("should throw");
74 <                    }catch(InterruptedException success){}
75 <                }
76 <            });
77 <        try {
78 <            t.start();
79 <            t.interrupt();
80 <            lock.writeLock().unlock();
81 <            t.join();
82 <        } catch(Exception e){
83 <            fail("unexpected exception");
84 <        }
88 >    /**
89 >     * write-locking and read-locking an unlocked lock succeed
90 >     */
91 >    public void testLock() {
92 >        ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
93 >        rl.writeLock().lock();
94 >        assertTrue(rl.isWriteLocked());
95 >        assertTrue(rl.isWriteLockedByCurrentThread());
96 >        assertTrue(rl.writeLock().isHeldByCurrentThread());
97 >        assertEquals(0, rl.getReadLockCount());
98 >        rl.writeLock().unlock();
99 >        assertFalse(rl.isWriteLocked());
100 >        assertFalse(rl.isWriteLockedByCurrentThread());
101 >        assertFalse(rl.writeLock().isHeldByCurrentThread());
102 >        assertEquals(0, rl.getReadLockCount());
103 >        rl.readLock().lock();
104 >        assertFalse(rl.isWriteLocked());
105 >        assertFalse(rl.isWriteLockedByCurrentThread());
106 >        assertEquals(1, rl.getReadLockCount());
107 >        rl.readLock().unlock();
108 >        assertFalse(rl.isWriteLocked());
109 >        assertFalse(rl.isWriteLockedByCurrentThread());
110 >        assertEquals(0, rl.getReadLockCount());
111      }
112  
113 <    public void testInterruptedException3(){
114 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
115 <        lock.writeLock().lock();
116 <        Thread t = new Thread(new Runnable() {
117 <                public void run(){
118 <                    try{
119 <                        lock.readLock().lockInterruptibly();
120 <                        fail("should throw");
121 <                    }catch(InterruptedException success){}
122 <                }
123 <            });
124 <        try {
125 <            t.start();
126 <            t.interrupt();
127 <            lock.writeLock().unlock();
128 <            t.join();
129 <        } catch(Exception e){
130 <            fail("unexpected exception");
131 <        }
132 <    }
133 <
134 <    public void testInterruptedException4(){
135 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
136 <        lock.writeLock().lock();
111 <        Thread t = new Thread(new Runnable() {
112 <                public void run(){
113 <                    try{
114 <                        lock.readLock().tryLock(1000,TimeUnit.MILLISECONDS);
115 <                        fail("should throw");
116 <                    }catch(InterruptedException success){}
117 <                }
118 <            });
119 <        try {
120 <            t.start();
121 <            t.interrupt();
122 <            t.join();
123 <        } catch(Exception e){
124 <            fail("unexpected exception");
125 <        }
113 >
114 >    /**
115 >     * locking an unlocked fair lock succeeds
116 >     */
117 >    public void testFairLock() {
118 >        ReentrantReadWriteLock rl = new ReentrantReadWriteLock(true);
119 >        rl.writeLock().lock();
120 >        assertTrue(rl.isWriteLocked());
121 >        assertTrue(rl.isWriteLockedByCurrentThread());
122 >        assertTrue(rl.writeLock().isHeldByCurrentThread());
123 >        assertEquals(0, rl.getReadLockCount());
124 >        rl.writeLock().unlock();
125 >        assertFalse(rl.isWriteLocked());
126 >        assertFalse(rl.isWriteLockedByCurrentThread());
127 >        assertFalse(rl.writeLock().isHeldByCurrentThread());
128 >        assertEquals(0, rl.getReadLockCount());
129 >        rl.readLock().lock();
130 >        assertFalse(rl.isWriteLocked());
131 >        assertFalse(rl.isWriteLockedByCurrentThread());
132 >        assertEquals(1, rl.getReadLockCount());
133 >        rl.readLock().unlock();
134 >        assertFalse(rl.isWriteLocked());
135 >        assertFalse(rl.isWriteLockedByCurrentThread());
136 >        assertEquals(0, rl.getReadLockCount());
137      }
138  
139 <    
140 <    public void testTryLockWhenLocked() {
141 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
142 <        lock.writeLock().lock();
143 <        Thread t = new Thread(new Runnable() {
144 <                public void run(){
145 <                    assertFalse(lock.writeLock().tryLock());
146 <                }
147 <            });
148 <        try {
138 <            t.start();
139 <            t.join();
139 >    /**
140 >     * getWriteHoldCount returns number of recursive holds
141 >     */
142 >    public void testGetWriteHoldCount() {
143 >        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
144 >        for (int i = 1; i <= SIZE; i++) {
145 >            lock.writeLock().lock();
146 >            assertEquals(i,lock.getWriteHoldCount());
147 >        }
148 >        for (int i = SIZE; i > 0; i--) {
149              lock.writeLock().unlock();
150 <        } catch(Exception e){
142 <            fail("unexpected exception");
150 >            assertEquals(i-1,lock.getWriteHoldCount());
151          }
152 <    }
152 >    }
153  
154 <    public void testTryLockWhenLocked2() {
155 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
156 <        lock.writeLock().lock();
157 <        Thread t = new Thread(new Runnable() {
158 <                public void run(){
159 <                    assertFalse(lock.readLock().tryLock());
160 <                }
161 <            });
162 <        try {
163 <            t.start();
156 <            t.join();
154 >    /**
155 >     * WriteLock.getHoldCount returns number of recursive holds
156 >     */
157 >    public void testGetHoldCount() {
158 >        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
159 >        for (int i = 1; i <= SIZE; i++) {
160 >            lock.writeLock().lock();
161 >            assertEquals(i,lock.writeLock().getHoldCount());
162 >        }
163 >        for (int i = SIZE; i > 0; i--) {
164              lock.writeLock().unlock();
165 <        } catch(Exception e){
159 <            fail("unexpected exception");
165 >            assertEquals(i-1,lock.writeLock().getHoldCount());
166          }
167 <    }
167 >    }
168  
169 <    public void testMultipleReadLocks() {
170 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
171 <        lock.readLock().lock();
172 <        Thread t = new Thread(new Runnable() {
173 <                public void run(){
174 <                    assertTrue(lock.readLock().tryLock());
175 <                    lock.readLock().unlock();
176 <                }
171 <            });
172 <        try {
173 <            t.start();
174 <            t.join();
175 <            lock.readLock().unlock();
176 <        } catch(Exception e){
177 <            fail("unexpected exception");
169 >    /**
170 >     * getReadHoldCount returns number of recursive holds
171 >     */
172 >    public void testGetReadHoldCount() {
173 >        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
174 >        for (int i = 1; i <= SIZE; i++) {
175 >            lock.readLock().lock();
176 >            assertEquals(i,lock.getReadHoldCount());
177          }
178 <    }
180 <
181 <    public void testWriteAfterMultipleReadLocks() {
182 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
183 <        lock.readLock().lock();
184 <        Thread t1 = new Thread(new Runnable() {
185 <                public void run(){
186 <                    lock.readLock().lock();
187 <                    lock.readLock().unlock();
188 <                }
189 <            });
190 <        Thread t2 = new Thread(new Runnable() {
191 <                public void run(){
192 <                    lock.writeLock().lock();
193 <                    lock.writeLock().unlock();
194 <                }
195 <            });
196 <
197 <        try {
198 <            t1.start();
199 <            t2.start();
200 <            Thread.sleep(SHORT_DELAY_MS);
201 <            lock.readLock().unlock();
202 <            t1.join(MEDIUM_DELAY_MS);
203 <            t2.join(MEDIUM_DELAY_MS);
204 <            assertTrue(!t1.isAlive());
205 <            assertTrue(!t2.isAlive());
206 <          
207 <        } catch(Exception e){
208 <            fail("unexpected exception");
209 <        }
210 <    }
211 <
212 <    public void testReadAfterWriteLock() {
213 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
214 <        lock.writeLock().lock();
215 <        Thread t1 = new Thread(new Runnable() {
216 <                public void run(){
217 <                    lock.readLock().lock();
218 <                    lock.readLock().unlock();
219 <                }
220 <            });
221 <        Thread t2 = new Thread(new Runnable() {
222 <                public void run(){
223 <                    lock.readLock().lock();
224 <                    lock.readLock().unlock();
225 <                }
226 <            });
227 <
228 <        try {
229 <            t1.start();
230 <            t2.start();
231 <            Thread.sleep(SHORT_DELAY_MS);
