Effective Objective-C 2.0: Item 41: Prefer Dispatch Queues to Locks for Synchronization
Item41:PreferDispatchQueuestoLocksforSynchronizationSometimesinObjective-C,youwillcomeacrosscodethatyou’rehavingtroublewithbecauseit’sbeingaccessedfrommultiplethreads.Thissituationusuallycallsfortheap