Re: GetNamedLWLockTranche crashes on Windows in normal backend

On Thu, Sep 04, 2025 at 08:35:13PM -0500, Nathan Bossart wrote:
> On Thu, Sep 04, 2025 at 04:12:09PM -0500, Sami Imseih wrote:
>>> Yeah, I think modeling this after commit 4f2400c is a reasonable thing to
>>> explore.
>> 
>> Here it is as described above.
> 
> Thanks.  This looks like the right idea to me, but let's give some time for
> others to comment.

I've started preparing this for commit, and I realized that restricting
GetNamedLWLockTranche() to shmem_startup_hook is not sufficient.
EXEC_BACKEND builds will run this hook in every backend, so unless it's
guarded behind some sort of "if (!found)" condition (i.e., only run in the
postmaster), it'll still crash.  I think we just need to add some extra
notes to the docs and check for !IsUnderPostmaster, as discussed upthread.

-- 
nathan