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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. |
BMSBK
Cross Reference (Contains links to field and bit definitions)
BMSBK Prolog
NAME : HCPBMSBK
DESCRIPTION: BUFFER MANAGEMENT SERVICE CONTROL BLOCK
DSECT : BMSBK
FUNCTION : CONTAINS THE CURRENT STATUS OF A BUFFER
MANAGEMENT TASK
LOCATED BY : USAGE DEPENDENT
CREATED BY : HCPBMSIN
DELETED BY : HCPBMSTM
EMPLOYED BY- HCPBMSRA : WHEN RETURNING A LIST OF BUFFERS
TO THE AVAILABLE STACK
HCPBMSOA : WHEN OBTAINING A LIST OF BUFFERS
FROM THE AVAILABLE STACK
HCPBMSGA : WHEN GETTING A BUFFER FROM THE
AVAILABLE STACK
HCPBMSAA : WHEN ADDING BUFFERS FROM FREE
STORAGE TO THE AVAILABLE STACK
HCPBMSSA : WHEN RETURNING BUFFERS FROM THE
AVAILABLE STACK TO FREE STORAGE
HCPBMSPP : WHEN PUTTING A BUFFER ON THE
PENDING QUEUE
HCPBMSOP : WHEN OBTAINING A LIST OF BUFFERS
FROM THE PENDING QUEUE
HCPBMSQP : WHEN GETTING THE COUNT OF BUFFERS
ON THE PENDING QUEUE
COMMENTS : SERIALIZED BY THE BMSBK LOCK, BMSLOCK FOR
ALL ENTRY POINTS EXCEPT HCPBMSIN.
BMSBK Control Block Content
BMSBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure BMSBK BUFFER MANAGEMENT SERVICE CONTROL BLOCK BUFFER MANAGEMENT SERVICE INFORMATION 0000 0 Signed 4 * (0) BLOCK STATUS 0000 0 Bitstring 1 BMSSTTYP FREE STORAGE INDICATOR .... ...1 BMSPAG X'01' BMSBK IS A REAL FRAME (PAGE) .... ..1. BMSFRE X'02' BMSBK IS FROM FREE STORAGE .... .1.. BMSFIXED X'04' BMSBK DESCRIBES A BUFFER POOL THAT IS A FIXED SIZE (USED BY TRSAVE FOR CP ON) .... 1... BMSDFRIO X'08' Wrap buffers in real storage 0001 1 Bitstring 1 * RESERVED FOR FUTURE USE 0002 2 Signed 2 BMSDWSZ DOUBLE WORD SIZE OF BLOCK THIS FIELD IS ONLY USED WHEN THIS BLOCK IS CREATED FORM FREE STORAGE 0004 4 Signed 4 BMSBUFCT COUNT OF TOTAL BUFFERS Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain 0008 8 Signed 4 BMSAVBCT COUNT OF AVAILABLE BUFFERS Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain 000C 12 Signed 4 BMSPDBCT COUNT OF PENDING BUFFERS Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain 0010 16 Signed 4 BMSRTBCT COUNT OF BUFFERS RETURNED TO THE AVAILABLE STACK 0014 20 Signed 4 * RESERVED FOR FUTURE USE BUFFER LOCKS 0018 24 Dbl-Word 8 BMSLOCK (3) SPIN LOCK FOR THE BMS BLOCK Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain AVAILABLE BUFFERS 0030 48 Address 4 BMSAVPTR POINTER TO AVAILABLE BUFFERS Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain PENDING BUFFERS 0034 52 Address 4 BMSNEXT Pointer to next BMSBK in chain of BMSBKs 0038 56 Address 4 BMSBMOFF Pointer to BMSBK which contains oldest pending buffer. Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain 003C 60 Address 4 BMSBMON Pointer to BMSBK which contains next available slot. Within a chain of BMSBKs, this field is only meaningful in the first BMSBK of the chain 0040 64 Address 4 BMSPDOFF POINTER TO FIRST BUFFER ON THE QUEUE 0044 68 Address 4 BMSPDON POINTER TO NEXT AVAILABLE SLOT ON THE QUEUE 0048 72 Address 4 BMSPDLST ADDRESS OF THE LAST SLOT IN THE ARRAY 0000000A BMSHSIZE (*-BMSBK+7)/8 SIZE OF THE BMS HEADER 004C 76 Address 4 BMSPDST (0) START OF VARIABLE LENGTH DATA ARRAY OF POINTERS TO PENDING BUFFERS 1000 BUFFERS ARE MAXIMUM
BMSBK Storage Layout
*** BMSBK - BUFFER MANAGEMENT SERVICE CONTROL BLOCK * * +------+------+-------------+---------------------------+ * 0 |:STTYP|//////| BMSDWSZ | BMSBUFCT | * +------+------+-------------+---------------------------+ * 8 | BMSAVBCT | BMSPDBCT | * +---------------------------+---------------------------+ * 10 | BMSRTBCT |///////////////////////////| * +---------------------------+---------------------------+ * 18 | | * = BMSLOCK = * | | * +---------------------------+---------------------------+ * 30 | BMSAVPTR | BMSNEXT | * +---------------------------+---------------------------+ * 38 | BMSBMOFF | BMSBMON | * +---------------------------+---------------------------+ * 40 | BMSPDOFF | BMSPDON | * +---------------------------+---------------------------+ * 48 | BMSPDLST | | * +---------------------------+ | * 50 | | * = BMSPDST = * | | * +-------------------------------------------------------+ * *** BMSBK - BUFFER MANAGEMENT SERVICE CONTROL BLOCK
BMSBK Cross Reference
(contains links to field and bit definitions)Symbol Dspl Value -------------- ---- -----BMSAVBCT 0008
BMSAVPTR 0030
BMSBMOFF 0038
BMSBMON 003C
BMSBUFCT 0004
BMSDFRIO 0000 08
BMSDWSZ 0002
BMSFIXED 0000 04
BMSFRE 0000 02
BMSHSIZE 0048 0000000A
BMSLOCK 0018
BMSNEXT 0034
BMSPAG 0000 01
BMSPDBCT 000C
BMSPDLST 0048
BMSPDOFF 0040
BMSPDON 0044
BMSPDST 004C
BMSRTBCT 0010
BMSSTTYP 0000
Last updated on 3 Aug 1999 at 11:42:19 EDT.
Copyright IBM Corporation, 1990, 1999