The following reply was made to PR kern/32682; it has been noted by GNATS.

From: christos@zoulas.com (Christos Zoulas)
To: Hauke Fath <hf@spg.tu-darmstadt.de>
Cc: gnats-bugs@NetBSD.org, kern-bug-people@NetBSD.org,
	gnats-admin@NetBSD.org, netbsd-bugs@NetBSD.org
Subject: Re: kern/32682: netbsd-3 ptyfs intermittent failure with Matlab
Date: Mon, 17 Jul 2006 10:58:55 -0400

 On Jul 17,  4:54pm, hf@spg.tu-darmstadt.de (Hauke Fath) wrote:
 -- Subject: Re: kern/32682: netbsd-3 ptyfs intermittent failure with Matlab
 
 | Am 31.01.2006 um 12:52 Uhr -0500 schrieb Christos Zoulas:
 | >
 | >Can you show what w(1) prints and the "interesting" ptys in /dev/[pt]ty??.
 | >I suspect what is going on, is that you have a rogue program that is
 | >opening old style pty's behind the pty subsystem's back, so when ptyfs
 | >tries to open the same pty, it fails. So when it fails for pts/4 for
 | >example, what does lsof say for /dev/{t,p}typ4?
 | 
 | Getting back to this after a while...
 | 
 | I have pkgsrc-2006Q1 packages out now which were built on a machine 
 | without the /dev/[pt]ty[pqrs]? pty device files, and deployed on 
 | clients that do not have them, either, but use ptyfs mounted to 
 | /dev/pts instead.
 | 
 | But I still see matlab failing to open a /dev/pts/? every now and 
 | then, although the /dev/ptmx && /dev/pts/? way should be the only way 
 | to get a pty on the machine now, so no concurrent access, right?
 | 
 | The details:
 
 I have a theory. The pty returned by ptmx is not being marked as in
 use immediately, so it can be potentially returned twice to two different
 processes. I will check.
 
 christos