NTLBK | Back to Index page

| Prolog Control Block Contents NTLBK 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.

NTLBK Prolog | Top of page

     NAME       : HCPNTLBK
     DESCRIPTION: Network Lock Block.
     DSECT      : NTLBK (256 Byte Aligned)
     FUNCTION   :
                  HCPNTLBK maps a 256-byte ALIGNED memory area that is
                  intended to be used for a Lock that is required to be in
                  it's own cache line for performance reason.
     LOCATED BY : Functions exploiting network locks.
     CREATED BY : HCPNIDNA
     DELETED BY : HCPNIDNA
     REFERENCES :
                  HCPSYNBK - Formal Exclusive-Only SpinLock Block
     SERIALIZED :
                  It is up to the callers of HCPNIDNA to ensure proper
                  serialization is in place for the desired use of a
                  NTLBK.
     RELOCATION CONSIDERATIONS : None
     COMPATIBILITY AND MIGRATION CONCERNS : None

NTLBK Control Block Content | Top of page

     NTLBK DSECT
    Top of page

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      NTLBK          Network Lock Block.
    0000    0 Dbl-Word     8 NTL$HDR        NTLBK Header
    0008    8 Dbl-Word     8 NTLSPNLK (6)   Spin lock
    0038   56 Bitstring    1 * (192)        Reserved for IBM use.
    00F8  248 Dbl-Word     8 NTL$EYE        NTLBK Trailer
          End of the NTLBK.
              00000100       NTL$END        * End of the NTLBK
              00000100       NTLBKLN        256 Length of NTLBK in bytes
              00000020       NTLBKSZ        ((256)+7)/8 Size of NTLBK in
                                            doublewords
                                                                    */

NTLBK Storage Layout | Top of page

    *** NTLBK - Network Lock Block.
    *
    *     +-------------------------------------------------------+
    *   0 |                       NTL$HDR                         |
    *     +-------------------------------------------------------+
    *   8 |                                                       |
    *     =                       NTLSPNLK                        =
    *     |                                                       |
    *     +-------------------------------------------------------+
    *  38 |///////////////////////////////////////////////////////|
    *     =///////////////////////////////////////////////////////=
    *     |///////////////////////////////////////////////////////|
    *     +-------------------------------------------------------+
    *  F8 |                       NTL$EYE                         |
    *     +-------------------------------------------------------+
    * 100
    *
    *** NTLBK - Network Lock Block.

NTLBK Cross Reference | Top of page

    Symbol         Dspl Value
    -------------- ---- -----
    NTL$END        00F8 00000100
    NTL$EYE        00F8
    NTL$HDR        0000
    NTLBKLN        00F8 00000100
    NTLBKSZ        00F8 00000020
    NTLSPNLK       0008

This information is based on z/VM 7.2.0 Last updated on 24 Jun 2020 at 09:29:28 EDT.
Copyright IBM Corporation, 1990, 2020