Programming Interface Information: This information is NOT intended to be used as Programming Interfaces of z/VM.

#### ALCBK

Prolog

Control Block Contents
ALCBK DSECT

Storage Layout

Cross Reference (Contains links to field and bit definitions)

#### ALCBK Prolog

     Name       : HCPALCBK
     Description: Access-List Control Block
     DSECT      : ALCBK
     Function   : This DSECT maps the control block used to manage an
                  ESA/370 access list.
     Located by : ALEALCBK in the second access-list entry of an access
                  list built by CP (the one with ALEN=1).
     Created by : HCPALMCR when an access list is created.
     Deleted by : HCPALMDS when an access list is destroyed.
     Notes      : The contents of this control block, and the access-list
                  designation indicated by ALCALD are serialized by the
                  access-list-control lock, the lockword for which is
                  ASCLOCK.

#### ALCBK Control Block Content

#### ALCBK DSECT

    Hex   Dec Type/Val   Lng Label (dup)    Comments
    ---- ---- --------- ---- -------------- --------
    0000    0 Structure      ALCBK          Access-List Control Block
                                      block.
    0000    0 Address      4 ALCALD         Address of access-list
                                            designation.
    0004    4 Address      4 ALCAL          Address of access list
    0008    8 Address      4 ALCOWNER       Address of VMDBK which owns the
                                            access list.
    000C   12 Signed       4 *              Reserved for IBM use
    0010   16 Address      4 ALCSPIBK       Anchor for chain of SPIBKs
                                            defining what address spaces may
                                            be attached to this access list.
                                            This is serialized by the
                                            space-permission-manager lock
                                            (RSASPMLK in HCPRSMCM).
    0014   20 Address      4 ALCDEFRQ       Anchor for queue of tasks adding
                                            entries to the CP-use AL which
                                            have been deferred because the
                                            CP-use access list is full.
    0018   24 Dbl-Word     8 ALCLOCK (3)    Lockword for access-list-control
                                            lock.
    0030   48 Signed       4 ALCALSIZ       Size of access list, in bytes.
    0034   52 Signed       4 ALCMAXSZ       Largest permitted size of access
                                            list, in bytes.
    0038   56 Signed       4 ALCFREE        Number of ALEs in the invalid
                                            state (not including ALENs 0 and
                                            1). This is the number of ALEs
                                            available for allocation.
    003C   60 Signed       4 ALCNXTCP       Next ALE to allocate in the
                                            CP-use access list.
              00000040       ALCLEN         *-ALCBK Length in bytes of ALCBK.
              00000008       ALCSIZE        (ALCLEN+7)/8 Size in doublewords
                                            of an ALCBK

#### ALCBK Storage Layout

    *** ALCBK - Access-List Control Block
    *
    *     +---------------------------+---------------------------+
    *   0 |          ALCALD           |          ALCAL            |
    *     +---------------------------+---------------------------+
    *   8 |         ALCOWNER          |///////////////////////////|
    *     +---------------------------+---------------------------+
    *  10 |         ALCSPIBK          |         ALCDEFRQ          |
    *     +---------------------------+---------------------------+
    *  18 |                                                       |
    *     =                       ALCLOCK                         =
    *     |                                                       |
    *     +---------------------------+---------------------------+
    *  30 |         ALCALSIZ          |         ALCMAXSZ          |
    *     +---------------------------+---------------------------+
    *  38 |         ALCFREE           |         ALCNXTCP          |
    *     +---------------------------+---------------------------+
    *  40
    *
    *** ALCBK - Access-List Control Block

#### ALCBK Cross Reference

    Symbol         Dspl Value
    -------------- ---- -----
    ALCAL          0004
    ALCALD         0000
    ALCALSIZ       0030
    ALCDEFRQ       0014
    ALCFREE        0038
    ALCLEN         003C 00000040
    ALCLOCK        0018
    ALCMAXSZ       0034
    ALCNXTCP       003C
    ALCOWNER       0008
    ALCSIZE        003C 00000008
    ALCSPIBK       0010

This information is based on z/VM V5R2.0. Last updated on 12 Apr 2006 at 16:39:19 EDT.
Copyright IBM Corporation, 1990, 2005