Re: EPICS Clients in C++

["Johnson, Andrew N. via Tech-talk" <tech-talk at aps.anl.gov>]

Actually, the CA client library implementation in Base is written in C++, but it was designed to provide the exact same C API as the original C-based version. It was also written long before modern C++ standards, and was designed for targets where real-time code was required to minimize how often it allocated and released memory to avoid fragmentation.

 

If someone were so inclined it should be possible to create a new C++ API for it that calls the private implementation, but there might be some impedance mismatches when doing that because of the way the code does memory allocation and uses containers.

 

The libCa code was written by Jeff Hill who retired from the Los Alamos National Lab quite a few years ago now, and the current Core Developers don’t often make changes to the implementation. It is very stable code that does what it was designed for well, but the community went in a different direction when we chose to use PV Access as a new network protocol. Some labs are likely to continue using CA for many years so we won’t be throwing it out, but new projects are being steered towards PVA since it can support IPv6 and secure communications. Those could be retro-fitted onto CA, but we have chosen to spend the effort on the newer protocol.

 

- Andrew

 

-- 

Complexity comes for free, Simplicity you have to work for.

 

 

On 6/24/25, 4:26 AM, "Tech-talk" <tech-talk-bounces at aps.anl.gov> wrote:

 

Hi Laurenz and Abdalla,

I too have some experience with CAFE from PSI.  It is quite good in my opinion once you get the CAFE working (not difficult).  On the other hand, I am not sure if CAFE is what Abdalla is after; he is looking for C++ library, not a wrapper.  At least when I looked at CAFE the last, it was more of a wrapper than a true C++ library (except that I have not used it for several years that it might have changed).

In fact, I thought about replying to Abdalla with CAFE, until I read his original e-mail very carefully. 

Best,
Jiro

 

On 06/24/2025 9:28 AM, Laurenz Rettig via Tech-talk wrote:

Hi Abdalla, 

I have used café in the past: https://gitlab.psi.ch/cafe

 

Best, Laurenz 

 

 

 

Sent mobile 

 

 

-------- Ursprüngliche Nachricht --------

Von: Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>

Datum: 24.06.25 08:42 (GMT+02:00)

An: Ralph Lange <ralph.lange at gmx.de>

Cc: "tech-talk at aps.anl.gov" <Tech-talk at aps.anl.gov>

Betreff: RE: EPICS Clients in C++

 

Thanks Ralph. Is there something similar for channel access? In other words, a C++ implementation of channel access?

 

Best Regards,

Abdalla Al-Dalleh

Control Engineer

SESAME

P.O. Box 7, Allan 19252, Jordan
Tel: +96253511348 , ext. 265

Fax: +96253511423

Email : abdalla.ahmad at sesame.org.jo
Website: www.sesame.org.jo

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Ralph Lange via Tech-talk
Sent: Sunday, June 22, 2025 4:15 PM
To: EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: Re: EPICS Clients in C++

 

On Sun, 22 Jun 2025 at 10:57, Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov> wrote:

 

Is there a client API for EPICS implemented in C++ not just a wrapper for the C API? Possibly using recent C++ standards?

 

PVXS.

https://epics-base.github.io/pvxs/

 

Cheers,
~Ralph