QueryEnq is a Rexx function, written in assembler language, to return information on existing ENQs. With QueryEnq, any z/OS Rexx program can find out who is using a data set, who holds resources and even what ENQ contention exists on the system.
QueryEnq is available as source code.
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To return ENQ status on a data set or any rname/qname. This is a Rexx function and it sets Rexx variables.
Call QueryEnq rname
Call QueryEnq rname,qname
xx=QueryEnq(rname)
xx=QueryEnq(rname,qname)Call QueryEnq 'contention'
rname is assumed to be a data set name that follows TSO naming conventions. If it is not in quotes, the user prefix will be added. If qname is specified and is not SYSDSN then the rname is not treated as a TSO style data set name. If rname is the word contention then all ENQs causing contention are returned (both owners and waiters).
qname is the major name of the ENQ to be queried. Qname will default to SYSDSN. Qname must not be specified when rname is 'contention'.
Some combinations you might see include (from dynalloc & ISPF doc):
| QNAME | RNAME |
| SYSDSN | data set name |
| SPFEDIT | data set name (optional member name in cols 45 to 52) |
| SYSZOPEN | data set name |
| SYSZVOLS | volume serial number |
ENQJOB.n Stem variable containing jobs enqueued to a resource.
ENQTYPE.n ENQ information about the request made for the address space listed in ENQJOB.n.
Col 1-3 'SHR' or 'OLD' Col 5-8 'OWN ' or 'WAIT' Col 10-17 'SYSTEM ', 'SYSTEMS', or 'NONSYS ' Col 10-17 'SYSTEM ', 'SYSTEMS', or 'NONSYS ' COL 19-25 'STEP ' or 'NONSTEP' COL 27-34 system name on which request was made
ENQQNAME.n The QNAME associated with the enq in ENQJOB.n.
ENQRNAME.n The RNAME associated with the enq in ENQJOB.n. When ENQQNAME.n is 'SYSDSN', ENQRNAME.n is a data set name. The maximum length returned for ENQRNAME.n is 52. If the real rname is longer than 52 bytes, it is truncated to 52 bytes.
ENQTYPE.0, ENQJOB.0, ENQQNAME.0 and ENQRNAME.0 all contain the number of elements returned and will all contain the same number.
RC and RESULT values: RC=0 - RESULT = 'OK' RC=16 - RESULT = 'TOO MANY PARAMETERS' RC=20 - RESULT = 'RNAME NOT SPECIFIED'
Assemble AMODE(31),RMODE(ANY). Place load module in any accessable load library.
Sample
/* Rexx - QueryEnq example */
Say center(' ENQs on SYS1.BROADCAST ',78,'-')
s = queryenq("'SYS1.BRODCAST'")
Do a = 1 to enqjob.0
Say enqjob.a enqtype.a
End
Say center(' ISPF edits of CLIST(MEMBER) ',78,'-')
s = queryenq(left(userid()'.CLIST',44)||'MEMBER ','SPFEDIT')
Do a = 1 to enqjob.0
Say enqjob.a enqtype.a enqrname.a
End
Say center(' ENQ Contention ',78,'-')
Call queryenq 'contention'
If enqjob.0 > 0 Then
Do a = 1 to enqjob.0
Say enqjob.a enqtype.a enqqname.a enqrname.a
End
Else
Say 'No enq contention exists on this system.'
|
produces
--------------------------- ENQs on SYS1.BROADCAST --------------------------- AOCON4 SHR OWN SYSTEM NONSTEP VS1C R469663 SHR OWN SYSTEM NONSTEP VS1C R521960 SHR OWN SYSTEM NONSTEP VS1C NADEL SHR OWN SYSTEM NONSTEP VS1C NADELY OLD WAIT SYSTEM NONSTEP VS1C ------------------------ ISPF edits of CLIST(MEMBER) ------------------------- NADEL OLD OWN SYSTEMS NONSTEP VS1C NADEL.CLIST MEMBER ------------------------------- ENQ Contention ------------------------------- NADEL SHR OWN SYSTEM NONSTEP VS1C SYSDSN NADEL.ISRDDN NADELY OLD WAIT SYSTEM NONSTEP VS1C SYSDSN NADEL.ISRDDN NADEL SHR OWN SYSTEM NONSTEP VS1C SYSDSN NADEL.CLIST NADELY OLD WAIT SYSTEM NONSTEP VS1C SYSDSN NADEL.CLIST AOCON4 SHR OWN SYSTEM NONSTEP VS1C SYSDSN SYS1.BRODCAST R469663 SHR OWN SYSTEM NONSTEP VS1C SYSDSN SYS1.BRODCAST R521960 SHR OWN SYSTEM NONSTEP VS1C SYSDSN SYS1.BRODCAST NADEL SHR OWN SYSTEM NONSTEP VS1C SYSDSN SYS1.BRODCAST NADELY OLD WAIT SYSTEM NONSTEP VS1C SYSDSN SYS1.BRODCAST *** |