THRBK

Prolog  

Control Block Contents  
   THRBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

THRBK Prolog

 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

THRBK Control Block Content

THRBK DSECT

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

          
*** 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

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