PI94491: A CICS REGION MAY STOP FUNCTIONING AFTER A PTHREAD_CREATE_TIMEDOUT CONDITION.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• A task wanted to create a new pthread (T8 TCB), and waited for
  10 seconds for the IPT (initial process thread) to create the
  pthread.
  
  A response didn't come back in that 10 seconds, so it is
  assumed that the IPT had died and timed out the request.
  
  It appears that the lpar was so busy that the IPT could not
  respond to this request in that period of time. The task that
  wanted a new pthread will get an abend, and the rest of the
  system will continue.
  
  It looks like the IPT woke up later and found the request
  to create a pthread. That request still appeared to be "active",
  i.e. the IPT didn't know that the requestor had given up and
  timed out the request. The IPT would have created the new
  pthread anyway, but at this point the whole infrastructure
  around that request (KTCB, SJKE etc) could have been reused for
  other purposes.
  
  This may lead to an 0C4/AKEA in MODULE DFHDSTCB AT OFFSET
  X'331E' and a hanging CICS region.
  
  
  CICS exception trace entries  :
  -------------------------------
  
  95019 TP000 SJ 024D SJIN  *EXC* PTHREAD_CREATE_TIMEDOUT
                                  CREATE_PTHREAD,2E6C4D00
  
  95019 TP000 KE 050A KEDS  *EXC* PTHREAD-INSUFFICIENT-STORAGE
                                  CREATE_TCB
                                  5583B900,T8,FFFB,EXEC_YES,
                                  LE_MVS,KEY8,
  
  95043 ..... DS 0055 DSTCB *EXC* DSTCB_RECOVERY
                                  TCB_REPLY,4256CA0C
  
  
  CICS Joblog :
  -------------
  DFHDS0001  AN ABEND (CODE 0C4/AKEA) HAS OCCURRED AT OFFSET
  X'331E' IN MODULE DFHDSTCB.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHDS0001 reports S0C4 in MODULE        *
  *                      DFHDSTCB AT OFFSET X'331E'              *
  ****************************************************************
  CICS attempted to create a new T8 TCB (pthread).
  The IPT was woken by DFHSJIN to issue a pthread_create,
  but DFHSJIN timed out before the IPT could complete creating
  the pthread. In the reported problem, the system was heavily
  constrained on available CPU at this time.
  DFHSJIN stops waiting, and reports the time out condition:
  SJ 024D SJIN  *EXC* PTHREAD_CREATE_TIMEDOUT
  Shortly afterwards, the pthread_create does complete and
  a new pthread is attached.
  The SJKE and DS_TCB CICS control blocks which were allocated
  to this new T8 TCB are reused for other purposes. This allows
  the new T8 to start running and look for work to process.
  This can give rise to an 0C4 protection exception in
  DFHDSTCB.
  Additional Keyword: AbendS0C4
  

Problem conclusion

• CICS has been updated to prevent a T8 TCB from being attached
  after the timeout time has expired.
  

Temporary fix

Comments

APAR Information

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

  PI86332

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

  UI54498 UI54499 UI54500

Modules/Macros

• DFHAPJVM DFHAPLJ1 DFHAPLJP DFHAXIS2 DFHCAL64 DFHCDJNI DFHCDK64
  DFHKEDD  DFHKEDS  DFHKEIN  DFHKESTX DFHKETA  DFHKETCB DFHKETIX
  DFHSJBD  DFHSJDM  DFHSJDS  DFHSJDUF DFHSJIN  DFHSJINT DFHSJIS
  DFHSJJS  DFHSJL   DFHSJNT  DFHSJPTI DFHSJRE  DFHSJRL  DFHSJRM
  DFHSJSA  DFHSJSC  DFHSJSM  DFHSJSR  DFHSJST  DFHSJTE  DFHSJTH
  DFHSJTRI DFHSJWL  DFHSJXM  DFJ@H356 DFJ@H360 DFJ@H427 DFJ@H467
  DFJ@H468 DFJDTCOE DFJOUTRE DFJWLPPL
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R100 PSY UI54498

     UP18/03/16 P F803

• R103 PSY UI54500

     UP18/03/17 P F803

• R10D PSY UI54499

     UP18/03/17 P F803

Fix is available

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