🚀 go-pugleaf

In article <bsm.9.0@utrcv1.res.utc.com> bsm@utrcv1.res.utc.com writes:

>I need to have a big (very big, maybe 300K) global array in a DLL.
>
>It seems to be telling me I can't have more than 32K in my global array.
>
>Is there any way I can do what I'm trying to?  I'm using Borland C.
>
>Thanks for any information!
>---------------------------------------
>Any opinions expressed here are mine alone,
>and are not those of my employer or anyone else.
>
>Brian McCarthy
>United Technologies Research Center
>East Hartford, Connecticut
>(203)727-7638
>bsm@utrc.utc.com
>---------------------------------------
>

Any data which you declare global in an application of DLL goes into the
default data segment which is limited to a total of 64k in size.  This 64k
includes all global variables, strings, stack (in the case of an
application, etc).

What you should do is have a *pointer* as a global variable, and allocate
memory using the Windows global memory functions.

ie,
    #include <windowsx.h>

    char huge *hpData;
    hpData = (char huge *) GlobalAllocPtr( GMEM_MOVEABLE | GMEM_ZEROINIT,
                                           300*1024 );

This will allocate a 300k array and store its address in the huge pointer
"hpData".  Note, incidentally, that if you allocate a block of memory >128k
in size and treat it as an array of items, each item must be an exact
power of 2 bytes in size, otherwise you'll run into segment boundary problems.

GlobalAllocPtr is a macro in "windowsx.h".  It just does a "GlobalAlloc"
followed by a "GlobalLock".  There's no problems with keeping memory locked
in protected mode windows, so it's easier to do it this way.
-- 
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| Chris Marriott                           | chris@chrism.demon.co.uk    |
| Warrington, UK                           | BIX: cmarriott              |
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