RSSBK - 32-bit CP - V4R4.0
Programming Interface Information:
This information is NOT intended to be
used as Programming Interfaces of z/VM.

RSSBK

Prolog  

Control Block Contents  
   RSSBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  


RSSBK Prolog

 NAME       : HCPRSSBK
 DESCRIPTION: RECORDING SYSTEM SERVICE BLOCK
 DSECT      : RSSBK
 FUNCTION   : MAPS OUT THE HEADER OF SYSTEM RECORDS ON THE
              RECORDING QUEUE.
 LOCATED BY : RTHQUE
              RSSNEXT CHAINED
 DELETED BY : HCPREC
 NOTES      : This control block gets checkpointed during SHUTDOWN and
              will be read back in during a WARM start.  Therefore, if
              the format of the block changes due to service being
              applied before the warm start, code should be in place to
              distinguish between the old and new format.  (See the
              note below describing the RSSVERS field.)

 

RSSBK Control Block Content


RSSBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      RSSBK          RECORDING SYSTEM SERVICE BLOCK
0000    0 Signed       4 RSSNEXT        POINTER TO NEXT RSSBK
0004    4 Signed       2 RSSUSCNT       SYSTEM RECORD USE COUNT
0006    6 Signed       2 RSSVN00M (0)   PLACE HOLDER (VERSION 00 INFO)
0006    6 Signed       2 *              RESERVED
0008    8 Bitstring    1 *              RESERVED
0009    9 Bitstring    1 RSSRID         SYSTEM RECORD ID. FROM GSDRID IN
                                        GSDBK
000A   10 Signed       2 RSSFRESZ       RSSBK BLOCK SIZE IN DOUBLE WORDS
000C   12 Bitstring    1 RSSFLAG        FLAGS DEFINED FOR RECORDING
                                        SYSTEM SERVICES
          1... ....      RSSRINIT       X'80' RECORD INITIALIZED TO
                                        RECORDING TABLE
          .1.. ....      RSSRINC        X'40' RECORD INCOMPLETE
          ..1. ....      RSSNOMON       X'20' Record not monitored by
                                        Free Storage Limit Detection
                                        function NOTES : The following
                                        field is used to indicate when
                                        the RSSBK format has changed and
                                        what that change was due to. Any
                                        code defined here should be
                                        checked in HCPRECKP when old
                                        format RSSBKs are read from the
                                        checkpoint cylinders. The old
                                        format RSSBKs should then be
                                        updated appropriately to the new
                                        format. Code should also be added
                                        to HCPRIUCF and HCPRECRI to set
                                        the code for any RSSBKs that are
                                        being newly created AFTER the
                                        format change. A new code should
                                        only need to be defined here when
                                        a change to the RSSBK causes it
                                        to be incompatible with a
                                        previous format (as in the case
                                        of the RSSMSGN field being
                                        expanded from a halfword to a
                                        fullword). Due to compatibility,
                                        the displacement of RSSVERS
                                        should NEVER change. Previous
                                        versions of this control block
                                        had this field marked 'RESERVED'
                                        and the field was known to be
                                        zero. Therefore, previous
                                        versions were version X'00'. In
                                        addition, RSSFLAG should never be
                                        moved. This field is used without
                                        regard to the version of the
                                        RSSBK.
000D   13 Bitstring    1 RSSVERS        RSSBK VERSION INDICATOR
          00000000       RSSVN00        X'00' For version 00, original
                                        format
          00000001       RSSVN01        X'01' For version 01, the RSSMSGN
                                        field was expanded from a
                                        halfword to fullword
000E   14 Signed       2 RSSDCNT        LENGTH OF RSSDATA IN BYTES
0010   16 Signed       4 RSSMSGN        SYSTEM RECORD MESSAGE NUMBER
0014   20 Signed       4 *              RESERVED
0018   24 Character    1 RSSDATA (0)    START OF VARIABLE LENGTH SYSTEM
                                        RECORD DATA
          00000018       RSSBLEN        *-RSSBK RSSBK HEADER LENGTH IN
                                        BYTES
          00000003       RSSSIZE        (*-RSSBK+7)/8 RSSBK ENTRY IN
                                        DOUBLEWORDS
     The following mapping shows what the fields changed for the Version 01
     RSSBK looked like in Version 00. The following fields are used when
     updating Version 00 RSSBKs to Version 01.
0006    6 Signed       2 RSSV00MN       RSSMSGN FIELD (Version 00 Format)
0010   16 Character    1 RSSV00DA (0)   RSSDATA FIELD (Version 00 Format)
          00000010       RSSV00HL       *-RSSBK Length of a Version 00
                                        Header

 

RSSBK Storage Layout

          
*** RSSBK - RECORDING SYSTEM SERVICE BLOCK
*
*     +---------------------------+-------------+-------------+
*   0 |         RSSNEXT           |  RSSUSCNT   |/////////////|
*     +------+------+-------------+------+------+-------------+
*   8 |//////|RSSRID|  RSSFRESZ   |:FLAG |:VERS |  RSSDCNT    |
*     +------+------+-------------+------+------+-------------+
*  10 |         RSSMSGN           |///////////////////////////|
*     +---------------------------+---------------------------+
*
*** RSSBK - RECORDING SYSTEM SERVICE BLOCK
          
*** Overlay for RSSVN00M in RSSBK
*
*                                               +-------------+
*   0 ...                                     6 |  RSSV00MN   |
*                                               +-------------+
*   8
*
*** Overlay for RSSVN00M in RSSBK
          
*** Overlay for RSSMSGN in RSSBK
*
*
*** Overlay for RSSMSGN in RSSBK

 

RSSBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
RSSBLEN        0018 00000018
RSSDATA        0018
RSSDCNT        000E
RSSFLAG        000C
RSSFRESZ       000A
RSSMSGN        0010
RSSNEXT        0000
RSSNOMON       000C 20
RSSRID         0009
RSSRINC        000C 40
RSSRINIT       000C 80
RSSSIZE        0018 00000003
RSSUSCNT       0004
RSSVERS        000D
RSSVN00        000D 00000000
RSSVN00M       0006
RSSVN01        000D 00000001
RSSV00DA       0010
RSSV00HL       0010 00000010
RSSV00MN       0006

This information is based on z/VM V4R4.0. Last updated on 29 Jul 2003 at 16:11:17 EDT.
Copyright IBM Corporation, 1990, 2003