jsr166-mirror.jsr166tck.1.7.0.source-code.ReentrantReadWriteLockTest Maven / Gradle / Ivy
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/*
* 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(); }
PublicReentrantReadWriteLock(boolean fair) { super(fair); }
public Thread getOwner() {
return super.getOwner();
}
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(PublicReentrantReadWriteLock lock) {
ReentrantReadWriteLock.WriteLock writeLock = lock.writeLock();
assertWriteLockedBy(lock, Thread.currentThread());
assertEquals(1, lock.getWriteHoldCount());
writeLock.unlock();
assertNotWriteLocked(lock);
}
/**
* Spin-waits until lock.hasQueuedThread(t) becomes true.
*/
void waitForQueuedThread(PublicReentrantReadWriteLock lock, Thread t) {
long startTime = System.nanoTime();
while (!lock.hasQueuedThread(t)) {
if (millisElapsedSince(startTime) > LONG_DELAY_MS)
throw new AssertionError("timed out");
Thread.yield();
}
assertTrue(t.isAlive());
assertTrue(lock.getOwner() != t);
}
/**
* Checks that lock is not write-locked.
*/
void assertNotWriteLocked(PublicReentrantReadWriteLock lock) {
assertFalse(lock.isWriteLocked());
assertFalse(lock.isWriteLockedByCurrentThread());
assertFalse(lock.writeLock().isHeldByCurrentThread());
assertNull(lock.getOwner());
assertEquals(0, lock.getWriteHoldCount());
}
/**
* Checks that lock is write-locked by the given thread.
*/
void assertWriteLockedBy(PublicReentrantReadWriteLock lock, Thread t) {
assertTrue(lock.isWriteLocked());
assertSame(t, lock.getOwner());
assertEquals(t == Thread.currentThread(),
lock.isWriteLockedByCurrentThread());
assertEquals(t == Thread.currentThread(),
lock.writeLock().isHeldByCurrentThread());
assertEquals(t == Thread.currentThread(),
lock.getWriteHoldCount() > 0);
assertEquals(0, lock.getReadLockCount());
}
/**
* 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() {
PublicReentrantReadWriteLock lock;
lock = new PublicReentrantReadWriteLock();
assertFalse(lock.isFair());
assertNotWriteLocked(lock);
assertEquals(0, lock.getReadLockCount());
lock = new PublicReentrantReadWriteLock(true);
assertTrue(lock.isFair());
assertNotWriteLocked(lock);
assertEquals(0, lock.getReadLockCount());
lock = new PublicReentrantReadWriteLock(false);
assertFalse(lock.isFair());
assertNotWriteLocked(lock);
assertEquals(0, lock.getReadLockCount());
}
/**
* write-locking and read-locking an unlocked lock succeed
*/
public void testLock() {
PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
assertNotWriteLocked(lock);
lock.writeLock().lock();
assertWriteLockedBy(lock, Thread.currentThread());
lock.writeLock().unlock();
assertNotWriteLocked(lock);
assertEquals(0, lock.getReadLockCount());
lock.readLock().lock();
assertNotWriteLocked(lock);
assertEquals(1, lock.getReadLockCount());
lock.readLock().unlock();
assertNotWriteLocked(lock);
assertEquals(0, lock.getReadLockCount());
}
/**
* locking an unlocked fair lock succeeds
*/
public void testFairLock() {
PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(true);
assertNotWriteLocked(lock);
lock.writeLock().lock();
assertWriteLockedBy(lock, Thread.currentThread());
lock.writeLock().unlock();
assertNotWriteLocked(lock);
assertEquals(0, lock.getReadLockCount());
lock.readLock().lock();
assertNotWriteLocked(lock);
assertEquals(1, lock.getReadLockCount());
lock.readLock().unlock();
assertNotWriteLocked(lock);
assertEquals(0, lock.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 lock = new ReentrantReadWriteLock();
try {
lock.writeLock().unlock();
shouldThrow();
} catch (IllegalMonitorStateException success) {}
}
/**
* read-unlocking an unlocked lock throws IllegalMonitorStateException
*/
public void testReadUnlock_IllegalMonitorStateException() {
ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
try {
lock.readLock().unlock();
shouldThrow();
} catch (IllegalMonitorStateException success) {}
}
/**
* write-lockInterruptibly is interruptible
*/
public void testWriteLockInterruptibly_Interrupted() throws Exception {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
lock.writeLock().lock();
Thread t = newStartedThread(new CheckedInterruptedRunnable() {
public void realRun() throws InterruptedException {
lock.writeLock().tryLock(2 * LONG_DELAY_MS, MILLISECONDS);
}});
waitForQueuedThread(lock, t);
t.interrupt();
awaitTermination(t);
releaseWriteLock(lock);
}
/**
* read-lockInterruptibly is interruptible
*/
public void testReadLockInterruptibly_Interrupted() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
lock.writeLock().lock();
Thread t = newStartedThread(new CheckedInterruptedRunnable() {
public void realRun() throws InterruptedException {
lock.readLock().tryLock(2 * LONG_DELAY_MS, MILLISECONDS);
}});
waitForQueuedThread(lock, t);
t.interrupt();
awaitTermination(t);
releaseWriteLock(lock);
}
/**
* write-tryLock fails if locked
*/
public void testWriteTryLockWhenLocked() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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 a reading thread unlocks
*/
public void testWriteAfterReadLock() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
