CCTBK | Back to Index page

| Prolog Control Block Contents CCTBK DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

CCTBK Prolog | Top of page

     NAME       : HCPCCTBK
     DESCRIPTION: Communications Control Table
     DSECT      : CCTBK
     FUNCTION   : THIS CONTROL BLOCK DEFINES THE COMMUNICATION CONTROL
                  TABLE FOR AN IUCV USER.
     LOCATED BY : IUCVCCT FIELD OF HCPIUCVB
     CREATED BY : HCPIUJDB - IUCV DECLARE BUFFER FUNCTION
     DELETED BY : HCPIUERB - IUCV RETRIEVE BUFFER FUNCTION
     RELOCATION CONSIDERATIONS : This control block is relocated as part of a live
                  guest relocation (LGR).  The bits and fields that
                  need to be relocated are defined in the
                  corresponding LGRCCTBK COPY file.  Whenever changes
                  are made to this control block, consideration must
                  be given to any effects these changes will have on
                  a relocation.  If any new fields or bits are
                  defined, they may need to be relocated.  If
                  existing bits or fields are changed, corresponding
                  modifications may be required in the LGR version of
                  this control block.  Consider also the effects of
                  these changes on a relocation involving a back-level
                  release of CP.

CCTBK Control Block Content | Top of page

     CCTBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      CCTBK          Communications Control Table
    0000    0 Signed       2 CCTMXPID       CURRENT MAX PATH ID FOR THIS CCT
    0002    2 Bitstring    1 *              Reserved
    0003    3 Bitstring    1 CCTFLAG2       IUCV INTERRUPTS PENDING
              1... ....      CCTPNDSN       X'80' CCTPNDSN IUCV NON-PRIORITY
                                            MSGS PENDING
              .1.. ....      CCTPNDSP       X'40' CCTPNDSP IUCV PRIORITY
                                            MESSAGES PENDING
              ..1. ....      CCTPNDRN       X'20' CCTPNDRN IUCV NON-PRIORITY
                                            REPLIES PENDING
              ...1 ....      CCTPNDRP       X'10' CCTPNDRP IUCV PRIORITY
                                            REPLIES PENDING
              .... 1...      CCTPNDCT       X'08' CCTPNDCT IUCV CONTROL
                                            INTERRUPT PENDING
    0004    4 Address      4 CCTIUCV        POINTER TO THE USER'S IUCVBK
    0008    8 Address      4 CCTSNDHD       SEND QUEUE HEAD
    000C   12 Address      4 CCTSNDTL       SEND QUEUE TAIL
    0010   16 Address      4 CCTSNDPR       SEND PRIORITY QUEUE TAIL
    0014   20 Address      4 CCTRCVHD       RECEIVE QUEUE HEAD
    0018   24 Address      4 CCTRCVTL       RECEIVE QUEUE TAIL
    001C   28 Address      4 CCTRPYHD       REPLY QUEUE HEAD
    0020   32 Address      4 CCTRPYTL       REPLY QUEUE TAIL
    0024   36 Address      4 CCTRPYPR       REPLY PRIORITY QUEUE TAIL
    0028   40 Signed       4 CCTMSGCT       TOTAL MSGS SENT ON ALL PATHS
    002C   44 Bitstring    1 *              Reserved
    002D   45 Bitstring    1 CCTCPSYS       CP SYSTEM SERVICE CODE
          NOTES      : SYSTEM SERVICE CODES MUST MATCH WITH THE SAME VALUES
                LISTED IN CSSTABLE ENTRIES IN HCPIUG AND VALUES USED
                TO INITIALIZE IPCPSYS IN THE IUCV MACRO
              .... .111      CCTSSCCS       X'07' CODE FOR *CCS SYSTEM
                                            SERVICE
    002E   46 Bitstring    1 CCTSTAT        STATUS
              1... ....      CCTRTVBF       X'80' CCTRTVBF RETRIEVE BUFFER IN
                                            PROGRESS
              .1.. ....      CCTSYNC        X'40' CCTSYNC ABLE TO PROCESS
                                            SYNC SENDS
              ..1. ....      CCTCPINT       X'20' CCTCPINT CP server
                                            interrupt in progress
              ...1 ....      CCTSTKED       X'10' CCTSTKED IUCV INTERRUPT IS
                                            STACKED
    002F   47 Bitstring    1 *              RESERVED
    0030   48 Signed       4 *              Reserved for future use
    0034   52 Signed       4 *              Reserved for future use
           THE CCTDESCT FIELD HAS BEEN ADDED TO KEEP TRACK OF THE
           NUMBER OF MESSAGE PENDING INTERRUPTS THAT NEED TO BE
           REFLECTED.  THIS COUNT IS INCREMENTED WHEN A MESSAGE IS
           PLACED ON THE SEND QUEUE AND IS DECREMENTED WHEN EITHER THE
           INTERRUPT IS REFLECTED OR THE MESSAGE IS DESCRIBED.
    0038   56 Signed       4 CCTDESCT       SEND QUEUE MSGS TO BE DESCRIBED
           ADD A RESERVED FIELD TO FORCE A DOUBLEWORD BOUNDARY FOR
           THE CCTPDSEG FIELD SO BLOCKDEF WILL WORK PROPERLY.
    003C   60 Signed       4 *              RESERVED
           START OF PATH DESCRIPTION SEGMENT POINTERS (DWD ALIGNED)
    0040   64 Dbl-Word     8 * (0)          ALIGNMENT
    0040   64 Signed       4 CCTPDSEG (0)   N (1<=N<=256) PDSEG
                                            POINTERS
              .1.. ..11      CCTPDSLO       CCTPDSEG+3 CCTPDSLO BYTE FOR
                                            INVALID PDSEG TEST
              .... ...1      CCTSINV        X'01' CCTSINV PDSEG INVALID BIT
              00000008       CCTSIZE        (*-CCTBK+7)/8 CCTBK SIZE IN
                                            DOUBLEWORDS

