SRQBK | Back to Index page

| Prolog Control Block Contents SRQBK 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.

SRQBK Prolog | Top of page

     NAME       : HCPSRQBK
     DESCRIPTION: IVL Outstanding Message Block
     DSECT      : SRQBK
     FUNCTION   : This block is created to maintain a record of
                  an incomplete IVL message.  SRQTYPE may be one
                  of the following:
                  - SRQTYSR - The SRQBK is tracking an
                  outstanding SEND_REQUEST message.  It is
                  being used to gather replies.  When all
                  replies are received (or when the request
                  times out) control is returned to the
                  SEND_REQUEST issuer by posting SRQECB.
                  - SRQTYIN - The SRQBK is tracking an incoming
                  segmented messages.  It is being used to
                  gather the segments.  The message is
                  delivered to the target sub-manager when all
                  segments have arrived and have been put in
                  order in NDMCHAIN.
     CREATED BY : Dynamically created by the appropiate HCPIVC
                  entry point depending on the type (SRQTYPE)
                  of SRQBK being created.
                  SRQTYSR = HCPIVCRA to maintain a record of an
                  outstanding SEND_REQUEST.
                  SRQTYIN = HCPIVCIN to maintain a record of
                  an IVL multi-segment input message
                  that is still missing segments.
     DELETED BY : Deleted by HCPIVC entry point depending on
                  the type (SRQTYPE) of SRQBK being deleted.
                  SRQTYSR = HCPIVCTX when the last expected
                  response for an outstanding
                  SEND_REQUEST arrives.
                  SRQTYIN = HCPIVCIN when the last segment of
                  an IVL input message arrives
      NCHORED   - A HCPGALSE Hash Table Lookup using a 4 byte
                  key and a 4 byte host identifier subkey for
                  collision management.
                  In addition, all SRQBKs are pointed to by a
                  chain based in HCPIVLBK field IVLHSRQ.
     RELOCATION CONSIDERATIONS : None
     SERIALIZED :
                  ($COMLOCK) Local IVL Communications Lock (HCPIVC) HELD
                  EXCLUSIVE when modifying fields within this
                  control block.
     COMMENTS   :
                  - The following tags are used to described the
                  address type for pointers within this control block:
                  A : Host absolute address
                  R : Host real address
                  L : Logical address in the system execution space
                  G : Guest absolute address

SRQBK Control Block Content | Top of page

     SRQBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      SRQBK          IVL Outstanding Message Block
          SRQBK Hash Table Key
    0000    0 Dbl-Word     8 SRQKEY (0)     Transaction ID ---------------*
    0000    0 Signed       2 SRQHOST        2 Byte Host Prefix
    0002    2 Bitstring    1 *              1 Byte Reserved
    0003    3 Bitstring    1 SRQTFLG        Transaction Token Flags
    0004    4 Signed       4 SRQSEQ         4 Byte Sequence Number * End of
                                            Transaction ID-------
          Active SEND_REQUEST Chain Pointers
    0008    8 Dbl-Word     8 SRQ_PTRS (0)   L:SRQBK Pointers -------------*
    0008    8 Address      4 SRQ_NEXT       Next L:SRQBK
    000C   12 Address      4 SRQ_PREV       Previous L:SRQBK End of L:SRQBK
                                            Pointers ------
          TimeStamps
    0010   16 Dbl-Word     8 SRQ_TTL        Time to Live (TOD) Time
          Type of SRQBK
    0018   24 Bitstring    1 SRQTYPE        Type of outstanding IVL message
              00000000       SRQTYSR        0 SRQTYSR Outstanding message is
                                            a SEND_REQUEST message waiting
                                            for replies.
              00000004       SRQTYIN        4 SRQTYIN Outstanding message is
                                            an incomplete segmented input
                                            message.
    0019   25 Bitstring    1 SRQFLAGS       Processing Flags
              1... ....      SRQMULT        X'80' SRQMULT Multiple Responses
                                            Possible
              .1.. ....      SRQACTIV       X'40' SRQACTIV Queued on Active
                                            SEND_REQ Q
    001A   26 Bitstring    2 *              Reserved for Future IBM Use
          Chain of Associated L:NDMBKs
    001C   28 Address      4 SRQNDMBK       Chain of L:NDMBKs Containing
                                            Replies or segments from other
                                            IVL Members
    0020   32 Dbl-Word     8 *              Reserved for Future IBM Use
          L:SRQBK Overlay Area
          The following area of the L:SRQBK is mapped based on the
          type of L:SRQBK specified in SRQTYPE.
    0028   40 Dbl-Word     8 SRQOVRLY (9)   L:SRQBK Overlay Area
    0070  112 Bitstring    1 SRQ$END (0)
          Notes      : The following assembler equates are defined and can be
                used but do not appear in the control block expansion
                because they are in the PLX section and PRINT OFF,
                NOGEN are in effect.
          SRQBSIZE EQU   (SRQ$END-SRQBK)       Size in bytes
                           SEND_REQUEST REPLY SRQBK
                          SRQTYSR Overlay Area DSECT
          Expected TARGET Mask
          A mask of known IVL Members active in the IVL Domain that
          sre expected to respond to this Transaction ID.
    0028   40 Signed       2 SRQEMASK       Mask of Expected Members to Reply
          REPLY Mask
          A mask of known IVL Members which replied to this
          Transaction Transaction ID.
    002A   42 Signed       2 SRQRMASK       Mask of Replied IVL Members
    002C   44 Signed       4 *              Reserved for Future IBM Use
          Embedded ECBBK Area
          The embedded ECBBK area is mapped by HCPECBBK COPY.  A
          CHKMAINT verifies the length of an ECBBK is not increased
          without increasing the size of this area in the SRQBK.
    0030   48 Dbl-Word     8 SRQ_ECB (8)    Embedded ECBBK Area
                          Multi-Segment IVL-MPDU SRQBK
                          SRQTYIN Overlay Area DSECT
          Total Segment Count
          Total number of L:NDMBKs (segments) we expect to receive
          from the sending host for this Multi-Segment IVL-MPDU.
    0028   40 Signed       2 SRQSGCNT       Total Number of Segments in this
                                            DataGram
          Current Segment Count
          Number of er of L:NDMBKs (segments) received so far from
          the sending host.
    002A   42 Signed       2 SRQCURCT       Current Count of Segments
                                            Received
    002C   44 Signed       4 *              Reserved for Future IBM Use
          L:NDMBK Collection Segment Array
          As segments arrive from a sending IVL member, the L:NDMBK
          containing the segment is stored in order into a 16 entry
          collection array within the L:SRQBK. Each L:NDMBK received
          is stored into the array based on its segment number.
          Segments 1 to 16 are stored into array entries 1 to 16
          respectively.  Segment numbers greater than 16 (if any)
          are linked from L:SRQNDMBK.
    0030   48 Address      4 SRQCOLAR (16)  L:NDMBK Segment Collection ARY
              ...1 ....      SRQENTRY       16 SRQENTRY # of Entries in Array
              ..1. ....      SRQMAX         SRQENTRY*2 SRQMAX Max Entries
                                            Supported
              0000003C       SRQLAST        (SRQENTRY-1)*L'SRQCOLAR Last
                                            valid ARY Index