232 <            lock.writeLock().unlock();
233 <            t1.join(MEDIUM_DELAY_MS);
234 <            t2.join(MEDIUM_DELAY_MS);
235 <            assertTrue(!t1.isAlive());
236 <            assertTrue(!t2.isAlive());
237 <          
238 <        } catch(Exception e){
239 <            fail("unexpected exception");
240 <        }
241 <    }
242 <
243 <
244 <    public void testTryLockWhenReadLocked() {
245 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
246 <        lock.readLock().lock();
247 <        Thread t = new Thread(new Runnable() {
248 <                public void run(){
249 <                    assertTrue(lock.readLock().tryLock());
250 <                    lock.readLock().unlock();
251 <                }
252 <            });
253 <        try {
254 <            t.start();
255 <            t.join();
178 >        for (int i = SIZE; i > 0; i--) {
179              lock.readLock().unlock();
180 <        } catch(Exception e){
258 <            fail("unexpected exception");
180 >            assertEquals(i-1,lock.getReadHoldCount());
181          }
182 <    }
182 >    }
183  
262    
184  
185 <    public void testWriteTryLockWhenReadLocked() {
186 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
187 <        lock.readLock().lock();
188 <        Thread t = new Thread(new Runnable() {
189 <                public void run(){
269 <                    assertFalse(lock.writeLock().tryLock());
270 <                }
271 <            });
185 >    /**
186 >     * write-unlocking an unlocked lock throws IllegalMonitorStateException
187 >     */
188 >    public void testUnlock_IllegalMonitorStateException() {
189 >        ReentrantReadWriteLock rl = new ReentrantReadWriteLock();
190          try {
191 <            t.start();
192 <            t.join();
193 <            lock.readLock().unlock();
194 <        } catch(Exception e){
277 <            fail("unexpected exception");
278 <        }
279 <    }
191 >            rl.writeLock().unlock();
192 >            shouldThrow();
193 >        } catch (IllegalMonitorStateException success) {}
194 >    }
195  
281    
196  
197 <    public void testTryLock_Timeout(){
198 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
199 <        lock.writeLock().lock();
200 <        Thread t = new Thread(new Runnable() {
201 <                public void run(){
202 <                    try {
203 <                        assertFalse(lock.writeLock().tryLock(1, TimeUnit.MILLISECONDS));
204 <                    } catch (Exception ex) {
205 <                        fail("unexpected exception");
206 <                    }
207 <                }
208 <            });
209 <        try {
210 <            t.start();
211 <            t.join();
212 <            lock.writeLock().unlock();
299 <        } catch(Exception e){
300 <            fail("unexpected exception");
301 <        }
302 <    }
197 >    /**
198 >     * write-lockInterruptibly is interruptible
199 >     */
200 >    public void testWriteLockInterruptibly_Interrupted() throws Exception {
201 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
202 >        lock.writeLock().lock();
203 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
204 >            public void realRun() throws InterruptedException {
205 >                lock.writeLock().lockInterruptibly();
206 >            }});
207 >
208 >        Thread.sleep(SHORT_DELAY_MS);
209 >        t.interrupt();
210 >        t.join();
211 >        releaseLock(lock.writeLock());
212 >    }
213  
214 <    public void testTryLock_Timeout2(){
215 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
216 <        lock.writeLock().lock();
217 <        Thread t = new Thread(new Runnable() {
218 <                public void run(){
219 <                    try {
220 <                        assertFalse(lock.readLock().tryLock(1, TimeUnit.MILLISECONDS));
221 <                    } catch (Exception ex) {
222 <                        fail("unexpected exception");
223 <                    }
224 <                }
225 <            });
226 <        try {
227 <            t.start();
228 <            t.join();
229 <            lock.writeLock().unlock();
320 <        } catch(Exception e){
321 <            fail("unexpected exception");
322 <        }
323 <    }
214 >    /**
215 >     * timed write-tryLock is interruptible
216 >     */
217 >    public void testWriteTryLock_Interrupted() throws InterruptedException {
218 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
219 >        lock.writeLock().lock();
220 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
221 >            public void realRun() throws InterruptedException {
222 >                lock.writeLock().tryLock(SMALL_DELAY_MS, MILLISECONDS);
223 >            }});
224 >
225 >        Thread.sleep(SHORT_DELAY_MS);
226 >        t.interrupt();
227 >        t.join();
228 >        releaseLock(lock.writeLock());
229 >    }
230  
231 +    /**
232 +     * read-lockInterruptibly is interruptible
233 +     */
234 +    public void testReadLockInterruptibly_Interrupted() throws InterruptedException {
235 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
236 +        lock.writeLock().lock();
237 +        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
238 +            public void realRun() throws InterruptedException {
239 +                lock.readLock().lockInterruptibly();
240 +            }});
241 +
242 +        Thread.sleep(SHORT_DELAY_MS);
243 +        t.interrupt();
244 +        t.join();
245 +        releaseLock(lock.writeLock());
246 +    }
247  
248 <    public void testLockInterruptibly() {
249 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
250 <        try {
251 <            lock.writeLock().lockInterruptibly();
252 <        } catch(Exception e) {
253 <            fail("unexpected exception");
254 <        }
255 <        Thread t = new Thread(new Runnable() {
256 <                public void run() {
257 <                    try {
258 <                        lock.writeLock().lockInterruptibly();
259 <                        fail("should throw");
260 <                    }
261 <                    catch(InterruptedException success) {
262 <                    }
341 <                }
342 <            });
343 <        try {
344 <            t.start();
345 <            t.interrupt();
346 <            t.join();
347 <            lock.writeLock().unlock();
348 <        } catch(Exception e){
349 <            fail("unexpected exception");
350 <        }
248 >    /**
249 >     * timed read-tryLock is interruptible
250 >     */
251 >    public void testReadTryLock_Interrupted() throws InterruptedException {
252 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
253 >        lock.writeLock().lock();
254 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
255 >            public void realRun() throws InterruptedException {
256 >                lock.readLock().tryLock(LONG_DELAY_MS, MILLISECONDS);
257 >            }});
258 >
259 >        Thread.sleep(SHORT_DELAY_MS);
260 >        t.interrupt();
261 >        t.join();
262 >        releaseLock(lock.writeLock());
263      }
264  
265 <    public void testLockInterruptibly2() {
266 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
267 <        try {
268 <            lock.writeLock().lockInterruptibly();
269 <        } catch(Exception e) {
270 <            fail("unexpected exception");
271 <        }
272 <        Thread t = new Thread(new Runnable() {
273 <                public void run() {
274 <                    try {
275 <                        lock.readLock().lockInterruptibly();
276 <                        fail("should throw");
277 <                    }
278 <                    catch(InterruptedException success) {
279 <                    }
280 <                }
281 <            });
282 <        try {
283 <            t.start();
284 <            t.interrupt();
285 <            t.join();
286 <            lock.writeLock().unlock();
287 <        } catch(Exception e){
288 <            fail("unexpected exception");
289 <        }
265 >
266 >    /**
267 >     * write-tryLock fails if locked
268 >     */
269 >    public void testWriteTryLockWhenLocked() throws InterruptedException {
270 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
271 >        lock.writeLock().lock();
272 >        Thread t = newStartedThread(new CheckedRunnable() {
273 >            public void realRun() {
274 >                assertFalse(lock.writeLock().tryLock());
275 >            }});
276 >
277 >        t.join();
278 >        lock.writeLock().unlock();
279 >    }
280 >
281 >    /**
282 >     * read-tryLock fails if locked
283 >     */
284 >    public void testReadTryLockWhenLocked() throws InterruptedException {
285 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
286 >        lock.writeLock().lock();
287 >        Thread t = newStartedThread(new CheckedRunnable() {
288 >            public void realRun() {
289 >                assertFalse(lock.readLock().tryLock());
290 >            }});
291 >
292 >        t.join();
