Normal Processing

The following is an overview of how the XCF status monitoring service interacts with the status user routine during normal processing. See Figure 1 and Figure 2 for a summary of the process.

The member identifies a status user routine, a status field (which must be in fixed or disabled reference (DREF) common storage), and a status-checking interval on the IXCJOIN macro (STATEXIT, STATFLD, and INTERVAL parameters).
The member is responsible for regularly updating its own status field (see Updating the Status Field for suggestions on how to do this).
Note: Updating the status field is not mandatory. A member can request status monitoring and never update its status field. However, this results in XCF scheduling the status user routine every time the member's status-checking interval expires, and could consume system resources unnecessarily.
XCF starts monitoring the status field. This monitoring might begin before the IXCJOIN service returns to the caller.
If the member fails to update the status field within the status-checking interval, XCF schedules the status user routine as a local SRB to run in the member's primary address space.
XCF passes a parameter list (mapped by the IXCYSEPL mapping macro and pointed to by GPR 1) to the status user routine. The SEPLSTCH field indicates that XCF is checking for a status update missing (SEPLSTCH=SEUPDMIS, where SEUPDMIS is a system-defined constant).