X-Authentication-Warning: delorie.com: mail set sender to djgpp-bounces using -f
Date: Tue, 17 Mar 2009 15:25:04 -0400
Message-Id: <200903171925.n2HJP4UD026185@envy.delorie.com>
From: DJ Delorie <dj AT delorie DOT com>
To: djgpp AT delorie DOT com
In-reply-to: 
	<4fbb7d75-05a8-4f6b-887b-ab5ba2f4b3f2 AT p20g2000yqi DOT googlegroups DOT com>
	(message from themouse on Tue, 17 Mar 2009 11:45:53 -0700 (PDT))
Subject: Re: demand loaded?
References: <0211e58d-1d17-494d-9411-28dc3b6d6571 AT c36g2000yqn DOT googlegroups DOT com> 
	<200903171651 DOT n2HGp9Cr021772 AT envy DOT delorie DOT com> <4fbb7d75-05a8-4f6b-887b-ab5ba2f4b3f2 AT p20g2000yqi DOT googlegroups DOT com>
Errors-To: nobody AT delorie DOT com


> but when you create a new object malloc or whatever. would that be
> considered on demand? Or are you talking about something completely
> different.?

There are two things to consider here:

1. when the program is first loaded off disk, it can be loaded all at
   once or demand loaded.

2. when you ask the DPMI server for memory, the server can demand page
   it or not.

I'm not sure, but djgpp might zero out allocated memory (at least, the
first time) to make sure it's not "dirty" from the OS.  If it does
that, then it won't be demand paged in (although the os might still
demand page it *out*).

Once memory is paged in, the os can still swap it out if it needs to.
That's up to the DPMI provider, not djgpp itself.