Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Tue, 21 Aug 2007 09:09:46 -0500

Hi Heinrich,

You should use the data value that is passed in the callback.  The interrupt callback should never call the read function in the asyn interface directly (it would need to go through queueRequest to ensure that the read runs in the port thread in case the driver is asynchronous, and to ensure correct locking even for synchronous drivers).  In principle it could call queueRequest, and then call read() from the queueRequest callback, but there's really no need to do that.

Mark

________________________________

From: [email protected] on behalf of Heinrich du Toit
Sent: Tue 8/21/2007 8:44 AM
To: Tech-Talk EPICS
Subject: asyn - interrupts

Hi

Just want to make sure about something and what is the general practice
that should be used.

When an interrupt callback is called.
Then there is an parameter to send the "new" data in also.

Ok so when the record support code's interrupt callback is called it
already receive the new data...
But it can obviously still call the read command for the asyn interface
and get the data that way.

So do we assume that the data passed to the interrupt callback is
correct and that no further asyn calls is needed. Or can/should it still
call the read function to get data?

I'm assuming it accepts the data in the callback and go ahead with that
as that would make sense to me.

-Heinrich

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System