Re: fix worker_spi to run as non-dynamic background worker

On Fri, May 23, 2014 at 10:38 AM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
> On Fri, May 23, 2014 at 6:29 PM, Shigeru Hanada
> <shigeru(dot)hanada(at)gmail(dot)com> wrote:
>> I noticed that contrib/worker_spi can't run as non-dynamic background
>> worker (IOW, load via shared_preload_libraries), because of
>> uninitialized bgw_notify_pid.
> That's actually the case of all the bgworkers that have been developed
> with 9.3 and not only worker_spi. If bgw_notify_pid needs to be
> specifically initialized with 9.4, this should be mentioned in the
> release notes or users will be surprised.

I agree that it would be appropriate to mention this in the release
notes, maybe in the incompatibilities section. The basic idea is:
When registering a background worker, the new bgw_notify_pid field
should be initialized to zero, except if you're using the new
notification feature.

That feature (introduced in commit
090d0f2050647958865cb495dff74af7257d2bb4) doesn't seem to really be
mentioned in the release notes at present, so we might want to add
that too. It doesn't necessarily have to be separate from the
existing background worker item, although it could be, but it should
be mentioned somehow, particularly because of the related
incompatibility.

--
Robert Haas
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