PI65891: TCB SWITCHING OCCURS IN IMS OPENTHREAD ENVIRONMENT EVEN WITH A COMPLETELY THREADSAFE CICS APPLICATION AFTER GN CALL.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• After activating threadsafe, the customer sees switching
  between the QR and L8 TCBs once for each GN call (but not for
  each ISRT call).
  Review of the CICS trace shows CICS switching to the QR to
  process an EXEC DLI GET NEXT command. The switch happens in
  DFHERM as it is preparing to invoke DFHEDP for the DLI True. At
  the time of the EXEC DLI GET NEXT command, the application is
  running on its L8 TCB. DFHERM forces the switch to the QR
  because of code around label SPECIAL_CASE. There it checks that
  arg0, looking for the x'02' bit at +x'2' with this instruction:
  TM    EIDOPT2,EIDSOTR     START OF TASK?
  That bit is on, and then since the DLI TRUE (DFHEDP) is
  Threadsafe, the call is forced to the QR.
  The problem is the EIDSOTR bit is on and being checked but the
  bytes at x'02' and x'03' are just existence bits.
  Additional Symptom(s) Search Keyword(s): KIXREVACC
  

Local fix

• N/A
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All                                          *
  ****************************************************************
  * PROBLEM DESCRIPTION: A threadsafe CICS IMS program switches  *
  *                      from an L8 TCB to QR for EXEC CICS DLI  *
  *                      GET NEXT requests.                      *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  For a CICS program with EXEC DLI requests, DFHERM invokes DFHEDP
  after it has tried to determine whether to switch to the QR TCB
  or not. One of the bits it tests is EIDSOTR in EIDOPT2 but,
  since that bit is also used as an existence bit for EXEC DLI
  calls, it wrongly switches to QR.
  Keywords: GN GETNEXT
  

Problem conclusion

• DFHERM has been changed to bypass the test of EIDSOTR for EXEC
  DLI calls.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

  PI57094

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

  PI65892 UI39896 UI39897

Modules/Macros

• DFHERM
  

Fix information

• Fixed component name

  CICS TS Z/OS V5

• Fixed component ID

  5655Y0400

Applicable component levels

• R800 PSY UI39896

     UP16/08/11 P F608

• R900 PSY UI39897

     UP16/08/11 P F608

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.