Lock Types API Reference¶

This page documents the API for all distributed lock types. For detailed explanations and sequence diagrams, see the Locking Primitives section.

Quick Reference¶

Type	Interface	Details
Redlock	`Lock`	Standard distributed lock
FairLock	`Lock`	FIFO ordering
MultiLock	`Lock`	Multi-resource
ReadWriteLock	`ReadWriteLock`	Reader/writer
Semaphore	Custom	Permit-based
CountDownLatch	Custom	Coordination

Lock Interface Methods¶

Applies to: Redlock, FairLock, MultiLock, read/write locks

Method	Description
`void lock()`	Acquires the lock, blocking until available
`void lockInterruptibly()`	Acquires the lock, can be interrupted
`boolean tryLock()`	Tries to acquire immediately
`boolean tryLock(long time, TimeUnit unit)`	Tries to acquire within timeout
`boolean tryLock(Duration timeout)`	Tries to acquire within timeout
`void unlock()`	Releases the lock
`boolean isHeldByCurrentThread()`	Returns true if current thread holds lock

RedlockReadWriteLock Methods¶

Method	Description
`Lock readLock()`	Returns the read lock
`Lock writeLock()`	Returns the write lock

RedlockSemaphore Methods¶

Method	Description
`void acquire()`	Acquires one permit, blocking
`void acquire(int permits)`	Acquires multiple permits
`boolean tryAcquire()`	Tries to acquire one permit immediately
`boolean tryAcquire(Duration timeout)`	Tries to acquire one permit
`boolean tryAcquire(int permits, Duration timeout)`	Tries to acquire multiple permits
`void release()`	Releases one permit
`void release(int permits)`	Releases multiple permits
`int availablePermits()`	Returns estimated available permits

RedlockCountDownLatch Methods¶

Method	Description
`void countDown()`	Decrements the count by one
`void await()`	Waits until count reaches zero
`boolean await(Duration timeout)`	Waits with timeout
`long getCount()`	Returns current count

Creation Methods¶

All locks are created via RedlockManager:

// Standard lock
Lock lock = manager.createLock("resource");

// Fair lock
Lock fairLock = manager.createFairLock("resource");

// Multi-lock
Lock multiLock = manager.createMultiLock(Arrays.asList("res1", "res2"));

// Read-write lock
RedlockReadWriteLock rwLock = manager.createReadWriteLock("resource");

// Semaphore
RedlockSemaphore sem = manager.createSemaphore("resource", 5);

// Countdown latch
RedlockCountDownLatch latch = manager.createCountDownLatch("latch", 3);

Next Steps¶

Async & Reactive - Async and reactive APIs
Configuration - Configuration options