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Re: ownership of devices
>>>>> Martin == Martin P Holland <m.holland [at] noether.freeserve.co.uk> writes:
Martin> Stephen's theory that this is a _deliberate_ mistake is
Martin> interesting but even if this is so, in practice, (until
Martin> other programs are aware of it) it definitely operates as
Martin> a bug. For example, if I am logged in as one user and
Martin> startx then shutdown x but _don't_ logout and then login
Martin> on another terminal as another user then startup x this
Martin> screws up the sound in kde, presumably because the sound
Martin> devices are still owned by the previous user.
To some extent it _should_ block other users. I don't know what you
use your sound card for, but one of my correspondents doesn't type
anymore due to RSI-like symptoms. I do not want one of the other
users privileged to log on my machine starting up a Stones CD in the
middle of reading a thread containing Ben's mail. Also, when you
write terminal do you mean virtual console on the same machine? I
would not want remote users (telnet, say) playing with my sound card.
(Think about it: do you have a mike attached? Do you ever say nasty
or salacious things about anybody near that mike?) In that situation
I would use xdm to manage the X display; then you have to logout.
(The scripts may still be broken, and may not take notice of the
logout.)
If the wrapper is correctly designed (see the docs for super(1) or
tcp-wrappers = tcpd(8)), then it should release the devices when no
longer needed. This of course is a tough decision if you leave your
MUA running all day as I do.
The real solution for this is a network-ready audio daemon like NAS.
It is primitive, since it was developed before the advent of MIDI in
hardware and so on and has not been very actively maintained since.
But it explicitly allows for some applications (my MUA, which, BTW,
lives on a different host from the sound card) being able to preempt
the audio device and others to nice themselves (the CD player). You
could even allow for a multi-headed system playing multi-player games
with appropriate sharing of the sound card by all of the client
processes. (This is all theory; in practice I use super to run
Workman, the only non-NAS app I use.)
Dunno if ESounD is up to all that; it might be a more modern
alternative.
Since most Linux systems are one box-one sound card-one user, though,
the developers of most packages are rather lazy and assume that they
can take over the sound device any time they feel like it. Why
constrain myself to NAS? Everybody has a sound card! To DOS with
'em!
Martin> I also found that when I recompiled the kernel (sued from
Martin> martin) and as is my custom used the mkbootdisk command to
Martin> make the first stage of a rescue set it barfed. Presumably
Martin> again because of the owner of floppy was martin.
Did you umount the floppy? If you were su to root, you should be able
to do anything, but if the floppy was still in the mount table, you're
hosed even if you're root.
Martin> I did seriously consider going for debian to get something
Martin> stable (I even boosted the Linux Emporiums's profits) but
Martin> in the end of I decided I couldn't do without the very
Martin> latest technology (and I didn't want to be relying on a
Martin> version of debian that was described as _unstable_). I'd
Martin> be interested to hear other people's take on this.
<chortle> My only beef with Debian unstable is that if I forget to
run dselect at least once a week, getting a new package installed can
be a massive pain because the new updated list runs about 100
packages per week.
If you stay away from packages that are labelled alpha you should be
OK. If you do C++ development, you should put your gcc package on
hold because the GCC developers don't care if every new version
contains newly implemented features that break the old workarounds.
(Anybody tried to build a recent CODA with gcc-2.95?)
OTOH, it looks like my definition of hot technology is different
from yours, so get other opinions. I achieved satori years ago and
don't need Enlightenment, I don't know GNOME from a hole in the
ground, for drug'n'drip I use aspirin and coffee, etc. :-) And my
personal user is logged in whenever I'm there, other users come and go
as I need them, which sounds like a very different MO from yours.
But Debian unstable has been far more reliable than any RedHat
distribution (4.0, 4.1 Sparc, 4.2, 5.1) or TurboLinux distribution
(various pre-3.0 Japanese betas) I've used.
--
University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN
Institute of Policy and Planning Sciences Tel/fax: +81 (298) 53-5091
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