I was using the term task manager instead of scheduler, sorry. I still believe that there will be a significant load in the scheduler. I guess I have Windows on the brain.
Anyhoo...
I thought I read that
flock was a portable command based on the Unix
flock, not necessarily a direct pass-through. If you use it on Windows NT/2000 it should work (according to the documentation that I read). The difference, though, is that flock on Linux is only advisory while on NT/2000 it would enforced. Your code would still be portable.