|
Programming Interface Information:
This information is NOT
intended to be
used as Programming Interfaces of VM/ESA. It is to be used for diagnosis only. |
RTHBK
Cross Reference (Contains links to field and bit definitions)
RTHBK Prolog
NAME : HCPRTHBK
DESCRIPTION: RECORDING TABLE HEADER BLOCK
DSECT : RTHBK
FUNCTION : MAPS OUT THE HEADER INFORMATION ON THE RECORDING
SYSTEM SERVICE TABLE
LOCATED BY : SYSRECQU
SERIALIZED : SYSRECLK
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 RTHVERS field.)
RTHBK Control Block Content
RTHBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure RTHBK RECORDING TABLE HEADER BLOCK 0000 0 Signed 4 RTHQUE ADDRESS OF THE FIRST SYSTEM RECORD ON THE RECORDING QUEUE. 0004 4 Signed 2 * RESERVED 0006 6 Signed 2 * RESERVED. Previously: RTHMSGN field NOTES : The following field is used to indicate when the RTHBK format has changed and what that change was due to. Any code defined here should be checked in HCPRECKP when old format RTHBK is read from the checkpoint cylinders. The old format RTHBK should then be updated appropriately to the new format. Code should also be added to HCPRIURI to set the code for the RTHBK that is being newly created AFTER the format change. A new code should only need to be defined here when a change to the RTHBK causes it to be incompatible with a previous format. Due to compatibility, the displacement of the RTHVERS field 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'. 0008 8 Bitstring 1 RTHVERS RTHBK Version indicator 00000000 RTHVN00 X'00' For version 00, original format 00000001 RTHVN01 X'01' For version 01, Full Page RTHBK 0009 9 Bitstring 1 RTHRID RECORDING TABLE IDENTIFIER. SET TO X'FF' AT INITIALIZATION TIME. 000A 10 Signed 2 RTHFRESZ RTHBK BLOCK SIZE IN DOUBLE WORDS 000C 12 Bitstring 1 RTHFLAG RECORDING TABLE FLAGS. 1... .... RTHRINIT X'80' PURGE IN PROGRESS .1.. .... RTHRINC X'40' I/O COMPLETE IN PROGRESS 000D 13 Bitstring 1 * RESERVED 000E 14 Signed 2 RTHDCNT LENGTH OF RTHDATA IN BYTES. RTHDATA IS MAPPED OUT INTO INDIVIDUAL RECORDING TABLE ENTRIES WITH THE RECBK DSECT. 0010 16 Character 1 RTHDATA (0) FIRST RECBK ENTRY IN THE RECORDING TABLE. COMMON EQUATES OFFSET TO RECBK WORK AREA IN RECORDING TABLE. 00000FB0 RTHRECWK (100*RECBLEN)+(RTHDATA-RTHBK) OFFSET TO RSSBK WORK AREA IN RECORDING TABLE. 00000FD8 RTHRSSWK RTHRECWK+RECBLEN SIZE OF THE RTHBK (RECORDING TABLE) IN DOUBLE WORDS 000001FE RTHDWRDS (RTHRSSWK+RSSBLEN+7)/8 SIZE OF RTHDATA IN BYTES. 00000FE0 RTHDATAB (RTHDWRDS*8)-(RTHDATA-RTHBK)
RTHBK Storage Layout
*** RTHBK - RECORDING TABLE HEADER BLOCK * * +---------------------------+-------------+-------------+ * 0 | RTHQUE |/////////////|/////////////| * +------+------+-------------+------+------+-------------+ * 8 |:VERS |RTHRID| RTHFRESZ |:FLAG |//////| RTHDCNT | * +------+------+-------------+------+------+-------------+ * 10 | | * = RTHDATA = * | | * +-------------------------------------------------------+ * *** RTHBK - RECORDING TABLE HEADER BLOCK
RTHBK Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----RTHDATA 0010
RTHDATAB 0010 00000FE0
RTHDCNT 000E
RTHDWRDS 0010 000001FE
RTHFLAG 000C
RTHFRESZ 000A
RTHQUE 0000
RTHRECWK 0010 00000FB0
RTHRID 0009
RTHRINC 000C 40
RTHRINIT 000C 80
RTHRSSWK 0010 00000FD8
RTHVERS 0008
RTHVN00 0008 00000000
RTHVN01 0008 00000001
Last updated on 3 Aug 1999 at 12:28:37 EDT.
Copyright IBM Corporation, 1990, 1999