--- jsr166/src/test/tck/ReentrantReadWriteLockTest.java 2003/08/31 19:24:55 1.1 +++ jsr166/src/test/tck/ReentrantReadWriteLockTest.java 2011/05/07 11:15:04 1.57 @@ -1,114 +1,1464 @@ /* - * Written by members of JCP JSR-166 Expert Group and released to the - * public domain. Use, modify, and redistribute this code in any way - * without acknowledgement. Other contributors include Andrew Wright, - * Jeffrey Hayes, Pat Fischer, Mike Judd. + * Written by Doug Lea with assistance from members of JCP JSR-166 + * Expert Group and released to the public domain, as explained at + * http://creativecommons.org/publicdomain/zero/1.0/ + * Other contributors include Andrew Wright, Jeffrey Hayes, + * Pat Fisher, Mike Judd. */ import junit.framework.*; +import java.util.concurrent.atomic.AtomicBoolean; import java.util.concurrent.locks.*; import java.util.concurrent.*; +import static java.util.concurrent.TimeUnit.MILLISECONDS; +import java.io.*; +import java.util.*; -public class ReentrantReadWriteLockTest extends TestCase { - static int HOLD_COUNT_TEST_LIMIT = 20; - +public class ReentrantReadWriteLockTest extends JSR166TestCase { public static void main(String[] args) { - junit.textui.TestRunner.run (suite()); + junit.textui.TestRunner.run(suite()); } - public static Test suite() { - return new TestSuite(ReentrantReadWriteLockTest.class); + return new TestSuite(ReentrantReadWriteLockTest.class); } + /** + * A runnable calling lockInterruptibly + */ + class InterruptibleLockRunnable extends CheckedRunnable { + final ReentrantReadWriteLock lock; + InterruptibleLockRunnable(ReentrantReadWriteLock l) { lock = l; } + public void realRun() throws InterruptedException { + lock.writeLock().lockInterruptibly(); + } + } + + /** + * A runnable calling lockInterruptibly that expects to be + * interrupted + */ + class InterruptedLockRunnable extends CheckedInterruptedRunnable { + final ReentrantReadWriteLock lock; + InterruptedLockRunnable(ReentrantReadWriteLock l) { lock = l; } + public void realRun() throws InterruptedException { + lock.writeLock().lockInterruptibly(); + } + } + + /** + * Subclass to expose protected methods + */ + static class PublicReentrantReadWriteLock extends ReentrantReadWriteLock { + PublicReentrantReadWriteLock() { super(); } + public Collection getQueuedThreads() { + return super.getQueuedThreads(); + } + public Collection getWaitingThreads(Condition c) { + return super.getWaitingThreads(c); + } + } + + /** + * Releases write lock, checking that it had a hold count of 1. + */ + void releaseWriteLock(ReentrantReadWriteLock lock) { + ReentrantReadWriteLock.WriteLock writeLock = lock.writeLock(); + assertTrue(writeLock.isHeldByCurrentThread()); + writeLock.unlock(); + assertFalse(writeLock.isHeldByCurrentThread()); + } + + /** + * Spin-waits until lock.hasQueuedThread(t) becomes true. + */ + void waitForQueuedThread(ReentrantReadWriteLock lock, Thread t) { + long startTime = System.nanoTime(); + while (!lock.hasQueuedThread(t)) { + if (millisElapsedSince(startTime) > LONG_DELAY_MS) + throw new AssertionError("timed out"); + Thread.yield(); + } + } + + /** + * Checks that lock is not write-locked. + */ + void assertNotWriteLocked(ReentrantReadWriteLock lock) { + assertFalse(lock.isWriteLocked()); + assertFalse(lock.isWriteLockedByCurrentThread()); + assertEquals(0, lock.getWriteHoldCount()); + } + + /** + * Checks that condition c has no waiters. + */ + void assertHasNoWaiters(PublicReentrantReadWriteLock lock, Condition c) { + assertHasWaiters(lock, c, new Thread[] {}); + } + + /** + * Checks that condition c has exactly the given waiter threads. + */ + void assertHasWaiters(PublicReentrantReadWriteLock lock, Condition c, + Thread... threads) { + lock.writeLock().lock(); + assertEquals(threads.length > 0, lock.hasWaiters(c)); + assertEquals(threads.length, lock.getWaitQueueLength(c)); + assertEquals(threads.length == 0, lock.getWaitingThreads(c).isEmpty()); + assertEquals(threads.length, lock.getWaitingThreads(c).size()); + assertEquals(new HashSet(lock.getWaitingThreads(c)), + new HashSet(Arrays.asList(threads))); + lock.writeLock().unlock(); + } + + /** + * Constructor sets given fairness, and is in unlocked state + */ + public void testConstructor() { + ReentrantReadWriteLock rl = new ReentrantReadWriteLock(); + assertFalse(rl.isFair()); + assertFalse(rl.isWriteLocked()); + assertEquals(0, rl.getReadLockCount()); + ReentrantReadWriteLock r2 = new ReentrantReadWriteLock(true); + assertTrue(r2.isFair()); + assertFalse(r2.isWriteLocked()); + assertEquals(0, r2.getReadLockCount()); + ReentrantReadWriteLock r3 = new ReentrantReadWriteLock(false); + assertFalse(r3.isFair()); + assertFalse(r3.isWriteLocked()); + assertEquals(0, r3.getReadLockCount()); + } + + /** + * write-locking