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From: Sami Imseih <samimseih@gmail.com>
Date: Thu, 26 Mar 2026 11:34:32 -0500
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Subject: Re: Clean up NamedLWLockTranche stuff
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Nathan Bossart <nathandbossart@gmail.com>,
 Robert Haas <robertmhaas@gmail.com>,
	"pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
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Hi,

Thanks for the patches!

> I propose the attached refactorings to make this less confusing. See
> commit messages for details.

I only took a look at 0001 so far, and I do agree with this statement
in the commit message:

"The "user defined" term was already used in LWTRANCHE_FIRST_USER_DEFINED,
so let's standardize on that to mean tranches allocated with either
RequestNamedLWLockTranche() or LWLockNewTrancheId()."

I do wonder if 0001 is going far enough though.

Instead of just standardizing that "user defined" could mean tranches allocated
with RequestNamedLWLockTranche() or LWLockNewTrancheId(), how about we also
rename these APIs to reflect that as well? This way we remove all concept of
"named tranche" which is what it sounds like to me you are proposing.

rename RequestNamedLWLockTranche() to RequestUserDefinedLWLockTranche()
and LWLockNewTrancheId() to RegisterUserDefinedLWLockTranche()

RequestNamedLWLockTranche() requests the lwlock at shmem_request time,
which is later registered via LWLockNewTrancheId() when lwlocks are
initialized by the postmaster.

Also, the name LWLockNewTrancheId() is selling what this function does
too short.
It does return a new tranche ID, but it also takes in a user-defined tranche
name and copies ("registers") that name into LWLockTrancheNames.

v19 is already changing the signature of LWLockNewTrancheId(), so maybe
improving the names of these APIs makes sense to do.

--
Sami Imseih
Amazon Web Services (AWS)