Re: system views for walsender activity

On Wed, Jan 12, 2011 at 03:03, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Tue, Jan 11, 2011 at 7:24 AM, Magnus Hagander <magnus(at)hagander(dot)net> wrote:
>>> No, do this at top
>>>
>>> if (walsnd->state == state)
>>>  return;
>>>
>>> Keep spinlocks when actually setting it.
>
> I think this is safe...
>
>> Aha. Thanks for the pointers, pfa a new version.
>
> ...but I think you also need to take the spinlock when reading the value.

Even when it can only ever be set by one process (the owning
walsender), and the variable is atomic (as it should be, since it's a
single enum/int)?

Anyway, it should be as simple as copying it out to a local variable
when it's already in the spinlock and then use that, right?

--
 Magnus Hagander
 Me: http://www.hagander.net/
 Work: http://www.redpill-linpro.com/