IBM Support

PK48047: DOUBLE FREEMAIN OF IECCB CAUSES STORAGE VIOLATION DFHSM0002 X'0305'

A fix is available

Subscribe

You can track all active APARs for this component.

 

APAR status

  • Closed as program error.

Error description

  • Two tasks using ECI over TCP/IP facilities enter into a logical
    conflict in the use of a CICS Socket, resulting in both tasks
    requesting a Freemain of the same IECCB control block.  This
    causes message DFHSM0002 (x'0305'), a "double Freemain" error.
    CICS' internal trace clearly shows 2 seperate CIEP tasks, each
    requesting a Freemain for the same IECCB address.
    

Local fix

Problem summary

  • ****************************************************************
    * USERS AFFECTED: All CICS users.                              *
    ****************************************************************
    * PROBLEM DESCRIPTION: ECI is being used over TCP/IP. Under    *
    *                      some circumstances, a conversation      *
    *                      ping request from a client causes a     *
    *                      storage violation DFHSM0002 X'0305'.    *
    ****************************************************************
    * RECOMMENDATION:                                              *
    ****************************************************************
    ECI is being used over TCP/IP. A conversation is in progress
    between CICS and a client. A send last_yes flow is about to
    be sent from CICS but a conversation ping request is received
    from the client as well. The normal send has a lock on the
    socket, so the ping response cannot flow. Since the send is
    the last flow from CICS to the client on the normal
    conversation, DFHIEIE freemains the IE domain control
    blocks and buffers associated with the conversation including
    the IECCB.
    The ping response is then sent. By the time this completes,
    the freed IECCB has been reused. The task processing the ping
    continues to reference the freemained IECCB and decides to
    cleanup the IECCB itself due to false IECCB state information.
    
    This was reported as a double freemain attempt on an IECCB,
    but it is also possible that this problem will manifest
    itself as a double freemain attempt on IE_BUFF.
    
    ADDITIONAL KEYWORDS :- SM0002 MSGDFHSM0002
    

Problem conclusion

  • DFHIEIE has been changed so that conversation ping abend checks
    if the IECCB for the conversation is still active before using
    it.
    

Temporary fix

  • FIX AVAILABLE BY PTF ONLY
    

Comments

APAR Information

  • APAR number

    PK48047

  • Reported component name

    CICSTS V3 Z/OS

  • Reported component ID

    5655M1500

  • Reported release

    400

  • Status

    CLOSED PER

  • PE

    NoPE

  • HIPER

    NoHIPER

  • Special Attention

    NoSpecatt

  • Submitted date

    2007-06-28

  • Closed date

    2007-11-01

  • Last modified date

    2007-12-03

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

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

    PK52991 UK30837 UK30838

Modules/Macros

  •    DESIEIE  DFHIEIE
    

Fix information

  • Fixed component name

    CICSTS V3 Z/OS

  • Fixed component ID

    5655M1500

Applicable component levels

  • R400 PSY UK30837

       UP07/11/07 P F711

  • R500 PSY UK30838

       UP07/11/07 P F711

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.

[{"Business Unit":{"code":"BU058","label":"IBM Infrastructure w\/TPS"},"Product":{"code":"SSGMGV","label":"CICS Transaction Server"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"3.1","Edition":"","Line of Business":{"code":"LOB35","label":"Mainframe SW"}},{"Business Unit":{"code":"BU054","label":"Systems w\/TPS"},"Product":{"code":"SG19M","label":"APARs - z\/OS environment"},"Component":"","ARM Category":[],"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"3.1","Edition":"","Line of Business":{"code":"","label":""}}]

Document Information

Modified date:
03 December 2007