Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!rit!ultb!ritcsh!sabin!bjm
From: bjm@sabin.UUCP (Brendan J. McMahon)
Newsgroups: comp.lang.c
Subject: Malloc Trouble with Large Memory Model
Message-ID: <208@sabin.UUCP>
Date: 19 Apr 89 19:42:35 GMT
Reply-To: bjm@sabin.UUCP (Brendan J. McMahon)
Organization: Sabin Metal Corp., Scottsville, NY
Lines: 43


We have never had any need for any memory module other than the 
default small.

We are switching to a new machine (intel 386 ) and our database libraries
(informix) only came in the large model.

So all programs that use these have to be compiled with -Ml2 (large model 286). 
(Or do they?)

Jist of a Problem:

struct labelrec{
    int blah;
    .
    .
};
struct labelrec  *lrec[20];

lrec[0]=(struct labelrec *)malloc(sizeof(struct labelrec));

Compile Message:
Warning: cast of int expression to far pointer

Run time problems:

Printf(sizeof(struct labelrec)) = Some huge number 

It should be around 64.

So it looks like it has put the lrec pointers into a seperate data segment,
but the int return value from malloc does not give lrec[0] the
large full address (segment:offset pair) needed to access this data.

I am not familiar with memory modules, so many attempts to throw in
near/far keywords around different definitions did no good.

Thanks for any help!
-- 
Brendan J. McMahon
Sabin Metal Corp. |     Refiners of Precious Metals    | Hardware Trouble?
Scottsville, NY   |  ****** Au  Ag  Pt  Pd  Rh ******  | Give us a call, we'll
716-538-2194      |lazlo!sabin!bjm  || ritcsh!sabin!bjm| melt your trouble away