and read-locking an unlocked lock succeed + */ + public void testLock() { + ReentrantReadWriteLock rl = new ReentrantReadWriteLock(); + rl.writeLock().lock(); + assertTrue(rl.isWriteLocked()); + assertTrue(rl.isWriteLockedByCurrentThread()); + assertTrue(rl.writeLock().isHeldByCurrentThread()); + assertEquals(0, rl.getReadLockCount()); + rl.writeLock().unlock(); + assertFalse(rl.isWriteLocked()); + assertFalse(rl.isWriteLockedByCurrentThread()); + assertFalse(rl.writeLock().isHeldByCurrentThread()); + assertEquals(0, rl.getReadLockCount()); + rl.readLock().lock(); + assertFalse(rl.isWriteLocked()); + assertFalse(rl.isWriteLockedByCurrentThread()); + assertEquals(1, rl.getReadLockCount()); + rl.readLock().unlock(); + assertFalse(rl.isWriteLocked()); + assertFalse(rl.isWriteLockedByCurrentThread()); + assertEquals(0, rl.getReadLockCount()); + } + + /** + * locking an unlocked fair lock succeeds + */ + public void testFairLock() { + ReentrantReadWriteLock rl = new ReentrantReadWriteLock(true); + rl.writeLock().lock(); + assertTrue(rl.isWriteLocked()); + assertTrue(rl.isWriteLockedByCurrentThread()); + assertTrue(rl.writeLock().isHeldByCurrentThread()); + assertEquals(0, rl.getReadLockCount()); + rl.writeLock().unlock(); + assertFalse(rl.isWriteLocked()); + assertFalse(rl.isWriteLockedByCurrentThread()); + assertFalse(rl.writeLock().isHeldByCurrentThread()); + assertEquals(0, rl.getReadLockCount()); + rl.readLock().lock(); + assertFalse(rl.isWriteLocked()); + assertFalse(rl.isWriteLockedByCurrentThread()); + assertEquals(1, rl.getReadLockCount()); + rl.readLock().unlock(); + assertFalse(rl.isWriteLocked()); + assertFalse(rl.isWriteLockedByCurrentThread()); + assertEquals(0, rl.getReadLockCount()); + } + + /** + * getWriteHoldCount returns number of recursive holds + */ + public void testGetWriteHoldCount() { + ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + for (int i = 1; i <= SIZE; i++) { + lock.writeLock().lock(); + assertEquals(i,lock.getWriteHoldCount()); + } + for (int i = SIZE; i > 0; i--) { + lock.writeLock().unlock(); + assertEquals(i-1,lock.getWriteHoldCount()); + } + } + + /** + * WriteLock.getHoldCount returns number of recursive holds + */ + public void testGetHoldCount() { + ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + for (int i = 1; i <= SIZE; i++) { + lock.writeLock().lock(); + assertEquals(i,lock.writeLock().getHoldCount()); + } + for (int i = SIZE; i > 0; i--) { + lock.writeLock().unlock(); + assertEquals(i-1,lock.writeLock().getHoldCount()); + } + } + + /** + * getReadHoldCount returns number of recursive holds + */ + public void testGetReadHoldCount() { + ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + for (int i = 1; i <= SIZE; i++) { + lock.readLock().lock(); + assertEquals(i,lock.getReadHoldCount()); + } + for (int i = SIZE; i > 0; i--) { + lock.readLock().unlock(); + assertEquals(i-1,lock.getReadHoldCount()); + } + } + + /** + * write-unlocking an unlocked lock throws IllegalMonitorStateException + */ + public void testWriteUnlock_IllegalMonitorStateException() { + ReentrantReadWriteLock rl = new ReentrantReadWriteLock(); + try { + rl.writeLock().unlock(); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * read-unlocking an unlocked lock throws IllegalMonitorStateException + */ + public void testReadUnlock_IllegalMonitorStateException() { + ReentrantReadWriteLock rl = new ReentrantReadWriteLock(); + try { + rl.readLock().unlock(); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * write-lockInterruptibly is interruptible + */ + public void testWriteLockInterruptibly_Interrupted() throws Exception { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lockInterruptibly(); + }}); + + waitForQueuedThread(lock, t); + t.interrupt(); + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * timed write-tryLock is interruptible + */ + public void testWriteTryLock_Interrupted() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().tryLock(LONG_DELAY_MS, MILLISECONDS); + }}); + + waitForQueuedThread(lock, t); + t.interrupt(); + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * read-lockInterruptibly is interruptible + */ + public void testReadLockInterruptibly_Interrupted() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.readLock().lockInterruptibly(); + }}); + + waitForQueuedThread(lock, t); + t.interrupt(); + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * timed read-tryLock is interruptible + */ + public void testReadTryLock_Interrupted() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.readLock().tryLock(LONG_DELAY_MS, MILLISECONDS); + }}); + + waitForQueuedThread(lock, t); + t.interrupt(); + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * write-tryLock