PI93248: DFHDS0001 0C4 IN DFHDSTCB, 2 TASKS USING SAME DTA

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CICS abends after putting out message:
  .
  DFHDS0001 An abend (code 0C4/AKEA) has occurred at
   offset X'09EE' in module DFHDSTCB.
  .
  The 0C4 occurs because 2 tasks are using the same DTA
  control block. Kernel domain shows the two tasks with the same
  DTA (DS_TASK). CICS trace also shows both tasks being attached
  with the same DTA (field ATTACH_TOKEN).
  .
  Additional Symptom(s) Search Keyword(s): KIXREVxxx
  DFHDSDS3 DFHDSKE DFHDSAT TASK_REPLY  Unused chain free
  executable double_chain_sort_merge check_executables
  unused_usertask
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: CICS terminates following msgDFHDS0001  *
  *                      and abend0C4 abendAKEA in DFHDSTCB.     *
  ****************************************************************
  In the reported problem, an abend S0C4 AKEA occurred in DFHDSTCB
  and CICS terminated. Two tasks were incorrectly sharing a DTA
  (Dispatcher Task Area (DS_TASK)) control block.
                                                                 .
  CICS Dispatcher code uses Compare Double and Swap instructions
  to support concurrent multi TCB programming techniques but a
  guard count field was not being incremented when it should have.
  This caused a DTA chain management malfunction which presented
  as 2 tasks sharing the same DTA, a subsequent abendS0C4 and
  CICS terminating.
  

Problem conclusion

• CICS dispatcher code has been amended to correctly manage the
  DTA chains.
  

Temporary fix

Comments

APAR Information

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

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

  UI54626 UI54627

Modules/Macros

• DFHDSAT  DFHDSDS3
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R000 PSY UI54627

     UP18/03/22 P F803 ¢

• R100 PSY UI54626

     UP18/03/22 P F803 ¢

Fix is available

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