NSRecursiveLock
A lock that may be acquired multiple times by the same thread without causing a deadlock.
Declaration
class NSRecursiveLockOverview
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.