Experimental Physics and
Industrial Control System

[email protected] (Jeff Hill) · Thu, 5 Oct 2000 13:02:12 -0600

My tests using catime indicate that the new C++ "portable" ca server library 
is roughly equivalent in speed to the original CA server. However,
during my tests the server was spending 100% of its idle time in
fdManager::process (). I was hoping that a thread safe version of the 
new CA server library would be available in EPICS R3.14, but it now
appears that this will not occur until EPICS R3.15.

Jeff

> 
> Now I found the answer why the cas-server is that slow. The Problem is
> that the cas-server is working only if called by
> fileDescriptorManager.process(). This is called by a Timer. If I call
> the fd-manager all 50ms all sync reads are 70 times more slow as a read
> from a IOC variable. If I call it all 5 ms this factor is 14 times!
> 
> That means on a more sophisticated operating system as vxWorx and a
> processor involved in more than answer epics requests it will be
> impossible to achieve the same response times.
> 
> Bernhard Kuner
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System