NSLocking — Mac OS X 10.0
This protocol is adopted by a class that
implements
lock objects. Locks are used in
multithreaded applications to coordinate access to shared,
thread-sensitive storage, or to control execution of critical
portions of code (which usually deal with these same kinds of
resources) that two or more threads may attempt to access
simultaneously. The protocol declares two methods:
lock and unlock. The
lock message is used by clients to acquire a lock
before executing critical sections of code, and the
unlock method is used to relinquish a previously
acquired lock.
The Foundation framework defines three classes that adopt the
NSLocking protocol: NSLock,
NSConditionLock, and
NSRecursiveLock. See the class descriptions for
these three classes, and Chapter 2 for more
information.