ThreadingLocks

ThreadingLocks is a collection of synchronization primitives designed to coordinate access to shared resources in multi-threaded software. It provides locking mechanisms such as mutual exclusion locks, recursive locks, and reader–writer locks, enabling threads to acquire exclusive or shared access as needed. The term is used across languages and frameworks to describe a cohesive API for thread synchronization.

Core concepts include lock acquisition and release semantics. Blocking variants cause the caller to wait until the lock becomes available, while non-blocking try-lock attempts return immediately with a success or failure result. Some implementations support timeouts to avoid indefinite waiting. Recursive (or reentrant) locks allow the owning thread to acquire the same lock multiple times. Reader–writer locks permit simultaneous access for multiple readers or exclusive access for a writer, improving performance for read-heavy workloads.

Design considerations involve avoiding deadlocks, minimizing contention, and choosing appropriate lock granularity. Correct usage often relies on consistent lock ordering and keeping critical sections short. Some ThreadingLocks implementations offer fairness guarantees to reduce thread starvation. In low-latency environments, spin locks may be used, though they can waste CPU cycles if held for long.

Typical usage patterns include protecting shared data structures, guarding invariants, and implementing higher-level synchronization constructs such as condition notifications or bounded queues. ThreadingLocks interfaces are commonly provided as part of standard libraries or concurrent utilities, sometimes integrating with condition variables or futures to wait for state changes.

See also: Synchronization primitives; Concurrency; Thread safety.