Re: GetNamedLWLockTranche crashes on Windows in normal backend

> On Fri, Aug 22, 2025 at 02:21:55PM -0500, Sami Imseih wrote:
> > While working on [0], I observed that $SUBJECT. I encountered this issue
> > while building test cases for [0], and in which GetNamedLWLockTranche is
> > called outside of startup.
> >
> > [...]
> >
> > I repro'd this on a Windows machine, but one can also enable EXEC_BACKEND
> > in pg_config_manual.h and call GetNamedLWLockTranche by a normal backend.
> >
> > I did this by injecting
> > ```
> > GetNamedLWLockTranche("pg_stat_statements");
> > ```
> > inside pgss_ExecutorEnd
>
> If this fails, why doesn't the call in pgss_shmem_startup() also fail?  Was
> pg_stat_statements not loaded via shared_preload_libraries?

because the array is valid in postmaster, but it's not for a normal backend,
since it's not getting copied.

Yes, pg_stat_statements was loaded via shared_preload_libraries. Nothing
was done out of the ordinary.

> And is the
> failure a segfault or a "requested tranche is not registered" error?

It's a segfault.

--
Sami