On 09 Sep 2021 10:24, Eli Zaretskii wrote:
> > Date: Thu,  9 Sep 2021 02:38:36 -0400
> > From: Mike Frysinger via Gdb-patches <gdb-patches@sourceware.org>
> > 
> > Replace various custom ad-hoc fcntl/O_NONBLOCK implementations with
> > the gnulib nonblocking module.  This makes our code much tidier and
> > portable to other systems (e.g. Windows).
> 
> I'm not familiar with the sim's code, but Gnulib AFAIK supports
> non-blocking flag on MinGW only for named pipes and sockets, not for
> real files.  Are all the file descriptors in the places where you make
> the changes of one of those kinds?  E.g., I see the fcntl calls on
> file descriptor zero in some places.

sim only uses nonblocking on sockets or tty's (e.g. stdin), not files on disk.
i don't know offhand about the specifics of Windows stdio and whether those are
actually pipes.
-mike