Hello, thank you for understanding.
At Mon, 25 Apr 2016 10:26:49 -0400, Robert Haas <robertmhaas@gmail.com> wrote in
<CA+TgmoZDcaGCF0n9PaF5kzwj0CNRa-E+tDgzW80GVxg77gPdSA@mail.gmail.com>
> On Thu, Apr 21, 2016 at 9:47 PM, Kyotaro HORIGUCHI
> <horiguchi.kyotaro@lab.ntt.co.jp> wrote:
> > A lock was already held in BackendPidGetProc(). Is it also
> > needless? If so, we should use BackendPidGetProcWithLock() instad
> > (the name seems a bit confusing, though).
>
> Oh, that's really sad. No, that lock is definitely needed. We should
> probably try to figure out some day if there is a way to make this
> completely lockless, but that'll have to be 9.7 material or later.
> :-(
Agreed.
> > What I did in the patch was just extending the lock duration
> > until reading the pointer proc. I didn't added any additional
> > lock.
>
> Sorry, I didn't realize that. Good point.
I'm happy that you understand me:)
> >> > The
> >> > only thing we need to do is to prevent the value from being read
> >> > twice, and we already have precedent for how to prevent that in
> >> > freelist.c.
> >
> > However, I don't have objections for the patch applied.
>
> OK, let's leave it like that for now, then.
regards,
--
Kyotaro Horiguchi
NTT Open Source Software Center