lock.readLock().lock();
Thread t = newStartedThread(new CheckedRunnable() {
public void realRun() {
assertEquals(1, lock.getReadLockCount());
lock.writeLock().lock();
assertEquals(0, lock.getReadLockCount());
lock.writeLock().unlock();
}});
waitForQueuedThread(lock, t);
assertNotWriteLocked(lock);
assertEquals(1, lock.getReadLockCount());
lock.readLock().unlock();
assertEquals(0, lock.getReadLockCount());
awaitTermination(t);
assertNotWriteLocked(lock);
}
/**
* A writelock succeeds only after reading threads unlock
*/
public void testWriteAfterMultipleReadLocks() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
lock.readLock().lock();
lock.readLock().lock();
Thread t1 = newStartedThread(new CheckedRunnable() {
public void realRun() {
lock.readLock().lock();
assertEquals(3, lock.getReadLockCount());
lock.readLock().unlock();
}});
awaitTermination(t1);
Thread t2 = newStartedThread(new CheckedRunnable() {
public void realRun() {
assertEquals(2, lock.getReadLockCount());
lock.writeLock().lock();
assertEquals(0, lock.getReadLockCount());
lock.writeLock().unlock();
}});
waitForQueuedThread(lock, t2);
assertNotWriteLocked(lock);
assertEquals(2, lock.getReadLockCount());
lock.readLock().unlock();
lock.readLock().unlock();
assertEquals(0, lock.getReadLockCount());
awaitTermination(t2);
assertNotWriteLocked(lock);
}
/**
* A thread that tries to acquire a fair read lock (non-reentrantly)
* will block if there is a waiting writer thread.
*/
public void testReaderWriterReaderFairFifo() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(true);
final AtomicBoolean t1GotLock = new AtomicBoolean(false);
lock.readLock().lock();
Thread t1 = newStartedThread(new CheckedRunnable() {
public void realRun() {
assertEquals(1, lock.getReadLockCount());
lock.writeLock().lock();
assertEquals(0, lock.getReadLockCount());
t1GotLock.set(true);
lock.writeLock().unlock();
}});
waitForQueuedThread(lock, t1);
Thread t2 = newStartedThread(new CheckedRunnable() {
public void realRun() {
assertEquals(1, lock.getReadLockCount());
lock.readLock().lock();
assertEquals(1, lock.getReadLockCount());
assertTrue(t1GotLock.get());
lock.readLock().unlock();
}});
waitForQueuedThread(lock, t2);
assertTrue(t1.isAlive());
assertNotWriteLocked(lock);
assertEquals(1, lock.getReadLockCount());
lock.readLock().unlock();
awaitTermination(t1);
awaitTermination(t2);
assertNotWriteLocked(lock);
}
/**
* Readlocks succeed only after a writing thread unlocks
*/
public void testReadAfterWriteLock() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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);
assertWriteLockedBy(lock, Thread.currentThread());
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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);
assertWriteLockedBy(lock, Thread.currentThread());
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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);
assertWriteLockedBy(lock, Thread.currentThread());
assertEquals(1, lock.getWriteHoldCount());
lock.writeLock().lock();
assertWriteLockedBy(lock, Thread.currentThread());
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(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);
assertWriteLockedBy(lock, Thread.currentThread());
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(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);
assertWriteLockedBy(lock, Thread.currentThread());
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock(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);
assertWriteLockedBy(lock, Thread.currentThread());
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 {
long startTime = System.nanoTime();
long timeoutMillis = 10;
assertFalse(lock.writeLock().tryLock(timeoutMillis, MILLISECONDS));
assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
}});
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 {
long startTime = System.nanoTime();
long timeoutMillis = 10;
assertFalse(lock.readLock().tryLock(timeoutMillis, MILLISECONDS));
assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
}});
awaitTermination(t);
assertTrue(lock.writeLock().isHeldByCurrentThread());
lock.writeLock().unlock();
}
/**
* write lockInterruptibly succeeds if lock free else is interruptible
*/
public void testWriteLockInterruptibly() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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();
long startTime = System.nanoTime();
long timeoutMillis = 10;
java.util.Date d = new java.util.Date();
assertFalse(c.awaitUntil(new java.util.Date(d.getTime() + timeoutMillis)));
assertTrue(millisElapsedSince(startTime) >= timeoutMillis);
lock.writeLock().unlock();
}
/**
* await returns when signalled
*/
public void testAwait() 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();
locked.countDown();
c.await();
lock.writeLock().unlock();
}});
locked.await();
lock.writeLock().lock();
assertHasWaiters(lock, c, t);
c.signal();
assertHasNoWaiters(lock, c);
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);
