# NSRecursiveLock A lock that may be acquired multiple times by the same thread without causing a deadlock. ``` class NSRecursiveLock ``` ## Overview [`NSRecursiveLock`](/documentation/Foundation/NSRecursiveLock) defines a lock that may be acquired multiple times by the same thread without causing a deadlock, a situation where a thread is permanently blocked waiting for itself to relinquish a lock. While the locking thread has one or more locks, all other threads are prevented from accessing the code protected by the lock. ## Topics ### Acquiring a Lock [`lock(before:)`](/documentation/Foundation/NSRecursiveLock/lock(before:)) Attempts to acquire a lock before a given date. [`try()`](/documentation/Foundation/NSRecursiveLock/try()) Attempts to acquire a lock, and immediately returns a Boolean value that indicates whether the attempt was successful. ### Naming the Lock [`name`](/documentation/Foundation/NSRecursiveLock/name) The name associated with the receiver. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)