NSRecursiveLock

This class is an implementation of the NSLocking protocol that provides a lock that may be acquired multiply by a single thread without creating a deadlock condition. See Chapter 2 for more information on how locking works.

@interface NSRecursiveLock : NSObject <NSLocking>

 // Instance Methods

   - (BOOL)lockBeforeDate:(NSDate *)limit;

   - (BOOL)tryLock;

 // Methods Implementing NSLocking

   - (void)lock;

   - (void)unlock;