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PK77869: CICS TS 3.1 DEADLOCK (CICS HANGS) AFTER TWO USER TASKS WANT SMLOCK AND XMLOCK

A fix is available

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APAR status

  • Closed as program error.

Error description

  • CICS TS 3.1 deadlock ( CICS hangs) after two user tasks both
    want SMLOCK and XMLOCK at the same time,  other tasks then
    queue in LMLM  for these locks.
    
    Both tasks seem to have a valid claim for both SMLOCK and XMLOCK
    but presumably, for task 92341, DFHSMMC2 should release the
    SMLOCK in step "inquire_task_storage" before the
    INQUIRE_TRANSACTION call to to DFHXMIQ which is where the
    XMLOCK is requested.
    

Local fix

  • No Local Fix
    

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All.                                         *
    ****************************************************************
    * PROBLEM DESCRIPTION: Deadlock between two tasks due to       *
    *                      conflicting XMLOCK and SMLOCK requests. *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    There is a deadlock between a transaction that owns the SMLOCK
    and is waiting for the XMLOCK to be freed, and another that owns
    XMLOCK and is waiting for SMLOCK:
    (1) CICS has attached a transaction which requires the XMLOCK
    while it does its work.
    (2) Another task is issuing an EXEC CICS INQUIRE STORAGE call.
    DFHSMMC2 is called to perform INQUIRE_TASK_STORAGE. This holds
    the SMLOCK within DFHSMMC2.
    (3) The attach of the first transaction requires storage, so it
    waits for SMLOCK.
    (4) The code in DFHSMMC2 needs to call XM to return
    transactional information, so requires the XMLOCK.
    
    Keywords: SM XM smmc2 jvm gc
    

Problem conclusion

  • DFHSMMC2 has been changed to release and reacquire the SMLOCK
    around the calls to transaction manager for this particular
    operation.
    

Temporary fix

  •             *********
                * HIPER *
                *********
    FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PK77869

  • Reported component name

    CICSTS V3 Z/OS

  • Reported component ID

    5655M1500

  • Reported release

    400

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    YesHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2008-12-29

  • Closed date

    2009-01-30

  • Last modified date

    2009-03-03

  • APAR is sysrouted FROM one or more of the following:

    PK65070

  • APAR is sysrouted TO one or more of the following:

    UK43542

Modules/Macros

  •    DESSMMC2 DFHSMMC2
    

Fix information

  • Fixed component name

    CICSTS V3 Z/OS

  • Fixed component ID

    5655M1500

Applicable component levels

  • R400 PSY UK43542

       UP09/02/03 P F902

Fix is available

  • Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.

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Document Information

Modified date:
03 March 2009