THRBK | Back to Index page

| Prolog Control Block Contents THRBK 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.

THRBK Prolog | Top of page

     NAME       : HCPTHRBK
     DESCRIPTION: Throttle Control Block
     DSECT      : THRBK
     FUNCTION   : The Throttle Control Block is used to control the rate at
                  which I/O operations are permitted to occur for devices
                  under the control of the Throttle Facility.
     LOCATED BY :
                  SYSTHRPR Anchor in HCPSYSCM
                  RDEVTHPT Anchor in HCPRDEV
     CREATED BY : THRBK'S are dynamically created by HCPTHR via the
                  "SET THROTTLE ON" command.
     DELETED BY : THRBK'S are deleted by HCPTHR via:
                  1- The "SET THROTTLE OFF" command
                  2- The "SET THROTTLE CLEAR" command
                  3- The "DETACH" command
     RELOCATION CONSIDERATIONS : None

THRBK Control Block Content | Top of page

     THRBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      THRBK          Throttle Control Block
    0000    0 Signed       4 THRNEXT        Pointer to next THRBK in the
                                            chain
    0004    4 Signed       4 THRPREV        Pointer to previous THRBK in the
                                            chain
    0008    8 Dbl-Word     8 THRTGTTM       Target time for this device (TOD
                                            format) Updated at time of last
                                            I/O to device
    0010   16 Signed       4 THRRDEV        Pointer to RDEV for device
    0014   20 Signed       4 THRDLYS        Count of times I/O delayed for
                                            device
    0018   24 Bitstring    2 THRDEVNO       Device number
    001A   26 Bitstring    2 *              Reserved
    001C   28 Signed       4 THRRTEBN       Current rate in binary
    0020   32 Dbl-Word     8 THRIORTE       I/O rate for the device
    0028   40 Dbl-Word     8 * (2)          Reserved
    0038   56 Dbl-Word     8 THR$END (0)    End of THRBK
              00000007       THRSIZE        (*-THRBK+7)/8 THRBK size in
                                            double words

THRBK Storage Layout | Top of page

    *** THRBK - Throttle Control Block
    *
    *     +---------------------------+---------------------------+
    *   0 |         THRNEXT           |         THRPREV           |
    *     +---------------------------+---------------------------+
    *   8 |                       THRTGTTM                        |
    *     +---------------------------+---------------------------+
    *  10 |         THRRDEV           |         THRDLYS           |
    *     +-------------+-------------+---------------------------+
    *  18 |  THRDEVNO   |/////////////|         THRRTEBN          |
    *     +-------------+-------------+---------------------------+
    *  20 |                       THRIORTE                        |
    *     +-------------------------------------------------------+
    *  28 |///////////////////////////////////////////////////////|
    *     |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *
    *** THRBK - Throttle Control Block

THRBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    THR$END        0038
    THRDEVNO       0018
    THRDLYS        0014
    THRIORTE       0020
    THRNEXT        0000
    THRPREV        0004
    THRRDEV        0010
    THRRTEBN       001C
    THRSIZE        0038 00000007
    THRTGTTM       0008

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:31:16 EDT.
Copyright IBM Corporation, 1990, 2020