Experimental Physics and
Industrial Control System

[email protected] · Mon, 18 Apr 2011 16:59:10 +0800

Hi Lorna,

On Friday 15 April 2011 02:34:53 [email protected] wrote:

> 

> We developed a client based on libca (EPICS Base 3.14.9), which will

> create it's own worker thread on construction. But we found it working

> strangely on vxWorks (ppc-603). Whenever a second EPICS client is
created

> (meaning there are now 2 EPICS worker threads on vxWorks), the CPU
usage

> became 100%.

> 

> From the profile, we found the ca_pend_event is consuming lots of
the CPU.

> 

> Meanwhile, it seems epicsMutex is failing to do the lock for the second

> EPICS client??

EPICS should work fine on your hardware and OS combination, this is probably

an application programming issue.

Are these two threads sharing a single CA client context?  Hopefully
Jeff Hill 

will respond here too, but you might want to read this and the following

sections of the CA Reference Manual for some ideas:

http://www.aps.anl.gov/epics/base/R3-14/12-docs/CAref.html#Thread

In particular if you're experienced in writing multi-threaded code you
might 

want to use ca_enable_preemptive_callback mode and completely avoid having
to 

call ca_pend_event() in your code.

- Andrew

-- 

An error is only a mistake if you don't learn from it.

When you learn something from it, it becomes a lesson.

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System