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From: petey@bjcong.bj.co.uk (PETE YOXALL)
Newsgroups: comp.windows.ms.programmer
Subject: Re: Allocating Fixed Memory
Keywords: Fixed Memory Locking
Message-ID: <1163@bjcong.bj.co.uk>
Date: 19 Mar 91 17:08:34 GMT
References: <23883@hydra.gatech.EDU> <1991Mar12.183751.26640@sunee.waterloo.edu>
Reply-To: petey@bjcong.UUCP (PETE YOXALL)
Organization: Boldon James Limited (Congleton, UK)
Lines: 13

In article <1991Mar12.183751.26640@sunee.waterloo.edu> gpsteffl@sunee.waterloo.edu (Glenn Patrick Steffler) writes:
>
>GlobalDOSAlloc () is to be used to pass data to DOS TSR's or provide
>buffers for real mode device drivers.  Please use this sparingly.
>
It may be worth adding that this type of buffer only exists in the Windows
virtual machine. If a VM switch occurs (e.g a DOS shell gets a timeslice),
a TSR that had remembered the buffer address and tried to use it (maybe because
a h/w interrupt occurs) would scribble where it shouldn't or read garbage.

-- 
Peter Yoxall                      : email   : petey@boldon-james-limited.co.uk
Boldon James Ltd, Congleton, UK   : phone   : +44 260 280465