From mboxrd@z Thu Jan 1 00:00:00 1970 To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu> Subject: Re: [9fans] gcc on plan9 In-reply-to: Your message of "Fri, 09 Jun 2006 17:30:35 CDT." <5890eb0cb7b6853fe9a78c321fcc7e5e@quanstro.net> From: Bakul Shah Date: Fri, 9 Jun 2006 16:22:30 -0700 Message-Id: <20060609232230.D9853294C1@mail.bitblocks.com> Topicbox-Message-UUID: 65a5f228-ead1-11e9-9d60-3106f5b1d025 quanstro@quanstro.net wrote: > 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. You are assuming a very traditional system. But there are other ways of solving the same problems. For instance, you can have a separate thread of control in the same address space and not have it share anything with another thread. If the system guaranteed you that (modulo h/w malfunction) it will behave sanely (no buffer overflows, no wild ptrs, no "accidental" sharing, no way to reference freed up storage as a normal variable), that is a viable solution with some significant benefits as well as some shortcomings. > i have no experience with lisp machines, but i'm fairly confident that > it is not true that s-expressions are processes. Whoever said s-expressions are processes? > did lisp machines even do multiprogramming? They did. Symbolics even provided virtual memory. You may wish to check out the wikipedia entries on lisp machines and symbolics and follow some links if interested. Perhaps you and nemo are assuming that a Lisp machine is just a single threaded Lisp interpreter? Not so. They were sophisticated beasts with excellent debugging support, networking, graphics and what not.