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

#### IUCVB

Prolog

Control Block Contents
IUCVB DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### IUCVB Prolog

     NAME       : HCPIUCVB
     DESCRIPTION: IUCV CONTROL BLOCK
     DSECT      : IUCVB
     FUNCTION   : THIS CONTROL BLOCK DEFINES THE INTER-USER COMMUNICATIONS
                  VEHICLE CONTROL BLOCK FOR AN IUCV USER.
     LOCATED BY : -VMDIUCV FIELD OF HCPVMDBK FOR VIRTUAL MACHINES
                  -CALL TO HCPIUGAI FOR CP SYSTEM SERVICES
     CREATED BY : IUCV DECLARE BUFFER FUNCTION - HCPIUJDB
     DELETED BY : IUCV RETRIEVE BUFFER FUNCTION - HCPIUERB
     NOTES      : The following fields are valid in the base IUCVB only (all
                  other fields are valid in the base and local IUCVBs):
        IUCVCCT   - Pointer to user's CCTBK
        IUCVBWIN  - Dispatch window event count
        IUCMXCN   - Maximum number of connections
        IUCPNDHD  - Pending control interrupt queue head
        IUCPNDTL  - Pending control interrupt queue tail
        IUCVSTAT  - IUCV status
        IUCANYFL  - *IDENT authorization particulars
        IUCTOTCN  - Total number of connections
        IUCVBCPX  - CPEBK for HCPIVKRS call
        IUCBUFCT  - Buffer counts
        IUCPPAS   - Chain of PPABKs

#### IUCVB Control Block Content

#### IUCVB DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      IUCVB          IUCV CONTROL BLOCK
    0000    0 Address      4 IUCVMB         ADDRESS OF VMDBK
    0004    4 Address      4 IUCBFAD1       ADDRESS OF EXTERNAL BUFFER
    0008    8 Address      4 IUCBFAD2       2ND PAGE OF EXTERNAL BUFFER
    000C   12 Signed       2 IUCBFLN1       LENGTH OF BUFF IN 1ST PAGE - 1
    000E   14 Signed       2 IUCBFLN2       LENGTH OF BUFF IN 2ND PAGE - 1
    0010   16 Address      4 IUCCBFA1       ADDRESS OF EXTERNAL CNTL BUFFER
    0014   20 Address      4 IUCCBFA2       2ND PAGE OF EXTERNAL CNTL BUFFER
    0018   24 Signed       2 IUCCBFL1       LENGTH OF CNTL BUFF IN 1ST PAGE
    001A   26 Signed       2 IUCCBFL2       LENGTH OF CNTL BUFF IN 2ND PAGE
    001C   28 Address      4 IUCVCCT        POINTER TO THE USER'S CCT
    0020   32 Bitstring    1 IUCVBWIN       Dispatch window event count
              1... ....      IUCVBMAX       X'80' Event threshhold value
              .1.. ....      IUCVBFRE       X'40' Free storage threshhold
                                            count
    0021   33 Bitstring    1 *              RESERVED
          NOTES      :  The event threshhold for IUCVBWIN is actually x'100'.
                 For performance reasons IUCVBMAX has been defined as
                 an equate so that a TM cam be used to test for the
                 threshhold.
    0022   34 Signed       2 IUCMXCN        MAX NUM OF CONN FROM DIRECTORY OR
                                            DEFAULT
    0024   36 Signed       4 IUCPNDHD       PENDING CONTROL INT QUEUE HEAD
    0028   40 Signed       4 IUCPNDTL       PENDING CONTROL INT QUEUE TAIL
    002C   44 Bitstring    1 IUCVSTAT       IUCV STATUS
              1... ....      IUCVWAIT       X'80' IUCV WAIT
              .1.. ....      IUCIDENT       X'40' CONNECT TO *IDENT
                                            AUTHORIZED
              ..1. ....      IUCCPBUF       X'20' CP CREATED IUCVB
              ...1 ....      IUCBROUT       X'10' VIRTUAL MACHINE IS BREAKING
                                            OUT
              .... 1...      IUCBUFA        X'08' Application buffer exists
                                            in complex
              .... .1..      IUCBUFC        X'04' Control buffer exists in
                                            complex
    002D   45 Bitstring    1 IUCANYFL       *IDENT AUTHORIZATION PARTICULARS
              1... ....      IUCANYLI       X'80' RESANY LOCAL IDENTIFY
              .1.. ....      IUCANYLR       X'40' RESANY LOCAL REVOKE
              ..1. ....      IUCANYGI       X'20' RESANY GLOBAL IDENTIFY
              ...1 ....      IUCANYGR       X'10' RESANY GLOBAL REVOKE
              .... 1...      IUCANYWI       X'08' GATEANY IDENTIFY
              .... .1..      IUCANYWR       X'04' GATEANY REVOKE
              .... ..1.      IUCANYRE       X'02' RESANY AUTHORITY CHECKED
              .... ...1      IUCANYGT       X'01' GATEANY AUTHORITY CHECKED
    002E   46 Signed       2 IUCTOTCN       TOTAL NUMBER OF CONNECTIONS
    0030   48 Address      4 IUCIBFA1       FIRST PAGE-INTERRUPT BUFFER EXT
    0034   52 Address      4 IUCIBFA2       SECOND PAGE-INTERRUPT BUFFER EXT
    0038   56 Signed       2 IUCIBFL1       INTERRUPT BUFFER EXT LEN - PG 1
    003A   58 Signed       2 IUCIBFL2       INTERRUPT BUFFER EXT LEN - PG 2
    003C   60 Signed       4 IUCVBCPX       CPEBK for HCPIVKRS call
    0040   64 Bitstring    1 IUCAPIN        IUCV interrupts enabled
              1... ....      IUCSNDN        X'80' IUCV Non-priority msgs
                                            enabled
              .1.. ....      IUCSNDP        X'40' IUCV priority messages
                                            enabled
              ..1. ....      IUCRPYN        X'20' IUCV non-priority reply
                                            enabled
              ...1 ....      IUCRPYP        X'10' IUCV priority replies
                                            enabled
              .... 1...      IUCICTRL       X'08' IUCV control interrupts
                                            enabled
    0041   65 Bitstring    1 IUCTLIN        IUCV control interrupts enabled
              1... ....      IUCCLPC        X'80' Pending connections enabled
              .1.. ....      IUCCLCC        X'40' Complete connections
                                            enabled
              ..1. ....      IUCCLPS        X'20' Sever interrupts enabled
              ...1 ....      IUCCLPQ        X'10' Quiesce interrupts enabled
              .... 1...      IUCCLPR        X'08' Resume interrupts enabled
    0042   66 Signed       2 *              Reserved
           IUCBUFCT contains both buffer counts.  This enables the
           code to test if both of these fields are zero at the same
           time.  IUCAPBCT and IUCTLBCT must be kept together.
    0044   68 Signed       4 IUCBUFCT (0)   Buffer counts
    0044   68 Signed       2 IUCAPBCT       Count of the number of
                                            application buffers declared in
                                            the complex
    0046   70 Signed       2 IUCTLBCT       Count of the number of control
                                            buffers declared in the complex
    0048   72 Signed       4 IUCPPAS        Pointer to first point to point
                                            accounting block in a chain of
                                            PPABKs.
    004C   76 Signed       4 *              Reserved.
           Constant values used throughout IUCV
              00004000       IUCINTC        X'4000' IUCV Interrupt code
              0000001E       IUCR0MSK       30 IUCV CR0 mask bit
              0000000A       IUCSIZE        (*-IUCVB+7)/8 IUCVB SIZE IN
                                            DOUBLEWORDS

