Experimental Physics and
Industrial Control System

"Johnson, Andrew N. via Core-talk" <[email protected]> · Thu, 17 Jan 2019 22:25:59 +0000

On 1/11/19 4:51 PM, Hugo Slepicka via Core-talk wrote:
> How are the core maintainers thinking about releasing patches for
> Known Problems of EPICS Base 7.x series?
We haven't really discussed that question in the core group yet let
alone answered it, hence my delayed response. The Known Problems patches
were something that I developed and released myself for V3, but they
haven't been translated into the new EPICS 7 world yet.
> Will we have the patch files separated for each of the submodules?
In my experience of V3 the majority of bug-fix patches tended to be
fairly localized, changing only a small set of files that would normally
fall within a single module. That may no longer be the case with the
plethora of PVA modules though. We will probably be using git to
generate patch files now, so creating a patch that crosses a git repo
boundary would involve extra work and I think it more likely that we
would post a separate patch for each repo in that case. Note that in the
EPICS 7.0.2 release we re-combined the code from the V3 libcom, ca and
database modules into the core repository, so a single patch file can
still modify files in all 3 of those if necessary.
> Should we track the HEAD of each submodule to ensure that we have the
> latest and greatest even if there is no official EPICS Base release
> tagged with this new combination of versions?
Doing that is a 2-edged sword; it should get you bug-fixes as soon as
they are available, but it might give you additional features (not
necessarily documented) and code that might break your systems. We do
build the code and run automated self-tests on many platforms after
every git push, but even though their numbers have been growing in
recent years those tests don't check everything.
> Will we have more frequent releases of the 7.x series to go along with
> releases of the submodules adding features needed?
I can't promise that for sure, although we would like to increase the
frequency of releases. There aren't many core developers and we all have
other responsibilities as well, so we get a limited amount of time to
review merge proposals, develop our own enhancements, work on fixing
bugs and answer questions from the community.

One point of keeping the PVA submodules in separate repositories was to
allow them to be developed and released on their own if the module owner
so wishes. This has certainly happened with the pvaPy Python bindings
module, which is not included in the EPICS 7 releases and has produced
several updates on its own time-scales. Michael Davidsaver has also
talked about tagging and releasing some of his PVA modules separately,
but those may have been for a limited audience who asked for them.

The frequency of EPICS releases in recent years has mostly been driven
by requests from ITER, who repackage EPICS and a set of support modules
annually into their Codac Core system (this is the SDK for their
domestic agencies to use). If another lab wants more frequent releases
of EPICS and is willing to provide some development help to get them
done I don't think the core group would have any problem working with
them. As I said above we are mostly limited by available developer
resources at the moment...

HTH,

- Andrew

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System