Re: Christmas list for the kernel

[Bill Davidsen <davidsen@tmr.com>]

Vojtech Pavlik wrote:
> On Wed, Nov 23, 2005 at 11:37:23AM -0500, Jon Smirl wrote:
>
>
> > Before everyone gets excited, I realize that all of this has
> > historical implications. But that doesn't mean we can't discuss
> > possible future alternative solutions.
> >
> > Thinking about this for a while it seems to me that the problem is
> > that the various apps (init, syslog) etc should not have a tty name as
> > part of their command line parameters. Instead these apps could use
> > ptys instead. Ptys would solve all of the race problems too.
> >
> > Is there any good reason (other than history) for using a device node
> > name (tty0, etc) instead of some other naming scheme if names are
> > needed at all?
> >
> > If init, syslog, etc can be converted to ptys, do we need ttys? Xterms
> > use ptys I don't notice that they aren't connect to a fix tty name.
> > The virtual consoles would still be 0,1,2 but do they have to be
> > hooked to tty0, 1, 2 instead of a pty?
>
>  
> The basic difference between a pty and tty is that a pty connects to a
> program (that created it by opening the ptmx node, for example xterm or
> ssh) on the other end, while a tty connects to the kernel doing all the
> character drawing in the framebuffer.
>
> You can't easily use one instead of the other, they're very different
> beasts.
>
> Of course, a way to use a pty would be to have the console
> implementation in userspace.
>
> The fact that no program is on the other end of a tty is also the reason
> why they cannot be created dynamically like ptys, there is noone to open
> a "ttmx" to create the ttys.
>
> Hence, the device nodes are pre-created by the kernel, while the real
> devices are only created on open.
Thank you, you can omit answering my previous post if you like, I can 
understand ugly but necessary.

--
   -bill davidsen (davidsen@tmr.com)
"The secret to procrastination is to put things off until the
 last possible moment - but no longer"  -me

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