293 >        lock.writeLock().unlock();
294 >    }
295 >
296 >    /**
297 >     * Multiple threads can hold a read lock when not write-locked
298 >     */
299 >    public void testMultipleReadLocks() throws InterruptedException {
300 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
301 >        lock.readLock().lock();
302 >        Thread t = newStartedThread(new CheckedRunnable() {
303 >            public void realRun() {
304 >                assertTrue(lock.readLock().tryLock());
305 >                lock.readLock().unlock();
306 >            }});
307 >
308 >        t.join();
309 >        lock.readLock().unlock();
310 >    }
311 >
312 >    /**
313 >     * A writelock succeeds after reading threads unlock
314 >     */
315 >    public void testWriteAfterMultipleReadLocks() throws InterruptedException {
316 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
317 >        lock.readLock().lock();
318 >        Thread t1 = newStartedThread(new CheckedRunnable() {
319 >            public void realRun() {
320 >                lock.readLock().lock();
321 >                lock.readLock().unlock();
322 >            }});
323 >        Thread t2 = newStartedThread(new CheckedRunnable() {
324 >            public void realRun() {
325 >                lock.writeLock().lock();
326 >                lock.writeLock().unlock();
327 >            }});
328 >
329 >        Thread.sleep(SHORT_DELAY_MS);
330 >        lock.readLock().unlock();
331 >        t1.join(MEDIUM_DELAY_MS);
332 >        t2.join(MEDIUM_DELAY_MS);
333 >        assertTrue(!t1.isAlive());
334 >        assertTrue(!t2.isAlive());
335 >    }
336 >
337 >    /**
338 >     * Readlocks succeed after a writing thread unlocks
339 >     */
340 >    public void testReadAfterWriteLock() throws InterruptedException {
341 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
342 >        lock.writeLock().lock();
343 >        Thread t1 = newStartedThread(new CheckedRunnable() {
344 >            public void realRun() {
345 >                lock.readLock().lock();
346 >                lock.readLock().unlock();
347 >            }});
348 >        Thread t2 = newStartedThread(new CheckedRunnable() {
349 >            public void realRun() {
350 >                lock.readLock().lock();
351 >                lock.readLock().unlock();
352 >            }});
353 >
354 >        Thread.sleep(SHORT_DELAY_MS);
355 >        lock.writeLock().unlock();
356 >        t1.join(MEDIUM_DELAY_MS);
357 >        t2.join(MEDIUM_DELAY_MS);
358 >        assertTrue(!t1.isAlive());
359 >        assertTrue(!t2.isAlive());
360 >    }
361 >
362 >    /**
363 >     * Read trylock succeeds if write locked by current thread
364 >     */
365 >    public void testReadHoldingWriteLock() {
366 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
367 >        lock.writeLock().lock();
368 >        assertTrue(lock.readLock().tryLock());
369 >        lock.readLock().unlock();
370 >        lock.writeLock().unlock();
371 >    }
372 >
373 >    /**
374 >     * Read lock succeeds if write locked by current thread even if
375 >     * other threads are waiting for readlock
376 >     */
377 >    public void testReadHoldingWriteLock2() throws InterruptedException {
378 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
379 >        lock.writeLock().lock();
380 >        Thread t1 = newStartedThread(new CheckedRunnable() {
381 >            public void realRun() {
382 >                lock.readLock().lock();
383 >                lock.readLock().unlock();
384 >            }});
385 >        Thread t2 = newStartedThread(new CheckedRunnable() {
386 >            public void realRun() {
387 >                lock.readLock().lock();
388 >                lock.readLock().unlock();
389 >            }});
390 >
391 >        lock.readLock().lock();
392 >        lock.readLock().unlock();
393 >        Thread.sleep(SHORT_DELAY_MS);
394 >        lock.readLock().lock();
395 >        lock.readLock().unlock();
396 >        lock.writeLock().unlock();
397 >        t1.join(MEDIUM_DELAY_MS);
398 >        t2.join(MEDIUM_DELAY_MS);
399 >        assertTrue(!t1.isAlive());
400 >        assertTrue(!t2.isAlive());
401 >    }
402 >
403 >    /**
404 >     * Read lock succeeds if write locked by current thread even if
405 >     * other threads are waiting for writelock
406 >     */
407 >    public void testReadHoldingWriteLock3() throws InterruptedException {
408 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
409 >        lock.writeLock().lock();
410 >        Thread t1 = newStartedThread(new CheckedRunnable() {
411 >            public void realRun() {
412 >                lock.writeLock().lock();
413 >                lock.writeLock().unlock();
414 >            }});
415 >        Thread t2 = newStartedThread(new CheckedRunnable() {
416 >            public void realRun() {
417 >                lock.writeLock().lock();
418 >                lock.writeLock().unlock();
419 >            }});
420 >
421 >        lock.readLock().lock();
422 >        lock.readLock().unlock();
423 >        Thread.sleep(SHORT_DELAY_MS);
424 >        lock.readLock().lock();
425 >        lock.readLock().unlock();
426 >        lock.writeLock().unlock();
427 >        t1.join(MEDIUM_DELAY_MS);
428 >        t2.join(MEDIUM_DELAY_MS);
429 >        assertTrue(!t1.isAlive());
430 >        assertTrue(!t2.isAlive());
431 >    }
432 >
433 >
434 >    /**
435 >     * Write lock succeeds if write locked by current thread even if
436 >     * other threads are waiting for writelock
437 >     */
438 >    public void testWriteHoldingWriteLock4() throws InterruptedException {
439 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
440 >        lock.writeLock().lock();
441 >        Thread t1 = newStartedThread(new CheckedRunnable() {
442 >            public void realRun() {
443 >                lock.writeLock().lock();
444 >                lock.writeLock().unlock();
445 >            }});
446 >        Thread t2 = newStartedThread(new CheckedRunnable() {
447 >            public void realRun() {
448 >                lock.writeLock().lock();
449 >                lock.writeLock().unlock();
450 >            }});
451 >
452 >        lock.writeLock().lock();
453 >        lock.writeLock().unlock();
454 >        Thread.sleep(SHORT_DELAY_MS);
455 >        lock.writeLock().lock();
456 >        lock.writeLock().unlock();
457 >        lock.writeLock().unlock();
458 >        t1.join(MEDIUM_DELAY_MS);
459 >        t2.join(MEDIUM_DELAY_MS);
460 >        assertTrue(!t1.isAlive());
461 >        assertTrue(!t2.isAlive());
462 >    }
463 >
464 >
465 >    /**
466 >     * Fair Read trylock succeeds if write locked by current thread
467 >     */
468 >    public void testReadHoldingWriteLockFair() {
469 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
470 >        lock.writeLock().lock();
471 >        assertTrue(lock.readLock().tryLock());
472 >        lock.readLock().unlock();
473 >        lock.writeLock().unlock();
474 >    }
475 >
476 >    /**
477 >     * Fair Read lock succeeds if write locked by current thread even if
478 >     * other threads are waiting for readlock
479 >     */
480 >    public void testReadHoldingWriteLockFair2() throws InterruptedException {
481 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
482 >        lock.writeLock().lock();
483 >        Thread t1 = newStartedThread(new CheckedRunnable() {
484 >            public void realRun() {
485 >                lock.readLock().lock();
486 >                lock.readLock().unlock();
487 >            }});
488 >        Thread t2 = newStartedThread(new CheckedRunnable() {
489 >            public void realRun() {
490 >                lock.readLock().lock();
491 >                lock.readLock().unlock();
492 >            }});
493 >
494 >        lock.readLock().lock();
495 >        lock.readLock().unlock();
496 >        Thread.sleep(SHORT_DELAY_MS);
497 >        lock.readLock().lock();
498 >        lock.readLock().unlock();
499 >        lock.writeLock().unlock();
500 >        t1.join(MEDIUM_DELAY_MS);
501 >        t2.join(MEDIUM_DELAY_MS);
502 >        assertTrue(!t1.isAlive());
503 >        assertTrue(!t2.isAlive());
504 >    }
505 >
506 >
507 >    /**
508 >     * Fair Read lock succeeds if write locked by current thread even if
509 >     * other threads are waiting for writelock
510 >     */
511 >    public void testReadHoldingWriteLockFair3() throws InterruptedException {
512 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
513 >        lock.writeLock().lock();
514 >        Thread t1 = newStartedThread(new CheckedRunnable() {
515 >            public void realRun() {
516 >                lock.writeLock().lock();
517 >                lock.writeLock().unlock();
518 >            }});
519 >        Thread t2 = newStartedThread(new CheckedRunnable() {
520 >            public void realRun() {
521 >                lock.writeLock().lock();
522 >                lock.writeLock().unlock();
523 >            }});
524 >
525 >        lock.readLock().lock();
526 >        lock.readLock().unlock();
