From:	"John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Q. dpmi_free_memory() under allegro.
Date:	Sun, 03 May 1998 00:22:01 -0400
Organization:	Two pounds of chaos and a pinch of salt.
Lines:	35
Message-ID:	<354BF0E9.7440@cs.com>
References:	<2 DOT 2 DOT 16 DOT 19980503100545 DOT 1da75fda AT alphalink DOT com DOT au>
NNTP-Posting-Host:	ppp142.cs.net
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

aj wrote:
> 
> int main(void)
> {
>     __dpmi_free_mem_info *info;         // define pointer
> 
>     __dpmi_get_free_memory_information( info );                 // call to get info

Come on now, you should know better than to write to an unitialized
pointer.

   __dpmi_free_mem_info info;

   __dpmi_get_free_memory_information( &info );

BTW, the structure returned by this function is not guaranteed to be
useful or even meaningful under any particular DPMI host.  It's very
difficult to accurately determine free memory once your program has
started malloc()'ing and free()'ing.  To determine how much free memory
you have _before_ you allocate or free anything, use
_go32_dpmi_remaining_physical_memory() and
_go32_dpmi_remaining_virtual_memory().  See chapter 15.2 of the DJGPP
FAQ for more information (and you should probably read all of chapter 15
when you can, as it is useful for people who use lots of memory in their
programs).

hth

-- 
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|      John M. Aldrich       | "Courage is the complement of fear.  |
|       aka Fighteer I       | A man who is fearless cannot be      |
|   mailto:fighteer AT cs DOT com   | courageous.  (He is also a fool.)"   |
| http://www.cs.com/fighteer |                    - Lazarus Long    |
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