SHRBK

Prolog  

Control Block Contents  
   SHRBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

SHRBK Prolog

 NAME       : HCPSHRBK
 DESCRIPTION: SHARE BLOCK
 DSECT      : SHRBK
 FUNCTION   : This block is used to keep track of each NSS or DCSS
              that a user is attached to.
 LOCATED BY : All SHRBKs for the NSS and/or DCSSs that the
              virtual machine user is accessing are chained
              together in a list anchored off the VMDBK.
              VMDSHRPT is the pointer to the first SHRBK
              for this user.  A zero pointer indicates
              that the user's chain is empty.
              SHRFWDPT is the pointer to the next SHRBK
              in the user's chain. The chain end is
              indicated when SHRFWDPT is zero.
              - All SHRBKs for users using a specific SNTBK are
              chained together in a doubly linked list
              anchored off the SNTBK.  This list represents
              all users who have loaded the NSS or DCSS.
              SNTSHRPT is the pointer to the first SHRBK
              in the chain for this SNTBK.  A zero pointer
              indicates that the chain is empty.
              SHRQUEFW is the pointer to the next SHRBK
              in the chain for this SNTBK.  The chain end
              is indicated when SHRQUEFW is zero.
              SHRQUEBK is the pointer to the previous SHRBK
              in the chain for this SNTBK.
 CREATED BY : HCPNSL when loading an NSS or DCSS.
 DELETED BY : HCPNSP - when the user purges the DCSS.
              HCPNSP - when the user IPLs a system, all
              SHRBKs for that user are purged.
 COMMENTS   : None.

SHRBK Control Block Content

SHRBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      SHRBK          SHARE BLOCK
0000    0 Address      4 SHRFWDPT       Forward pointer to this user's
                                        next SHRBK.
0004    4 Address      4 SHRSNTPT       Pointer to the SNTBK for this NSS
                                        or DCSS.
0008    8 Character    8 SHRNAME        The name for this NSS or DCSS.
0010   16 Signed       4 SHRFLAGS (0)   Flags for SHRBK.
0010   16 Bitstring    1 SHRTYPE        Type information byte.
          .... ...1      SHREXCL        X'01' This bit indicates that the
                                        NSS or DCSS is an exclusive copy.
0011   17 Bitstring    1 * (3)          Reserved for IBM use.
0014   20 Address      4 SHRVMDBK       @ of VMDBK that owns this SHRBK.
0018   24 Address      4 SHRQUEFW       Next SHRBK on a chain of SHRBKs
                                        associated with a specific SNTBK.
001C   28 Address      4 SHRQUEBK       Prev.SHRBK on a chain of SHRBKs
                                        associated with a specific SNTBK.
0020   32 Address      4 SHRLSSA        Address of the SNTBK defining the
                                        segment space through which the
                                        named member segment was loaded.
                                        When this field is equal to
                                        SHRSNTPT, SHRNAME is not a member
                                        segment. It is a named saved
                                        segment or segment space.
0024   36 Signed       4 *              Reserved for IBM use
          00000005       SHRSIZE        ((*-SHRBK+7)/8) Block in double
                                        words.

SHRBK Storage Layout

          
*** SHRBK - SHARE BLOCK
*
*     +---------------------------+---------------------------+
*   0 |         SHRFWDPT          |         SHRSNTPT          |
*     +---------------------------+---------------------------+
*   8 |                       SHRNAME                         |
*     +------+--------------------+---------------------------+
*  10 |:TYPE |////////////////////|         SHRVMDBK          |
*     +------+--------------------+---------------------------+
*  18 |         SHRQUEFW          |         SHRQUEBK          |
*     +---------------------------+---------------------------+
*  20 |         SHRLSSA           |///////////////////////////|
*     +---------------------------+---------------------------+
*  28
*
*** SHRBK - SHARE BLOCK

SHRBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
SHREXCL        0010 01
SHRFLAGS       0010
SHRFWDPT       0000
SHRLSSA        0020
SHRNAME        0008
SHRQUEBK       001C
SHRQUEFW       0018
SHRSIZE        0024 00000005
SHRSNTPT       0004
SHRTYPE        0010
SHRVMDBK       0014