SRQBK Storage Layout | Top of page

    *** SRQBK - IVL Outstanding Message Block
    *
    *     +-------------+------+------+---------------------------+
    *   0 |  SRQHOST    |//////|:TFLG |          SRQSEQ           |
    *     +-------------+------+------+---------------------------+
    *   8 |         SRQ_NEXT          |         SRQ_PREV          |
    *     +---------------------------+---------------------------+
    *  10 |                       SRQ_TTL                         |
    *     +------+------+-------------+---------------------------+
    *  18 |:TYPE |:FLAGS|/////////////|         SRQNDMBK          |
    *     +------+------+-------------+---------------------------+
    *  20 |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *  28 |                                                       |
    *     =                       SRQOVRLY                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *
    *** SRQBK - IVL Outstanding Message Block

    *** Overlay for SRQOVRLY in SRQBK
    *
    *     +-------------+-------------+---------------------------+
    *  28 |  SRQEMASK   |  SRQRMASK   |///////////////////////////|
    *     +-------------+-------------+---------------------------+
    *  30 |                                                       |
    *     =                       SRQ_ECB                         =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  70
    *
    *** Overlay for SRQOVRLY in SRQBK

    *** Overlay for SRQOVRLY in SRQBK
    *
    *     +-------------+-------------+---------------------------+
    *  28 |  SRQSGCNT   |  SRQCURCT   |///////////////////////////|
    *     +-------------+-------------+---------------------------+
    *  30 |                                                       |
    *     =                       SRQCOLAR                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  70
    *
    *** Overlay for SRQOVRLY in SRQBK

SRQBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    SRQ$END        0070
    SRQ_ECB        0030
    SRQ_NEXT       0008
    SRQ_PREV       000C
    SRQ_PTRS       0008
    SRQ_TTL        0010
    SRQACTIV       0019 40
    SRQCOLAR       0030
    SRQCURCT       002A
    SRQEMASK       0028
    SRQENTRY       0030 10
    SRQFLAGS       0019
    SRQHOST        0000
    SRQKEY         0000
    SRQLAST        0030 0000003C
    SRQMAX         0030 20
    SRQMULT        0019 80
    SRQNDMBK       001C
    SRQOVRLY       0028
    SRQRMASK       002A
    SRQSEQ         0004
    SRQSGCNT       0028
    SRQTFLG        0003
    SRQTYIN        0018 00000004
    SRQTYPE        0018
    SRQTYSR        0018 00000000

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:30:46 EDT.
Copyright IBM Corporation, 1990, 2020