Message-ID: <3426B8C0.15EF@EnchantedLearning.com>
Date: Mon, 22 Sep 1997 11:28:17 -0700
From: Mitchell Spector <spector AT EnchantedLearning DOT com>
Reply-To: spector AT EnchantedLearning DOT com
Organization: Enchanted Learning Software
MIME-Version: 1.0
To: djgpp AT delorie DOT com
CC: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
Subject: Re: DJGPP, interprocess communication, and DPMI
References: <Pine DOT SUN DOT 3 DOT 91 DOT 970918120449 DOT 1776B-100000 AT is>
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Eli Zaretskii wrote:
> 
> On Wed, 17 Sep 1997, Mitchell Spector wrote:
> 
> > Can a DJGPP program running in a DOS box under Windows 95
> > communicate with another currently-running program (either
> > another DJGPP program in a different DOS box or a regular
> > Win32 app)?
> 
> One way that's simple to implement is to use the Windows clipboard.
> A bunch of functions of Interrupt 2Fh let DOS programs get and put
> text from and to the Windows clipboard.  Look in Ralf Brown's
> Interrupt List, under W-2F1700 (WINOLDAP) and thereabouts....
[I clipped the rest of the article.]

Thanks for the suggestion -- it's a good idea, and I wasn't aware of
the WINOLDAP interrupts.

I wrote a small test program, and unfortunately this seems too slow
to use for the intended purpose, but I haven't traced down yet where
the bottleneck is.  I don't have any timing figures yet, but my casual
impression is that the slowdown is huge.  To use this for interprocess
communication, I need to be able to poll quickly to see if there is a
new message waiting.  It's the polling that seems to bog things down.

This is a useful technique to be aware of, even if it turns out not
to solve this particular problem -- thanks.

Mitchell
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Mitchell Spector, Enchanted Learning Software
E-mail: spector AT EnchantedLearning DOT com
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