Re: EPICS and EPICS+PVXS internal threading of IOCs

[Ralph Lange via Tech-talk <tech-talk at aps.anl.gov>]

That is more or less the basic setup.

Note that there are already network specific threads in this list, which are generated per network interface configured.

When EPICS network connections are active, the server(s) on the IOC will usually start one pair of threads per client.

If your IOC uses the parallel callback threads functionality (to utilize parallel processing on multiple CPUs), there will be (highly configurable) more instances of the cbLow/cbMedium/cbHigh threads.

Many drivers and device support modules start their own threads. ASYN ports often have a thread associated with each port, AreaDetector plugins (as they are implemented as ASYN ports) most often start a thread per plugin.

MCoreUtils is a module that you can use to have more control over priorities, scheduling mechanisms and CPU allocation of IOC threads. This is convenient when you're running real-time applications on the same host and want to keep the IOC from running on your dedicated real-time core(s). (Except maybe for that one device support thread that does the communication between the IOC and the real-time parts...)

Cheers,
~Ralph