Re: BUG #19520: PANIC when concurrently manipulating stored procedures with pg_stat_statements and track_functions =

On Wed, Jun 17, 2026 at 03:26:33PM -0500, Sami Imseih wrote:
>> Was the idea to leave it as a backstop, or would folding the handling into
>> one place (or making _internal's an Assert) be cleaner?
>
> The check in _internal should be converted to an Assert. This documents
> that callers must only pass "live" entries, which will be the case
> for all callers after
> the patch

Yeah, I was hesitating to do so, but perhaps you are right that there
is little meaning in keeping this extra elog() anymore in the internal
routine: all its callers discard entries marked as dropped. And we do
so while holding an exclusive lock.

>> - In the missing_ok path the wrapper returns true, so the post-commit
>> caller skips the not_freed_count++/GC request that a "real" not-freed
>> drop would do. That seems harmless since the entry self-heals
>> but was returning true there a deliberate choice over mirroring
>> the not-freed/false path? I need to take a look again at this, maybe
>> I missed something.
>
> Finding an already dropped entry tells me that the first caller to drop the
> entry also triggered a gc request, so we should not request it again.

Nope, we should not trigger multiple requests.

Attaching an updated patch for now. I am still testing it locally
across all the branches to make sure that the issue is gone (that
takes quite a bit of time). I'll probably apply it in a few hours
down to v15 if nothing pops up.
--
Michael