task scheduling...

[Francesco Poletti]

Hi all,
one question about task scheduling...
I'm pointing out that is not available a primitive that enable us to osyield
(i.e. ask the os to schedule another task) and place that task in the back of
the list of active task. Am I wrong?
Is there some real time or scheduling constraint which doesn't allow to do that?
 Because it results to me that also p-thread doesn't allow to do something
similar....

Thanks in advance Francesco.