Experimental Physics and
Industrial Control System

"Johnson, Andrew N. via Tech-talk" <[email protected]> · Mon, 15 Apr 2019 18:33:20 +0000

Hi Marcio,

On 4/15/19 12:49 PM, Paduan Donadio, Marcio via Tech-talk wrote:
>  
>
> We are thinking about creating a function in EPICS base like
> stopOnDbLoadErrorto be called before dbLoad* functions. The idea is to
> freeze the IOC boot with a message on the IOC shell or to completely
> abort, exiting. Alternatively, we could also place an additional
> optional parameter to the dbLoad* functions to have the same behavior.
>
>  
>
> What we intend with this is:
>
> 1.) bring the error to the attention of the responsible IOC engineer and,
>
> 2.) stop corruption of Autosave files due to missing PVs.
>
>  
>
> Do you think it would be something valuable to be added in an official
> EPICS release?
>

That sounds like a very reasonable thing to add, I would be happy to
review an implementation of this with a view to merging it. Your local
experts at SLAC on how to go about creating a merge request are Bruce
Hill and Till Straumann.

I would prefer to control the abort-on-error switch with an int variable
that is registered in dbCore.dbd so it can be displayed and set set with
the iocsh 'var' command — there's no need for a new command or to add
parameters to the existing routines. The default value for that variable
should keep the current behaviour though, so users have to opt in for
the IOC start-up to abort on a bad database.

The code in modules/database/src/ioc/dbStatic already checks some
variables like that during database loading, so you can refer to say the
dbRecordsOnceOnly variable to see how the registration is done.

Thanks!

- Andrew

-- 
Arguing for surveillance because you have nothing to hide is no
different than making the claim, "I don't care about freedom of
speech because I have nothing to say." -- Edward Snowdon

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System