527 >        Thread.sleep(SHORT_DELAY_MS);
528 >        lock.readLock().lock();
529 >        lock.readLock().unlock();
530 >        lock.writeLock().unlock();
531 >        t1.join(MEDIUM_DELAY_MS);
532 >        t2.join(MEDIUM_DELAY_MS);
533 >        assertTrue(!t1.isAlive());
534 >        assertTrue(!t2.isAlive());
535 >    }
536 >
537 >
538 >    /**
539 >     * Fair Write lock succeeds if write locked by current thread even if
540 >     * other threads are waiting for writelock
541 >     */
542 >    public void testWriteHoldingWriteLockFair4() throws InterruptedException {
543 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
544 >        lock.writeLock().lock();
545 >        Thread t1 = newStartedThread(new CheckedRunnable() {
546 >            public void realRun() {
547 >                lock.writeLock().lock();
548 >                lock.writeLock().unlock();
549 >            }});
550 >        Thread t2 = newStartedThread(new CheckedRunnable() {
551 >            public void realRun() {
552 >                lock.writeLock().lock();
553 >                lock.writeLock().unlock();
554 >            }});
555 >
556 >        Thread.sleep(SHORT_DELAY_MS);
557 >        assertTrue(lock.isWriteLockedByCurrentThread());
558 >        assertEquals(1, lock.getWriteHoldCount());
559 >        lock.writeLock().lock();
560 >        assertEquals(2, lock.getWriteHoldCount());
561 >        lock.writeLock().unlock();
562 >        lock.writeLock().lock();
563 >        lock.writeLock().unlock();
564 >        lock.writeLock().unlock();
565 >        t1.join(MEDIUM_DELAY_MS);
566 >        t2.join(MEDIUM_DELAY_MS);
567 >        assertTrue(!t1.isAlive());
568 >        assertTrue(!t2.isAlive());
569 >    }
570 >
571 >
572 >    /**
573 >     * Read tryLock succeeds if readlocked but not writelocked
574 >     */
575 >    public void testTryLockWhenReadLocked() throws InterruptedException {
576 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
577 >        lock.readLock().lock();
578 >        Thread t = newStartedThread(new CheckedRunnable() {
579 >            public void realRun() {
580 >                assertTrue(lock.readLock().tryLock());
581 >                lock.readLock().unlock();
582 >            }});
583 >
584 >        t.join();
585 >        lock.readLock().unlock();
586 >    }
587 >
588 >    /**
589 >     * write tryLock fails when readlocked
590 >     */
591 >    public void testWriteTryLockWhenReadLocked() throws InterruptedException {
592 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
593 >        lock.readLock().lock();
594 >        Thread t = newStartedThread(new CheckedRunnable() {
595 >            public void realRun() {
596 >                assertFalse(lock.writeLock().tryLock());
597 >            }});
598 >
599 >        t.join();
600 >        lock.readLock().unlock();
601 >    }
602 >
603 >
604 >    /**
605 >     * Fair Read tryLock succeeds if readlocked but not writelocked
606 >     */
607 >    public void testTryLockWhenReadLockedFair() throws InterruptedException {
608 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
609 >        lock.readLock().lock();
610 >        Thread t = newStartedThread(new CheckedRunnable() {
611 >            public void realRun() {
612 >                assertTrue(lock.readLock().tryLock());
613 >                lock.readLock().unlock();
614 >            }});
615 >
616 >        t.join();
617 >        lock.readLock().unlock();
618 >    }
619 >
620 >
621 >
622 >    /**
623 >     * Fair write tryLock fails when readlocked
624 >     */
625 >    public void testWriteTryLockWhenReadLockedFair() throws InterruptedException {
626 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true);
627 >        lock.readLock().lock();
628 >        Thread t = newStartedThread(new CheckedRunnable() {
629 >            public void realRun() {
630 >                assertFalse(lock.writeLock().tryLock());
631 >            }});
632 >
633 >        t.join();
634 >        lock.readLock().unlock();
635 >    }
636 >
637 >
638 >
639 >    /**
640 >     * write timed tryLock times out if locked
641 >     */
642 >    public void testWriteTryLock_Timeout() throws InterruptedException {
643 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
644 >        lock.writeLock().lock();
645 >        Thread t = newStartedThread(new CheckedRunnable() {
646 >            public void realRun() throws InterruptedException {
647 >                assertFalse(lock.writeLock().tryLock(1, MILLISECONDS));
648 >            }});
649 >
650 >        t.join();
651 >        assertTrue(lock.writeLock().isHeldByCurrentThread());
652 >        lock.writeLock().unlock();
653 >    }
654 >
655 >    /**
656 >     * read timed tryLock times out if write-locked
657 >     */
658 >    public void testReadTryLock_Timeout() throws InterruptedException {
659 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
660 >        lock.writeLock().lock();
661 >        Thread t = newStartedThread(new CheckedRunnable() {
662 >            public void realRun() throws InterruptedException {
663 >                assertFalse(lock.readLock().tryLock(1, MILLISECONDS));
664 >            }});
665 >
666 >        t.join();
667 >        assertTrue(lock.writeLock().isHeldByCurrentThread());
668 >        lock.writeLock().unlock();
669 >    }
670 >
671 >
672 >    /**
673 >     * write lockInterruptibly succeeds if lock free else is interruptible
674 >     */
675 >    public void testWriteLockInterruptibly() throws InterruptedException {
676 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
677 >        lock.writeLock().lockInterruptibly();
678 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
679 >            public void realRun() throws InterruptedException {
680 >                lock.writeLock().lockInterruptibly();
681 >            }});
682 >
683 >        Thread.sleep(SHORT_DELAY_MS);
684 >        t.interrupt();
685 >        t.join();
686 >        releaseLock(lock.writeLock());
687 >    }
688 >
689 >    /**
690 >     * read lockInterruptibly succeeds if lock free else is interruptible
691 >     */
692 >    public void testReadLockInterruptibly() throws InterruptedException {
693 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
694 >        lock.writeLock().lockInterruptibly();
695 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
696 >            public void realRun() throws InterruptedException {
697 >                lock.readLock().lockInterruptibly();
698 >            }});
699 >
700 >        Thread.sleep(SHORT_DELAY_MS);
701 >        t.interrupt();
702 >        t.join();
703 >        releaseLock(lock.writeLock());
704      }
705  
706 <    public void testAwait_IllegalMonitor() {
707 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
706 >    /**
707 >     * Calling await without holding lock throws IllegalMonitorStateException
708 >     */
709 >    public void testAwait_IllegalMonitor() throws InterruptedException {
710 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
711          final Condition c = lock.writeLock().newCondition();
712          try {
713              c.await();
714 <            fail("should throw");
715 <        }
387 <        catch (IllegalMonitorStateException success) {
388 <        }
389 <        catch (Exception ex) {
390 <            fail("should throw IMSE");
391 <        }
714 >            shouldThrow();
715 >        } catch (IllegalMonitorStateException success) {}
716      }
717  
718 +    /**
719 +     * Calling signal without holding lock throws IllegalMonitorStateException
720 +     */
721      public void testSignal_IllegalMonitor() {
722 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
722 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
723          final Condition c = lock.writeLock().newCondition();
724          try {
725              c.signal();
726 <            fail("should throw");
727 <        }
401 <        catch (IllegalMonitorStateException success) {
402 <        }
403 <        catch (Exception ex) {
404 <            fail("should throw IMSE");
405 <        }
726 >            shouldThrow();
727 >        } catch (IllegalMonitorStateException success) {}
728      }
729  
730 <    public void testAwaitNanos_Timeout() {
731 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
730 >    /**
731 >     * awaitNanos without a signal times out
732 >     */
733 >    public void testAwaitNanos_Timeout() throws InterruptedException {
734 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
735          final Condition c = lock.writeLock().newCondition();
736 <        try {
737 <            lock.writeLock().lock();
738 <            long t = c.awaitNanos(100);
739 <            assertTrue(t <= 0);
740 <            lock.writeLock().unlock();
416 <        }
417 <        catch (Exception ex) {
418 <            fail("unexpected exception");
419 <        }
736 >
737 >        lock.writeLock().lock();
738 >        long t = c.awaitNanos(100);
739 >        assertTrue(t <= 0);
740 >        lock.writeLock().unlock();
741      }
742  
743 <    public void testAwait_Timeout() {
