Re: pgsql: Make archiver process an auxiliary process.

On Mon, Mar 15, 2021 at 5:14 PM Fujii Masao <fujii(at)postgresql(dot)org> wrote:
> Make archiver process an auxiliary process.
>
> This commit changes WAL archiver process so that it's treated as
> an auxiliary process and can use shared memory. This is an infrastructure
> patch required for upcoming shared-memory based stats collector patch
> series. These patch series basically need any processes including archiver
> that can report the statistics to access to shared memory. Since this patch
> itself is useful to simplify the code and when users monitor the status of
> archiver, it's committed separately in advance.

I think this needs to handle ProcSignalBarrierPending. Otherwise,
code that tries to use proc signal barriers (like CF #2962 and #2602)
might hang forever when an archiver is running.