From:	sandmann AT clio DOT rice DOT edu (Charles Sandmann)
Message-Id:	<10108091447.AA13261@clio.rice.edu>
Subject:	Re: Selector Exhaustion
To:	eliz AT is DOT elta DOT co DOT il (Eli Zaretskii)
Date:	Thu, 9 Aug 2001 09:47:19 -0500 (CDT)
Cc:	djgpp-workers AT delorie DOT com
In-Reply-To:	<Pine.SUN.3.91.1010809091937.7420J-100000@is> from "Eli Zaretskii" at Aug 09, 2001 09:23:49 AM
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> It also assumes all the selectors in between belong to the child program, 
> and thus are not used anymore.  Isn't that a dangerous assumption?

I worried about it.  Then I did lots of testing and each LDT appeared to
be independent, even on W95.  So it would only be a problem if we 
fragment the selectors ourselves.

> I'd say post the patch and lets ask people to patch their libraries, 
> rebuild as many applications which spawn other programs, such as Make, 
> GCC, Emacs, and Bash, and lets test how well does it work for some
> time.

Gotta go do real work now, but I'll try to post it before Andrew can
try it tomorrow.  One enhancement I considered was to not do anything
unless the absolute selector number is above some threshold.

So, if the DPMI provder doesn't leak you don't take any risk.

> This seems to be unlike what happens on Windows 9X, where exiting the 
> parent application back to COMMAND.COM frees all the selectors.

I think this is one reason why build problems are worse on W2K.

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