Re: Fix locking issue with fixed-size stats template in injection_points

Chao Li <li.evan.chao@gmail.com>

From: Chao Li <li.evan.chao@gmail.com>

To: Michael Paquier <michael@paquier.xyz>

Cc: Postgres hackers <pgsql-hackers@lists.postgresql.org>

Date: 2025-09-29T07:29:25Z

Lists: pgsql-hackers

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

injection_points: Add proper locking when reporting fixed-variable stats
- b5f898944d12 18.1 landed
- 3cc689f833b1 19 (unreleased) landed


> On Sep 29, 2025, at 14:27, Michael Paquier <michael@paquier.xyz> wrote:
> 
> On Mon, Sep 29, 2025 at 09:46:05AM +0800, Chao Li wrote:
>> I saw pg_state_begin_changecount_write() is called multiple places,
>> as you mention, for example bgwriter.
> 
> I've mentioned that in my first email, and put in details:
> - pgstat_report_bgwriter() is called once, by the bgwriter.
> - pgstat_report_checkpointer() is called three time, all by the
> checkpointer.
> - pgstat_report_archiver() is called twice, all by pgarch.c.
> 
> So all of them don't have a problem, two calls cannot happen
> concurrently.
> --
> Michael


Thanks for the clarification. Then the patch looks good to me.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/