🚀 go-pugleaf

jja@wsl.ie (John J. Allen) writes:

>harris@garfield.catt.ncsu.edu (Michael Harris) writes:
>: mn87504@cs.tut.fi (Naatula Mika) writes:
>: 
>: >I thought that OS/2 could detect writes to non-allocated areas and
>: >give me a segmentation fault right away.  Like it usually does. 
>: 

>OS/2 2.0 = Flat memory model
>OS/2 1.x = Segmented memory model.
>
>The segmented memory model had some advantages over the flat model. If I
>used DosAllocSeg() to create a 20k block and then ran off the end of
>it I'd get a segmentation violation as soon as I did that. (As in Win 3.x)

This discussion has nothing to do with Flat vs Segmented memory model.  What
it deals with is WHERE some housekeeping info for your process is kept.  True,
if you used DosAllocSeg() only, you wouldn't experience this particular
problem.  HOWEVER, if you then used DosSubAlloc() you might experience the
same problem.  And then there is the other highly unlikely situation (yet
still possible) where your pointer is so screwed up that it points back to
your application stack space.
______________________________________________________________________________
     Michael Harris - harris@catt.ncsu.edu or harris@carvm3.vnet.ibm.com
 System Administrator, Computer & Technologies Theme Program, NC State Univ.
(My opinions are my own and do not represent those of NCSU or IBM Corporation)