IBM: XITBK

Programming Interface Information: This information is NOT intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only.

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
 STATUS     : VM/ESA Version 2, Release 4.0
 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 : none

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 EQU X'80' Reserved
                                        EQU X'40' Reserved EQU X'20'
                                        Reserved
          ...1 ....      XITENABL       X'10' This exit has been enabled
          .... 1...      XITRESOL       X'08' Resolve exit when
                                        associated EQU X'04' Reserved EQU
                                        X'02' Reserved EQU X'01' Reserved
003D   61 Bitstring    1 XITFLAG2       A byte of bits EQU X'80' Reserved
                                        EQU X'40' Reserved EQU X'20'
                                        Reserved EQU X'10' Reserved EQU
                                        X'08' Reserved EQU X'04' Reserved
                                        EQU X'02' Reserved EQU X'01'
                                        Reserved
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                        |
*     +-------------------------------------------------------+
*  60 |                                                       |
*     =                       XIT$END                         =
*     |                                                       |
*     +-------------------------------------------------------+
*
*** XITBK - CP Exit Block
*** Overlay for XITSWAP1 in XITBK
*
*                                 +------+------+-------------+
*  38 ...                      3C |:FLAG1|:FLAG2|/////////////|
*                                 +------+------+-------------+
*  40
*
*** Overlay for XITSWAP1 in XITBK