The Notification Service supports subscription sharing between channels and channel clients through the CosNotifyComm::NotifyPublish and CosNotifyComm::NotifySubscribe interfaces.Supplier admins and proxy consumers inherit the CosNotifyComm::NotifyPublish interface. Suppliers may use the offer_change method to notify the channel that it is about to start supplying new event types or is about to stop supplying an existing type. The channel maintains an aggregate list of all event types currently offered; and when this changes it notifies consumers through the offer_change method.
Consumer admins and proxy suppliers inherit the NotifySubscribe interface. Consumers may use the subscription_change method to subscribe/unsubscribe to a set of channel events. Again, the channel maintains an aggregate list of all subscriptions; and when this changes it notifies suppliers through the subscription_change method.
Subscription sharing allows sophisticated suppliers and consumers to dynamically control the types of events that flow through the channel. This can increase channel efficiency since unwanted events are no longer produced.
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