fails if locked + */ + public void testWriteTryLockWhenLocked() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertFalse(lock.writeLock().tryLock()); + }}); + + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * read-tryLock fails if locked + */ + public void testReadTryLockWhenLocked() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertFalse(lock.readLock().tryLock()); + }}); + + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * Multiple threads can hold a read lock when not write-locked + */ + public void testMultipleReadLocks() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.readLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertTrue(lock.readLock().tryLock()); + lock.readLock().unlock(); + }}); + + awaitTermination(t); + lock.readLock().unlock(); + } + + /** + * A writelock succeeds only after reading threads unlock + */ + public void testWriteAfterMultipleReadLocks() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.readLock().lock(); + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + delay(SHORT_DELAY_MS); + lock.readLock().unlock(); + awaitTermination(t1); + awaitTermination(t2); + assertNotWriteLocked(lock); + } + + /** + * Readlocks succeed only after a writing thread unlocks + */ + public void testReadAfterWriteLock() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Read trylock succeeds if write locked by current thread + */ + public void testReadHoldingWriteLock() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + assertTrue(lock.readLock().tryLock()); + lock.readLock().unlock(); + lock.writeLock().unlock(); + } + + /** + * Read lock succeeds if write locked by current thread even if + * other threads are waiting for readlock + */ + public void testReadHoldingWriteLock2() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + lock.readLock().lock(); + lock.readLock().unlock(); + + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + assertTrue(lock.isWriteLockedByCurrentThread()); + lock.readLock().lock(); + lock.readLock().unlock(); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Read lock succeeds if write locked by current thread even if + * other threads are waiting for writelock + */ + public void testReadHoldingWriteLock3() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + lock.readLock().lock(); + lock.readLock().unlock(); + + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + assertTrue(lock.isWriteLockedByCurrentThread()); + lock.readLock().lock(); + lock.readLock().unlock(); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Write lock succeeds if write locked by current thread even if + * other threads are waiting for writelock + */ + public void testWriteHoldingWriteLock4() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + lock.writeLock().lock(); + lock.writeLock().unlock(); + + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertEquals(1, lock.getWriteHoldCount()); + lock.writeLock().lock(); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertEquals(2, lock.getWriteHoldCount()); + lock.writeLock().unlock(); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Fair Read trylock succeeds if write locked by current thread + */ + public void testReadHoldingWriteLockFair() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true); + lock.writeLock().lock(); + assertTrue(lock.readLock().tryLock()); + lock.readLock().unlock(); + lock.writeLock().unlock(); + } + + /** + * Fair Read lock succeeds if write locked by current thread even if + * other threads are waiting for readlock + */ + public void testReadHoldingWriteLockFair2() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true); + lock.writeLock().lock(); + lock.readLock().lock(); + lock.readLock().unlock(); + + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.readLock().lock(); + lock.readLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + assertTrue(lock.isWriteLockedByCurrentThread()); + lock.readLock().lock(); + lock.readLock().unlock(); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Fair Read lock succeeds if write locked by current thread even if + * other threads are waiting for writelock + */ + public void testReadHoldingWriteLockFair3() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true); + lock.writeLock().lock(); + lock.readLock().lock(); + lock.readLock().unlock(); + + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + assertTrue(lock.isWriteLockedByCurrentThread()); + lock.readLock().lock(); + lock.readLock().unlock(); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Fair Write lock succeeds if write locked by current thread even if + * other threads are waiting for writelock + */ + public void