Re: Strange failure in LWLock on skink in REL9_5_STABLE

On Tue, Nov 6, 2018 at 10:18 AM Robert Haas <robertmhaas@gmail.com> wrote:
> On Mon, Nov 5, 2018 at 2:28 AM Michael Paquier <michael@paquier.xyz> wrote:
> > Hm.  Don't we need to worry about anybody potentially using these APIs
> > in a custom module on platforms where it was actually working?  I
> > imagine that their reaction is not going be nice if any code breaks
> > suddenly after a minor release.  No issues with removing the interface
> > on HEAD of course.
>
> +1.
>
> The fact that the code exists there at all is my fault.  I thought it
> might be useful someday, but now I don't think so any more.  Thomas's
> solution -- in the DSA machinery -- of allocating entirely new
> segments seems like a better approach for now, and in the long run, I
> think we should convert the whole backend to use threads,
> nonwithstanding the TODO entry that says otherwise.  Even if we never
> do that, extending a segment in place is pretty difficult to make
> practical, since it may involve remapping the segment, which
> invalidates cached pointers to anything in the segment.  And then
> there are the portability problems on top of that.  So I'm not very
> optimistic about this any more.
>
> But ripping it out in the back branches seems unnecessary.  I'd just
> leave the bugs unfixed there.  Most likely nobody is using that stuff,
> but if they are, let's not break it.

Thanks.  Pushed to master only.

-- 
Thomas Munro
http://www.enterprisedb.com