In 'NSNotificationCenter Class Reference' it says:
Each task has a default notification center.
I wonder what a task is?
The meaning of the word "task" depends on the context. Often (as in
this instance), it means the same thing as "process".
In 'Multithreading Programming Topics' it says:
In Mac OS X, each process (application) is made up of one or more
threads. ...Threads let your program perform multiple tasks in
parallel.... Each
thread has its own execution stack and is scheduled for runtime
separately by the kernel.
In this instance, "task" is being used as a generic term for some
unit of work (the word "job" is also commonly used for this, though
historically that might also have been confusing). It isn't the same
meaning.
From the above description it is clear what a thread is. But what
is a task? Can a thread have several tasks with each task having
its own default notification center?
No. The process (the first meaning of "task") has a default
notification centre. Threads share that notification centre, though
it's important to note that notifications will be delivered on the
thread that sent them.
