CICS syncpoint manager parameters

Parameters 2 through 9 contain values only when the syncpoint manager makes a “Commit Unconditionally” or “Backout” call to the TRUE, for resynchronization purposes after a session or system failure. These extra parameters point to fields that identify the task, the transaction that started the task, the terminal from which it was initiated, the identity of the terminal operator, the date and time of the failing syncpoint, and (if there are no further units of recovery associated with the task) the next transaction code. Typically, you would use these values to create meaningful messages for resource recovery. They are presented explicitly because, after a system failure, the task driving the exit is not the task that originally scheduled the recoverable work. These additional parameters describe the original task’s environment and are accessed directly.

The full parameter list is as follows:

Parameter 1

The address of operation byte 1, which contains the following flags:

UERTPREP

(X'80') Prepare to commit (that is, perform the first phase of a two-phase commit).

UERTCOMM

(X'40') Commit unconditionally (perform the second phase of a two-phase commit).

UERTBACK

(X'20') Backout.

UERTDGCS

(X'10') Unit of recovery has been lost because of an initial start of CICS.

UERTDGNK

(X'08') Resource manager should not be in doubt about this unit of recovery.

UERTWAIT

(X'04') Resource manager must wait for the outcome of this unit of recovery. This value is set at phase two of a two-phase commit, if CICS is indoubt about the outcome of a UOW. It occurs only if the task-related user exit is enabled with the INDOUBTWAIT option (see Enabling for specific invocation-types).

UERTRSYN

(X'02') This syncpoint request was generated as the result of an EXEC CICS RESYNC command.

UERTLAST

(X'01') There are no further units of recovery associated with this task. Note that when this bit is not set, there may or may not be further units of recovery. For this reason, it is not recommended that you rely on this bit to signal end-of-task. You should instead schedule the CICS task manager to drive you at end-of-task by setting the task manager bit in the schedule flag word. If you do use UERTLAST to signal end-of-task, and if at that stage you can complete your clean-up process, you can set the task manager bit off in the schedule flag word when the clean-up process is finished, to avoid an unnecessary invocation by the CICS task manager.

The only valid bit combinations are those produced by combining one of UERTPREP, UERTCOMM, UERTBACK, UERTDGCS, and UERTDGNK with either UERTLAST or UERTRSYN, or both; or by combining UERTWAIT and UERTLAST.

Your exit program should examine the flags set both in this byte and in operation byte 2 (see parameter 10), to determine what action is expected of it.

Parameter 2

If not zero, the address of a 4-byte, packed-decimal field identifying the original task. But note that, on many invocations of the exit program, parameters 2 through 9 do not contain values. See note 1.

Parameter 3

Address of a 4-character field identifying the transaction that started the original task. See note 1.

Parameter 4

Address of a 4-character field identifying the terminal from which the original task was initiated. See note 1.

Parameter 5

Address of a 4-character field containing the identity of the terminal operator (OPID) who initiated the original task. See note 1.

Parameter 6

Address of a 4-byte, packed-decimal field containing the date of the failing syncpoint, in the format 0Cyyddds, where:

• C is a century indicator. (0=1900, 1=2000, 2=2100, and so on.)
• yy=years.
• ddd=days.
• s is the sign.

See note 1.

Parameter 7

Address of a 4-byte, packed-decimal field containing the time of the failing syncpoint, in the format 0hhmmss+. See note 1.

Parameter 8

Address of an 8-byte field containing the resource manager qualifier. See note 1.

To verify that this is a resync for this instance of the resource manager, your exit program should check that the qualifier passed is the one that is currently in use. If it is not, the exit program should ignore the resync and set a return code of UERFHOLD, to indicate that CICS should keep the disposition of the unit of work.

Parameter 9

Address of a 4-character field containing the next transaction code. If the transaction ended with an EXEC CICS RETURN without specifying the next transaction code, the addressed field is set to nulls; otherwise, it is set to the value specified by the application. See note 2.

Parameter 10

The address of operation byte 2, which contains the following flags:

UERTONLY

(X'80') Perform a single-phase commit. (No recoverable resources other than those owned by the resource manager being invoked have been updated during the current UOW.)

UERTELUW

(X'40') Perform a single-phase commit. (The resource manager was in read-only mode throughout the current UOW.)

Your exit program should examine the flags set both in this byte and in operation byte 1 (see parameter 1), to determine what action is expected of it.