CCTBK Storage Layout | Top of page

    *** CCTBK - Communications Control Table
    *
    *     +-------------+------+------+---------------------------+
    *   0 |  CCTMXPID   |//////|:FLAG2|         CCTIUCV           |
    *     +-------------+------+------+---------------------------+
    *   8 |         CCTSNDHD          |         CCTSNDTL          |
    *     +---------------------------+---------------------------+
    *  10 |         CCTSNDPR          |         CCTRCVHD          |
    *     +---------------------------+---------------------------+
    *  18 |         CCTRCVTL          |         CCTRPYHD          |
    *     +---------------------------+---------------------------+
    *  20 |         CCTRPYTL          |         CCTRPYPR          |
    *     +---------------------------+------+------+------+------+
    *  28 |         CCTMSGCT          |//////|:CPSYS|:STAT |//////|
    *     +---------------------------+------+------+------+------+
    *  30 |///////////////////////////|///////////////////////////|
    *     +---------------------------+---------------------------+
    *  38 |         CCTDESCT          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *
    *** CCTBK - Communications Control Table

CCTBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    CCTCPINT       002E 20
    CCTCPSYS       002D
    CCTDESCT       0038
    CCTFLAG2       0003
    CCTIUCV        0004
    CCTMSGCT       0028
    CCTMXPID       0000
    CCTPDSEG       0040
    CCTPDSLO       0040 43
    CCTPNDCT       0003 08
    CCTPNDRN       0003 20
    CCTPNDRP       0003 10
    CCTPNDSN       0003 80
    CCTPNDSP       0003 40
    CCTRCVHD       0014
    CCTRCVTL       0018
    CCTRPYHD       001C
    CCTRPYPR       0024
    CCTRPYTL       0020
    CCTRTVBF       002E 80
    CCTSINV        0040 01
    CCTSIZE        0040 00000008
    CCTSNDHD       0008
    CCTSNDPR       0010
    CCTSNDTL       000C
    CCTSSCCS       002D 07
    CCTSTAT        002E
    CCTSTKED       002E 10
    CCTSYNC        002E 40

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:27:11 EDT.
Copyright IBM Corporation, 1990, 2020