PH68808: TWO TASKS RACING THROUGH THE SHUTDOWN PROCESS CORRUPT STORAGE HOLDING NAMES OF SHUTDOWN PLT PROGRAMS

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• If two tasks issue an EXEC CICS PERFORM SHUTDOWN command around
  the same time, there is a timing window where they both may
  attempt to read and parse the shutdown PLT programs. When this
  occurs, the storage which should end up holding the names of the
  shutdown PLT programs becomes corrupted and points to garbage.
  .
  CICS does not realize this and tries to link to programs with
  garbage names until it comes across some values which end the
  loop.
  .
  This may result in many DFHTM1752 messages, DFHME0121 messages,
  and perhaps 0C4 and similar abends.
  
  01.00.59 STC12345  +DFHTM1752 CICSABCD PLT - program not
  available.
  01.00.59 STC12345  +DFHME0121 CICSABCD   400
    400              The first attempt at formatting message
  DFHTM1718, TD queue CSSL, has
    400              failed - Invalid DBCS format
  
  Additional Keyword(s): Termination, TM1752, ME0121
  KIXREVACC
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHTM1752 PLT - program   not available *
  *                      issued during CICS Shutdown if two      *
  *                      tasks issue SHUTDOWN at the same time.  *
  ****************************************************************
  Two CICS tasks each issue PERFORM SHUTDOWN at the same time.
  The second SHUTDOWN task does not detect that shutdown is in
  progress and causes storage corruption which results in many
     DFHTM1752 PLT - program not available
  messages being produced.
  Additional keywords: MSGDFHTM1752 PROGBUFF
  

Problem conclusion

• CICS has been corrected to prevent storage corruption
  in the situation where two tasks issue PERFORM SHUTDOWN
  at the same time.
  

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:

  UO06935 UO06936

Modules/Macros

• DFHAPTB
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R500 PSY UO06936

     UP26/03/06 P F603

• R600 PSY UO06935

     UP26/02/26 P F602

Fix is available

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