When using the callback model, you must register a general callback function for each Broker client by calling the awRegisterCallback function. When an event is received, if there are no specific callback functions registered which match the event's subscription identifier or tag, the general callback function will be invoked to handle the event.

You may have a single callback function process all of your application's events by making a separate awRegisterCallback call for each BrokerClient that your application uses, specifying the same callback function each time.

Depending on the complexity of your design, you may find that a single, general callback function is all that your client application requires.