[jwakeman]

Originally Posted by Greg McKaskle

I'm eager to hear the answer to your questions too, Ether. I don't know what the time quantum is for thread scheduling, but I'm pretty sure that equal priority threads are sliced out.

Excerpts for the VxWorks Application Programmer's Guide, 6.6:

The VxWorks traditional scheduler provides priority-based preemptive
scheduling as well as the option of programmatically initiating round-robin
scheduling. The traditional scheduler may also be referred to as the original or
native scheduler.

A priority-based preemptive scheduler preempts the CPU when a task has a higher priority than the current task running. Thus, the kernel ensures that the CPU is always allocated to the highest priority task that is ready to run

The disadvantage of this scheduling policy is that, when multiple tasks of equal priority must share the processor, if a single task is never blocked, it can usurp the processor. Thus, other equal-priority tasks are never given a chance to run. Round-robin scheduling solves this problem.

Round-robin scheduling is enabled by calling kernelTimeSlice( ), which takes a parameter for a time slice, or interval.