cpu usage limit

[elbertlev at hotmail.com]

I understand, that what I suggest does not solve the problem you want,
but..

Why do you want to restrict CPU usage to 30%? In Windows I run CPU
intesive therads on IDLE priority, while interfacand/or communication
threads run on normal. This gives me best of two worlds:
1. I use 100% CPU (good) and
2. progam i responcive (very good).

There is no  cross platform way to change the thread priority. But most
OS (as well as thread libraries) support setting priorities.