Message-Id: <m0x8OaJ-000S1uC@inti.edu.ar>
Comments: Authenticated sender is <salvador AT natacha DOT inti DOT edu DOT ar>
From: "Salvador Eduardo Tropea (SET)" <salvador AT inti DOT edu DOT ar>
Organization: INTI
To: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>, djgpp-workers AT delorie DOT com
Date: Tue, 9 Sep 1997 15:00:35 +0000
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Subject: Re: fread slowstart
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Eli replayed:

> > In DOS memory there should be at most a single pointer
> > (descriptor:offset) to the memory that programs have to use.
> > So the tb remains only a bucket where we pass stuff that MUST be in the
> > first MB and where we get the results. So a single tb (or at least one
> > for each process running, if/when mtasking implemented) should be
> > enough.
> 
> A single tb is not good enough, even if there's no multitasking, because 
> the child program would overwrite the contents of the buffer, and when 
> controls gets back to the parent, it will see in the tb something 
> different from what it put there before spawning the child.  This might 
> lead to very subtle bugs.
I agree, but what if the child makes a copy at start-up and restores it on 
shut-down? Of course that doesn't work for multitask, but perhaps can be used 
as a configurable option to run programs with a lot of nested childs ...
It just an idea.
 
> > Well, I'm really non a so low-level programmer, but I can't see why
> > shouldn't it work. If I remember well it's nearly what Win31 does...
> 
> You can do anything in a software that is many megabytes large and takes 
> up about 10MB of memory when it runs.  In particular, Windows catches all 
> the software interrupts and serves as a DOS extender, in addition to 
> being a DPMI server.  You can do a lot if you have such a complete 
> control of the machine.  
Yes!, and you can waste the machine as Winblows does :-)))) 

> Simple DOS DPMI servers cannot do all that.

SET
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