>Hi all,
>
>is it possible to reserve a certain maximum cpu power to process a tread ? So when the vpf is dealing with a heavy calculations the pc is not blocking ?

You could take a look at the application .AutoYield property and the DOEVENTS command. For example, putting DOEVENTS calls in loops can help improve responsiveness of other apps running on the same box.

It's difficult to get some single VFP commands such as a long-running SELECT - SQL to yield the processor. However in such a case you might experiment with something like this:

SELECT ;
    SomeColumnsIWant ;
    , SomeUDF() AS DummyColumn ;
    ...

* SomeUDF
FUNCTION SomeUDF

DOEVENTS

RETURN SomeDummyValue

I haven't tested the above code at all, it's just a concept. It might slow down performance a lot.