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<== Date ==> | <== Thread ==> |
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Subject: | group PV question |
From: | Timo Korhonen <[email protected]> |
To: | EPICS Core Talk <[email protected]> |
Date: | Fri, 26 Oct 2018 10:45:33 +0000 |
Hi,
I guess this is addressed to Michael but maybe this is a question worth asking in the group:
I am wondering about the difference in group PV atomicity. I tried to follow the circle.db example.
It seems to work as I expected. However, when I use pvget:
$ pvget circle circle epics:nt/NTTable:1.0 structure record structure _options uint queueSize 0 boolean atomic true double angle 279 alarm_t alarm NO_ALARM NO_STATUS NO_ALARM time_t timeStamp 2018-10-26T12:35:48.132 0 structure value double X 0.156434 double Y -0.987688 The attribute "atomic" is true, as I expected (set it using info tags). But with monitoring, I get:
circle epics:nt/NTTable:1.0 structure record structure _options uint queueSize 0 boolean atomic false double angle 349 alarm_t alarm NO_ALARM NO_STATUS NO_ALARM time_t timeStamp 2018-10-26T12:36:57.948 0 structure value double X 0.981627 double Y -0.190809 for the same group pv.
Trying to dig into the code (I have not been able to go deep), I see references to "pgatomic" and "monatomic".
This suggests to me that there is a difference in how monotonicity is set/handled with monitors. Is this true? How can one make groups be handled atomically?
Or is this just my over-interpretation?
I tried to figure this out from the documentation but I could not.
Thanks,
Timo
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