Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!POSTGRES.BERKELEY.EDU!dillon
From: dillon@POSTGRES.BERKELEY.EDU (Matt Dillon)
Newsgroups: comp.sys.amiga.tech
Subject: Re: address spaces
Message-ID: <8906122014.AA25923@postgres.Berkeley.EDU>
Date: 12 Jun 89 20:14:58 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 18

jms@tardis.Tymnet.COM (Joe Smith) Writes:
:Parts of this prediction are already here.  BiiN (formed by Intel + Siemens)
:has a system with 2**26 address spaces.  Any of which can be shared or
:private, at the programmer's whim.  A process can ask the OS to create an
:address space which refers one structure in an array of structures, and
:then pass an Access Descriptor (pointer) of this limited address space to
:another process.  Even if the second process is buggy, and tries to write
:at random offsets from the pointer, the first process is protected since the
:hardware limits what the second process is allowed to access.  
:
:Implementations along these lines have much more than just pointers to char,
:int, double, etc.  A "pointer to file" has meaning to the hardware page table.

	This sounds like Multics... nothing new at all.  It turned out that
(w/ Multics) the overhead made for very slow memory access as well as a huge
overhead for inter process / shared library calls.

				-Matt