Re: Questions about EPICSv4 (Ricardo Herrero)

[Marty Kraimer <mrkraimer@comcast.net>]

On 03/16/2015 10:49 AM, Ricardo Herrero wrote:
> Hello,
>
>  I´m still trying to get a Monitor to work in JAVA, and even I´m 
> learning a lot, there are many things I don´t understand yet. If 
> someone could help me with these questions I would really appreciate it.
> 1. There´s an package in pvData called Monitor, in which you have 
> MonitorAlgorithm class, Do I have to create the algorithm of the 
> Monitor? MonitorQueue, do I need to create a Queue to store the 
> Monitor Elements?
> 2. Object Monitor does exist both in server and client, or (in the 
> server side) do I just have to create a PVAccessServer and it creates 
> automatically a Monitor?
> 3. What is the function of the Requester, I can´t see the way they 
> work, its functions.
> 4. I have also found org.epics.pvaccess.server.impl.remote.handlers, 
> they seem to have implemented most of the interfaces, like 
> MonitorHandler, how can I use them? Do I avoid using directly Monitor, 
> Channel and PVAccessServer, on behalf of the MonitorHandler?
> 5. When I try to create a Server throught ServerFactory I have seen 
> that the Threads are created with the name PVAccessServer, hardcoded, 
> and I don´t know how can I change it.
> Any help will be welcomed, thanks in advance.
> Yours, Ricardo Herrero

Quick answer.

There is a new mercurial repository pvDatabaseJava.
Please try it.

Longer answer.

There is a mercurial  repository that is not a component of the V4 
releases named pvIOCJava.
It has lots of code  including a complete implementation of a local 
pvAccess server.
It also has lots that seemed, at the time, to be good ideas but no one 
has bought in.
For C++, pvDatabaseCPP is a component of the latest V4 release.
It provides a complete implementation of a local pvAccess server except 
channelRPC which is provided by pvAccess itself.
It  does not implement any of the other features that pvIOCJava provides.

I hope that pvDatabaseJava will be a component of the next V4 release.
It also has  a complete implementation of a local pvAccess server except 
channelRPC.
And again does not implement any of the other features of pvIOCJava.

What you have to do to implement a service is to provide a PVStructure 
with the data your service requires and a process method.
pvDatabase does the rest, i.e. implements ChannelProvider, Channel, 
ChannelGet, ChannelPut, ChannelPutGet, Monitor, and ChannelArray.
With regards to monitor plugins.
I implemented something in pvIOCJava but again no one bought in.
So for now pvDatabaseJava does nothing for monitor plugins.

For now the only way to get pvDatabaseJava is to get it from the 
mercurial repository.
Hope this helps.


Also if you are implementing pvAccess client code then please look at 
easyPVAJava.
It is part of the latest V4 release.
easyPVACPP is currently under development.


Marty Kraimer