>>i don't know if it's capable of running multiple instances of the same
>>program or not. single-user OSi usually don't bother with that, because
>>it can be confusing to the end-user.. launching a separate instance of the
>>word processor every time you open a document, for instance.
>
>Well -- Win95 does this. It drives me crazy -- am I the only one? I've
>never understood why it couldn't "tell" that Word was already open! Or
>Netscape. I've gone down to the hidden Win95 horizontal "programs open bar"
>before and have had four instances of netscape and three of Word. Too wierd.
hmm.. that's news to me. apparently the Win95 system has multiprogramming
capability, and has gone with the easy way of handing events.
to be fair, i don't know of any really usable multiprogram interface that
tries to guess which instance of a program should get the next available
event. it's easy to let the OS know a single instance of a word processor
is running, and that it should catch all 'open this file' events caused by
the user clicking an icon on the desktop. the hard part comes when you
have more than one instance. if one of the active instances of the word
processor is supposed to catch the event, how does the user tell the OS
which one? or does the user want a whole new instance, independent from
any of the ones currently active? the general solution is to say, "heck
with it" and launch a new instance every time.
>OK - I've heard a complaint that it (unix) isn't happy with users that
>log-in and "stay in" a long time. Contrasted with a web client -- which
>sends a little request and then "turns off." Is my question clear/muddy?
>Comment?
well, as far as most versions of unix are concerned, you can camp out in
RAM until both you and the machine die of old age without causing any undue
problems. there are several user accounts which effectively stay logged
in the entire time the machine is running, in fact.. most of them are
related to system administration.
something which would cause the same general effect is the fact that unix
is a rather high-maintenance OS.. it expects to be fed, watered, petted,
and cleaned-up after on a fairly tight schedule. if it doesn't get the
treatment it wants, it can get mean.
over the course of any user login session, there are chances for programs
to leave small messes in the user's memory space, and eventually those can
cause enough clutter to kill the session itself. it's not really an OS
problem per se as much as a software problem. the same is true of any
system.. even a beta version of Windows will run stably for quite a while,
as long as nobody tries to run any software. OTOH, if you load a mildly
flaky version of MSIE on it and start browsing lots of ActiveX sites, the
mean time between bluescreens asymptotically approaches the reboot time.
>But why would I want "server-type" software on my Desktop?? I think of
>server's as having a far more troublesome job -- getting requests from lots
>of different "other people." My desktop PC only gets requests from Moi.
>Right?
well, you know that, and i know that, but as far as the OS is concerned
there's very little difference between a hundred keystrokes from a single
person and one keystroke from each of a hundred people.
having a server-style OS on your desktop system means that your computer
can go kinda schizophrenic and deal specifically with the different
snapshots of you it sees from inside the screen. one thread can
concentrate on making the Kathy who wants to print a file happy, while
another caters to the Kathy who wants to read her email. another dozen
can team up and provide cheerful service for the Kathy who wants her
browser to load & display a webpage. the more powerful the OS is, the
more completely each thread can believe that it's the *only* thing Kathy
wants her machine to do, and that makes them happier and better motivated.
it's not so much a question of having server software, but having the power
to drive a server all to yourself.
mike stone <[EMAIL PROTECTED]>
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