the mmu business is a red herring. the point here is that a process and a file are fundamentally different. a file is a sequence of bytes. a process is a collection of resources (threads, file descriptors, memory segments, etc.) which are scheduled together.
i have no experience with lisp machines, but i'm fairly confident that it is not true that s-expressions are processes. did lisp machines even do multiprogramming? - erik On Fri Jun 9 17:23:28 CDT 2006, [EMAIL PROTECTED] wrote: > > > Lisp machines/environments did this 25+ years ago. > > > Everything is an s-expression is even more fun than > > > everything is a file! > > > > I don't agree. The problem with lisp is that you don't have > > protection. Didn't you manage to bring down the whole emacs > > by, say, implementing your CD player in elisp?. Now, in > > Plan 9 processes are really isolated. If one of them crashes, the other > > ones stay alive (Probably). > > Isolation by MMU is a separate issue. If you wish you can > think of a Lisp machine as analogous to Inferno, with Lisp as > its virtual machine language! Also Lisp machine != emacs. > In any case even you admit (with your parenthetical > "Probably") that while at process level there is isolation > you can still run into trouble as there may be higher level > dependencies.
