Experimental Physics and
Industrial Control System

John Dobbins <[email protected]> · Wed, 08 Jun 2011 09:01:31 -0400

Greetings,

I have an IOC on which all records stopped updating for 5 seconds at a

time followed by resumption of normal operation. The IOC would operate

normally for hours at a time and then would suffer a burst of stop/go

activity lasting several minutes.

The IOC has multiple thread implementing asynchronous device support and

uses the general purpose IOC callback tasks. I think the problem is that

callbackRequest(), which can fail silently, was overflowing the callback

queue.

My problem appears to be fixed by increasing the callback queue size.

My question: Is there a way to know about the callback queue status or

otherwise avoid this situation?

John Dobbins

Cornell Laboratory for Accelerator-based Sciences and Education
Cornell University
Ithaca, NY