Members Of Cocoa Concurrency Operation Queue abstract base class NSOperation concrete subclass NSInvocation concrete subclass NSBlockOperation Dispatch Queue Dispatch Source Operation Queue Features graph-based dependencies completion block execution status monitoring prioritizeing canceling
Run Loop 4 roles participate in the run loop game: Run Loop which is represented by NSRun Loop & CFRunLoop. Run Loop Mode which is represented by CFStringRef associated to each instance of run loop object. Run Loop Source which is represented by CFRunloopSource. Input source Port-based source Perform selctor on other threads Custom source Timer which is represented by CFRunloopTimerRef. Explictly defined timer Perform selector on current thread with delay Perform selector Run Loop Observer 4 ways to kill a run loop iteration: no sources exists since some system routines may install certain input sources to the run loop implictly, we should not kill a run loop iteration by clearing ‘all‘ sources we known.