testWriteHoldingWriteLockFair4() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true); + lock.writeLock().lock(); + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + lock.writeLock().unlock(); + }}); + + waitForQueuedThread(lock, t1); + waitForQueuedThread(lock, t2); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertEquals(1, lock.getWriteHoldCount()); + lock.writeLock().lock(); + assertEquals(2, lock.getWriteHoldCount()); + lock.writeLock().unlock(); + lock.writeLock().lock(); + lock.writeLock().unlock(); + releaseWriteLock(lock); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * Read tryLock succeeds if readlocked but not writelocked + */ + public void testTryLockWhenReadLocked() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.readLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertTrue(lock.readLock().tryLock()); + lock.readLock().unlock(); + }}); + + awaitTermination(t); + lock.readLock().unlock(); + } + + /** + * write tryLock fails when readlocked + */ + public void testWriteTryLockWhenReadLocked() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.readLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertFalse(lock.writeLock().tryLock()); + }}); + + awaitTermination(t); + lock.readLock().unlock(); + } + + /** + * Fair Read tryLock succeeds if readlocked but not writelocked + */ + public void testTryLockWhenReadLockedFair() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true); + lock.readLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertTrue(lock.readLock().tryLock()); + lock.readLock().unlock(); + }}); + + awaitTermination(t); + lock.readLock().unlock(); + } + + /** + * Fair write tryLock fails when readlocked + */ + public void testWriteTryLockWhenReadLockedFair() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(true); + lock.readLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + assertFalse(lock.writeLock().tryLock()); + }}); + + awaitTermination(t); + lock.readLock().unlock(); + } + + /** + * write timed tryLock times out if locked + */ + public void testWriteTryLock_Timeout() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + assertFalse(lock.writeLock().tryLock(1, MILLISECONDS)); + }}); - private static long SHORT_DELAY_MS = 100; - private static long MEDIUM_DELAY_MS = 1000; - private static long LONG_DELAY_MS = 10000; - - /* - * Unlocks an unlocked lock, throws Illegal Monitor State - * - */ - - public void testIllegalMonitorStateException(){ - ReentrantReadWriteLock rl = new ReentrantReadWriteLock(); - try{ - rl.writeLock().unlock(); - fail("Should of thown Illegal Monitor State Exception"); - - }catch(IllegalMonitorStateException sucess){} - - - } - - /* - * makes a lock, locks it, tries to aquire the lock in another thread - * interrupts that thread and waits for an interrupted Exception to - * be thrown. - */ - - public void testInterruptedException(){ - final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); - lock.writeLock().lock(); - Thread t = new Thread(new Runnable() { - public void run(){ - try{ - lock.writeLock().lockInterruptibly(); - fail("should throw"); - }catch(InterruptedException sucess){} - } - }); - t.start(); - t.interrupt(); - lock.writeLock().unlock(); - } - - /* - * tests for interrupted exception on a timed wait - * - */ - - - public void testInterruptedException2(){ - final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); - lock.writeLock().lock(); - Thread t = new Thread(new Runnable() { - public void run(){ - try{ - lock.writeLock().tryLock(1000,TimeUnit.MILLISECONDS); - fail("should throw"); - }catch(InterruptedException sucess){} - } - }); - t.start(); - t.interrupt(); - } - - - - /* - * current thread locks interruptibly the thread - * another thread tries to aquire the lock and blocks - * on the call. interrupt the attempted aquireLock - * assert that the first lock() call actually locked the lock - * assert that the current thread is the one holding the lock - */ - - public void testLockedInterruptibly() { - final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); - try {lock.writeLock().lockInterruptibly();} catch(Exception e) {} - Thread t = new Thread(new Runnable() { - public void run() { - try { - lock.writeLock().lockInterruptibly(); - fail("Failed to generate an Interrupted Exception"); - } - catch(InterruptedException e) {} - } - }); - t.start(); - t.interrupt(); + awaitTermination(t); + assertTrue(lock.writeLock().isHeldByCurrentThread()); + lock.writeLock().unlock(); + } + + /** + * read timed tryLock times out if write-locked + */ + public void testReadTryLock_Timeout() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lock(); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + