Re: background sessions

2017-03-14 19:08 GMT+01:00 Robert Haas <robertmhaas(at)gmail(dot)com>:

> On Tue, Mar 14, 2017 at 3:31 AM, Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
> wrote:
> > Very often strategy can be recheck of parent process in some waiting
> > cycles. It should not to impact performance.
>
> I think that's going to be hard to arrange, and I think it isn't
> necessary. If the leader wants to arrange for the worker to die when
> it exits, it can use TerminateBackgroundWorker() from a
> PG_ENSURE_ERROR_CLEANUP block or on_shmem_exit hook.
>
> > I afraid so some waiting times in bg process can be high probable with
> this
> > patch - and then is probable so somebody use pg_terminate_backend. This
> > situation should not to finish by server restart.
>
> I don't understand. The only way you'd need a server restart is if a
> background process wasn't responding to SIGTERM, and that's a bug
> independent of anything this patch does. It would be cause by the
> background process not doing CHECK_FOR_INTERRUPTS() or the moral
> equivalent regularly.
>

It is bug, and I don't know if it s this extension bug or general bug.

There is not adequate cleaning after killing.

How can be implemented pg_cancel_backend on background process if there are
not CHECK_FOR_INTERRUPTS?

Regards

Pavel

>
> --
> Robert Haas
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