Feedback-ID: i0fe9450f:Fastmail
Date: Fri, 7 Jun 2024 08:20:21 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Noah Misch <noah@leadboat.com>, pgsql-hackers@postgresql.org,
	Tom Lane <tgl@sss.pgh.pa.us>, Smolkin Grigory <smallkeen@gmail.com>
Subject: Re: race condition in pg_class
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On Thu, Jun 06, 2024 at 09:48:51AM -0400, Robert Haas wrote:
> It's not this patch set's fault, but I'm not very pleased to see that
> the injection point wait events have been shoehorned into the
> "Extension" category - which they are not - instead of being a new
> wait_event_type. That would have avoided the ugly wait-event naming
> pattern, inconsistent with everything else, introduced by
> inplace050-tests-inj-v1.patch.

Not sure to agree with that.  The set of core backend APIs supporting
injection points have nothing to do with wait events.  The library
attached to one or more injection points *may* decide to use a wait
event like what the wait/wakeup calls in modules/injection_points do,
but that's entirely optional.  These rely on custom wait events,
plugged into the Extension category as the code run is itself in an
extension.  I am not arguing against the point that it may be
interesting to plug in custom wait event categories, but the current
design of wait events makes that much harder than what core is
currently able to handle, and I am not sure that this brings much at
the end as long as the wait event strings can be customized.

I've voiced upthread concerns over the naming enforced by the patch
and the way it plugs the namings into the isolation functions, by the
way.
--
Michael

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