IBM CICS Transaction Server for OS/390 SC33-1686-02 - Manual (Page 98)

CEMT INQUIRE ENQ
|
CEMT INQUIRE ENQ
| Function: Retrieve information about enqueues held or
| waited on by a UOW, or about UOWs holding or waiting on a
| specified enqueue.
| Description: INQUIRE ENQ returns information about the
| enqueues held by a UOW. Enqueues are used by CICS to
| lock recoverable resources such as file records or queues to
| the UOW that is updating them. User enqueues obtained by
| the EXEC CICS ENQ command are also returned.
| You can use INQUIRE ENQ to indicate which records and
| queues would be affected if the UOW were forced.
| The transaction also returns information about UOWs that
| are waiting on the enqueues. This enables you to diagnose
| enqueue deadlocks between tasks wanting to update the
| same resources.
| Enqueues are typically held in active state, which means that
| other tasks are allowed to wait for the enqueue. However, if
| the UOW that owns the enqueue suffers an in-doubt failure,
| the enqueue is usually converted to the retained state until
| the in-doubt failure can be resolved. INQUIRE ENQ also
| retrieves information about these enqueues and can be used
| to identify which records and queues would be affected if the
| UOW were forced.
| Notes:
| 1. Both UOW-lifetime and task-lifetime enqueues are
| returned by INQUIRE ENQ. (For an explanation of
| UOW- and task-lifetime enqueues, see the
| MAXLIFETIME option of the EXEC CICS ENQ command
| in the CICS System Programming Reference manual.)
| 2. On an in-doubt failure, user enqueues are released,
| unless the EXEC CICS ENQ command specified
| MAXLIFETIME(TASK) and it is not the end-of-task
| syncpoint that suffers the failure.
| Input: Press the Clear key to clear the screen. There are
| two ways of commencing this transaction:
| Type CEMT INQUIRE ENQ (the minimum abbreviation is
| CEMT I ENQ ). You get a display that lists all enqueues for
| all the current UOWs.
| Type CEMT INQUIRE ENQ ( CEMT I ENQ ) followed by as
| many of the other attributes as are necessary to limit the
| range of information that you require. So, for example, if
| you enter cemt i enq d , the resulting display shows you
| the details only of enqueues on records in VSAM data
| sets open in non-RLS mode or CICS-maintained data
| tables.
|
| ─ ─ ─CEMT Inquire Enq ─ ─┬ ┬ ──────────── ──────────
| └ ┘ ─ ─Uow(value)
| ─ ─ ─┬ ┬ ──────────────── ─ ─┬ ┬ ─────────────── ──────
| └ ┘ ─ ─TRansid(value) └ ┘ ─ ─TAskid(value)
| ─ ─ ─┬ ┬ ────────── ─ ─┬ ┬ ───────────── ──────────────
| ├ ┤ ─ACtive─── ├ ┤ ─Dataset─────
| └ ┘ ─RETained─ ├ ┤ ─File────────
| ├ ┤ ─EXecenq─────
| ├ ┤ ─ADdrexecenq─
| ├ ┤ ─TDq─────────
| └ ┘ ─TSq─────────
| ─ ─ ─┬ ┬ ──────── ─ ─┬ ┬ ───────────────── ────────────
| ├ ┤ ─Owner── └ ┘ ─ ─Netuowid(value)
| └ ┘ ─Waiter─
| ─ ─ ─┬ ┬ ───────────────── ─ ─┬ ┬ ───────────────── ───
| └ ┘ ─ ─ENqfails(value) └ ┘ ─ ─RESource(value)
| ─ ─ ─┬ ┬ ───────────── ─ ─┬ ┬ ────────────────── ──────
| └ ┘ ─ ─RLen(value) └ ┘ ─ ─QUalifier(value)
| ─ ─ ─┬ ┬ ───────────── ─
| └ ┘ ─ ─QLen(value)
| Sample screen
||
|
INQ ENQ |
STATUS: RESULTS |
Enq(AC143 1D4A726 1) Tra(CECI) Tas( 38) Act Exe Own |
Res(ACCOUNTS.DBASE1 ) Rle( 15) Enq( ) |
Enq(AC143 1D4A726 1) Tra(CECI) Tas( 38) Act Add Own |
Res(g... ) Rle( 4) Enq( )
| Figure 69. CEMT INQUIRE ENQ screen
| Note: There are blank fields on the screen where a value
|
does not apply or is ‘negative’; that is, the value
| begins with ‘No’. To modify these fields, locate them
| by tabbing (they appear in the same sequence as in
| the expanded format), and overtype with input valid
| for that field. You may find it more convenient to use
| the expanded format when setting one of these
| values, (negating is easier because you are
| overtyping a displayed field with its negative causing
| the result to become non-displayed).
| If you place the cursor against a specific entry in the list and
| press ENTER, CICS displays an expanded format as shown
| in Figure 70.
||
|
INQ ENQ |
RESULT |
Enq |
Enq(AC143 1D4A726 1) |
Transid(CECI) |
Taskid( 38) |
State(Active) |
Type(Execenq) |
Relation(Owner) |
Duration() |
Resource(ACCOUNTS.DBASE1) |
Rlen( 15) |
Enqfails( ) |
Netuowid(..GBIBMIYA.IYA2T5C2...Mx...) |
Qualifier() |
Qlen( )
| Figure 70. The expanded display of an individual entry
80 CICS Supplied Transactions