Re: [PATCH] lock_timeout and common SIGALRM framework

2012-07-11 21:47 keltezéssel, Tom Lane írta:
> Boszormenyi Zoltan <zb@cybertec.at> writes:
>> Attached are the refreshed patches. InitializeTimeouts() can be called
>> twice and PGSemaphoreTimedLock() returns bool now. This saves
>> two calls to get_timeout_indicator().
> I'm starting to look at this patch now.  There are a number of cosmetic
> things I don't care for, the biggest one being the placement of
> timeout.c under storage/lmgr/.  That seems an entirely random place,
> since the functionality provided has got nothing to do with storage
> let alone locks.  I'm inclined to think that utils/misc/ is about
> the best option in the existing backend directory hierarchy.  Anybody
> object to that, or have a better idea?

Good idea, storage/lmgr/timeout.c was chosen simply because
it was born out of files living there.

> Another thing that needs some discussion is the handling of
> InitializeTimeouts.  As designed, I think it's completely unsafe,
> the reason being that if a process using timeouts forks off another
> one, the child will inherit the parent's timeout reasons and be unable
> to reset them.  Right now this might not be such a big problem because
> the postmaster doesn't need any timeouts, but what if it does in the
> future?  So I think we should drop the base_timeouts_initialized
> "protection", and that means we need a pretty consistent scheme for
> where to call InitializeTimeouts.  But we already have the same issue
> with respect to on_proc_exit callbacks, so we can just add
> InitializeTimeouts calls in the same places as on_exit_reset().
>
> Comments?
>
> I'll work up a revised patch and post it.
>
>             regards, tom lane
>


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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
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