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IY96282: TWO THREADS HAVE BEEN CONCURRENTLY ALLOCATED THE SAME SEMAPHORE

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APAR status

  • Closed as program error.

Error description

  • A large range of unpredictable results are likely to occur.
    FDC's with probes
    XC332035
    XC307070
    XC027020
    accompanied by queue manager hangs or crashes would be typical.
    

Local fix

Problem summary

  • ****************************************************************
    USERS AFFECTED:
    Users running MQ on Linux and exposing the queue manager to
    significant stress, in particular a high rate of applications
    connecting and disconnecting from the queue manager.
    
    Platforms affected:
    Linux (x86)
    
    ****************************************************************
    PROBLEM SUMMARY:
    The basic problem here is that two threads have been
    concurrently allocated the same semaphore as the primitive used
    to suspend/resume that thread. When the thread is resumed then
    the state of the resource being waited upon is found to be
    invalid and FDC's and hangs can result.
    

Problem conclusion

  • Corrected the locking when releasing semaphores via
    xcsCloseEventSem.
    
    ---------------------------------------------------------------
    The fix is targeted for delivery in the following PTFs:
    
                       v6.0
    Platform           Fix Pack 6.0.2.2
    --------           --------------------
    Linux (x86)        U809950
    
    The latest available maintenance can be obtained from
    'WebSphere MQ Recommended Fixes'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006037
    
    If the maintenance level is not yet available, information on
    its planned availability can be found in 'WebSphere MQ
    Planned Maintenance Release Dates'
    http://www-1.ibm.com/support/docview.wss?rs=171&uid=swg27006309
    ---------------------------------------------------------------
    

Temporary fix

Comments

APAR Information

  • APAR number

    IY96282

  • Reported component name

    WMQ LIN X86 V6

  • Reported component ID

    5724H7204

  • Reported release

    600

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-03-20

  • Closed date

    2007-03-29

  • Last modified date

    2007-07-27

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

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

Fix information

  • Fixed component name

    WMQ LIN X86 V6

  • Fixed component ID

    5724H7204

Applicable component levels

  • R600 PSY

       UP

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Document Information

Modified date:
27 July 2007