Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uunet!auspex!guy
From: guy@auspex.auspex.com (Guy Harris)
Newsgroups: comp.os.misc
Subject: Re: What constitutes a good OS?
Message-ID: <5258@auspex.auspex.com>
Date: 15 Jan 91 19:02:12 GMT
References: <1991Jan14.042520.18150@acc.stolaf.edu> <5233@auspex.auspex.com> <41679@nigel.ee.udel.edu>
Organization: Auspex Systems, Santa Clara
Lines: 59

>From the 15 pages I've read about it, I see Plan-9 doing all the same
>things wrong that UNIX did.  They seem to have only files which are
>byte arrays,

As opposed to VMS, which has only files that are disk-block arrays? :-)

I.e., are you complaining about the fact that UNIX doesn't come standard
with an ISAM package (some vendors may actually provide one standard
with their UNIX releases, I dunno), or about the fact that UNIX doesn't
come standard with one *below user-mode*?

>in spite of the fact that 99.44% of programs I've seen
>want records, and most want keyed records.

Different people see different things; most of the programs I've seen
recently want lines or byte streams (not necessarily *character*
streams, just *byte* streams - and yes, I include compilers/assemblers
and linkers into the latter category).

>UNIX then seems to attempt to stuff every object that *isn't* a file
>into this same mode, and poorly at that. Plan-9 seems to be going the
>same way.

Eh?  To which objects are you referring?  Many devices either fit the
byte-stream model, or the sort-of record model wherein each "write()"
writes one record/block and each "read()" reads one.  The same applies
to many network connection types.  Even "/proc" actually seems to fit
the file model pretty well.

>They have put the windowing stuff neither in the kernel, where you
>would expect it to have to work to be commercially viable,

DEC, Sun, IBM, HP, etc. all seem to be commercially-viable companies
making products that use a window system implemented *not* in the
kernel of their systems, but in a user-mode process that accepts IPC
connections....  (You may not *like* X, but it seems to be "good enough"
for lots of people.)

>or totally out of the kernel where you can replace it when you need to (unless
>there are installable device drivers/servers/whatever).

From what I read of the Plan 9 paper, the only parts of the window system
that *might* be done in the kernel are the lowest-level "/dev/cons",
"/dev/mouse", and "/dev/bitblt" drivers.  The rest is in user mode,
where it's replaceable, as far as I can tell; it might be nice if you
could replace the remaining bits, but the same could be said about other
kernel features (in UNIX, and in other systems as well).

>In addition, the interface is via bitblt, leading to device dependance
>and probably inefficient display over a slower-speed network.

Anybody who's actually used it know how good or bad it actually *is*
over various speeds of network (how slow is a "slower-speed" network?)?

>I suspect that the security features of the file systems are just as
>bad as on UNIX too; however, I have no evidence to that effect except
>that they have kept the rest of the uglynesses too.

To what are you referring here?  The lack of ACLs?  Something else?