Plug/Unplug beta messages

These beta messages allow plugging and unplugging of filters from their clients. ORB provides a public interface-plug and unplug-for this purpose. This interface in turn makes use of private interface of Object, which stores a list of plugged filters. The filter object framework includes filterconf utility that facilitates sending these messages to client objects. We now present the algorithm for sending and handling these messages.

Scenario: Sending Plug/Unplug message

1. Convert a filter object reference to string.
2. Create StaticAny object representing stringified filter object reference.
3. Create StaticRequest object representing appropriate beta message.
4. Add the argument and invoke the request.

Scenario: Handling Plug/Unplug message

1. Create server side request and read the stringified reference using it.
2. Convert the stringified reference to object reference and narrow it to the filter reference.
3. If this is plug message, add the filter reference to filters list if it didn't exist already.
4. If this is unplug message, simply remove the filter reference from filters list if it exists.