Re: subscription/015_stream sometimes breaks

On Fri, Aug 25, 2023 at 8:15 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
>
> On Thu, Aug 24, 2023 at 3:48 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> >
> > On Thu, Aug 24, 2023 at 1:20 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> > >
> > > On 2023-Aug-24, Amit Kapila wrote:
> > >
> > > > On Wed, Aug 23, 2023 at 1:31 PM Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> > >
> > > > > Hmm, I think if worker->in_use is false, we shouldn't consult the rest
> > > > > of the struct at all, so I propose to add the attached 0001 as a minimal
> > > > > fix.
> > > >
> > > > I think that way we may need to add the check for in_use before
> > > > accessing each of the LogicalRepWorker struct fields or form some rule
> > > > about which fields (or places) are okay to access without checking
> > > > in_use field.
> > >
> > > As far as I realize, we have that rule already. It's only a few
> > > relatively new places that have broken it. I understand that the in_use
> > > concept comes from the one of the same name in ReplicationSlot, except
> > > that it is not at all documented in worker_internal.h.
> > >
> > > So I propose we do both: apply Zhijie's patch and my 0001 now; and
> > > somebody gets to document the locking design for LogicalRepWorker.
> > >
> >
> > Agreed.
> >
>
> Pushed both the patches.
>

IMO there are inconsistencies in the second patch that was pushed.

1. In the am_xxx functions, why is there Assert 'in_use' only for the
APPLY / PARALLEL_APPLY workers but not for TABLESYNC workers?

2. In the am_xxx functions there is now Assert 'in_use', so why are we
still using macros to check again what we already asserted is not
possible? (Or, if the checking overkill was a deliberate choice then
why is there no isLeaderApplyWorker macro?)

~

PSA a small patch to address these.

------
Kind Regards,
Peter Smith.
Fujitsu Australia