Re: pgsql: dshash: Add sequential scan support.

On Tue, Jul 5, 2022 at 3:21 PM Thomas Munro <thomas(dot)munro(at)gmail(dot)com> wrote:
> On Tue, Jul 5, 2022 at 11:25 AM Andres Freund <andres(at)anarazel(dot)de> wrote:
> > On 2022-07-05 11:20:54 +1200, Thomas Munro wrote:
> > > Since there were 6 places with I-hold-no-lock assertions, I shoved the
> > > loop into a function so I could do:
> > >
> > > - Assert(!status->hash_table->find_locked);
> > > + assert_no_lock_held_by_me(hash_table);
> >
> > I am a *bit* wary about the costs of that, even in assert builds - each of the
> > partition checks in the loop will in turn need to iterate through
> > held_lwlocks. But I guess we can also just later weaken them if it turns out
> > to be a problem.
>
> Maybe we should add assertion support for arrays of locks, so we don't
> need two levels of loop? Something like the attached?

Pushed.