Activity object Framework II: Activity object and activity Scheduler

The event is scheduled by the activity scheduler.

Events are handled by activity objects.

 

Activity object

* It can be used to process asynchronous function responses.
* Derived from cactive (all activity objects are derived directly or indirectly from cactive)
* Contains
-A trequeststatus base class member variable istatus, which is used to pass in asynchronous Functions
-Runl () function, called after the request is complete
-Docancel () function, called when the request is canceled
-Priority: used to determine the call priority.
 

 

Activity Scheduler

* For a GUI program, after the program is started, the operating system will create an activity Scheduler

* The activity scheduler runs in the main thread of the application.

* You can customize the activity scheduler by yourself, but each thread can have only one activity Scheduler

* Running mode of the activity Scheduler

-Synchronization is waiting for unfinished requests to be completed

-Check the registered activity object by priority and check whether there are incomplete requests or whether the requests have been completed (istatus! = Kpequestpending)

-After the activity Object Request is complete, runl () can be called.

-Other requests can be checked only when runl () is returned.