Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### XITBK

Prolog

Control Block Contents
XITBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### XITBK Prolog

     Name       : HCPXITBK
     Description: CP Exit Block
     DSECT      : XITBK
     Function   : This control block contains information used to
                  authorize user exit routines to find their entry
                  points.
     Located by : Radix tTree structure anchored by XCTBK.XCTRADIX.
     Created by : HCPZXUAD
     Deleted by : HCPZXUDL    (The deletion is only allowed if the XITBK
                  is for a Dynamic Exit that is NOT enabled
                  and is NOT associated at delete time)

#### XITBK Control Block Content

#### XITBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      XITBK          CP Exit Block
    0000    0 Dbl-Word     8 XITUSRD1       Reserved for non-IBM use
    0008    8 Dbl-Word     8 XITUSRD2       Reserved for non-IBM use
    0010   16 Signed       4 XITUSRF1       Reserved for non-IBM use
    0014   20 Signed       4 XITUSRF2       Reserved for non-IBM use
    0018   24 Signed       2 XITUSRH1       Reserved for non-IBM use
    001A   26 Signed       2 XITUSRH2       Reserved for non-IBM use
    001C   28 Bitstring    1 XITUSRX1       Reserved for non-IBM use
    001D   29 Bitstring    1 XITUSRX2       Reserved for non-IBM use
    001E   30 Bitstring    1 XITUSRX3       Reserved for non-IBM use
    001F   31 Bitstring    1 XITUSRX4       Reserved for non-IBM use
    0020   32 Dbl-Word     8 XITXCRLK (3)   Lock word to serialize
                                            manipulations of the XCRBK chain
    0038   56 Bitstring    2 *              Reserved
    003A   58 Bitstring    2 XITCODE        Exit number
    003C   60 Signed       4 XITSWAP1       A label for Compare-and-Swap
    0040   64 Address      4 XITPUSHD       Address of PUSHed XITBK
    0044   68 Signed       4 *              Reserved
    0048   72 Signed       4 XITCALLS       Count of calls to this exit
    004C   76 Signed       4 XITRETNS       Count of returns
    0050   80 Address      4 XITXCRBK       Address of list of XCRBKs
    0054   84 Address      4 XITDEDBK       Address of DEDBK
    0058   88 Signed       8 XITMSACT       Time (in micro-seconds) that the
                                            routines that comprise this exit
                                            were active.
    0060   96 Dbl-Word     8 XIT$END (0)    End on a dword
    003C   60 Bitstring    1 XITFLAG1       A byte of bits
              ...1 ....      XITENABL       X'10' XITENABL This exit has been
                                            enabled
              .... 1...      XITRESOL       X'08' XITRESOL Resolve exit when
                                            associated
    003D   61 Bitstring    1 XITFLAG2       A byte of bits
    003E   62 Bitstring    2 *              Reserved

#### XITBK Storage Layout

    *** XITBK - CP Exit Block
    *
    *     +-------------------------------------------------------+
    *   0 |                       XITUSRD1                        |
    *     +-------------------------------------------------------+
    *   8 |                       XITUSRD2                        |
    *     +---------------------------+---------------------------+
    *  10 |         XITUSRF1          |         XITUSRF2          |
    *     +-------------+-------------+------+------+------+------+
    *  18 |  XITUSRH1   |  XITUSRH2   |:USRX1|:USRX2|:USRX3|:USRX4|
    *     +-------------+-------------+------+------+------+------+
    *  20 |                                                       |
    *     =                       XITXCRLK                        =
    *     |                                                       |
    *     +-------------+-------------+---------------------------+
    *  38 |/////////////|  XITCODE    |         XITSWAP1          |
    *     +-------------+-------------+---------------------------+
    *  40 |         XITPUSHD          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *  48 |         XITCALLS          |         XITRETNS          |
    *     +---------------------------+---------------------------+
    *  50 |         XITXCRBK          |         XITDEDBK          |
    *     +---------------------------+---------------------------+
    *  58 |                       XITMSACT                        |
    *     +-------------------------------------------------------+
    *
    *** XITBK - CP Exit Block

    *** Overlay for XITSWAP1 in XITBK
    *
    *                                 +------+------+-------------+
    *  38 ...                      3C |:FLAG1|:FLAG2|/////////////|
    *                                 +------+------+-------------+
    *  40
    *
    *** Overlay for XITSWAP1 in XITBK

#### XITBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    XIT$END        0060
    XITCALLS       0048
    XITCODE        003A
    XITDEDBK       0054
    XITENABL       003C 10
    XITFLAG1       003C
    XITFLAG2       003D
    XITMSACT       0058
    XITPUSHD       0040
    XITRESOL       003C 08
    XITRETNS       004C
    XITSWAP1       003C
    XITUSRD1       0000
    XITUSRD2       0008
    XITUSRF1       0010
    XITUSRF2       0014
    XITUSRH1       0018
    XITUSRH2       001A
    XITUSRX1       001C
    XITUSRX2       001D
    XITUSRX3       001E
    XITUSRX4       001F
    XITXCRBK       0050
    XITXCRLK       0020

This information is based on z/VM V6R1.0. Last updated on 18 Feb 2010 at 09:26:14 EDT.
Copyright IBM Corporation, 1990, 2008