Pausing Frame Schedulers

Pausing Frame Schedulers

Any Frame Scheduler can be made to pause and restart. Any process (typically but not necessarily the FRS controller) can call frs_stop(), specifying a particular Frame Scheduler. That scheduler continues dispatching processes from the current minor frame until all have yielded. Then it goes into an idle loop until a call to frs_resume() tells it to start. It resumes on the next time-base interrupt, with the next minor frame in succession.

Note: If there is a process running Background discipline in the current minor frame, it will continue to execute until it yields or is blocked on a system service. Since a Frame Scheduler does not stop until the end of a minor frame, you can stop and restart a group of synchronized schedulers by calling frs_stop() for each one before the end of a minor frame. There is no way to restart all of a group of schedulers with the certainty that they start up on the same time-base interrupt.