PH59652: Message DFHDS0001 and abend S301/AKEB can be seen in DFHDSDS3.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• When a TCB goes through partition exit processing, there is a
  section of code that will be executed every so often to perform
  some general housekeeping tasks. In this case when the TP TCB
  goes into partition exit processing, this housekeeping code is
  due to run so the TP TCB is used to perform these tasks. In this
  particular instance one of these tasks requires a new STIMER
  value be set, the setting of this new STIMER needs to be
  performed on the QR TCB, so if not already running on QR, the QR
  TCB is set as the TCB_PTR and a call is made to wake up the
  ECB. When returning to the partition exit code the TCB_PTR is
  not restored back to the original callers TCB (The TCB that the
  housekeeping code was called on).In this case, this leads to the
  TP TCB issuing a WAIT on a QR ECB. The problem is then seen if
  the QR TCB also goes through partition exit processing at this
  time, and issues a WAIT against this same ECB.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: Message DFHDS0001 and abend S301/AKEB   *
  *                      can be seen in DFHDSDS3.                *
  ****************************************************************
  Every so often houskeeping tasks (for example; checking to see
  if any tasks need to be purged because they have timed out)
  need to be performed by the CICS dispatcher. In order to perform
  these tasks any available TCB can be used (one that currently
  has no work of its own to perform). In some cases issues can be
  seen when one of these housekeeping tasks results in a new
  STIMERM value needing to be set for a task. This requires the QR
  TCB, if the QR TCB is not the TCB that is performing the
  housekeeping work, then a switch is made to run on the QR TCB.
  This can lead to the TCB that is being used to perform the
  housekeeping work later incorrectly issuing a WAIT (SVC 01)
  against a QR ECB. If the QR TCB also waits on this ECB then
  abend S301 is seen.
  

Problem conclusion

• DFHDSDS3 has been corrected to ensure that the WAIT is issued
  against the correct TCB's ECB.
  

Temporary fix

Comments

APAR Information

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

  PH57874

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

  UI95852

Modules/Macros

• DFHDSDS3
  

Fix information

• Fixed component name

  CICS TS Z/OS V6

• Fixed component ID

  5655YA100

Applicable component levels

• R400 PSY UI95852

     UP24/03/02 P F403

Fix is available

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