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Mail Archives: djgpp/1997/03/12/06:26:22

From: gpt20 AT thor DOT cam DOT ac DOT uk (G.P. Tootell)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: problem with malloc in djgpp?
Date: 12 Mar 1997 09:30:35 GMT
Organization: University of Cambridge, England
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Sender: gpt20 AT hammer DOT thor DOT cam DOT ac DOT uk (G.P. Tootell)
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To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

|> > on startup the program claims (under pure dos) that it has 0.7meg real and 121meg
|> > virtual memory available.
|> 
|> What kind of system setup do you use?  If you have 8 or 16MB of RAM, how 
|> come DJGPP only sees 0.7MB free?  Did you install a huge disk cache 
|> and/or RAM disk?

nope i didn't do anything. it's someone else's machine :( i think the word is 'a
crap system' :) i tested on a 486dx66 and a p90 (the former with 8 meg the latter
with 16 meg) but i don't have the option to fiddle with their boot files and get
more memory, and besides i couldn't get 14meg out of an 8 meg machine :)

|> > now i get 7.1meg real and 120meg virtual available. this should be enough to 
|> > allocate the 14meg buffer that i require though. 
|> > dpmi_free_memory, or whatever the hugely long name for it is, says it has
|> > 127.1meg total therefore. but malloc returns a null pointer when i try to dim the
|> > block. why on earth should this be the case?
|> 
|> That's because the value returned by `_go32_dpmi_remaining_virtual_memory' 
|> *includes* the free physical memory.  When you add the two, you get 
|> larger amount than what you actually have, so `malloc' fails.

erk!! this isn't in the clib references, nor the faq methinks. or is it hiding
under some other heading maybe. i was under the impression this was the virtual
only and didn't include the physical memory. having said that, i should still
have 120meg however, so it doesn't actually explain why the malloc failed ;(

regards
nik

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