Re: Proposal: Add a callback data parameter to GetNamedDSMSegment

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Sami Imseih <samimseih@gmail.com>

Cc: Zsolt Parragi <zsolt.parragi@percona.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-12-12T19:41:30Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

Allow passing a pointer to GetNamedDSMSegment()'s init callback.
- 48d4a1423d2e 19 (unreleased) landed
Move dynamically-allocated LWLock tranche names to shared memory.
- 38b602b0289f 19 (unreleased) cited

On Fri, Dec 12, 2025 at 12:48:52PM -0600, Sami Imseih wrote:
> As far as testing, I did not think it's worth it since in the cases out
> there now a NULL void * will result in an error when calling
> LWLockNewTrancheId.

I think we should pass NULL to all the existing in-tree calls to
GetNamedDSMSegment(), except for perhaps a new test in test_dsm_registry
that verifies the pointer value in the initialization function.  In all the
other cases, there's no issue with hard-coding the tranche names, so we can
keep those simple.

-- 
nathan