Re: postmaster.pid

Dave Page wrote:

>
>
> ------------------------------------------------------------------------
> *From:* pgsql-hackers-win32-owner(at)postgresql(dot)org
> [mailto:pgsql-hackers-win32-owner(at)postgresql(dot)org] *On Behalf Of
> *Dave Page
> *Sent:* 20 August 2004 20:57
> *To:* Barry Lind; pgsql-hackers-win32(at)postgresql(dot)org
> *Cc:* Max Dunn
> *Subject:* Re: [pgsql-hackers-win32] postmaster.pid
>
>
>
> I've been thinking about this problem as well, and think you might
> just be on to something here. I'll look into this some more...
>
>
> The correct way to do this is MoveFileEx("postmaster.pid", NULL,
> MOVEFILE_DELAY_UNTIL_REBOOT);. This /should/ write a registry entry to
> tell the system to delete the file at reboot. Unfortunately, it seems
> that this is an administrator-only operation which of course means it
> won't work when run under the postgresql service account.
>
>

I think we're on the wrong track here. If there is a pid file then the
postmaster will try to see if the process is running by calling
kill(pid,0) - see backend/utils/init/miscinit.c.

However, on Windows we simulate kill(), and always return EINVAL if the
signal <= 0 (see port/kill.c). ISTM the correct solution would be to
implement the effect of kill(pid,0) in port/kill.c, presumably by a call
to some native Windows function that gives you the process info for a
given pid.

cheers

andrew