Experimental Physics and
Industrial Control System

"J. Lewis Muir" <[email protected]> · Tue, 05 Apr 2011 09:45:30 -0500

On 4/5/11 4:06 AM, Benjamin Franksen wrote:
> BTW, Ralph Lange suggested that to make it easier to write portable SNL
> code, I should allow use of the standard C fixed-size integer types in SNL.
> This would mean you can say
> 
> uint32_t x;
> assign x to "...";
> 
> and be sure that this is an unsigned 32 bit integer, regardless of
> architecture and OS. I think this is a good idea and I plan to add this to
> my development version, so it will be in 2.1, but not in 2.0.13.

Hi, Ben.

Say I have a longout record on an IOC and want to write to its
VAL field from an SNL program running in a different IOC.  What
type should I use for the SNL variable in order to be portable?
 int32_t?  Or is there actually no way to be portable because
the size of the longout record's DBF_LONG VAL field can vary
depending on the architecture for which the longout record was
built and because CA doesn't support 64-bit integer types?

It would seem to me that the only way to actually make anything
portable is to use fixed size types across the board.  That is,
in the example above, make the type of the longout record's VAL
field a 64-bit signed integer (e.g. DBF_INT64), make CA support
64-bit signed integers, and let me use int64_t as the type of
the variable in the SNL program used to write to the VAL field.

Thanks,

Lewis

-- 
J. Lewis Muir
Software Engineer
IMCA-CAT

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System