If a subscriber is an Oracle Tuxedo system client process and ctl is NULL, when the event to which the client has subscribed is posted, the EventBroker sends an unsolicited message to the subscriber as follows. When an event name is posted that evaluates successfully against eventexpr , the EventBroker tests the posted data against the associated filter rule. If the data passes the filter rule (or if there is no filter rule for the event), then the subscriber receives an unsolicited notification along with any data posted with the event.

In order to receive unsolicited notifications, the client must register an unsolicited message handling routine using the tpsetunsol() function.

ATMI clients receiving event notification via unsolicited messages must remove their subscriptions from the EventBroker list of active subscriptions before exiting. This is done using the tpunsubscribe() function.