assertFalse(lock.readLock().tryLock(1, MILLISECONDS)); + }}); + + awaitTermination(t); + assertTrue(lock.writeLock().isHeldByCurrentThread()); + lock.writeLock().unlock(); + } + + /** + * write lockInterruptibly succeeds if lock free else is interruptible + */ + public void testWriteLockInterruptibly() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lockInterruptibly(); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lockInterruptibly(); + }}); + + waitForQueuedThread(lock, t); + t.interrupt(); + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * read lockInterruptibly succeeds if lock free else is interruptible + */ + public void testReadLockInterruptibly() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + lock.writeLock().lockInterruptibly(); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.readLock().lockInterruptibly(); + }}); + + waitForQueuedThread(lock, t); + t.interrupt(); + awaitTermination(t); + releaseWriteLock(lock); + } + + /** + * Calling await without holding lock throws IllegalMonitorStateException + */ + public void testAwait_IllegalMonitor() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + try { + c.await(); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + try { + c.await(LONG_DELAY_MS, MILLISECONDS); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + try { + c.awaitNanos(100); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + try { + c.awaitUninterruptibly(); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * Calling signal without holding lock throws IllegalMonitorStateException + */ + public void testSignal_IllegalMonitor() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + try { + c.signal(); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * Calling signalAll without holding lock throws IllegalMonitorStateException + */ + public void testSignalAll_IllegalMonitor() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + try { + c.signalAll(); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * awaitNanos without a signal times out + */ + public void testAwaitNanos_Timeout() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + lock.writeLock().lock(); + long startTime = System.nanoTime(); + long timeoutMillis = 10; + long timeoutNanos = MILLISECONDS.toNanos(timeoutMillis); + long nanosRemaining = c.awaitNanos(timeoutNanos); + assertTrue(nanosRemaining <= 0); + assertTrue(millisElapsedSince(startTime) >= timeoutMillis); + lock.writeLock().unlock(); + } + + /** + * timed await without a signal times out + */ + public void testAwait_Timeout() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + lock.writeLock().lock(); + long startTime = System.nanoTime(); + long timeoutMillis = 10; + assertFalse(c.await(timeoutMillis, MILLISECONDS)); + assertTrue(millisElapsedSince(startTime) >= timeoutMillis); + lock.writeLock().unlock(); + } + + /** + * awaitUntil without a signal times out + */ + public void testAwaitUntil_Timeout() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + lock.writeLock().lock(); + java.util.Date d = new java.util.Date(); + assertFalse(c.awaitUntil(new java.util.Date(d.getTime() + 10))); + lock.writeLock().unlock(); + } + + /** + * await returns when signalled + */ + public void testAwait() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + locked.countDown(); + c.await(); + lock.writeLock().unlock(); + }}); + + locked.await(); + lock.writeLock().lock(); + c.signal(); + assertTrue(t.isAlive()); + lock.writeLock().unlock(); + awaitTermination(t); + } + + /** + * awaitUninterruptibly doesn't abort on interrupt + */ + public void testAwaitUninterruptibly() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + final AtomicBoolean canAwake = new AtomicBoolean(false); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() { + lock.writeLock().lock(); + locked.countDown(); + c.awaitUninterruptibly(); + assertTrue(Thread.interrupted()); + lock.writeLock().unlock(); + }}); + + locked.await(); + lock.writeLock().lock(); + lock.writeLock().unlock(); + t.interrupt(); + t.join(10); + assertTrue(t.isAlive()); + lock.writeLock().lock(); + c.signal(); + lock.writeLock().unlock(); + awaitTermination(t); + } + + /** + * await is interruptible + */ + public void testAwait_Interrupt() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertTrue(lock.isWriteLocked()); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertHasNoWaiters(lock, c); + locked.countDown(); + try { + c.await(); + } finally { + assertTrue(lock.isWriteLocked()); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertHasNoWaiters(lock, c); + lock.writeLock().unlock(); + assertFalse(Thread.interrupted()); + } + }}); + + locked.await(); + assertHasWaiters(lock, c, t); + t.interrupt(); + awaitTermination(t); + assertFalse(lock.isWriteLocked()); + } + + /** + * awaitNanos