Re: BUG #3242: FATAL: could not unlock semaphore: error code 298

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Magnus Hagander <magnus(at)hagander(dot)net>
Cc: Marcin Waldowski <M(dot)Waldowski(at)sulechow(dot)net>, pgsql-bugs(at)postgresql(dot)org, pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: BUG #3242: FATAL: could not unlock semaphore: error code 298
Date: 2007-04-20 14:58:35
Message-ID: 29400.1177081115@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs pgsql-hackers

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> On Fri, Apr 20, 2007 at 09:20:05AM +0200, Marcin Waldowski wrote:
>>> I've looked at the code there, and can't find a clear problem. One way it
>>> could happen is if the actual PGSemaphoreUnlock() is called once more than
>>> needed.

> CC:ing to hackers for this question:

> Any chance that's happening? If this happens with SysV semaphores, will
> they error out, or just say it was done and do nothing? (meaning should we
> actuallyi be ignoring this error on windows?)

How is it possible for a semaphore to be unlocked "too many times"?
It's supposed to be a running counter of the net V's minus P's, and
yes it had better be able to count higher than one. Have we chosen
the wrong Windows primitive to implement this?

regards, tom lane

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Tom Lane 2007-04-20 16:14:07 Re: BUG #3245: PANIC: failed to re-find shared lock object
Previous Message Rajeev 2007-04-20 12:57:52 BUG #3247: Porblem during Import

Browse pgsql-hackers by date

  From Date Subject
Next Message Heikki Linnakangas 2007-04-20 15:21:09 Re: Dead Space Map version 3 (simplified)
Previous Message Andrew Dunstan 2007-04-20 13:47:12 Re: [HACKERS] parser dilemma