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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 (view raw or flat)
Thread:
Lists: pgsql-bugspgsql-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

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