FRQBK | Back to Index page

| Prolog Control Block Contents FRQBK DSECT Storage Layout Cross Reference (Contains links to field and bit definitions) |
Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

FRQBK Prolog | Top of page

     NAME       : HCPFRQBK
     DESCRIPTION: Frame Request Block
     DSECT      : FRQBK
     FUNCTION   : A Frame Request Block is used by HCPFRQ to manage
                  deferred requests for one or more non-contiguous
                  frames.
     LOCATED BY : RSMFRQCR - points to the current FRQBK being serviced.
                  FRQNEXT/FRQPREV - FRQBKs for different requesters in
                  a circular doubly linked list.
                  FRQSNXT - FRQBKs for the same requester in a singly
                  linked list in ascending order of sequence number.
     CREATED BY : HCPFRQCR
     DELETED BY : HCPFRQAS, HCPFRQCN
     REFERENCES : See HCPFRQ for information about the usage of
                  this block.
     SERIALIZED : The RSMFRQLK informal spin lock must be
                  held when accessing the FRQBKs within the
                  chain structure, and also when accessing the
                  FRQBK related fields in the RSMBK.
     RELOCATION CONSIDERATIONS : None
     NOTES      :

FRQBK Control Block Content | Top of page

     FRQBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      FRQBK          Frame Request Block
    0000    0 Dbl-Word     8 * (0)
    0000    0 Address      4 FRQNEXT        Pointer to next requester FRQBK
                                            or zero
    0004    4 Address      4 FRQPREV        Pointer to prev requester FRQBK
                                            or zero
    0008    8 Address      4 FRQSNXT        Pointer to next FRQBK for same
                                            requester
    000C   12 Signed       4 FRQFRCNT       Count of frames requested
    0010   16 Dbl-Word     8 FRQSEQNO       Requester sequence number
    0018   24 Signed       4 FRQREQID       Requester ID
    001C   28 Address      4 FRQSVGBK       Address of requester's SVGBK to
                                            resume when request is satisfied
                                            or canceled
    0020   32 Signed       4 * (4)          Reserved for future IBM use
              00000006       FRQDSIZE       ((*-FRQBK)+7)/8 FRQBK size in
                                            double-words
              00000030       FRQBSIZE       FRQDSIZE*8 size in bytes

FRQBK Storage Layout | Top of page

    *** FRQBK - Frame Request Block
    *
    *     +---------------------------+---------------------------+
    *   0 |         FRQNEXT           |         FRQPREV           |
    *     +---------------------------+---------------------------+
    *   8 |         FRQSNXT           |         FRQFRCNT          |
    *     +---------------------------+---------------------------+
    *  10 |                       FRQSEQNO                        |
    *     +---------------------------+---------------------------+
    *  18 |         FRQREQID          |         FRQSVGBK          |
    *     +---------------------------+---------------------------+
    *  20 |///////////////////////////////////////////////////////|
    *     |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *  30
    *
    *** FRQBK - Frame Request Block

FRQBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    FRQBSIZE       0020 00000030
    FRQDSIZE       0020 00000006
    FRQFRCNT       000C
    FRQNEXT        0000
    FRQPREV        0004
    FRQREQID       0018
    FRQSEQNO       0010
    FRQSNXT        0008
    FRQSVGBK       001C

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:28:17 EDT.
Copyright IBM Corporation, 1990, 2020