Experimental Physics and
Industrial Control System

"Jeff Hill" <[email protected]> · Tue, 29 Oct 2002 11:04:27 -0700

John,

>   examine args.status
>
>   // status here is sometimes ECA_ANACHRONISM
> Has this always been possible?

I think you are asking if CA will set the status
field in the event_handler_args structure to
ECA_ANACHRONISM. The answer is no. I searched
all of the source code in the latest versions of
R3.13 and R3.14 and ECA_ANACHRONISM is returned
only when you call a very old CA interface from
R3.11 or probably earlier that is no-longer
supported.

Are you calling CA from a multi-threaded
application?

Jeff

> -----Original Message-----
> From: john sinclair [mailto:[email protected]]
> Sent: Tuesday, October 29, 2002 10:48 AM
> To: tech talk
> Subject: CA error
>
> One stress test I have applied to edm is performing a moderately rapid
> succession of connects/disconnects via a channel access server.
>
> I have recently noticed one problem.
>
> The logical code structure is shown below:
>
>
>
> global needInit
>
> ==========================
>
> main routine:
>
> needInit = false
> search_and_connect
>
> do {
>   pend io, event
>   if ( needInit ) {  // needInit is set in the connect callback
>     ca_get_callback(...)
>     needInit = false
>   }
> } until all outstanding io is complete
>
> ===========================
>
> connect_callback function (...) {
>
>   if ( pv is connected ) {
>     needInit = true
>   }
>   else {
>     needInit = false
>   }
>
> }
>
> ===========================
>
> get_callback function (
>   struct event_handler_args args
> ) {
>
>   examine args.status
>
>   // status here is sometimes ECA_ANACHRONISM
>   // and args.dbr is NULL
>
> }
>
>
>
> Has this always been possible? I'm sure I get the connect callback
> before
> the get callback (by examining other data that gets set in the connect
> callback {not shown in above simplified example}).
>
> John Sinclair
> [email protected]
> Oak Ridge National Lab
> 865-576-6362   865-574-1268 (fax)

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System