IBM SC34-6814-04 - Manual (Page 54)

Global user exit points by functional area
The exit points are grouped according to their functional relationships. This usually
means according to the CICS module or domain in which they occur. However,
where exit points in different modules serve a similar function, the exits are grouped
under a generic name. The groups of exits are presented in alphabetical order of
module or generic name.
Each of the global user exit points is described in detail, including:
v The exit identifier
v The location of the exit
v The DFHUEPAR parameters, if any, that are unique to the exit
v The return codes that are valid for this exit point
v XPI calls that can be invoked.
Activity keypoint program exit XAKUSER
The XAKUSER exit is invoked during the activity keypointing process. You can use
this exit to record, on the system log, user data that must be restored following an
emergency restart.
For best performance, journal control requests should not specify WAIT. CICS will
force the records by writing a synchronous end of keypoint record upon return from
the exit program.
Your exit program should be translated with the NOEDF option. Any program it links
to should also be translated with this option. It is not possible to link to programs
written in PL/I.
To ensure that it is called during every keypoint, your exit program should be
enabled by means of a first phase PLTPI program - see “Writing initialization
programs” on page 425. However, if it enabled at this stage, your program should
not attempt to link to any program coded in COBOL or C, as it might be invoked
before these are initialized.
Important
Your exit program forms part of a critical CICS system activity. If it fails, CICS
terminates. Only the listed EXEC CICS commands are allowed in the XAKUSER
exit. The exit should link only to other programs with the same restrictions.
Exit XAKUSER
When invoked
During the activity keypointing process.
Exit-specific parameters
UEPAKTYP
Address of a 1-byte field indicating the type of keypoint for which
the exit is invoked. The possible values are:
UEPAKPER
Activity keypoint
UEPAKWSD
Warm shutdown keypoint.
32 Customization Guide