Re: Improve LWLock tranche name visibility across backends

Sami Imseih <samimseih@gmail.com>

From: Sami Imseih <samimseih@gmail.com>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Andres Freund <andres@anarazel.de>, Rahila Syed <rahilasyed90@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2025-08-30T16:25:48Z
Lists: pgsql-hackers
>> I've also attached a rebased patch that addresses all the latest feedback.
>> A reworked verison of the test patch is also included, but that's mostly
>> intended for CI purposes and is still not intended for commit (yet).

> And here's an attempt at fixing the alignment problems revealed by cfbot.

This LGTM. Once we get this committed, will follow-up on [0]

[0] https://www.postgresql.org/message-id/CAA5RZ0v1_15QPg5Sqd2Qz5rh_qcsyCeHHmRDY89xVHcy2yt5BQ%40mail.gmail.com

--
Sami



Commits

  1. test_dsa: Avoid leaking LWLock tranches.

  2. Teach DSM registry to ERROR if attaching to an uninitialized entry.

  3. Add a test harness for the LWLock tranche code.

  4. Revert recent change to RequestNamedLWLockTranche().

  5. Move dynamically-allocated LWLock tranche names to shared memory.

  6. Prepare DSM registry for upcoming changes to LWLock tranche names.

  7. Add GetNamedDSA() and GetNamedDSHash().