From owner-freebsd-current@FreeBSD.ORG  Thu Aug  2 12:00:55 2012
Return-Path: <owner-freebsd-current@FreeBSD.ORG>
Delivered-To: freebsd-current@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id EAA9B10656E7;
	Thu,  2 Aug 2012 12:00:55 +0000 (UTC)
	(envelope-from phk@phk.freebsd.dk)
Received: from phk.freebsd.dk (phk.freebsd.dk [130.225.244.222])
	by mx1.freebsd.org (Postfix) with ESMTP id A31968FC16;
	Thu,  2 Aug 2012 12:00:55 +0000 (UTC)
Received: from critter.freebsd.dk (unknown [192.168.61.3])
	by phk.freebsd.dk (Postfix) with ESMTP id 38FF73B764;
	Thu,  2 Aug 2012 12:00:49 +0000 (UTC)
Received: from critter.freebsd.dk (localhost [127.0.0.1])
	by critter.freebsd.dk (8.14.5/8.14.5) with ESMTP id q72C0mwd079435;
	Thu, 2 Aug 2012 12:00:48 GMT (envelope-from phk@phk.freebsd.dk)
To: Ed Schouten <ed@80386.nl>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Thu, 02 Aug 2012 13:23:25 +0200."
	<CAJOYFBBbskRbXjKZdv-JgHi4vJgW0S0N2DGvZgm5_oDWcY65ig@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Date: Thu, 02 Aug 2012 12:00:47 +0000
Message-ID: <79434.1343908847@critter.freebsd.dk>
Cc: Konstantin Belousov <kostikbel@gmail.com>, freebsd-current@freebsd.org,
	Hans Petter Selasky <hselasky@c2i.net>
Subject: Re: ttydev_cdevsw has no d_purge
X-BeenThere: freebsd-current@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Discussions about the use of FreeBSD-current
	<freebsd-current.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>, 
	<mailto:freebsd-current-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-current>
List-Post: <mailto:freebsd-current@freebsd.org>
List-Help: <mailto:freebsd-current-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-current>,
	<mailto:freebsd-current-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Thu, 02 Aug 2012 12:00:56 -0000

In message <CAJOYFBBbskRbXjKZdv-JgHi4vJgW0S0N2DGvZgm5_oDWcY65ig@mail.gmail.com>
, Ed Schouten writes:
>2012/8/2 Julian Elischer <julian@freebsd.org>:

TTYs are used *two* ways:  As terminals and as comms to the real world.

If a terminal-tty disappears, it should be handled like a HUP would
be, analytically it is the exact same situation as a carrier drop
on a modem.  The implementation may need to do tricky stuff, but the
result should be exactly like a HUP seen from userland.

If a comms-tty disappears, it should be handled like any other
disappearing device: ENXIO.


-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.