A fix is available
APAR status
Closed as program error.
Error description
When the customer is stopping an IMS dependent region, sometimes an ABEND0C4 or ABEND0C2 occurs in CSQQWAIT. This problem started when a service parameter that affects the mechanism used wait on TCBs in the IMS adapter code was turned on. The ABEND0C4 is in CSQQWAIT because WAU control block storage was freed during a 1-second STIMER wait interval that occurs with the parameter turned on.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All users of IBM MQ for z/OS Version 9 * * Release 2 Modification 0 and * * Release 3 Modification 0. * **************************************************************** * PROBLEM DESCRIPTION: An 0C4 or an 0C2 abend is seen when an * * IMS dependent region is stopped in * * CSQQWAIT when a service parameter that * * affects the mechanism used wait on TCBs * * in the IMS adapter code is turned on. * **************************************************************** When stopping an IMS dependent region sometimes an 0C4 or 0C2 abend occurs in CSQQWAIT when a service parameter that affects the mechanism used wait on TCBs in the IMS adapter code was turned on. The abends occur due to a timing window where the WAU control block storage was freed during a 1 second STIMER wait interval that occurs with the parameter turned on. After the STIMER ends an attempt to use the WAL/WAU storage is made resulting in either the 0C4 or 0C2 abend depending on the exact timings.
Problem conclusion
The code has been updated to add defensive code to detect if the WAL has been freed during the STIMER call so that no attempt to access the storage is made if it has been found to be freed.
Temporary fix
Comments
APAR Information
APAR number
PH53690
Reported component name
IBM MQ Z/OS V9
Reported component ID
5655MQ900
Reported release
200
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2023-04-03
Closed date
2024-03-04
Last modified date
2024-04-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI95919 UI95920
Modules/Macros
CSQQTTHD CSQQWAIT
Fix information
Fixed component name
IBM MQ Z/OS V9
Fixed component ID
5655MQ900
Applicable component levels
Fix is available
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Document Information
Modified date:
11 April 2024