Date: Tue, 29 Oct 1996 14:22:39 +0100 (NFT)
From: "Garrido Freire, Fco. Javier ((R)JA.GAR. SOFT)" <garridof AT cs DOT us DOT es>
Reply-To: "Garrido Freire, Francisco Javier" <Francisco-Javier DOT Garrido AT cs DOT us DOT es>
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
cc: stow AT sask DOT usask DOT ca, djgpp AT delorie DOT com
Subject: RE: Preemptive Multitasking under DPMI
In-Reply-To: <Pine.SUN.3.91.961029085031.18709M-100000@is>
Message-ID: <Pine.A32.3.95.961029141455.12326K-100000@nervion.cs.us.es>
Organization: Infoalum Mail Gateway <Infoalum AT cs DOT us DOT es>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

On Tue, 29 Oct 1996, Eli Zaretskii wrote:

[snip] 
> With all due respect, what's wrong about a scheduler getting control on a
> timer tick (by hooking the timer interrupt) and switching tasks when ``i
> decides it is a good time''?  Isn't this as preemptive as you can get?  If
> so, this capability is there in both DOS and Windows.  It is unsupported
> by the OS, true, so you have lots of things to do on your own, but it's
> far from impossible.  Even ye olde PRINT.COM does this for a long time. 
>
Here you are!.
[snip] 
> 
> Last time I looked, Windows 95 also doesn't stop everything else when you 
> format a floppy.  The BIOS has hooks that you can use to do something 
> when the system is waiting for a track to be formatted, it's just that 
> DOS file I/O functions don't use those hooks.  But nobody prevents you 
  ^^^^^^^^^^^^^^^^^
Does DJGPP use that functions or BIOS's hooks?

> from using them in a multi-tasker.
>
IMHO, Isn't DJGPP the right arena where proof this one?
 
> Mind you, I don't want to start an OS holy war here, just to make the 
> case more objectively described.
> 
I don't want to, either.
Thanks.

-------------------------------------------------------------------
F. Javier Garrido F.   (R)JA.GAR. SOFT    Dpto. de Computacion e IA
MINIX, Linux, DJGPP User.                   Facultad de Informatica
Email: Francisco-Javier DOT Garrido AT cs DOT us DOT es  y Estadistica de Sevilla
URL: http://sierpes.cs.us.es/~garridof                     (SPAIN)
"The light that burns twice as bright, burns half as long ...
   ... and you have burned so very, very brightly, Roy."
					  TYRREL from Blade Runner