Curt Sampson <cjs@cynic.net> writes:
> Note that your proposal of using mmap to replace sysv shared memory
> relies on the behaviour I've described too.
True, but I was not envisioning mapping an actual file --- at least
on HPUX, the only way to generate an arbitrary-sized shared memory
region is to use MAP_ANONYMOUS and not have the mmap'd area connected
to any file at all. It's not farfetched to think that this aspect
of mmap might work differently from mapping pieces of actual files.
In practice of course we'd have to restrict use of any such
implementation to platforms where mmap behaves reasonably ... according
to our definition of "reasonably".
regards, tom lane