Cicode Programming Reference > Performing Advanced Tasks > Pre-emptive multitasking

Pre-emptive multitasking

Cicode supports pre-empted multitasking. If a Cicode task is running, and a higher priority task is scheduled, CitectSCADA will suspend the original task, complete the higher priority task and return to the original task.

Preemption is supported between Cicode threads and other internal processes performed by CitectSCADA. You can, therefore, write Cicode that runs forever (for example, a continuous while loop) without halting other Cicode threads or CitectSCADA itself. For example:

INT FUNCTION MyLoopFunction()
// Whatever is required in the continuous loop
Sleep(1); // Optional

In the above example, the function Sleep() is used to force preemption. The Sleep() function is optional, however it will reduce the load on the CPU, because the loop is suspended each second (it will not repeat at a high rate).

See Also

Performing Advanced Tasks