FORBK Back to Index page
 
Prolog 
Control Block Contents 
   FORBK DSECT
   FORCTBL 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.


  FORBK Prolog Top of page
  
 NAME       : HCPFORBK
 DESCRIPTION: The FOR control block.
 DSECT      : FORBK
 FUNCTION   : Provides a mapping of the FORBK control block containing
              the *ASYNCMD connection table for a virtual configuration.
 LOCATED BY : The VMDFORBK field in the base VMDBK points to the FORBK
 CREATED BY : Entry point HCPASYCN will create the FORBK on the first connection
              to the *ASYNCMD system service.
 DELETED BY : The following entry points:
              HCPFORSP - End of FOR command handler
              HCPFORRT - Reset handler
 REFERENCES : FORCTBL - mapping of a single *ASYNCMD connection table entry
 SERIALIZED : When accessing the FORBK, the lock hierarchy is
              as follows: first obtain the IUCV lock, then
              get the FORBK lock.
 RELOCATION CONSIDERATIONS : None
 COMPATIBILITY AND MIGRATION CONCERNS : None
 
 
  FORBK Control Block Content Top of page
  




 FORBK DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      FORBK          The FOR control block.
0000    0 Dbl-Word     8 FORLOCK (3)    FORBK Lock
0018   24 Bitstring    1 FORFLAG        Flag byte
          1... ....      FORORPHN       X'80' FORORPHN This FORBK is
                                        orphaned
          .1.. ....      FORALLSP       X'40' FORALLSP All slots in use
                                        are sever-pending
0019   25 Bitstring    1 *              Reserved for future IBM use
001A   26 Signed       2 FORNXFRE       The number of the next available
                                        slot in the *ASYNCMD connection
                                        table. Slots are numbered 0-7, if
                                        FORNXFRE is 8, then the table is
                                        full.
001C   28 Signed       2 FORMRCON       The number of the most recently
                                        connected slot
001E   30 Signed       2 *              Reserved for future IBM use
0020   32 Bitstring    8 FORTBL (2)     *ASYNCMD connection table
          00000060       FORSIZEB       *-FORBK Size of FORBK in bytes
          0000000C       FORSIZE        (FORSIZEB+7)/8 Size of FORBK in
                                        double words
      FORCTBL - mapping of a single *ASYNCMD connection table entry
          00000008       FORECNT        8 Number of entries in the
                                        *ASYNCMD connection table




 FORCTBL DSECT
Top of page


Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      FORCTBL        The FOR control block.
0000    0 Signed       2 FORCUPTH       User-side path ID
0002    2 Signed       2 FORCAPTH       *ASYNCMD-side path ID
0004    4 Signed       2 FORCUCTR       Count of outstanding FOR commands
0006    6 Bitstring    1 FORCFLAG       Flag byte
          1... ....      FORCSEVP       X'80' FORCSEVP Path is
                                        sever-pending
0007    7 Bitstring    1 *              Reserved for future IBM use
          00000008       FORCSIZB       *-FORCTBL Size in FORCTBL in
                                        bytes
          00000001       FORCSIZE       (FORCSIZB+7)/8 Size in FORCTBL in
                                        double words
 
 
  FORBK Storage Layout Top of page
  
          
*** FORBK - The FOR control block.
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       FORLOCK                         =
*     |                                                       |
*     +------+------+-------------+-------------+-------------+
*  18 |:FLAG |//////|  FORNXFRE   |  FORMRCON   |/////////////|
*     +------+------+-------------+-------------+-------------+
*  20 |                        FORTBL                         |
*     |                                                       |
*     +-------------------------------------------------------+
*  30
*
*** FORBK - The FOR control block.
          
*** FORCTBL - The FOR control block.
*
*     +-------------+-------------+-------------+------+------+
*   0 |  FORCUPTH   |  FORCAPTH   |  FORCUCTR   |:CFLAG|//////|
*     +-------------+-------------+-------------+------+------+
*   8
*
*** FORCTBL - The FOR control block.
 
 
  FORBK Cross Reference Top of page
  
 
Symbol         Dspl Value
-------------- ---- -----
FORALLSP       0018 40
FORCAPTH       0002
FORCFLAG       0006
FORCSEVP       0006 80
FORCSIZB       0007 00000008
FORCSIZE       0007 00000001
FORCUCTR       0004
FORCUPTH       0000
FORECNT        0020 00000008
FORFLAG        0018
FORLOCK        0000
FORMRCON       001C
FORNXFRE       001A
FORORPHN       0018 80
FORSIZE        0020 0000000C
FORSIZEB       0020 00000060
FORTBL         0020
 
This information is based on z/VM 7.3.0 Last updated on 22 Jun 2022 at 15:50:35 EDT.
Copyright IBM Corporation, 1990, 2022