From:	sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Message-Id:	<9807222106.AA14327@clio.rice.edu>
Subject:	Re: Ispell and pipes
To:	salvador AT inti DOT gov DOT ar (Salvador Eduardo Tropea)
Date:	Wed, 22 Jul 1998 16:06:37 -0600 (CDT)
Cc:	eliz AT is DOT elta DOT co DOT il, djgpp-workers AT delorie DOT com
In-Reply-To:	<m0yz4vV-000S56C@inti.gov.ar> from "Salvador Eduardo Tropea" at Jul 22, 98 05:00:57 pm

> > So, if you used the RMCB you would have to lock the buffers that you take 
> > bytes out of and the code, but this would be fairly small and localized.
> 
> But we want to make it: DJGPP program B calls a real mode function, 
> the real mode funtion is a RMCB that was created by djgpp program A 
> so the execution jumps to program A. 
> As program B is in protected mode and in normal execution (not inside 
> an ISR) we are shure that DOS isn't busy.
> That's our case. Now Eli question is if we need to lock the code just 
> because CWSDPMI will check it even when DOS isn't busy.

You need to lock the code, since program B may use lots of memory and
cause program A to be paged out.  When the page fault happens CWSDPMI
won't be sure what the DOS state is.  You know, but it doesn't ...

If you don't lock it it may work 99% of the time and only fail on
memory tight machines.

Locking the memory isn't that hard ...

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