PM87523: DFHSO0001 AN ABEND (CODE ---/ASOC) HAS OCCURRED AT OFFSET X'0C5A' IN MODULE DFHSOS14

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• You are running CICS transaction server 4.2 and receive
  the following error message:
  DFHSO0001 An abend (code ---/ASOC) has occurred at offset
                        X'0C5A'  in module DFHSOS14.
  The problem involves locks associated with a socket, caused by
  a timing issue with our main listener task CSOL.
  A task 1 owned socket 'A'.  It was suspended when issuing a
   RELINQUISH for SOCKET_TOKEN(A)
  While it was suspended, the CSOL task got contol and deleted
  this socket 'A', along with all its associated locks.
  In this case, CSOL processed a new socket request, giving it
  socket token 'B', but assigned this socket token the locks that
  were previously associated with socket 'A'. Task 2 is now the
  owner of these locks.
  When task 1, wakes up from its suspend, to continue its
  processing of the relinquish for socket 'A', it fails when
  accessing the SOCK_REL lock token, since it is no longer the
  owner of it. Here is that trace entry:
       LMLM EXIT - FUNCTION(UNLOCK) RESPONSE(EXCEPTION)
                   REASON(NOT_LOCK_OWNER)
  Additional Symptom(s) Search Keyword(s):ABENDASOC, Unlock,
  KIXREVEPH
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All CICS Users.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: DFHSO0001 An abend (code ---/ASOC)      *
  *                      has occurred at offset X'0C5A' in       *
  *                      module DFHSOS14.                        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A task is started from input received on a socket. The task
  completes successfully but gets suspended during end-of-task
  syncpoint.
  Whilst this task is suspended CSOL is driven to close the
  socket. CSOL gets the socket relinquish lock, SOCK_REL, but
  then itself loses control.
  The original task continues but suspends again, waiting for the
  SOCK_REL lock which is still held by CSOL.
  CSOL regains control and releases the SOCK_REL lock which
  causes the lock manager domain to RESUME the original task,
  however the system is busy and the task does not immediately
  resume processing.
  In the meantime CSOL continues to delete the socket and all its
  locks, including SOCK_REL.
  A new task is started via input from a socket. CSOL allocates
  all the storage and locks from the original socket to the new
  one. The token that belonged to SOCK_REL is now allocated to
  the SOCK_ATT lock.
  The original task finally continues and incorrectly gets a
  good return from the LOCK of SOCK_REL, even though that
  storage has been reallocated.
  It relinquishes the socket and then attempts to UNLOCK the
  SOCK_REL lock. However, SOCK_REL now has a different token
  so lock manager returns NOT_LOCK_OWNER, resulting in a
  reported msgDFHSO0001 for code ASOC and a system dump.
  A variation of this problem may occur if the SOCK_REL lock
  is deleted whilst the task is waiting for the lock, but not
  reallocated. In that case the LOCK command will fail with
  LOCK_TOKEN_NOT_FOUND, resulting in msgDFHSO0001 for code
  ASOB and a system dump.
  

Problem conclusion

• The DFHSOS14 RELINQUISH routine has been altered to save the
  socket token and the SOCK_REL lock token before issuing a LOCK
  on SOCK_REL.
  If lock manager returns a good response the routine will check
  that the socket token is still valid and if not will UNLOCK
  the original SOCK_REL lock, then return with an exception
  response and reason connection_closed.
  If lock manager returns LOCK_TOKEN_NOT_FOUND the routine will
  return an exception response and reason connection_closed.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

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

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

  PM97499 UK98234

Modules/Macros

•    DFHSOS14
  

Fix information

• Fixed component name

  CICS TS Z/OS V4

• Fixed component ID

  5655S9700

Applicable component levels

• R700 PSY UK98234

     UP13/10/13 P F310

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.