Experimental Physics and
Industrial Control System

Hi Iain,

 

asyn does queue both write and read operations if you create your driver with the ASYN_CANBLOCK flag.  Did you do that?

 

How does your polling record work, i.e. is it going through your quadEM driver and then the underlying drvAsynIPPort driver?

 

Changing parameter A and having no message sent does not make sense to me unless the asyn queueRequest is timing out.  Are there any messages on the IOC console when this happens?

 

> All writes, which includes the 1 Hz record mentioned above, write to the same shared buffer that is then sent, so might there be contention there?

 

Does your polling record write to a record which then results in your driver's writeOctet or similar method being called?  If so, then it should be OK because if you set ASYN_CANBLOCK then both the drvAsynIPPort driver lock, and the asynPortDriver lock for your quadEM driver will be held when writeOctet is called.  If you then write to the shared buffer and immediately call the underlying drvAsynIPPort->write() function then it should not be possible for 2 threads to be trying to use the shared buffer at the same time.

 

Mark