QDGBL

Prolog  

Control Block Contents  
   QDGBL DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

QDGBL Prolog

 NAME       : Virtual Disk in Storage Global Control Block
 DESCRIPTION: V-Disk Global Control Block
 DSECT      : QDGBL
 FUNCTION   : This control block maps the global V-Disk
              control block for the system.
 LOCATED BY : HCPSYSCM - System Common Area
 CREATED BY : HCPQDLIN
 DELETED BY : none
 SERIALIZED : QDGALOCK is used to serialize the QDGBL control block
              fields.  QDGCLOCK is used to serialize the VDISK MDISK
              chain (located by QDGMDISK).  Either QDGALOCK or
              QDGCLOCK should be held shared when looking at the
              VDISK MDISK chain.  Both must be held exclusive when
              changing the VDISK MDISK chain.
 RELOCATION CONSIDERATIONS : None

QDGBL Control Block Content

QDGBL DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      QDGBL          V-Disk Global Control Block
             Vdisk chain of MDISK blocks and allocation lockword
0000    0 Dbl-Word     8 QDGALOCK (3)   Vdisk Allocation Lockword
0018   24 Dbl-Word     8 QDGCLOCK (3)   Vdisk MDISK chain lock
0030   48 Signed       4 QDGMDISK       First MDISK block for Vdisk
             Fields for keeping track of limits (in blocks)
0034   52 Signed       4 QDGSYSLM       Limit of total Vdisk allocation
0038   56 Signed       4 QDGUSRLM       Limit of size of Vdisks DEFINEd
                                        by a user (using DEFINE)
003C   60 Signed       4 QDGSYSCA       Total currently-allocated Vdisk
                                        blocks
0040   64 Signed       4 QDGRELOC       Total relocation-allocated VDISK
                                        blocks
0044   68 Signed       2 *              Reserved
0046   70 Signed       2 QDGCOUNT       Vdisk counter for addr. space
                                        name (increment and save)
0048   72 Signed       4 QDGLKCNT       Total number of LINKs to all
                                        Vdisks (includes 1 for each
                                        DEFINEd VDisk)
004C   76 Signed       4 QDGDISKS       Total number of existing Vdisks
0050   80 Signed       4 QDGSYSLD       Default of QDGSYSLM
0054   84 Signed       4 QDGUSRLD       Default of QDGUSRLM
0058   88 Bitstring    1 QDGAFLAG       'A' flag byte
          1... ....      QDGASYSC       X'80' QDGASYSC - SYSTEM CONFIG
                                        set syslim
0059   89 Bitstring    1 * (3)          Reserved
          0000000C       QDGSIZE        ((*-QDGBL+7)/8) SIZE IN DWS FOR
                                        FREE/FRET

QDGBL Storage Layout

          
*** QDGBL - V-Disk Global Control Block
*
*     +-------------------------------------------------------+
*   0 |                                                       |
*     =                       QDGALOCK                        =
*     |                                                       |
*     +-------------------------------------------------------+
*  18 |                                                       |
*     =                       QDGCLOCK                        =
*     |                                                       |
*     +---------------------------+---------------------------+
*  30 |         QDGMDISK          |         QDGSYSLM          |
*     +---------------------------+---------------------------+
*  38 |         QDGUSRLM          |         QDGSYSCA          |
*     +---------------------------+-------------+-------------+
*  40 |         QDGRELOC          |/////////////|  QDGCOUNT   |
*     +---------------------------+-------------+-------------+
*  48 |         QDGLKCNT          |         QDGDISKS          |
*     +---------------------------+---------------------------+
*  50 |         QDGSYSLD          |         QDGUSRLD          |
*     +------+--------------------+---------------------------+
*  58 |:AFLAG|////////////////////| 5C
*     +------+--------------------+
*
*** QDGBL - V-Disk Global Control Block

QDGBL Cross Reference

Symbol         Dspl Value
-------------- ---- -----
QDGAFLAG       0058
QDGALOCK       0000
QDGASYSC       0058 80
QDGCLOCK       0018
QDGCOUNT       0046
QDGDISKS       004C
QDGLKCNT       0048
QDGMDISK       0030
QDGRELOC       0040
QDGSIZE        0059 0000000C
QDGSYSCA       003C
QDGSYSLD       0050
QDGSYSLM       0034
QDGUSRLD       0054
QDGUSRLM       0038