A fix is available
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 number
PI94491
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2018-03-01
Closed date
2018-03-15
Last modified date
2018-04-03
APAR is sysrouted FROM one or more of the following:
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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Document Information
Modified date:
03 April 2018