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PM95003: WMQ ABEND0C4 CSQL1RCL +0000090C

A fix is available


You can track all active APARs for this component.


APAR status

  • Closed as program error.

Error description

  • Level 3 sees that there is a window in which 64-bit storage
    contraction (as a result of the CSQY224E) can occur while a
    thread is in the process of obtaining a 64-bit quickcell
    element from the free-chain. The storage contraction
    (CSQSQC64) can then result in the freeing of the storage
    extent containing the allocated quickcell element, which
    results in the 0C4 seen here (this would occur if the
    storage contraction takes place after the CSQSGC64 macro
    has checked  CSQS_QP64_UNIQ_RES1 but before the CSQSGC64
    macro has set QCEL_64.csId.
    Additional Symptom(s) Search Keyword(s):

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
    *                 Release 1 Modification 0.                    *
    * PROBLEM DESCRIPTION: Erroneous free of 64bit quick cell pool *
    *                      storage when queue manager is           *
    *                      undergoing cell pool contraction may    *
    *                      result in S0C4 abends occurring.        *
    * RECOMMENDATION:                                              *
    When a queue manager is short on 64bit storage above the bar and
    issues message CSQY224I indicating that it is attempting to free
    all unused storage above the bar, it is possible that a timing
    condition occurs where a cell from a pool is allocated
    immediately before the pool contraction occurs, but it not
    marked as in use immediately. This in-use cell may be
    incorrectly classified as being free and the queue manager may
    subsequently free the extent even though there are elements in
    Once the storage has been freed, any procedure attempting to use
    the cell pool storage may abend with an S0C4.

Problem conclusion

  • Processing has been amended to allow for cell allocations from
    the pool, prior to initiating the contraction process.
    In addition, a logic error where subsequent contractions may
    fail to correctly occur has also been corrected.

Temporary fix

  • *********
    * HIPER *


APAR Information

  • APAR number


  • Reported component name

    WMQ Z/OS V7

  • Reported component ID


  • Reported release


  • Status


  • PE




  • Special Attention

    NoSpecatt / Xsystem

  • Submitted date


  • Closed date


  • Last modified date


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

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



  • CSQSQC64

Fix information

  • Fixed component name

    WMQ Z/OS V7

  • Fixed component ID


Applicable component levels

  • R100 PSY UI13094

       UP13/12/24 P F312 Ž

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:
02 January 2014