Xref: utzoo alt.sys.sun:1813 comp.unix.internals:853
Path: utzoo!attcan!uunet!zaphod.mps.ohio-state.edu!rpi!bu.edu!shelby!rutgers!njin!princeton!andante!mp
From: mp@andante.att.com (Mark Plotnick)
Newsgroups: alt.sys.sun,comp.unix.internals
Subject: ioctl's that flush typeahead on SunOS 4.0.3
Message-ID: <43727@andante.att.com>
Date: 26 Oct 90 14:50:12 GMT
Reply-To: mp@allegra.att.com (Mark Plotnick)
Organization: AT&T Bell Laboratories, Murray Hill, NJ
Lines: 21

One person here who wants absolute stability in his computing
environment reluctantly had his 4MB Sun-3/75 upgraded from SunOS 3.2 to
SunOS 4.0.3 (another manager wanted to retire the OS 3.2 fileserver).  He
is now pissed off because his typeahead is being flushed when the
'stty', 'more', and 'vi' commands are run (his objection to vi is that
typein after ZZ is flushed).  He said this never happened
before, and accuses Sun of changing the UNIX interface he's used for 15
years, and he wants us to fix this.
Maybe the problem is caused by ioctls that have changed.  Maybe the
increased slowness of OS 4.0 on memory-poor systems causes more of
a delay in process creation and exit, and this just exacerbates the race
condition that he's been toying with all these years.

We're prepared to either rebuild the user-level programs he objects to,
or make patches to the kernel.
Can anyone tell me, in SunOS 4.0.3 (and 4.1, which we may receive for
our psra server any week now) which ioctl's flush typeahead and which don't,
and how we might patch the kernel to disable implicit tty flushing?

	Mark Plotnick
	allegra!mp or mp@allegra.att.com