744 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
743 >
744 >    /**
745 >     * timed await without a signal times out
746 >     */
747 >    public void testAwait_Timeout() throws InterruptedException {
748 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
749          final Condition c = lock.writeLock().newCondition();
750 <        try {
751 <            lock.writeLock().lock();
752 <            assertFalse(c.await(10, TimeUnit.MILLISECONDS));
428 <            lock.writeLock().unlock();
429 <        }
430 <        catch (Exception ex) {
431 <            fail("unexpected exception");
432 <        }
750 >        lock.writeLock().lock();
751 >        assertFalse(c.await(SHORT_DELAY_MS, MILLISECONDS));
752 >        lock.writeLock().unlock();
753      }
754  
755 <    public void testAwaitUntil_Timeout() {
756 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
755 >    /**
756 >     * awaitUntil without a signal times out
757 >     */
758 >    public void testAwaitUntil_Timeout() throws InterruptedException {
759 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
760          final Condition c = lock.writeLock().newCondition();
761 <        try {
762 <            lock.writeLock().lock();
763 <            java.util.Date d = new java.util.Date();
764 <            assertFalse(c.awaitUntil(new java.util.Date(d.getTime() + 10)));
442 <            lock.writeLock().unlock();
443 <        }
444 <        catch (Exception ex) {
445 <            fail("unexpected exception");
446 <        }
761 >        lock.writeLock().lock();
762 >        java.util.Date d = new java.util.Date();
763 >        assertFalse(c.awaitUntil(new java.util.Date(d.getTime() + 10)));
764 >        lock.writeLock().unlock();
765      }
766  
767 <    public void testAwait() {
768 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
767 >    /**
768 >     * await returns when signalled
769 >     */
770 >    public void testAwait() throws InterruptedException {
771 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
772          final Condition c = lock.writeLock().newCondition();
773 <        Thread t = new Thread(new Runnable() {
774 <                public void run() {
775 <                    try {
776 <                        lock.writeLock().lock();
777 <                        c.await();
778 <                        lock.writeLock().unlock();
779 <                    }
780 <                    catch(InterruptedException e) {
781 <                        fail("unexpected exception");
782 <                    }
783 <                }
784 <            });
773 >        Thread t = newStartedThread(new CheckedRunnable() {
774 >            public void realRun() throws InterruptedException {
775 >                lock.writeLock().lock();
776 >                c.await();
777 >                lock.writeLock().unlock();
778 >            }});
779 >
780 >        Thread.sleep(SHORT_DELAY_MS);
781 >        lock.writeLock().lock();
782 >        c.signal();
783 >        lock.writeLock().unlock();
784 >        t.join(SHORT_DELAY_MS);
785 >        assertFalse(t.isAlive());
786 >    }
787  
788 <        try {
789 <            t.start();
790 <            Thread.sleep(SHORT_DELAY_MS);
791 <            lock.writeLock().lock();
792 <            c.signal();
793 <            lock.writeLock().unlock();
794 <            t.join(SHORT_DELAY_MS);
795 <            assertFalse(t.isAlive());
796 <        }
797 <        catch (Exception ex) {
798 <            fail("unexpected exception");
788 >    /** A helper class for uninterruptible wait tests */
789 >    class UninterruptableThread extends Thread {
790 >        private Lock lock;
791 >        private Condition c;
792 >
793 >        public volatile boolean canAwake = false;
794 >        public volatile boolean interrupted = false;
795 >        public volatile boolean lockStarted = false;
796 >
797 >        public UninterruptableThread(Lock lock, Condition c) {
798 >            this.lock = lock;
799 >            this.c = c;
800 >        }
801 >
802 >        public synchronized void run() {
803 >            lock.lock();
804 >            lockStarted = true;
805 >
806 >            while (!canAwake) {
807 >                c.awaitUninterruptibly();
808 >            }
809 >
810 >            interrupted = isInterrupted();
811 >            lock.unlock();
812          }
813      }
814  
815 <    public void testAwaitUninterruptibly() {
816 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
815 >    /**
816 >     * awaitUninterruptibly doesn't abort on interrupt
817 >     */
818 >    public void testAwaitUninterruptibly() throws InterruptedException {
819 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
820          final Condition c = lock.writeLock().newCondition();
821 <        Thread t = new Thread(new Runnable() {
822 <                public void run() {
823 <                    lock.writeLock().lock();
485 <                    c.awaitUninterruptibly();
486 <                    lock.writeLock().unlock();
487 <                }
488 <            });
821 >        UninterruptableThread thread = new UninterruptableThread(lock.writeLock(), c);
822 >
823 >        thread.start();
824  
825 +        while (!thread.lockStarted) {
826 +            Thread.sleep(100);
827 +        }
828 +
829 +        lock.writeLock().lock();
830          try {
831 <            t.start();
832 <            Thread.sleep(SHORT_DELAY_MS);
493 <            t.interrupt();
494 <            lock.writeLock().lock();
831 >            thread.interrupt();
832 >            thread.canAwake = true;
833              c.signal();
834 +        } finally {
835              lock.writeLock().unlock();
497            t.join(SHORT_DELAY_MS);
498            assertFalse(t.isAlive());
499        }
500        catch (Exception ex) {
501            fail("unexpected exception");
836          }
837 +
838 +        thread.join();
839 +        assertTrue(thread.interrupted);
840 +        assertFalse(thread.isAlive());
841      }
842  
843 <    public void testAwait_Interrupt() {
844 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
845 <        final Condition c = lock.writeLock().newCondition();
846 <        Thread t = new Thread(new Runnable() {
847 <                public void run() {
848 <                    try {
849 <                        lock.writeLock().lock();
850 <                        c.await();
851 <                        lock.writeLock().unlock();
852 <                        fail("should throw");
853 <                    }
854 <                    catch(InterruptedException success) {
855 <                    }
856 <                }
857 <            });
858 <
859 <        try {
860 <            t.start();
861 <            Thread.sleep(SHORT_DELAY_MS);
862 <            t.interrupt();
863 <            t.join(SHORT_DELAY_MS);
864 <            assertFalse(t.isAlive());
527 <        }
528 <        catch (Exception ex) {
529 <            fail("unexpected exception");
530 <        }
531 <    }
532 <
533 <    public void testAwaitNanos_Interrupt() {
534 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
535 <        final Condition c = lock.writeLock().newCondition();
536 <        Thread t = new Thread(new Runnable() {
537 <                public void run() {
538 <                    try {
539 <                        lock.writeLock().lock();
540 <                        c.awaitNanos(SHORT_DELAY_MS * 2 * 1000000);
541 <                        lock.writeLock().unlock();
542 <                        fail("should throw");
543 <                    }
544 <                    catch(InterruptedException success) {
545 <                    }
546 <                }
547 <            });
548 <
549 <        try {
550 <            t.start();
551 <            Thread.sleep(SHORT_DELAY_MS);
552 <            t.interrupt();
553 <            t.join(SHORT_DELAY_MS);
554 <            assertFalse(t.isAlive());
555 <        }
556 <        catch (Exception ex) {
557 <            fail("unexpected exception");
558 <        }
559 <    }
560 <
561 <    public void testAwaitUntil_Interrupt() {
562 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
563 <        final Condition c = lock.writeLock().newCondition();
564 <        Thread t = new Thread(new Runnable() {
565 <                public void run() {
566 <                    try {
567 <                        lock.writeLock().lock();
568 <                        java.util.Date d = new java.util.Date();
569 <                        c.awaitUntil(new java.util.Date(d.getTime() + 10000));
570 <                        lock.writeLock().unlock();
571 <                        fail("should throw");
572 <                    }
573 <                    catch(InterruptedException success) {
574 <                    }
575 <                }
576 <            });
577 <
578 <        try {
579 <            t.start();
580 <            Thread.sleep(SHORT_DELAY_MS);
581 <            t.interrupt();
582 <            t.join(SHORT_DELAY_MS);
583 <            assertFalse(t.isAlive());
