Re: Minimal logical decoding on standbys

On Sun, 2023-04-02 at 15:29 -0700, Andres Freund wrote:
> I agree that the *wait* has to go through condition_variable.c, but
> it doesn't
> seem right that creation of the WES needs to go through
> condition_variable.c.

The kind of WES required by a CV is an implementation detail, so I was
concerned about making too many assumptions across different APIs.

But what I ended up with is arguably not better, so perhaps I should do
it your way and then just have some comments about what assumptions are
being made?

> The only thing that ConditionVariableEventSleep() seems to require is
> that the
> WES is waiting for MyLatch. You don't even need a separate WES for
> that, the
> already existing WES should suffice.

By "already existing" WES, I assume you mean FeBeWaitSet? Yes, that
mostly matches, but it uses WL_POSTMASTER_DEATH instead of
WL_EXIT_ON_PM_DEATH, so I'd need to handle PM death in
condition_variable.c. That's trivial to do, though.

Regards,
    Jeff Davis