Shared Lib Question (ISC)

[Paul Barton-Davis]

In article <RANG.91May15231758 at nexus.cs.wisc.edu> rang at cs.wisc.edu (Anton Rang) writes:
>  I don't know of any operating systems which support multiple
>processes which use the load-time fixup approach.  Certain micro
>systems (e.g. the Apple //gs) do this, but the cost on a multi-user
>machine of not being able to share pages (and of paging everything in
>as you do the load-time fixup) is high.
>

Anton, I'm not quite sure what you mean by a load-time fixup appraoch,
but if it describes resolving the references to library symbols at
load time, then just check out OSF/1 :-)

Just got back from a 1 day seminar on OSF/1, and this behaviour
provoked some interesting questions from several people. Apparently,
some systems use another level of indirection to solve the problem of
globals during load-time resolution ("look at 0xXXXXXX to find out
where errno lives" type of thing). No-one at the seminar knew what
OSF/1 does, but it was claimed that Mach's lazy evaluation approach to
VM made whatever it does do much easier :-)

[ BTW - from the impression I received, I intend to stay as far
  away from OSF/1 as possible. Maybe OSF/2, if its a proper
  microkernel-based implementation of Mach, will be more
  satisfactory. However, my impressions may, of course, be wrong ]



-- 
Paul Barton-Davis <pauld at cs.washington.edu> UW Computer Science Lab	 

"People cannot cooperate towards common goals if they are forced to
 compete with each other in order to guarantee their own survival."