is interruptible + */ + public void testAwaitNanos_Interrupt() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertTrue(lock.isWriteLocked()); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertHasNoWaiters(lock, c); + locked.countDown(); + try { + c.awaitNanos(MILLISECONDS.toNanos(LONG_DELAY_MS)); + } finally { + assertTrue(lock.isWriteLocked()); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertHasNoWaiters(lock, c); + lock.writeLock().unlock(); + assertFalse(Thread.interrupted()); + } + }}); + + locked.await(); + assertHasWaiters(lock, c, t); + t.interrupt(); + awaitTermination(t); + assertFalse(lock.isWriteLocked()); + } + + /** + * awaitUntil is interruptible + */ + public void testAwaitUntil_Interrupt() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + Thread t = newStartedThread(new CheckedInterruptedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertTrue(lock.isWriteLocked()); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertHasNoWaiters(lock, c); + locked.countDown(); + java.util.Date d = new java.util.Date(); + try { + c.awaitUntil(new java.util.Date(d.getTime() + 10000)); + } finally { + assertTrue(lock.isWriteLocked()); + assertTrue(lock.isWriteLockedByCurrentThread()); + assertHasNoWaiters(lock, c); + lock.writeLock().unlock(); + assertFalse(Thread.interrupted()); + } + }}); + + locked.await(); + assertHasWaiters(lock, c, t); + t.interrupt(); + awaitTermination(t); + assertFalse(lock.isWriteLocked()); + } + + /** + * signalAll wakes up all threads + */ + public void testSignalAll() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(2); + final Lock writeLock = lock.writeLock(); + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + writeLock.lock(); + locked.countDown(); + c.await(); + writeLock.unlock(); + }}); + + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + writeLock.lock(); + locked.countDown(); + c.await(); + writeLock.unlock(); + }}); + + locked.await(); + writeLock.lock(); + assertHasWaiters(lock, c, t1, t2); + c.signalAll(); + assertHasNoWaiters(lock, c); + writeLock.unlock(); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * signal wakes up waiting threads in FIFO order. + */ + public void testSignalWakesFifo() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked1 = new CountDownLatch(1); + final CountDownLatch locked2 = new CountDownLatch(1); + final Lock writeLock = lock.writeLock(); + Thread t1 = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + writeLock.lock(); + locked1.countDown(); + c.await(); + writeLock.unlock(); + }}); + + locked1.await(); + + Thread t2 = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + writeLock.lock(); + locked2.countDown(); + c.await(); + writeLock.unlock(); + }}); + + locked2.await(); + + writeLock.lock(); + assertHasWaiters(lock, c, t1, t2); + assertFalse(lock.hasQueuedThreads()); + c.signal(); + assertHasWaiters(lock, c, t2); + assertTrue(lock.hasQueuedThread(t1)); + assertFalse(lock.hasQueuedThread(t2)); + c.signal(); + assertHasNoWaiters(lock, c); + assertTrue(lock.hasQueuedThread(t1)); + assertTrue(lock.hasQueuedThread(t2)); + writeLock.unlock(); + awaitTermination(t1); + awaitTermination(t2); + } + + /** + * A serialized lock deserializes as unlocked + */ + public void testSerialization() throws Exception { + ReentrantReadWriteLock l = new ReentrantReadWriteLock(); + l.readLock().lock(); + l.readLock().unlock(); + + ByteArrayOutputStream bout = new ByteArrayOutputStream(10000); + ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout)); + out.writeObject(l); + out.close(); + + ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray()); + ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin)); + ReentrantReadWriteLock r = (ReentrantReadWriteLock) in.readObject(); + r.readLock().lock(); + r.readLock().unlock(); + } + + /** + * hasQueuedThreads reports whether there are waiting threads + */ + public void testhasQueuedThreads() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + Thread t1 = new Thread(new InterruptedLockRunnable(lock)); + Thread t2 = new Thread(new InterruptibleLockRunnable(lock)); + assertFalse(lock.hasQueuedThreads()); + lock.writeLock().lock(); + assertFalse(lock.hasQueuedThreads()); + long startTime = System.nanoTime(); + t1.start(); + waitForQueuedThread(lock, t1); + t2.start(); + waitForQueuedThread(lock, t2); + assertTrue(lock.hasQueuedThreads()); + t1.interrupt(); + awaitTermination(t1); + assertTrue(lock.hasQueuedThreads()); + lock.writeLock().unlock(); + awaitTermination(t2); + assertFalse(lock.hasQueuedThreads()); + } + + /** + * hasQueuedThread(null) throws NPE + */ + public void testHasQueuedThreadNPE() { + final ReentrantReadWriteLock