problems with v3

[Roland McGrath]

I don't really know the gdb code, but I'm surprised it really has multiple
different "serial" backends.  I would have thought that after opening the
fd, you would treat them all about the same.  If tcsetattr et al work on
it, then you set the baud rate and whatever, if they say ENOTTY then fine.
It might make sense to default to a short read timeout for an actual serial
port (or UDP port), which might be unplugged or the other end dead, or
whatever; and to an infinite timeout for a non-tty, which should more
presumably have its fd shut down and read EOF or EPIPE or whatever when the
stub goes away, and otherwise perhaps the stub is just taking that long.
But aside from that, I don't know why you wouldn't treat all kinds of
remote protocol fd's the same wrt select/poll and blocking/nonblocking
reads/writes, be they serial-port fds, "pipe" socketpair sockets, network
sockets, or fds to a new magic file that pretends to be a tty or a socket
or whatever (or even a disk file of canned response playback!).


Thanks,
Roland