Date: Fri, 17 Aug 2001 13:25:57 +0300
From: "Eli Zaretskii" <eliz AT is DOT elta DOT co DOT il>
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To: pavenis AT lanet DOT lv
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Subject: Re: _open.c commit?  (was Re: Selector Exhaustion)
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> From: pavenis AT lanet DOT lv
> Date: Fri, 17 Aug 2001 12:33:37 +0300
> > 
> > I think it should be committed and we should ask people to build
> > applications (such as Make, RHIDE, and Bash) with it and test it in a
> > variety of environments.
> 
> I have built make-3.79.1 with such patch and bootstrapped gcc-3.0.1 
> development versions (from CVS) more than once

Thanks, that's good to know.

> > However, I'd like to see that patch changed so that plain DOS systems
> > aren't affected at all.  Why slow down systems which don't need that?
> > We already have the _windows_major variable that can be used to easily
> > test for whether we are on Windows, and _get_dos_version(1) can be
> > used for NT/W2K/XP.
> 
> Ok. But I would not like to rely only on Windows presence. One can 
> try to run DJGPP applications under DOSEMU under Linux and in this 
> case I have seen descriptors leak (as far as I remeber) at least with 
> some versions. We may also have bad DPMI providers for DOS which 
> leaks descriptors. 
> 
> So I would prefer to look whether we have good DPMI server.

Right.  So maybe we should only do that with CWSDPMI.  CWSDPMI can be
recognized by calling the Get Capabilities function.

> About wasted time in Win9X: Perhaps it would be best to build
> BASH and MAKE with included descriptor leak workaround and
> compare how big is slowdown for example in real configure
> scripts and building some packages.

I think it's a good idea.

In addition to your examples, I'd also try running some of them under
GDB, because DPMI calls have a large performance hit there.  I realize
that speed normally doesn't matter under GDB, but sometimes it does:
for example, I always run Emacs under GDB, for the slim possibility
that it will crash.