584 <        }
585 <        catch (Exception ex) {
586 <            fail("unexpected exception");
587 <        }
588 <    }
589 <
590 <    public void testSignalAll() {
591 <        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();      
592 <        final Condition c = lock.writeLock().newCondition();
593 <        Thread t1 = new Thread(new Runnable() {
594 <                public void run() {
595 <                    try {
596 <                        lock.writeLock().lock();
597 <                        c.await();
598 <                        lock.writeLock().unlock();
599 <                    }
600 <                    catch(InterruptedException e) {
601 <                        fail("unexpected exception");
602 <                    }
603 <                }
604 <            });
605 <
606 <        Thread t2 = new Thread(new Runnable() {
607 <                public void run() {
608 <                    try {
609 <                        lock.writeLock().lock();
610 <                        c.await();
611 <                        lock.writeLock().unlock();
612 <                    }
613 <                    catch(InterruptedException e) {
614 <                        fail("unexpected exception");
615 <                    }
616 <                }
617 <            });
618 <
619 <        try {
620 <            t1.start();
621 <            t2.start();
622 <            Thread.sleep(SHORT_DELAY_MS);
623 <            lock.writeLock().lock();
624 <            c.signalAll();
625 <            lock.writeLock().unlock();
626 <            t1.join(SHORT_DELAY_MS);
627 <            t2.join(SHORT_DELAY_MS);
628 <            assertFalse(t1.isAlive());
629 <            assertFalse(t2.isAlive());
630 <        }
631 <        catch (Exception ex) {
632 <            fail("unexpected exception");
633 <        }
843 >    /**
844 >     * await is interruptible
845 >     */
846 >    public void testAwait_Interrupt() throws InterruptedException {
847 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
848 >        final Condition c = lock.writeLock().newCondition();
849 >        final CountDownLatch locked = new CountDownLatch(1);
850 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
851 >            public void realRun() throws InterruptedException {
852 >                lock.writeLock().lock();
853 >                assertTrue(lock.isWriteLocked());
854 >                locked.countDown();
855 >                try { c.await(); }
856 >                finally { lock.writeLock().unlock(); }
857 >            }});
858 >
859 >        locked.await();
860 >        while (lock.isWriteLocked())
861 >            Thread.yield();
862 >        t.interrupt();
863 >        awaitTermination(t, LONG_DELAY_MS);
864 >        assertFalse(lock.isWriteLocked());
865      }
866  
867 <    public void testSerialization() {
867 >    /**
868 >     * awaitNanos is interruptible
869 >     */
870 >    public void testAwaitNanos_Interrupt() throws InterruptedException {
871 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
872 >        final Condition c = lock.writeLock().newCondition();
873 >        final CountDownLatch locked = new CountDownLatch(1);
874 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
875 >            public void realRun() throws InterruptedException {
876 >                lock.writeLock().lock();
877 >                assertTrue(lock.isWriteLocked());
878 >                locked.countDown();
879 >                try { c.awaitNanos(MILLISECONDS.toNanos(LONG_DELAY_MS)); }
880 >                finally { lock.writeLock().unlock(); }
881 >            }});
882 >
883 >        locked.await();
884 >        while (lock.isWriteLocked())
885 >            Thread.yield();
886 >        t.interrupt();
887 >        awaitTermination(t, LONG_DELAY_MS);
888 >        assertFalse(lock.isWriteLocked());
889 >    }
890 >
891 >    /**
892 >     * awaitUntil is interruptible
893 >     */
894 >    public void testAwaitUntil_Interrupt() throws InterruptedException {
895 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
896 >        final Condition c = lock.writeLock().newCondition();
897 >        final CountDownLatch locked = new CountDownLatch(1);
898 >        Thread t = newStartedThread(new CheckedInterruptedRunnable() {
899 >            public void realRun() throws InterruptedException {
900 >                lock.writeLock().lock();
901 >                assertTrue(lock.isWriteLocked());
902 >                locked.countDown();
903 >                java.util.Date d = new java.util.Date();
904 >                try { c.awaitUntil(new java.util.Date(d.getTime() + 10000)); }
905 >                finally { lock.writeLock().unlock(); }
906 >            }});
907 >
908 >        locked.await();
909 >        while (lock.isWriteLocked())
910 >            Thread.yield();
911 >        t.interrupt();
912 >        awaitTermination(t, LONG_DELAY_MS);
913 >        assertFalse(lock.isWriteLocked());
914 >    }
915 >
916 >    /**
917 >     * signalAll wakes up all threads
918 >     */
919 >    public void testSignalAll() throws InterruptedException {
920 >        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
921 >        final Condition c = lock.writeLock().newCondition();
922 >        Thread t1 = newStartedThread(new CheckedRunnable() {
923 >            public void realRun() throws InterruptedException {
924 >                lock.writeLock().lock();
925 >                c.await();
926 >                lock.writeLock().unlock();
927 >            }});
928 >
929 >        Thread t2 = newStartedThread(new CheckedRunnable() {
930 >            public void realRun() throws InterruptedException {
931 >                lock.writeLock().lock();
932 >                c.await();
933 >                lock.writeLock().unlock();
934 >            }});
935 >
936 >        Thread.sleep(SHORT_DELAY_MS);
937 >        lock.writeLock().lock();
938 >        c.signalAll();
939 >        lock.writeLock().unlock();
940 >        t1.join(SHORT_DELAY_MS);
941 >        t2.join(SHORT_DELAY_MS);
942 >        assertFalse(t1.isAlive());
943 >        assertFalse(t2.isAlive());
944 >    }
945 >
946 >    /**
947 >     * A serialized lock deserializes as unlocked
948 >     */
949 >    public void testSerialization() throws Exception {
950          ReentrantReadWriteLock l = new ReentrantReadWriteLock();
951          l.readLock().lock();
952          l.readLock().unlock();
953  
954 +        ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
955 +        ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
956 +        out.writeObject(l);
957 +        out.close();
958 +
959 +        ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
960 +        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
961 +        ReentrantReadWriteLock r = (ReentrantReadWriteLock) in.readObject();
962 +        r.readLock().lock();
963 +        r.readLock().unlock();
964 +    }
965 +
966 +    /**
967 +     * hasQueuedThreads reports whether there are waiting threads
968 +     */
969 +    public void testhasQueuedThreads() throws InterruptedException {
970 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
971 +        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
972 +        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
973 +        assertFalse(lock.hasQueuedThreads());
974 +        lock.writeLock().lock();
975 +        t1.start();
976 +        Thread.sleep(SHORT_DELAY_MS);
977 +        assertTrue(lock.hasQueuedThreads());
978 +        t2.start();
979 +        Thread.sleep(SHORT_DELAY_MS);
980 +        assertTrue(lock.hasQueuedThreads());
981 +        t1.interrupt();
982 +        Thread.sleep(SHORT_DELAY_MS);
983 +        assertTrue(lock.hasQueuedThreads());
984 +        lock.writeLock().unlock();
985 +        Thread.sleep(SHORT_DELAY_MS);
986 +        assertFalse(lock.hasQueuedThreads());
987 +        t1.join();
988 +        t2.join();
989 +    }
990 +
991 +    /**
992 +     * hasQueuedThread(null) throws NPE
993 +     */
994 +    public void testHasQueuedThreadNPE() {
995 +        final ReentrantReadWriteLock sync = new ReentrantReadWriteLock();
996          try {
997 <            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
998 <            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
999 <            out.writeObject(l);
645 <            out.close();
646 <
647 <            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
648 <            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
649 <            ReentrantReadWriteLock r = (ReentrantReadWriteLock) in.readObject();
650 <            r.readLock().lock();
651 <            r.readLock().unlock();
652 <        } catch(Exception e){
653 <            e.printStackTrace();
654 <            fail("unexpected exception");
655 <        }
997 >            sync.hasQueuedThread(null);
998 >            shouldThrow();
999 >        } catch (NullPointerException success) {}
1000      }
1001  
1002 +    /**
1003 +     * hasQueuedThread reports whether a thread is queued.