sync = new ReentrantReadWriteLock(); + try { + sync.hasQueuedThread(null); + shouldThrow(); + } catch (NullPointerException success) {} + } + + /** + * hasQueuedThread reports whether a thread is queued. + */ + public void testHasQueuedThread() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + Thread t1 = new Thread(new InterruptedLockRunnable(lock)); + Thread t2 = new Thread(new InterruptibleLockRunnable(lock)); + assertFalse(lock.hasQueuedThread(t1)); + assertFalse(lock.hasQueuedThread(t2)); + lock.writeLock().lock(); + long startTime = System.nanoTime(); + t1.start(); + waitForQueuedThread(lock, t1); + assertTrue(lock.hasQueuedThread(t1)); + assertFalse(lock.hasQueuedThread(t2)); + t2.start(); + waitForQueuedThread(lock, t2); + assertTrue(lock.hasQueuedThread(t1)); + assertTrue(lock.hasQueuedThread(t2)); + t1.interrupt(); + awaitTermination(t1); + assertFalse(lock.hasQueuedThread(t1)); + assertTrue(lock.hasQueuedThread(t2)); + lock.writeLock().unlock(); + awaitTermination(t2); + assertFalse(lock.hasQueuedThread(t1)); + assertFalse(lock.hasQueuedThread(t2)); + } + + /** + * getQueueLength reports number of waiting threads + */ + public void testGetQueueLength() throws InterruptedException { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + Thread t1 = new Thread(new InterruptedLockRunnable(lock)); + Thread t2 = new Thread(new InterruptibleLockRunnable(lock)); + assertEquals(0, lock.getQueueLength()); + lock.writeLock().lock(); + long startTime = System.nanoTime(); + t1.start(); + waitForQueuedThread(lock, t1); + assertEquals(1, lock.getQueueLength()); + t2.start(); + waitForQueuedThread(lock, t2); + assertEquals(2, lock.getQueueLength()); + t1.interrupt(); + awaitTermination(t1); + assertEquals(1, lock.getQueueLength()); + lock.writeLock().unlock(); + awaitTermination(t2); + assertEquals(0, lock.getQueueLength()); + } + + /** + * getQueuedThreads includes waiting threads + */ + public void testGetQueuedThreads() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + Thread t1 = new Thread(new InterruptedLockRunnable(lock)); + Thread t2 = new Thread(new InterruptibleLockRunnable(lock)); + assertTrue(lock.getQueuedThreads().isEmpty()); + lock.writeLock().lock(); + long startTime = System.nanoTime(); + assertTrue(lock.getQueuedThreads().isEmpty()); + t1.start(); + waitForQueuedThread(lock, t1); + assertEquals(1, lock.getQueuedThreads().size()); + assertTrue(lock.getQueuedThreads().contains(t1)); + t2.start(); + waitForQueuedThread(lock, t2); + assertEquals(2, lock.getQueuedThreads().size()); + assertTrue(lock.getQueuedThreads().contains(t1)); + assertTrue(lock.getQueuedThreads().contains(t2)); + t1.interrupt(); + awaitTermination(t1); + assertFalse(lock.getQueuedThreads().contains(t1)); + assertTrue(lock.getQueuedThreads().contains(t2)); + assertEquals(1, lock.getQueuedThreads().size()); + lock.writeLock().unlock(); + awaitTermination(t2); + assertTrue(lock.getQueuedThreads().isEmpty()); + } + + /** + * hasWaiters throws NPE if null + */ + public void testHasWaitersNPE() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + try { + lock.hasWaiters(null); + shouldThrow(); + } catch (NullPointerException success) {} + } + + /** + * getWaitQueueLength throws NPE if null + */ + public void testGetWaitQueueLengthNPE() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + try { + lock.getWaitQueueLength(null); + shouldThrow(); + } catch (NullPointerException success) {} + } + + /** + * getWaitingThreads throws NPE if null + */ + public void testGetWaitingThreadsNPE() { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + try { + lock.getWaitingThreads(null); + shouldThrow(); + } catch (NullPointerException success) {} + } + + /** + * hasWaiters throws IAE if not owned + */ + public void testHasWaitersIAE() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final ReentrantReadWriteLock lock2 = new ReentrantReadWriteLock(); + try { + lock2.hasWaiters(c); + shouldThrow(); + } catch (IllegalArgumentException success) {} + } + + /** + * hasWaiters throws IMSE if not locked + */ + public void testHasWaitersIMSE() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + try { + lock.hasWaiters(c); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * getWaitQueueLength throws IAE if not owned + */ + public void testGetWaitQueueLengthIAE() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final ReentrantReadWriteLock lock2 = new ReentrantReadWriteLock(); + try { + lock2.getWaitQueueLength(c); + shouldThrow(); + } catch (IllegalArgumentException success) {} + } + + /** + * getWaitQueueLength throws IMSE if not locked + */ + public void testGetWaitQueueLengthIMSE() { + final ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + