Overrunnable Discipline

Overrunnable Discipline

You specify Overrunnable discipline with Realtime discipline to prevent detection of overrun exceptions. You specify it in two cases:

When it truly does not matter if the process fails to complete its work within the minor frame--for example, a calculation of a game strategy which, if it fails to finish, merely makes the computer a less dangerous opponent.
When a process may need more than one minor frame (see "Using Multiple Consecutive Minor Frames").

When you specify Overrunnable+Realtime, the process is not required to call frs_yield() before the end of the frame. Even so, the process is preempted at the end of the frame. It does not have a chance to run again until the next minor frame in which it is enqueued. At that time it resumes where it was preempted, with no indication that it was preempted.