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();
long timeoutMillis = 10;
assertThreadJoinTimesOut(t, timeoutMillis);
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();
assertWriteLockedBy(lock, Thread.currentThread());
assertHasNoWaiters(lock, c);
locked.countDown();
try {
c.await();
} finally {
assertWriteLockedBy(lock, Thread.currentThread());
assertHasNoWaiters(lock, c);
lock.writeLock().unlock();
assertFalse(Thread.interrupted());
}
}});
locked.await();
assertHasWaiters(lock, c, t);
t.interrupt();
awaitTermination(t);
assertNotWriteLocked(lock);
}
/**
* 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();
assertWriteLockedBy(lock, Thread.currentThread());
assertHasNoWaiters(lock, c);
locked.countDown();
try {
c.awaitNanos(MILLISECONDS.toNanos(2 * LONG_DELAY_MS));
} finally {
assertWriteLockedBy(lock, Thread.currentThread());
assertHasNoWaiters(lock, c);
lock.writeLock().unlock();
assertFalse(Thread.interrupted());
}
}});
locked.await();
assertHasWaiters(lock, c, t);
t.interrupt();
awaitTermination(t);
assertNotWriteLocked(lock);
}
/**
* 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();
assertWriteLockedBy(lock, Thread.currentThread());
assertHasNoWaiters(lock, c);
locked.countDown();
java.util.Date d = new java.util.Date();
try {
c.awaitUntil(new java.util.Date(d.getTime() + 2 * LONG_DELAY_MS));
} finally {
assertWriteLockedBy(lock, Thread.currentThread());
assertHasNoWaiters(lock, c);
lock.writeLock().unlock();
assertFalse(Thread.interrupted());
}
}});
locked.await();
assertHasWaiters(lock, c, t);
t.interrupt();
awaitTermination(t);
assertNotWriteLocked(lock);
}
/**
* 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);
}
/**
* await after multiple reentrant locking preserves lock count
*/
public void testAwaitLockCount() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
final Condition c = lock.writeLock().newCondition();
final CountDownLatch locked = new CountDownLatch(2);
Thread t1 = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
lock.writeLock().lock();
assertWriteLockedBy(lock, Thread.currentThread());
assertEquals(1, lock.writeLock().getHoldCount());
locked.countDown();
c.await();
assertWriteLockedBy(lock, Thread.currentThread());
assertEquals(1, lock.writeLock().getHoldCount());
lock.writeLock().unlock();
}});
Thread t2 = newStartedThread(new CheckedRunnable() {
public void realRun() throws InterruptedException {
lock.writeLock().lock();
lock.writeLock().lock();
assertWriteLockedBy(lock, Thread.currentThread());
assertEquals(2, lock.writeLock().getHoldCount());
locked.countDown();
c.await();
assertWriteLockedBy(lock, Thread.currentThread());
assertEquals(2, lock.writeLock().getHoldCount());
lock.writeLock().unlock();
lock.writeLock().unlock();
}});
locked.await();
lock.writeLock().lock();
assertHasWaiters(lock, c, t1, t2);
c.signalAll();
assertHasNoWaiters(lock, c);
lock.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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
Thread t1 = new Thread(new InterruptedLockRunnable(lock));
Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
assertFalse(lock.hasQueuedThreads());
lock.writeLock().lock();
assertFalse(lock.hasQueuedThreads());
t1.start();
waitForQueuedThread(lock, t1);
assertTrue(lock.hasQueuedThreads());
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 lock = new ReentrantReadWriteLock();
try {
lock.hasQueuedThread(null);
shouldThrow();
} catch (NullPointerException success) {}
}
/**
* hasQueuedThread reports whether a thread is queued.
*/
public void testHasQueuedThread() throws InterruptedException {
final PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
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();
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 PublicReentrantReadWriteLock lock = new PublicReentrantReadWriteLock();
Thread t1 = new Thread(new InterruptedLockRunnable(lock));
Thread t2 = new Thread(new InterruptibleLockRunnable(lock));
assertEquals(0, lock.getQueueLength());
lock.writeLock().lock();
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();
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 IllegalArgumentException 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 IllegalMonitorStateException 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 IllegalArgumentException 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 IllegalMonitorStateException 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 IllegalArgumentException 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 IllegalMonitorStateException 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();
assertHasNoWaiters(lock, c);
assertFalse(lock.hasWaiters(c));
locked.countDown();
c.await();
assertHasNoWaiters(lock, c);
assertFalse(lock.hasWaiters(c));
lock.writeLock().unlock();
}});
locked.await();
lock.writeLock().lock();
assertHasWaiters(lock, c, t);
assertTrue(lock.hasWaiters(c));
c.signal();
assertHasNoWaiters(lock, c);
assertFalse(lock.hasWaiters(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);
}
}
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