Processes and Communication

Michael David WINIKOFF
Tue, 9 Mar 93 15:00:52 EST

> >> I think not -- most (all?) new machines have MMUs and memory protection  is
> >> quite useful for a programmer.
> >> (It;s also ESSENTIAL for a secure multi user system)
> >> 
> >> Any comments from anyone else?
> (that's always the good'ole question: what is in spec's and what is in impl')

I'd like to think of it as a simplifying assumption -- it's fairly safe
to assume that machines will have MMUs, it (probly) simplifies some design
to do so - so why not?

> Nope, if you're sure the compiler put the required checks (not too many checks
> but just what is needed); that's why a compiled program must have been ensured
> by the local host before execution (which ultimately sums up to a popup menu
> to ask the user his opinion)

You're relying on compiler correctness.
Furthermore you're requiring all programs to do run time checking when for many
(most?) machines out there the checking can be done by hardware.
THis results in an unneccessary speed loss.

Michael Winikoff
Computer science honours. University of Melbourne, Australia.