PM70109: WEBSPHERE MQ V7, ABEND 0C4-00000011 IN CSQXSGET, PROBLEM WILL ONLY OCCUR WHEN A WAS ADDRESS SPACE IS ENDING ABNORMALLY.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• Error DescriptionÏ
  The 0C4s in CSQXSGET are the follow-on problems from the abends
  in the WSAS address space and are occuring during clean-up
  processing. An async consume TCB is going through end-of-task
  processing. CSQMEOTC has been invoked and has invoked CSQADELT
  to delete conversion tables etc.. Before invoking CSQADELT,
  CSQMEOTC sets R13 to the address of CSQBSRV's working storage
  in the BLOA (CSQBSRV_WS). The prolog in CSQXSGET (CSQVLSM9)
  detects that there is a stack header block (XSTKH; indicated by
  'CSQA' in the first word of the save-area) and addresses the
  stack header (16 bytes prior to the save-area). It then picks
  up the address of the stack parm block, XSPM. However, the
  address is in another BLOA which has been released (due to the
  TCB which attached the async consume TCB ending), hence the 0C4
  occurs.
  

Local fix

• Local FixÏ
  none
  

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of WebSphere MQ for z/OS Version 7 *
  *                 Release 0 Modification 1 and Release 1       *
  *                 Modification 0.                              *
  ****************************************************************
  * PROBLEM DESCRIPTION: The application address space abends    *
  *                      with S0C4-00000011 when the using       *
  *                      async-consume.                          *
  *                      This problem can occur when async-      *
  *                      consume is not used properly (i.e.      *
  *                      stopping the async-consume thread       *
  *                      and the disconnect step is not done)    *
  *                      or an abend occurs in the application   *
  *                      address space whilst an async-consume   *
  *                      thread is active.                       *
  *                      This problem can occur when WebSphere   *
  *                      Application Server is abending.         *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  A control thread is started and connects to MQ. As part of this
  a BLOA control block is allocated, containing a space for stack
  storage. When the control thread starts the async-consume
  thread with MQCTL-MQOP_START, a new BLOA control block is
  allocated for the async-consume thread. However this one
  contains a pointer back to the control threads BLOA, in order
  to be able to use it's connection when doing MQAPI calls. It
  also shares the control threads BLOA's stack storage.
  In the case where the async-consume thread is left running
  after the control thread has gone through end of task
  processing, for instance if the application address space is
  abending, the async-consume thread is left with pointers to the
  control threads BLOA, which has now been freed. Any attempt to
  access it will cause an 0C4.
  

Problem conclusion

• The code was changed to correctly terminate the async consume
  thread with abend 5C6-00C20009 when the control thread goes
  through end of task processing whilst the async consume thread
  is still active.
  010Y
  100Y
  CSQBDSC
  CSQBSRV
  CSQMDALL
  CSQMEOTC
  

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:

  UK83774 UK83775

Modules/Macros

• CSQBDSC  CSQBSRV  CSQMDALL CSQMEOTC
  

Fix information

• Fixed component name

  WMQ Z/OS V7

• Fixed component ID

  5655R3600

Applicable component levels

• R010 PSY UK83774

     UP13/01/16 P F301

• R100 PSY UK83775

     UP13/01/16 P F301

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.