BPQBK

Prolog  

Control Block Contents  
   BPQBK DSECT

Storage Layout  

Cross Reference (Contains links to field and bit definitions)  

BPQBK Prolog

 NAME       : HCPBPQBK
 DESCRIPTION: BUFFER PENDING QUEUE BLOCK
 DSECT      : BPQBK
 FUNCTION   : DESCRIBES A QUEUE OF BUFFERS TO BE PROCESSED
 LOCATED BY : TSDBPQP IN THE TSDBK
 CREATED BY : HCPBMSSP - START A BPQBK
 DELETED BY : HCPBMSTP - TERMINATE A BPQBK
 RELOCATION CONSIDERATIONS : None

BPQBK Control Block Content

BPQBK DSECT

Hex   Dec Type/Val   Lng Label (dup)    Comments
---- ---- --------- ---- -------------- --------
0000    0 Structure      BPQBK          BUFFER PENDING QUEUE BLOCK
0000    0 Bitstring    1 BPQSTTYP       FREE STORAGE INDICATOR
          00000000       BPQFRE         X'00' BPQFRE BPQBK IS FROM FREE
                                        STORAGE
          00000001       BPQPAG         X'01' BPQPAG BPQBK IS A REAL
                                        FRAME (PAGE)
0001    1 Bitstring    1 *              RESERVED FOR FUTURE USE
0002    2 Signed       2 BPQDWSZ        DOUBLE WORD SIZE OF BLOCK THIS
                                        FIELD IS ONLY USED WHEN THIS
                                        BLOCK IS CREATED FORM FREE
                                        STORAGE
0004    4 Signed       4 BPQPDBCT       COUNT OF PENDING BUFFERS
0008    8 Address      4 BPQNXTOF       POINTER TO FIRST BUFFER ON THE
                                        QUEUE (NEXT TO BE TAKEN OFF)
000C   12 Address      4 BPQNXTON       POINTER TO NEXT AVAILABLE SLOT ON
                                        THE QUEUE (NEXT FILLED WHEN
                                        ADDING ON)
0010   16 Address      4 BPQLAST        POINTER TO LAST FULLWORD OF QUEUE
          00000003       BPQHSIZE       (*-BPQBK+7)/8 SIZE OF THE HEADER
                                        PORTION OF BPQBK IN DOUBLEWORDS
0014   20 Address      4 BPQSTART (0)   START OF PENDING BUFFERS

BPQBK Storage Layout

          
*** BPQBK - BUFFER PENDING QUEUE BLOCK
*
*     +------+------+-------------+---------------------------+
*   0 |:STTYP|//////|  BPQDWSZ    |         BPQPDBCT          |
*     +------+------+-------------+---------------------------+
*   8 |         BPQNXTOF          |         BPQNXTON          |
*     +---------------------------+---------------------------+
*  10 |         BPQLAST           |
*     +---------------------------+
*
*** BPQBK - BUFFER PENDING QUEUE BLOCK

BPQBK Cross Reference

Symbol         Dspl Value
-------------- ---- -----
BPQDWSZ        0002
BPQFRE         0000 00000000
BPQHSIZE       0010 00000003
BPQLAST        0010
BPQNXTOF       0008
BPQNXTON       000C
BPQPAG         0000 00000001
BPQPDBCT       0004
BPQSTART       0014
BPQSTTYP       0000