Exceptions in C

[Sad Clouds <cryintothebluesky%googlemail.com@localhost>]

Hi, I'm developing multithreaded code, where the nesting of functions gets  
quite deep and complicated. I'm looking into developing a small set  
routines to support exceptions in C. So instead of propagating error codes  
from one function to another, a function would simply raise an exception  
and a handler would handle it.

Before I start reinventing a wheel, does anyone know if there is already  
an API for doing this sort of thing, either in libc or some other library?