try { + lock.getWaitQueueLength(c); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * getWaitingThreads throws IAE if not owned + */ + public void testGetWaitingThreadsIAE() { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final PublicReentrantReadWriteLock lock2 = new PublicReentrantReadWriteLock(); + try { + lock2.getWaitingThreads(c); + shouldThrow(); + } catch (IllegalArgumentException success) {} + } + + /** + * getWaitingThreads throws IMSE if not locked + */ + public void testGetWaitingThreadsIMSE() { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + try { + lock.getWaitingThreads(c); + shouldThrow(); + } catch (IllegalMonitorStateException success) {} + } + + /** + * hasWaiters returns true when a thread is waiting, else false + */ + public void testHasWaiters() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertFalse(lock.hasWaiters(c)); + locked.countDown(); + assertEquals(0, lock.getWaitQueueLength(c)); + c.await(); + lock.writeLock().unlock(); + }}); + + locked.await(); + lock.writeLock().lock(); + assertTrue(lock.hasWaiters(c)); + assertEquals(1, lock.getWaitQueueLength(c)); + c.signal(); + assertHasNoWaiters(lock, c); + lock.writeLock().unlock(); + awaitTermination(t); + assertHasNoWaiters(lock, c); + } + + /** + * getWaitQueueLength returns number of waiting threads + */ + public void testGetWaitQueueLength() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked = new CountDownLatch(1); + Thread t = newStartedThread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertEquals(0, lock.getWaitQueueLength(c)); + locked.countDown(); + c.await(); + lock.writeLock().unlock(); + }}); + + locked.await(); + lock.writeLock().lock(); + assertHasWaiters(lock, c, t); + assertEquals(1, lock.getWaitQueueLength(c)); + c.signal(); + assertHasNoWaiters(lock, c); + assertEquals(0, lock.getWaitQueueLength(c)); + lock.writeLock().unlock(); + awaitTermination(t); + } + + /** + * getWaitingThreads returns only and all waiting threads + */ + public void testGetWaitingThreads() throws InterruptedException { + final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(); + final Condition c = lock.writeLock().newCondition(); + final CountDownLatch locked1 = new CountDownLatch(1); + final CountDownLatch locked2 = new CountDownLatch(1); + Thread t1 = new Thread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertTrue(lock.getWaitingThreads(c).isEmpty()); + locked1.countDown(); + c.await(); + lock.writeLock().unlock(); + }}); + + Thread t2 = new Thread(new CheckedRunnable() { + public void realRun() throws InterruptedException { + lock.writeLock().lock(); + assertFalse(lock.getWaitingThreads(c).isEmpty()); + locked2.countDown(); + c.await(); + lock.writeLock().unlock(); + }}); + + lock.writeLock().lock(); + assertTrue(lock.getWaitingThreads(c).isEmpty()); + lock.writeLock().unlock(); + + t1.start(); + locked1.await(); + t2.start(); + locked2.await(); + + lock.writeLock().lock(); + assertTrue(lock.hasWaiters(c)); + assertTrue(lock.getWaitingThreads(c).contains(t1)); + assertTrue(lock.getWaitingThreads(c).contains(t2)); + assertEquals(2, lock.getWaitingThreads(c).size()); + c.signalAll(); + assertHasNoWaiters(lock, c); + lock.writeLock().unlock(); + + awaitTermination(t1); + awaitTermination(t2); + + assertHasNoWaiters(lock, c); + } + + /** + * toString indicates current lock state + */ + public void testToString() { + ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + String us = lock.toString(); + assertTrue(us.indexOf("Write locks = 0") >= 0); + assertTrue(us.indexOf("Read locks = 0") >= 0); + lock.writeLock().lock(); + String ws = lock.toString(); + assertTrue(ws.indexOf("Write locks = 1") >= 0); + assertTrue(ws.indexOf("Read locks = 0") >= 0); + lock.writeLock().unlock(); + lock.readLock().lock(); + lock.readLock().lock(); + String rs = lock.toString(); + assertTrue(rs.indexOf("Write locks = 0") >= 0); + assertTrue(rs.indexOf("Read locks = 2") >= 0); + } + + /** + * readLock.toString indicates current lock state + */ + public void testReadLockToString() { + ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + String us = lock.readLock().toString(); + assertTrue(us.indexOf("Read locks = 0") >= 0); + lock.readLock().lock(); + lock.readLock().lock(); + String rs = lock.readLock().toString(); + assertTrue(rs.indexOf("Read locks = 2") >= 0); + } + + /** + * writeLock.toString indicates current lock state + */ + public void testWriteLockToString() { + ReentrantReadWriteLock lock = new ReentrantReadWriteLock(); + String us = lock.writeLock().toString(); + assertTrue(us.indexOf("Unlocked") >= 0); + lock.writeLock().lock(); + String ls = lock.writeLock().toString(); + assertTrue(ls.indexOf("Locked") >= 0); } - }