Experimental Physics and
Industrial Control System

"Oleg Makarov" <[email protected]> · Mon, 16 Mar 2009 16:43:26 -0500

Hi Lewis,

yes, you are right, adding a pvFlush() function call after each pvPut/pvGet

call solves the problem: test program being run on LINUX Soft IOC behaves as

expected.

It is strange though that it does not work without explicit pvFlush() calls.

If "+a" option is not set for snc compiler, one would expect synchronous IO

to be performed.

Oleg

----- Original Message -----

From: "J. Lewis Muir" <[email protected]>

To: "Oleg Makarov" <[email protected]>

Cc: "Mark Rivers" <[email protected]>; "EPICS tech-talk"

<[email protected]>; <[email protected]>; "Stepanov, Sergey"

<[email protected]>

Sent: Monday, March 16, 2009 3:34 PM

Subject: Re: weird behaviour of SNL test program running on Soft IOC on

LINUX

On 3/16/09 4:08 PM, Oleg Makarov wrote:

Hi Mark,

I tried the test with this fix. The problem is not resolved by
epicsThreadSleep code change in the osdThread.c.

CA requests are not being send out  as they arise, some buffering of the
requests occurs to make network communication more efficient. If you
look at the camonitor output, it shows a 3-second period, exactly as
expected.

Are there way to force CA requests to go out as they arise, with no
buffering?

Hi, Oleg.

pvFlush() will flush the SEQ PV layer, but maybe that's not what you're
asking about.

You can also do a synchronous put:

 pvPut(str_cmd, SYNC);

But still, I don't understand why str_rsp would ever contain one of the
commands from str_cmd (e.g. "I522") like your output shows, unless
something is messed up with what's happening in and beyond "{dev}StrCmd"
and "{dev}StrRsp".

Lewis

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System