Re: Feature: POSIX Shared memory support

To my knowledge there is unfortunately not a portable call that does
that.
I was actually referring to the check that the current SysV code does
on the pid that is stored in the shmem header. I presume that if the
backend is dead, the kill(hdr->creatorPID, 0) returning zero would
suffice for confirming the existence of the other backend process.

Chris Marcellino

On Feb 6, 2007, at 10:32 AM, Alvaro Herrera wrote:

> Chris Marcellino wrote:
>> Tom, that is a definitely valid point and thanks for the feedback. I
>> assume that the 'more modern' string segment naming gave the POSIX
>> methods an edge in avoiding collision between other apps.
>> As far as detecting a) whether anyone else is currently attached to
>> that segment and b) whether an earlier existence of the current
>> backend was still attached to a segment, I presumed that checking the
>> pid's of the backend that owns the shared memory segment and checking
>> the data directory (both which the SysV code already does) would
>> suffice?
>
> Is there an API call to list all PIDs that are connected to a
> particular
> segment?
>
> --
> Alvaro Herrera http://
> www.CommandPrompt.com/
> PostgreSQL Replication, Consulting, Custom Development, 24x7 support