IPCS calls the CTRF exit routine for each CTE.

The CTRF exit routine may use a 4-kilobyte work area. The address of the work area is in the CTXIUSWA field of the CTXI data area. Each time the routine is used, it can use the same work area, providing continuity across multiple invocations of the routine. However, this work area is not preserved for use by either the CTRACE buffer find exit routine or a CTRACE formatter.