1004 +     */
1005 +    public void testHasQueuedThread() throws InterruptedException {
1006 +        final ReentrantReadWriteLock sync = new ReentrantReadWriteLock();
1007 +        Thread t1 = new Thread(new InterruptedLockRunnable(sync));
1008 +        Thread t2 = new Thread(new InterruptibleLockRunnable(sync));
1009 +        assertFalse(sync.hasQueuedThread(t1));
1010 +        assertFalse(sync.hasQueuedThread(t2));
1011 +        sync.writeLock().lock();
1012 +        t1.start();
1013 +        Thread.sleep(SHORT_DELAY_MS);
1014 +        assertTrue(sync.hasQueuedThread(t1));
1015 +        t2.start();
1016 +        Thread.sleep(SHORT_DELAY_MS);
1017 +        assertTrue(sync.hasQueuedThread(t1));
1018 +        assertTrue(sync.hasQueuedThread(t2));
1019 +        t1.interrupt();
1020 +        Thread.sleep(SHORT_DELAY_MS);
1021 +        assertFalse(sync.hasQueuedThread(t1));
1022 +        assertTrue(sync.hasQueuedThread(t2));
1023 +        sync.writeLock().unlock();
1024 +        Thread.sleep(SHORT_DELAY_MS);
1025 +        assertFalse(sync.hasQueuedThread(t1));
1026 +        Thread.sleep(SHORT_DELAY_MS);
1027 +        assertFalse(sync.hasQueuedThread(t2));
1028 +        t1.join();
1029 +        t2.join();
1030 +    }
1031 +
1032 +
1033 +    /**
1034 +     * getQueueLength reports number of waiting threads
1035 +     */
1036 +    public void testGetQueueLength() throws InterruptedException {
1037 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1038 +        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
1039 +        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
1040 +        assertEquals(0, lock.getQueueLength());
1041 +        lock.writeLock().lock();
1042 +        t1.start();
1043 +        Thread.sleep(SHORT_DELAY_MS);
1044 +        assertEquals(1, lock.getQueueLength());
1045 +        t2.start();
1046 +        Thread.sleep(SHORT_DELAY_MS);
1047 +        assertEquals(2, lock.getQueueLength());
1048 +        t1.interrupt();
1049 +        Thread.sleep(SHORT_DELAY_MS);
1050 +        assertEquals(1, lock.getQueueLength());
1051 +        lock.writeLock().unlock();
1052 +        Thread.sleep(SHORT_DELAY_MS);
1053 +        assertEquals(0, lock.getQueueLength());
1054 +        t1.join();
1055 +        t2.join();
1056 +    }
1057 +
1058 +    /**
1059 +     * getQueuedThreads includes waiting threads
1060 +     */
1061 +    public void testGetQueuedThreads() throws InterruptedException {
1062 +        final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
1063 +        Thread t1 = new Thread(new InterruptedLockRunnable(lock));
1064 +        Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
1065 +        assertTrue(lock.getQueuedThreads().isEmpty());
1066 +        lock.writeLock().lock();
1067 +        assertTrue(lock.getQueuedThreads().isEmpty());
1068 +        t1.start();
1069 +        Thread.sleep(SHORT_DELAY_MS);
1070 +        assertTrue(lock.getQueuedThreads().contains(t1));
1071 +        t2.start();
1072 +        Thread.sleep(SHORT_DELAY_MS);
1073 +        assertTrue(lock.getQueuedThreads().contains(t1));
1074 +        assertTrue(lock.getQueuedThreads().contains(t2));
1075 +        t1.interrupt();
1076 +        Thread.sleep(SHORT_DELAY_MS);
1077 +        assertFalse(lock.getQueuedThreads().contains(t1));
1078 +        assertTrue(lock.getQueuedThreads().contains(t2));
1079 +        lock.writeLock().unlock();
1080 +        Thread.sleep(SHORT_DELAY_MS);
1081 +        assertTrue(lock.getQueuedThreads().isEmpty());
1082 +        t1.join();
1083 +        t2.join();
1084 +    }
1085 +
1086 +    /**
1087 +     * hasWaiters throws NPE if null
1088 +     */
1089 +    public void testHasWaitersNPE() {
1090 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1091 +        try {
1092 +            lock.hasWaiters(null);
1093 +            shouldThrow();
1094 +        } catch (NullPointerException success) {}
1095 +    }
1096 +
1097 +    /**
1098 +     * getWaitQueueLength throws NPE if null
1099 +     */
1100 +    public void testGetWaitQueueLengthNPE() {
1101 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1102 +        try {
1103 +            lock.getWaitQueueLength(null);
1104 +            shouldThrow();
1105 +        } catch (NullPointerException success) {}
1106 +    }
1107 +
1108 +
1109 +    /**
1110 +     * getWaitingThreads throws NPE if null
1111 +     */
1112 +    public void testGetWaitingThreadsNPE() {
1113 +        final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
1114 +        try {
1115 +            lock.getWaitingThreads(null);
1116 +            shouldThrow();
1117 +        } catch (NullPointerException success) {}
1118 +    }
1119 +
1120 +    /**
1121 +     * hasWaiters throws IAE if not owned
1122 +     */
1123 +    public void testHasWaitersIAE() {
1124 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1125 +        final Condition c = lock.writeLock().newCondition();
1126 +        final ReentrantReadWriteLock lock2 = new ReentrantReadWriteLock();
1127 +        try {
1128 +            lock2.hasWaiters(c);
1129 +            shouldThrow();
1130 +        } catch (IllegalArgumentException success) {}
1131 +    }
1132 +
1133 +    /**
1134 +     * hasWaiters throws IMSE if not locked
1135 +     */
1136 +    public void testHasWaitersIMSE() {
1137 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1138 +        final Condition c = lock.writeLock().newCondition();
1139 +        try {
1140 +            lock.hasWaiters(c);
1141 +            shouldThrow();
1142 +        } catch (IllegalMonitorStateException success) {}
1143 +    }
1144 +
1145 +
1146 +    /**
1147 +     * getWaitQueueLength throws IAE if not owned
1148 +     */
1149 +    public void testGetWaitQueueLengthIAE() {
1150 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1151 +        final Condition c = lock.writeLock().newCondition();
1152 +        final ReentrantReadWriteLock lock2 = new ReentrantReadWriteLock();
1153 +        try {
1154 +            lock2.getWaitQueueLength(c);
1155 +            shouldThrow();
1156 +        } catch (IllegalArgumentException success) {}
1157 +    }
1158 +
1159 +    /**
1160 +     * getWaitQueueLength throws IMSE if not locked
1161 +     */
1162 +    public void testGetWaitQueueLengthIMSE() {
1163 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1164 +        final Condition c = lock.writeLock().newCondition();
1165 +        try {
1166 +            lock.getWaitQueueLength(c);
1167 +            shouldThrow();
1168 +        } catch (IllegalMonitorStateException success) {}
1169 +    }
1170 +
1171 +
1172 +    /**
1173 +     * getWaitingThreads throws IAE if not owned
1174 +     */
1175 +    public void testGetWaitingThreadsIAE() {
1176 +        final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
1177 +        final Condition c = lock.writeLock().newCondition();
1178 +        final PublicReentrantReadWriteLock lock2 = new PublicReentrantReadWriteLock();
1179 +        try {
1180 +            lock2.getWaitingThreads(c);
1181 +            shouldThrow();
1182 +        } catch (IllegalArgumentException success) {}
