Windows API - GetLastError woes

[Esa Ilari Vuokko]

Hi,

My "use case" is in Win32-package, where we simply call a FFI
imported call and on failures call GetLastError to get extended
error code.  GetLastError of course only works on same OS thread
and contains sensible results only before next Windows API call.
It's much like C/posix errno.

So, we *must* call GetLastError in the same OS thread, and there
must not be any Windows API calls in between, including those caused
by, say, rts' memory allocation or calls to lock mutexes.  Unless the
error code is saved via Get/SetLastError.

Also, I'd like not to run the code in a another OS thread (and
that won't fix the rts-caused Windows API calls), because the calls
are supposed to be fast, and OS-level context switch isn't fast.

Is this problem real, or did I miss some magic feature of rts?

The only way to solve this problem seems to be to wrap all
calls in C-functions that take care of reading GetLastError.
Not that it's impossible, just very annoying.

Best regards,
--Esa Ilari Vuokko