SET TASK
Purges a user task.
Syntax
For more information about the use of CICS-value data areas (CVDAs), see CVDAs recognized by the translator.
Description
The SET TASK command allows you to request a change in the priority or the purge of a named user task.
Options
- PRIORITY(data-value)
- Specifies
the priority, as a 32-bit binary value in the range of 0 through 255, that
is to be used for the named task. If the named task is the current task, any
change of priority takes immediate effect; otherwise, the change occurs when
the named task issues an EXEC CICS® command.
TXSeries for Multiplatforms runs all tasks at the same relative priority; therefore, this option has no effect.
- PURGETYPE(cvda)
- Specifies
the conditions in which the named task can be purged. Valid CVDA values are
PURGE and FORCEPURGE:
- PURGE
- Specifies that the task is to be abnormally terminated, but only when CICS can maintain system and data integrity. A task is not purged if its associated Transaction Definitions (TD) entry has the Purgeability attribute set to NOTPURGEABLE.
- FORCEPURGE
- Specifies
that the task is to be abnormally terminated immediately.
The use of the FORCEPURGE option can lead to unpredictable results; it is to be used only in exceptional conditions.
CICS checks for the presence of the PURGE or FORCEPURGE option during the processing of EXEC CICS commands. When the check indicates that the task is to be purged or forcibly purged, the following actions are initiated:- Abnormal task termination is triggered.
- ENQ locks issued by the task are released.
- Resources, such as terminals, queues, and files that have been locked for use by the task are released.
- Outstanding Logical Units of Work (LUWs) are backed out.
- Recoverable automatic transaction initiation (ATI) requests are requeued.
Conditions can occur in which the check for the PURGE or FORCEPURGE option cannot be made. For example, if the program is looping, the user program can keep control without issuing any EXEC CICS commands. Another example occurs when, within the execution of an EXEC CICS command, the user program is waiting for a resource that is not to be released for some time.
In such conditions, the PURGE request has no effect. However, if the FORCEPURGE option is issued and CICS cannot check for this attribute (possibly for one of the reasons previously mentioned), CICS immediately forces abnormal termination of the task. The results of using the FORCEPURGE option depend on what the task was doing at the time of the request. CICS can possibly terminate the task tidily, or terminate the application server, or cause abnormal termination of the region.
- TASK(data-value)
- Specifies
the four-byte packed decimal sequence number that identifies the task. Possible
values are:
- COBOL: PIC S9(7) COMP-3
- C: char task_num[4];
- PL/I: fixed dec(7)
Conditions
- INVREQ
- Occurs
for the following conditions, depending on the options that are specified
on the SET TASK command:
- The PURGETYPE option has an invalid CVDA value (RESP2=3).
- The PRIORITY option has an out-of-range nonnull value (RESP2=4).
- The task is not in a valid state for purging (RESP2=5).
Default action: Terminates the task abnormally.
- TASKIDERR
- Occurs
for the following conditions (RESP2=1):
- The named task cannot be found.
- The named task is protected by CICS; that is, it is a CICS-supplied transaction that is normally invoked from within CICS and not by an operator.
Default action: Terminates the task abnormally.