IBM SC34-6814-04 - Manual (Page 89)

– applies only to resource names of length equal to or greater than that
of your replacement string.
– is an alternative to method A when a resource name too long to allow
the use of that method.
Method C
Place a 4-character Scope value in UEPSCOPE, and return UERCSCPE
in R15. This will bypass any installed ENQMODEL resource definition,
forcing a Sysplex Scope ENQ/DEQ request.
This method is not recommended if you have an ENQMODEL table,
because the latter is designed to preserve data integrity by preventing
the possibility of a region scope enqueue and a sysplex scope enqueue
(or two sysplex scope enqueues with different scopes) existing for the
same resource. (Because sysplex and region scope enqueues use
separate namespaces, a region scope enqueue will never wait on a
sysplex enqueue, nor will a sysplex scope enqueue wait on a region
enqueue.)
Related concepts
“The enqueue EXEC interface sample exit program” on page 19
Notes about the use of XNQEREQ to alter ENQ or DEQ scope.:
1. XNQEREQ enables you to allow existing applications to be converted to use
sysplex enqueues without changing the application.
Note: Use of either the ENQMODEL resource definition or the user exit allows
this in most cases, but those applications where the resource name is
determined dynamically and not known in advance can only be so
converted by use of this exit.
2. Sysplex and region scope enqueues use separate namespaces. A region scope
enqueue will never wait on a sysplex enqueue, nor will a sysplex scope
enqueue wait on a region enqueue.
Note: This situation can only arise when you use the exit. Use of the
ENQMODEL resource definitions as your only method of defining the
SCOPE of an ENQ or DEQ avoids this potential risk.
3. Both region and sysplex scope are supported for string ENQs, but sysplex
scope is not supported for address ENQs.
EXEC interface program exits XEIIN, XEIOUT, XEISPIN, and XEISPOUT
There are four global user exit points in the EXEC interface program:
XEIIN Invoked before the execution of any EXEC CICS application programming
interface (API) or system programming interface (SPI) command.
XEISPIN
Invoked before the execution of any EXEC CICS SPI command except:
v EXEC CICS ENABLE
v EXEC CICS DISABLE
v EXEC CICS EXTRACT EXIT
v EXEC CICS PERFORM DUMP
v EXEC CICS RESYNC ENTRYNAME
The sequence is:
TRACE – XEIIN – XEISPIN – EDF – command
Chapter 1. Global user exit programs 67