1183 +    }
1184 +
1185 +    /**
1186 +     * getWaitingThreads throws IMSE if not locked
1187 +     */
1188 +    public void testGetWaitingThreadsIMSE() {
1189 +        final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
1190 +        final Condition c = lock.writeLock().newCondition();
1191 +        try {
1192 +            lock.getWaitingThreads(c);
1193 +            shouldThrow();
1194 +        } catch (IllegalMonitorStateException success) {}
1195 +    }
1196 +
1197 +
1198 +    /**
1199 +     * hasWaiters returns true when a thread is waiting, else false
1200 +     */
1201 +    public void testHasWaiters() throws InterruptedException {
1202 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1203 +        final Condition c = lock.writeLock().newCondition();
1204 +        Thread t = newStartedThread(new CheckedRunnable() {
1205 +            public void realRun() throws InterruptedException {
1206 +                lock.writeLock().lock();
1207 +                assertFalse(lock.hasWaiters(c));
1208 +                assertEquals(0, lock.getWaitQueueLength(c));
1209 +                c.await();
1210 +                lock.writeLock().unlock();
1211 +            }});
1212 +
1213 +        Thread.sleep(SHORT_DELAY_MS);
1214 +        lock.writeLock().lock();
1215 +        assertTrue(lock.hasWaiters(c));
1216 +        assertEquals(1, lock.getWaitQueueLength(c));
1217 +        c.signal();
1218 +        lock.writeLock().unlock();
1219 +        Thread.sleep(SHORT_DELAY_MS);
1220 +        lock.writeLock().lock();
1221 +        assertFalse(lock.hasWaiters(c));
1222 +        assertEquals(0, lock.getWaitQueueLength(c));
1223 +        lock.writeLock().unlock();
1224 +        t.join(SHORT_DELAY_MS);
1225 +        assertFalse(t.isAlive());
1226 +    }
1227 +
1228 +    /**
1229 +     * getWaitQueueLength returns number of waiting threads
1230 +     */
1231 +    public void testGetWaitQueueLength() throws InterruptedException {
1232 +        final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1233 +        final Condition c = lock.writeLock().newCondition();
1234 +        Thread t = newStartedThread(new CheckedRunnable() {
1235 +            public void realRun() throws InterruptedException {
1236 +                lock.writeLock().lock();
1237 +                assertFalse(lock.hasWaiters(c));
1238 +                assertEquals(0, lock.getWaitQueueLength(c));
1239 +                c.await();
1240 +                lock.writeLock().unlock();
1241 +            }});
1242 +
1243 +        Thread.sleep(SHORT_DELAY_MS);
1244 +        lock.writeLock().lock();
1245 +        assertTrue(lock.hasWaiters(c));
1246 +        assertEquals(1, lock.getWaitQueueLength(c));
1247 +        c.signal();
1248 +        lock.writeLock().unlock();
1249 +        Thread.sleep(SHORT_DELAY_MS);
1250 +        lock.writeLock().lock();
1251 +        assertFalse(lock.hasWaiters(c));
1252 +        assertEquals(0, lock.getWaitQueueLength(c));
1253 +        lock.writeLock().unlock();
1254 +        t.join(SHORT_DELAY_MS);
1255 +        assertFalse(t.isAlive());
1256 +    }
1257 +
1258 +
1259 +    /**
1260 +     * getWaitingThreads returns only and all waiting threads
1261 +     */
1262 +    public void testGetWaitingThreads() throws InterruptedException {
1263 +        final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
1264 +        final Condition c = lock.writeLock().newCondition();
1265 +        Thread t1 = new Thread(new CheckedRunnable() {
1266 +            public void realRun() throws InterruptedException {
1267 +                lock.writeLock().lock();
1268 +                assertTrue(lock.getWaitingThreads(c).isEmpty());
1269 +                c.await();
1270 +                lock.writeLock().unlock();
1271 +            }});
1272 +
1273 +        Thread t2 = new Thread(new CheckedRunnable() {
1274 +            public void realRun() throws InterruptedException {
1275 +                lock.writeLock().lock();
1276 +                assertFalse(lock.getWaitingThreads(c).isEmpty());
1277 +                c.await();
1278 +                lock.writeLock().unlock();
1279 +            }});
1280 +
1281 +        lock.writeLock().lock();
1282 +        assertTrue(lock.getWaitingThreads(c).isEmpty());
1283 +        lock.writeLock().unlock();
1284 +        t1.start();
1285 +        Thread.sleep(SHORT_DELAY_MS);
1286 +        t2.start();
1287 +        Thread.sleep(SHORT_DELAY_MS);
1288 +        lock.writeLock().lock();
1289 +        assertTrue(lock.hasWaiters(c));
1290 +        assertTrue(lock.getWaitingThreads(c).contains(t1));
1291 +        assertTrue(lock.getWaitingThreads(c).contains(t2));
1292 +        c.signalAll();
1293 +        lock.writeLock().unlock();
1294 +        Thread.sleep(SHORT_DELAY_MS);
1295 +        lock.writeLock().lock();
1296 +        assertFalse(lock.hasWaiters(c));
1297 +        assertTrue(lock.getWaitingThreads(c).isEmpty());
1298 +        lock.writeLock().unlock();
1299 +        t1.join(SHORT_DELAY_MS);
1300 +        t2.join(SHORT_DELAY_MS);
1301 +        assertFalse(t1.isAlive());
1302 +        assertFalse(t2.isAlive());
1303 +    }
1304 +
1305 +    /**
1306 +     * toString indicates current lock state
1307 +     */
1308 +    public void testToString() {
1309 +        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1310 +        String us = lock.toString();
1311 +        assertTrue(us.indexOf("Write locks = 0") >= 0);
1312 +        assertTrue(us.indexOf("Read locks = 0") >= 0);
1313 +        lock.writeLock().lock();
1314 +        String ws = lock.toString();
1315 +        assertTrue(ws.indexOf("Write locks = 1") >= 0);
1316 +        assertTrue(ws.indexOf("Read locks = 0") >= 0);
1317 +        lock.writeLock().unlock();
1318 +        lock.readLock().lock();
1319 +        lock.readLock().lock();
1320 +        String rs = lock.toString();
1321 +        assertTrue(rs.indexOf("Write locks = 0") >= 0);
1322 +        assertTrue(rs.indexOf("Read locks = 2") >= 0);
1323 +    }
1324 +
1325 +    /**
1326 +     * readLock.toString indicates current lock state
1327 +     */
1328 +    public void testReadLockToString() {
1329 +        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1330 +        String us = lock.readLock().toString();
1331 +        assertTrue(us.indexOf("Read locks = 0") >= 0);
1332 +        lock.readLock().lock();
1333 +        lock.readLock().lock();
1334 +        String rs = lock.readLock().toString();
1335 +        assertTrue(rs.indexOf("Read locks = 2") >= 0);
1336 +    }
1337 +
1338 +    /**
1339 +     * writeLock.toString indicates current lock state
1340 +     */
1341 +    public void testWriteLockToString() {
1342 +        ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
1343 +        String us = lock.writeLock().toString();
1344 +        assertTrue(us.indexOf("Unlocked") >= 0);
1345 +        lock.writeLock().lock();
1346 +        String ls = lock.writeLock().toString();
1347 +        assertTrue(ls.indexOf("Locked") >= 0);
1348 +    }
1349  
1350   }

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