Scheduled-task pattern

A software design pattern scheduled-task pattern is keep track of actions and invokes them these actions, and invokes them at the appropriate times. (Note: it is not quite the same as scheduler pattern).

Intent: Ensure to ensure that desired operations are performed at specific points in the future.

Motivation: In Real-time systems, it is often necessary to ensure that something is done at a specific time. Times may be expressed as "wall time" or as some sort of internal time ("ticks", milliseconds-since-startup, etc.).

If highly accurate scheduling of tasks is needed (to milliseconds or less), the scheduler task needs to run at a very high priority, or be hooked into a high-frequency interrupt routine.

Consequences:

• To be completed

See also: Command pattern, Memento pattern

External Link

MartinFowler's Recurring Events document at PPR: http://c2.com/ppr/schedule.pdf

Credit

The first draft is based on an excerpt from WikiWikiWeb.