shared memory

[Doug Gwyn]

In article <20552 at pasteur.Berkeley.EDU> jas at 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.