Contention for the terminal

CICS satisfies requests for automatic task initiation (ATI) as soon as the terminal required as principal facility is available.

But when a task ends at a terminal, and CICS has an ATI request for that terminal, there may be contention between CICS, which wants to initiate the ATI task, and the terminal user, who wants to initiate a certain task by unsolicited input. In this situation, CICS always sets itself up as contention loser. That is, if the terminal sends unsolicited input quickly enough after the end of the previous transaction, CICS creates a task to process it and delay fulfilling the ATI request. This is intentional—it gives the user priority in contention situations.