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XFCLDEL global user exit
XFCLDEL is invoked when backing out a unit of work that performed a write
operation to a VSAM ESDS, or a BDAM data set.
XFCBOVER global user exit
XFCBOVER is invoked whenever CICS is about to decide not to backout an
uncommitted update, because the record could have been updated by a non-RLS
batch program.
This situation can occur after a batch program has opened a data set, even though
it has retained locks, by overriding the RLS data set protection.
XFCBOUT global user exit
XFCBOUT is invoked when CICS is about to backout a file update.
Coding transaction backout exits
You have access to all CICS services, except terminal control services, during exit
execution.
About this task
However, consider the following restrictions:
v The exit programs must be written in assembler code.
v They must be quasi-reentrant. They may use the exit programming interface
(XPI) and issue EXEC CICS commands.
v If an exit program acquires an area as a result of a file control request, it is the
responsibility of the exit to release that area.
v An exit must not attempt to make any file control requests to a file referring to a
VSAM data set opened in non-RLS mode with a string number of 1, unless no
action is specified for that file during the initialization exit.
v Task-chained storage acquired in an exit should be released by the exit as soon
as its contents are no longer needed.
v If an exit is not used, the default actions are taken.
v We strongly recommend that emergency restart global user exits do not change
any recoverable resource. If you do try to use temporary storage, transient data,
or file control, these resource managers may also be in a state of recovery. Access
to these services will, therefore, at best cause serialization of the recovery tasks
and, at worst, cause a deadlock.
162 CICS TS for z/OS 4.1: Recovery and Restart Guide