From: "Aya Iwata (Fujitsu)" <iwata.aya@fujitsu.com>
To: 'Michael Paquier' <michael@paquier.xyz>
CC: Chao Li <li.evan.chao@gmail.com>, "Hayato Kuroda (Fujitsu)"
	<kuroda.hayato@fujitsu.com>, pgsql-hackers <pgsql-hackers@postgresql.org>,
	Peter Smith <smithpb2250@gmail.com>
Subject: RE: [PROPOSAL] Termination of Background Workers for ALTER/DROP
 DATABASE
Thread-Topic: [PROPOSAL] Termination of Background Workers for ALTER/DROP
 DATABASE
Thread-Index: 
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Date: Wed, 24 Dec 2025 08:42:51 +0000
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Precedence: bulk

Hi

> FWIW, while reading this code, I was wondering about one improvement
> that could show benefits for more extension code than only what we are
> discussing here because external code has no access to
> BackgroundWorkerSlot while holding the LWLock BackgroundWorkerLock in
> a single loop, by rewriting this new routine with something like that:
> void TerminateBackgroundWorkerMatchin(
> bool (*do_terminate) (int pid, BackgroundWorker *, Datum))
>=20
> Then the per-database termination would be a custom routine, defined
> also in bgworker.c.  Other extension code could define their own
> filtering callback routine.  Just an idea in passing, to let extension
> code take more actions on bgworker slots in use-based on a PGPROC
> entry, like a role ID for example, or it could be a different factor.
> Feel free to dislike such a funky idea if you do not like it and say
> so, of course.

I'm sorry for the delayed response.
I tried implementing a callback function within the for loop to allow setti=
ng the termination
condition myself. However, I felt this method had few use-cases. Since LWlo=
ck exists in here, it can
only handle lightweight operations.
Therefore, I'd prefer not to include it at this time. If I later think of a=
 useful scenario for it, I'll=20
reconsider about this.

Best Regards,
Aya Iwata