Event Handling

The TLOOK error has special significance. TLOOK is set if an XTI/TLI routine is interrupted by an unexpected asynchronous transport event on the endpoint. TLOOK does not report an error with an XTI/TLI routine, but the normal processing of the routine is not done because of the pending event. The events defined by XTI/TLI are listed in Table 3-7.

Table 3-7 Asynchronous Endpoint Events

Name	Description
T_LISTEN	Connection request arrived at the transport endpoint
T_CONNECT	Confirmation of a previous connect request arrived (generated when a server accepts a connect request)
T_DATA	User data has arrived
T_EXDATA	Expedited user data arrived
T_DISCONNECT	Notice that an aborted connection or a rejected connect request arrived
T_ORDREL	A request for orderly release of a connection arrived
T_UDERR	Notice of an error in a previous datagram arrived. (See "Read/Write Interface".)

The state table in "State Transitions" shows which events can happen in each state. t_look() lets a user determine what event has occurred if a TLOOK error is returned. In the example, if a connect request is rejected, the client exits.