Path: utzoo!attcan!uunet!aplcen!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.unix.wizards
Subject: Re: shared memory
Keywords: portability
Message-ID: <11797@smoke.BRL.MIL>
Date: 12 Dec 89 02:58:23 GMT
References: <11383@csli.Stanford.EDU> <20552@pasteur.Berkeley.EDU>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 15

In article <20552@pasteur.Berkeley.EDU> jas@postgres.berkeley.edu (James Shankland) writes:
>Though I haven't used it, the SunOS4.x mmap interface seems like a much
>more rational approach to shared memory.  Can anyone comment on its
>usefulness and its future?  Also, are there incompatibilities between
>Sun's mmap and that of other vendors (doesn't Sequent have an mmap
>interface, too?), and the unimplemented mmap() described in the 4.2 docs?

UNIX System V Release 4 provides something like the SunOS approach.
(I don't know how compatible the various mmap() implementations are,
but I can certainly imagine application portability problems similar
to the ones that started this thread.)

Note that not all environments can provide reasonable shared-memory
facilities.  Typically real crunchers have only primitive memory
management hardware.