Interval control program exits XICREQ, XICEXP, and XICTENF

You can use some XPI calls in exit programs invoked from the interval control program. However, when any of these exits are invoked for expiry analysis, any actions that delay the execution of the interval control program can have adverse effects on other transactions that are waiting for intervals to expire.

You can determine whether the exits have been invoked for expiry analysis by examining the type-of-request field, TCAICTR, a copy of which is pointed to by the UEPICRQ1 exit-specific parameter.

The XICREQ exit is invoked by internal requests made by CICS® code, as well as by requests made by applications. DFHXRSP issues an interval control WAIT every 2 seconds; this means that any interval control exit programs are also invoked every 2 seconds.