Here are some code snipits. Now that I look at it, I did swap steps B and C. Calling 'put' inside the device's constructor function is horribly slow (like 5 seconds per PV).
So, to be more explicit:
A. I create a bunch of PV's with initial values.
B. Load the builder database.
C. Call softioc.iocInit()
D. Call do_startthread() with will call put() for each of the PV's that still need correct values from the configuration files.
RESULT: Some of the PV's get the correct values. Some still show init value.
I do not know exactly what is going on with these python wrappers. I presume that they're just calling EPICS functions of similar names.
The other report on this thread did sound similar. The workaround of adding a random delay to the startup process does suggest a synchronization failure in EPICS.
Paul
main.py
========
....
dev1 = MY_DEVICE(devicename,0, config_file1, map_file, sc_map, readout_map)
dev2 = MY_DEVICE(devicename,1, config_file2, map_file, sc_map, readout_map)
#run the ioc
builder.LoadDatabase()
softioc.iocInit()
dev1.do_startthread()
dev2.do_startthread()
my_device.py
....
self.some_pv.put(value)
Paul,
> A little later in the code another configuration file is read for values and put is called.
What do you mean by "put is called"? Is the effectively a Channel Access put? If so, and if you were not using the Python soft IOC the answer to this would be easy. Channel Access puts can only be done after iocInit is complete.
I am not familiar with the Python soft IOC, and I am not sure what you mean by "put", so I am not sure about the timing in that case.
Mark
________________________________
From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Paul Nord via Tech-talk <tech-talk at aps.anl.gov>
Sent: Tuesday, June 16, 2020 12:52 PM
To: EPICS tech-talk
Subject: IOC Startup - init value used sometimes instead of put
Strange problem.
A. I create a bunch of PV's with initial values.
B. A little later in the code another configuration file is read for values and put is called.
C. IOC is started.
D. Some of the PV's get the correct values. Some still show init value.
If I call the configure routine to set the PV's "some time" later, the load reliability.
I can add a 30 second delay, but I've lost confidence that I can guarantee initialization under circumstances where processor load might change. It looks like the "init" value is being set some random time after the PV is created. Possibly even overwriting later calls to put.
I'm using Python Soft IOC.
Thoughts?
Paul
