Re: dynamic monitoring

[Patrick Thomas <thomas_p@ligo-wa.caltech.edu>]

Do you mean calling ca_pend_event(0) in the main program, and 
subscribing/unsubscribing in a separate thread? Is there an advantage to 
this?
On 1/21/2011 5:34 PM, Jeff Hill wrote:
> Hi Patrick,
>
> The mechanism to start/stop a subscription is accessed via calls to
> ca_create_subscription/ca_clear_susbscription. If you have a single threaded
> application then you will need to start and stop the subscriptions from
> within the main loop. Therefore, yes, that could be accomplished by calling
> ca_pend_event with a finite timeout, deciding what subscriptions might be
> needed, and calling ca_create_subscription/ca_clear_susbscription to start
> stop the appropriate subscriptions - all of these actions in a loop. There
> are of course many other, more complex, ways to schedule this including
> changing to a preemptive callback mode application with multiple threads
> (emphasis on complex) but of course a simple, minimal approach is often
> just-a-fit for the design requirements.
>
> Jeff
> ______________________________________________________
> Jeffrey O. Hill           Email        johill@lanl.gov
> LANL MS H820              Voice        505 665 1831
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>
> Message content: TSPA
>
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>
>
> > -----Original Message-----
> > From: tech-talk-bounces@aps.anl.gov [mailto:tech-talk-
> > bounces@aps.anl.gov] On Behalf Of Patrick Thomas
> > Sent: Friday, January 21, 2011 6:01 PM
> > To: tech-talk@aps.anl.gov
> > Subject: dynamic monitoring
> >
> > Hi,
> >
> > I was wondering what the best way is to dynamically monitor channels in
> > C. That is to start and stop monitoring channels at run time. I
> > currently have a program that connects to and attaches monitors to a
> > predefined list of channels and then goes into a ca_pend_event(0), which
> > blocks forever. Should I change this to a loop and specify a certain
> > time period, i.e. ca_pend_event(1) and add or remove channels in that
> > loop?
> >
> > Thank you for your time,
> > Patrick