#### IUCVB Storage Layout

    *** IUCVB - IUCV CONTROL BLOCK
    *
    *     +---------------------------+---------------------------+
    *   0 |          IUCVMB           |         IUCBFAD1          |
    *     +---------------------------+-------------+-------------+
    *   8 |         IUCBFAD2          |  IUCBFLN1   |  IUCBFLN2   |
    *     +---------------------------+-------------+-------------+
    *  10 |         IUCCBFA1          |         IUCCBFA2          |
    *     +-------------+-------------+---------------------------+
    *  18 |  IUCCBFL1   |  IUCCBFL2   |         IUCVCCT           |
    *     +------+------+-------------+---------------------------+
    *  20 |:VBWIN|//////|  IUCMXCN    |         IUCPNDHD          |
    *     +------+------+-------------+------+------+-------------+
    *  28 |         IUCPNDTL          |:VSTAT|:ANYFL|  IUCTOTCN   |
    *     +---------------------------+------+------+-------------+
    *  30 |         IUCIBFA1          |         IUCIBFA2          |
    *     +-------------+-------------+---------------------------+
    *  38 |  IUCIBFL1   |  IUCIBFL2   |         IUCVBCPX          |
    *     +------+------+-------------+-------------+-------------+
    *  40 |:APIN |:TLIN |/////////////|  IUCAPBCT   |  IUCTLBCT   |
    *     +------+------+-------------+-------------+-------------+
    *  48 |         IUCPPAS           |///////////////////////////|
    *     +---------------------------+---------------------------+
    *  50
    *
    *** IUCVB - IUCV CONTROL BLOCK

#### IUCVB Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    IUCANYFL       002D
    IUCANYGI       002D 20
    IUCANYGR       002D 10
    IUCANYGT       002D 01
    IUCANYLI       002D 80
    IUCANYLR       002D 40
    IUCANYRE       002D 02
    IUCANYWI       002D 08
    IUCANYWR       002D 04
    IUCAPBCT       0044
    IUCAPIN        0040
    IUCBFAD1       0004
    IUCBFAD2       0008
    IUCBFLN1       000C
    IUCBFLN2       000E
    IUCBROUT       002C 10
    IUCBUFA        002C 08
    IUCBUFC        002C 04
    IUCBUFCT       0044
    IUCCBFA1       0010
    IUCCBFA2       0014
    IUCCBFL1       0018
    IUCCBFL2       001A
    IUCCLCC        0041 40
    IUCCLPC        0041 80
    IUCCLPQ        0041 10
    IUCCLPR        0041 08
    IUCCLPS        0041 20
    IUCCPBUF       002C 20
    IUCIBFA1       0030
    IUCIBFA2       0034
    IUCIBFL1       0038
    IUCIBFL2       003A
    IUCICTRL       0040 08
    IUCIDENT       002C 40
    IUCINTC        004C 00004000
    IUCMXCN        0022
    IUCPNDHD       0024
    IUCPNDTL       0028
    IUCPPAS        0048
    IUCRPYN        0040 20
    IUCRPYP        0040 10
    IUCR0MSK       004C 0000001E
    IUCSIZE        004C 0000000A
    IUCSNDN        0040 80
    IUCSNDP        0040 40
    IUCTLBCT       0046
    IUCTLIN        0041
    IUCTOTCN       002E
    IUCVBCPX       003C
    IUCVBFRE       0020 40
    IUCVBMAX       0020 80
    IUCVBWIN       0020
    IUCVCCT        001C
    IUCVMB         0000
    IUCVSTAT       002C
    IUCVWAIT       002C 80

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 17:00:11 EDT.
Copyright IBM Corporation, 1990, 2005