Experimental Physics and
Industrial Control System

Jack Smith <[email protected]> · Mon, 7 Jan 2013 14:44:03 -0500

On Fri, Nov 30, 2012 at 11:21 AM, Ralph Lange <[email protected]> wrote:
> On 30.11.2012 16:51, Jack Smith wrote:
>> I am trying to look through base-3.14.*/src/misc/iocInit.c. I guess
>> the only function related to caRepeater would be rsrv_init(). Then I
>> take a quick look at src/rsrv/caservertask.c, but still don't see how
>> the caRepeater get spawned. Could you tell me how the caRepeater is
>> started during iocInit?
>
> The repeater is a *client* side thing, as it fans out incoming beacons
> from other CA servers to local CA clients.
>
> In the "ca" directory (that has the ChannelAccess client code), the
> constructor of the udpiiu class (in udpiiu.cpp) calls
> caStartRepeaterIfNotInstalled(), which spawns off the repeater (around
> line 590 in udpiiu.c).
> There, depending on the architecture, the repeater is started as a
> process or (if not supported) as a thread.
>
>> Also what does "rsrv" mean / stand for?
>
> It is the old C Channel Access server. "srv" is for "server", I don't
> know what the "r" is for.
>
> Hope this helps,
> ~Ralph
>

I am starting a new thread about the two modules related to Channel
Access server: rsrv and cas.

As Ralph said below, rsrv is the old C Channel Access server. I
suppose cas is the new C++ Channel Access server. Here are my
questions:

1. Why do we need both rsrv and cas? What functionalities are provided
in each module?

2. When I use makeBaseApp to create an example IOC application, there
is one line "example_LIBS += $(EPICS_BASE_IOC_LIBS)" in the app's
src/Makefile and there is an output message "-lrecIoc -lsoftDevIoc
-lmiscIoc -lrsrvIoc -ldbtoolsIoc -lasIoc -ldbIoc -lregistryIoc
-ldbStaticIoc -lca -lCom"  during the app building. I see "rsrvIoc"
and "ca" are included in the IOC. I suppose the "ca" is the Channel
Access Client library because an IOC could be Channel Access Server as
well as Channel Access Client. But I don't see something like 'cas' in
the linked EPICS base libraries. Where is 'cas' included, dbIoc or
dbStaticIoc or some else?

Thanks,

Jack

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System