IBM SC34-6814-04 - Manual (Page 325)

operators. This section lists what you must do before you can use the adapter, and
describes the commands used by the supervisor to administer task-related user exit
programs.
What you must do before using the adapter
A task-related user exit program must be both enabled and started before it is
available for execution.
1. Use the CEDA INSTALL PROGRAM command to define the task-related user
exit program to the system.
2. Use the EXEC CICS ENABLE command to enable the task-related user exit
program and to define its working storage needs.
EXEC CICS ENABLE PROGRAM('EP9')
TALENGTH(750) GALENGTH(200) SHUTDOWN
EXEC CICS ENABLE PROGRAM('EP9')
START
The first command loads the task-related user exit program, EP9, and causes a
200-byte work area to be obtained and associated with it. The first command also
schedules the allocation of a further 750-byte work area for each task that
subsequently invokes EP9, and for the invocation of EP9 at CICS termination. The
second command starts the exit program: that is, it makes its entry point capable of
being invoked.
Enabling for specific invocation-types
Use the following options of the EXEC CICS ENABLE command to cause your exit
program to be invoked at specific events:
INDOUBTWAIT
specifies that, at phase 2 syncpoint time, if CICS is in-doubt about the
outcome of the UOW, the exit program is to be invoked with the UERTWAIT
verb (wait), instead of a forced definition of UERTCOMM (commit) or
UERTBACK (backout). UERTWAIT signifies that CICS does not yet know
the outcome of the UOW. In response to a UERTWAIT call, the task-related
user exit should invoke its resource manager to free any task-related
resources, such as the thread. However, the resource manager should
maintain any locks held by the UOW, and record that the UOW is in-doubt.
When CICS receives the outcome of the UOW from its coordinator, a
resynchronization task is attached to notify the task-related user exit about
the outcome of the UOW.
If CICS is in-doubt about the outcome of a UOW for which an external
resource manager has requested resynchronization (using the EXEC CICS
RESYNC command), CICS waits until the in-doubt has been resolved
before initiating a resynchronization task.
The effects of not enabling a task-related user exit with the INDOUBT
keyword are:
v If CICS is in-doubt about a UOW, a forced decision is taken and the
task-related user exit invoked with the forced decision.
v If CICS is forced to take a decision because a task-related user exit is
not enabled with INDOUBTWAIT, it takes a forced decision for all
resources updated by the UOW, even if all the other resources are
Chapter 2. Task-related user exit programs 303