PK07909: ABEND0C4 AT DFSIDPF0 (PQ84167) +X'2CC'.

APAR status

• Closed as program error.

Error description

• DFSIDPF0 is processing the RRE chain at ENTRY2.  Upon return
  from NEXTRRE, the RRE address (R5=142A7840) is saved, a few
  checks are made, and R1 is loaded from RREEZSA (00A2AD60).
  However, '00A2A000.:A2AFFF. --Storage not available'
  leading to ABEND0C4 at DFSIDPF0+x'2CC'.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All IMS 910 users using External Subsystem   *
  *                 Attach Facility, ESAF, and the /DIS SUBSYS   *
  *                 command                                      *
  ****************************************************************
  * PROBLEM DESCRIPTION: ABENDS0C4 encountered in the DFSIDPF0   *
  *                      module after issuing a /DIS SUBSYSTEM   *
  *                      command.                                *
  ****************************************************************
  * RECOMMENDATION: INSTALL CORRECTIVE SERVICE FOR APAR/PTF      *
  ****************************************************************
  This failure occurs when dependent region signoff ( DFSSDA40 ),
  external subsystem signoff ( DFSESCL0 ) and the /DIS SUBSYSTEM
  command processor ( DFSIDPF0 ) execute concurrently, simultane-
  ously accessing the same RRE. Specifically, the failure occurs
  when DFSSDA40 unchains a dependent region RRE from the PST and
  then must wait for an exclusive SIDX latch.  The SIDX latch is
  held shared by DFSIDPF0 while referencing the RRE and the EZSE.
  At this point, DFSESCL0 executes, finds the RRE, but is unable
  to determine that the RRE and EZSE are in use by DFSIDPF0, and
  will be freed by DFSSDA40, because the RRE has been unchained
  from the PST. Having found no reason not to, DSFESCL0 releases
  the storage. Storage compression then frees the IPAGE of EZSEs
  that are no longer required.  And finally, DFSIDPF0 references
  the freed storage and an ABENDS0C4 is encountered.
  
  ADDITIONAL PROBLEMS:
  This failure can also occur when an ODBA application ODS task
  completes a sync request and the module handling this process,
  DFSAERN0, calls DFSSDA40 to clean up PST resources.  DFSSDA40
  will dequeue the RRE from the PST and then attempt to dequeue
  the RRE from the SIDX.  If the SIDX dequeue does not complete
  successfully, returning with a non-zero code, DFSSDA40 leaves
  the RRE chained to the SIDX with the EZSE intact and chained
  to the RRE. DFSAERN0 then invokes the SIGNOFF function, which
  calls DFSESCL0, which in turn, deletes the EZSE as previously
  described. Storage compression can then run to free the IPAGE
  of EZSEs that are no longer required. At this point, the /DIS
  SUBSYS ALL command will invoke DFSIDPF0 which then references
  the freed storage and an ABENDS0C4 is encountered.
  

Problem conclusion

• AIDS: RIDS/DCS RIDS/CMD DCS CMD
    DEP: NONE
    GEN:
  
  *** END IMS KEYWORDS ***
  The DFSSDA40 module has been updated to set the EZSE EZS40REL
  flag, prior to unchaining the RRE from the PST, to inform the
  DFSESCL0 module that DFSSDA40 will release the EZSE.
  
  The DFSESCL0 module has been updated to test the EZS40REL flag
  prior to releasing the EZSE.  If the flag is on, DFSESCL0 will
  not release the EZSE.
  
  The DFSEZS macro has been updated to define the EZSE EZS40REL
  flag.
  
  The DFSIDPF0 module has been updated to test for a valid EZSE
  prior to accessing it.
  
  ADDITIONAL KEYWORDS:
  S0C4 ABEND0C4 ABENDS0C4 ABENDS0C4-10
  S0C4 ABEND0C4 ABENDS0C4 ABENDS0C4-11
  CMDDIS /DIS /DISPLAY
  

Temporary fix

• *********
  * HIPER *
  *********
  

Comments

APAR Information

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

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

  UK06648

Modules/Macros

• DFSESCL0 DFSEZS   DFSIDPF0 DFSSDA40
  

Fix information

• Fixed component name

  IMS V9

• Fixed component ID

  5655J3800

Applicable component levels

• R900 PSY UK06648

     UP05/08/30 P F508 Ž