errno issues.

[Stefan Burstroem]

Hi!
While trying to create a threadsystem that works on AmigaOS, I realized that the errno value isn't preserved
when between processes.
I know that the possibility is quite small that there is a context switch just when an IO function returns
and the calling function reads errno, but it is there.

Any ideas anyone?

On those systems where errno is an external int errno, it shouldn't be more complicated than saving
it during the context switch and restoring it afterwards, but what to do on those systems where
errno is a macro?

regards,
Stefan Burström
stefan@omnipresence.com