Date: Wed, 2 Feb 94 11:27:21 EST
From: peprbv AT cfa0 DOT harvard DOT edu (Bob Babcock)
To: djgpp AT sun DOT soe DOT clarkson DOT edu
Subject: Re: GO32 paging in interrupt handlers, was: Multitasking under djgpp
Reply-To: babcock AT cfa DOT harvard DOT edu

> Go32 supports "un-page-out-able pages" but has no way of marking them
> as such from an application.  I suppose it would be a trivial addition
> to go32 for a maintainence release to provide such a hook, but I don't
> know how it would handle out-of-memory conditions (probably a panic
> for starters).

I think I'm avoiding problems by having my critical error handler in the
lower 640K set a flag without doing a callback, but I'd like to be able
to mark the page as unswappable to make sure.  I also like the idea of a
_go32_dpmi_lock_pages routine which handles the details of figuring out
whether I'm in DPMI mode or not.  As far as out-of-memory conditions, if
there are no pages which can be swapped out when you have to page something
in, I don't see any hope of recovering gracefully.