Experimental Physics and
Industrial Control System

"Kasemir, Kay" <[email protected]> · Tue, 24 Mar 2009 15:01:43 -0400

On 3/24/09 14:43 , "GaryCarr" <[email protected]> wrote:
> Are there any limitations that apply to one, and not the other?
Other differences:

When you close a JNI JCA channel, that's it.
CAJ will send a final value update to indicate that
the channel is now invalid, in case you registered monitors.

When you create duplicate channels like this
   final Channel ch1 = jca_context.createChannel("fred", conn_callback);

   final Channel ch2 = jca_context.createChannel("fred", conn_callback);

JNI JCA will give you 2 different ones,
while CAJ, within the same context, you will return
the same, i.e. ch2 == ch1.

If you then later clean up like this

  ch2.destroy();
  ch1.destroy();

you get a problem in CAJ because ch2.destroy actually
destroys both.
==> To be compatible, you do your own reference counting,
keep a hash of used channel names.

-Kay

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System