Skip site navigation (1) Skip section navigation (2)

Re: Win32 question: getppid() with no parent?

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: Magnus Hagander <mha(at)sollentuna(dot)net>
Cc: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>,PgSql-Win32 <pgsql-hackers-win32(at)postgresql(dot)org>
Subject: Re: Win32 question: getppid() with no parent?
Date: 2004-05-27 18:10:06
Message-ID: (view raw, whole thread or download thread mbox)
Lists: pgsql-hackers-win32
Seems we removed a few getppid() calls in January:

I agree --- I don't like the pipe usage we have now.


Magnus Hagander wrote:
> >On Unix, it is possible to tell whether your parent process has died
> >by checking to see if you have become a child of init:
> >
> >	if (getppid() == 1)
> >	   /* oh dear, I am an orphan */
> >
> >Is there equivalent functionality available on Windows?
> >
> >Currently, we have the pgstat child process checking for postmaster
> >death by watching for read-ready on a pipe.  This does not scale
> >pleasantly to multiple long-lived postmaster children, though, so
> >I'm wondering about ways for the children to detect a postmaster crash
> >without requiring any direct postmaster cooperation.
> Not really.
> Can be done, but that's really ugly.
> Question though - we keep a PostmasterPid variable, right? One way to do
> it is if we n child startup do OpenProcess() on this pid, to return a
> HANDLE (the pid may be reused, but an open handle certainly can't). We
> can then do a simple:
> if (WaitForSingleObject(PostmasterHandle, 0) == WAIT_OBJECT_0)
>    /* oh dear, postmaster is gone */
> This exepects that we know whom our parent is at process start, which
> gettpid doesn't. But it might be enough?
> (If we can't rely on that variable, we could do a win32 specific hack
> that passes the HANDLE of the postmaster down to the child on exec, I
> guess.)
> //Magnus
> ---------------------------(end of broadcast)---------------------------
> TIP 3: if posting/reading through Usenet, please send an appropriate
>       subscribe-nomail command to majordomo(at)postgresql(dot)org so that your
>       message can get through to the mailing list cleanly

  Bruce Momjian                        |
  pgman(at)candle(dot)pha(dot)pa(dot)us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

In response to

pgsql-hackers-win32 by date

Next:From: Magnus HaganderDate: 2004-05-27 18:14:37
Subject: Re: Win32 question: getppid() with no parent?
Previous:From: Tom LaneDate: 2004-05-27 18:04:52
Subject: Re: Win32 question: getppid() with no parent?

Privacy Policy | About PostgreSQL
Copyright © 1996-2017 The PostgreSQL Global Development Group