Re: Improve LWLock tranche name visibility across backends

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Sami Imseih <samimseih@gmail.com>

Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2025-08-04T19:12:30Z

Lists: pgsql-hackers

On Mon, Aug 04, 2025 at 11:32:19AM -0500, Sami Imseih wrote:
> With a local hash table, I don't think it's necessary to introduce new
> code for managing
> a DSA based list of tranche names as is done in v3. We can go back to
> storing the shared
> trance names in dshash.
> 
> What do you think?

My first thought is that a per-backend hash table seems too
expensive/complicated for this.  Couldn't it just be an array like we have
now?

-- 
nathan

Commits

test_dsa: Avoid leaking LWLock tranches.
- c5c74282f2ea 19 (unreleased) landed
Teach DSM registry to ERROR if attaching to an uninitialized entry.
- b26d76f64327 18.2 landed
- ac2800ddc185 17.8 landed
- 1165a933aab1 19 (unreleased) landed
Add a test harness for the LWLock tranche code.
- 16607718c010 19 (unreleased) landed
Revert recent change to RequestNamedLWLockTranche().
- d814d7fc3d52 19 (unreleased) landed
Move dynamically-allocated LWLock tranche names to shared memory.
- 38b602b0289f 19 (unreleased) landed
Prepare DSM registry for upcoming changes to LWLock tranche names.
- 5487058b56e0 19 (unreleased) landed
Add GetNamedDSA() and GetNamedDSHash().
- fe07100e82b0 19 (unreleased) cited