dave@cs.arizona.edu (Dave P. Schaumann) (01/11/91)
In article <17368@cbmvax.commodore.com> kevin@cbmvax.commodore.com (Kevin Klop) writes:
![ lots of stuff about memory protection & robustness deleted ]
!
!The problem with this is the difficulty in a non memory protected model.
!There is nothing to stop the user program from trashing system structures,
!passing pointers that ostensibly point to buffers and actually point to
!program code, etc. to the operating system, nor is there any way to stop
!a program from trashing some OTHER program's code and data.
!
!"So put memory protection in" sounds like a possible answer, but has been
!hashed over and over again, this is no easy task. The ramifications are
!pretty far reaching and too detailed for me to get into now.
!
!Ditto for resource tracking so that memory, devices, etc. are freed when a
!program exits. I have more than one program that opens something and then
!passes the IO request to some OTHER task. The original task then exits.
!I certainly do NOT want the OS closing that device or deallocating the IO
!request memory on me.
!
!The question you raise, while a valid concern, is a tough one. How much
!are we willing to trade off? Do we need to put an MMU in the A500s and
!thereby raise the price of them significantly? If not, then we need
!two (or more) operating systems. One to deal with MMU systems and one that
!doesn't. The two OSs would be VERY dissimilar, and would thereby at least
!double the R&D load here at Commodore.
!
! -- Kevin --
I realize that there are some tough problems to be solved to increase the
robustness of the AmigaOS. It distresses me though when I see people post
that the guru is something we should just live with.
Obviously, no one wants to OS's, or a radically more expensive A500.
At this point, I'd settle for knowing that increasing the AmigaOS's robustness
was an important goal in future Workbench releases.
Dave Schaumann | You are in a twisty maze of little
dave@cs.arizona.edu | C statements, all different.