RE: CA error

["Jeff Hill" <johill@lanl.gov>]

John,

Do you check the status from ca_get_callback() when you call it?
It's possible to get ECA_DISCONN back as status if the connection
is down at the instant that ca_get_callback() is called. You will
also see ECA_DISCONN in the status field of event_handler_args if
the virtual circuit disconnects sometime after the get callback
request is made, but before the response arrives from the server.

If you think that your situation is occurring in a situation that is
not related to disconnects then I will need to research this in
more detail.

Jeff

> -----Original Message-----
> From: john sinclair [mailto:sinclair@mail.phy.ornl.gov]
> Sent: Tuesday, October 29, 2002 11:23 AM
> To: Jeff Hill
> Cc: 'tech talk'
> Subject: RE: CA error
>
>
> My mistake, the error is ECA_DISCONN (which makes more sense)
> and not ECA_ANACHRONISM (I shifted the value twice instead
> of 3 times).
>
> And, no, I'm not calling CA from a multi-threaded application.
>
> John
>
>
> On Tue, 29 Oct 2002, Jeff Hill wrote:
>
> >
> > 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:sinclair@mail.phy.ornl.gov]
> > > 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
> > > sinclair@mail.phy.ornl.gov
> > > Oak Ridge National Lab
> > > 865-576-6362   865-574-1268 (fax)
> >
> >
>
> John Sinclair
> sinclair@mail.phy.ornl.gov
> Oak Ridge National Lab
> 865-576-6362   865-574-1268 (fax)