/* * 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 JSR166TestCase { public static void main(String[] args) { junit.textui.TestRunner.run(suite()); } public static Test suite() { 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)); }}); 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); } }