/sys$common/syshlp/helplib.hlb RTL Routines, LIB$, LIB$CREATE_VM_ZONE, Arguments  *Conan The Librarian (sorry for the slow response - running on an old VAX)

 zone-id

    OpenVMS usage:identifier
    type:         longword (unsigned)
    access:       write only
    mechanism:    by reference

    Zone identifier. The zone-id argument is the address of a
    longword that is set to the zone identifier of the newly created
    zone.

 algorithm

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Algorithm. The algorithm argument is the address of a longword
    integer that contains a value representing one of the LIB$VM
    algorithms. Use one of the predefined symbols to specify this
    value.

    Symbol                  Value  Algorithm

    LIB$K_VM_FIRST_FIT      1      First fit
    LIB$K_VM_QUICK_FIT      2      Quick fit, lookaside list
    LIB$K_VM_FREQ_SIZES     3      Frequent sizes, lookaside list
    LIB$K_VM_FIXED          4      Fixed-size blocks

    If algorithm is not specified, a default of 1 (first fit) is
    used.

 algorithm-argument

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Algorithm argument. The algorithm-argument argument is the
    address of a longword integer that contains a value specific
    to the particular allocation algorithm as shown in the following
    table.

    Algorithm      Value

    First fit      Not used, may be omitted.
    Quick fit      The number of lookaside lists used. The number of
                   lists must be between 1 and 128.
    Frequent       The number of lookaside lists used. The number of
    sizes          lists must be between 1 and 16.
    Fixed size     The fixed request size (in bytes) for each get
    blocks         or free request. The request size must be greater
                   than 0.

    The algorithm-argument argument must be specified if you are
    using the quick-fit, frequent-sizes or fixed-size-blocks
    algorithms. However, this argument is optional, but ignored,
    if you are using the first-fit algorithm.

 flags

    OpenVMS usage:mask_longword
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference

    Flags. The flags argument is the address of a longword integer
    that contains flag bits that control various options, as follows:

    Bit    Value                 Description

    0      LIB$M_VM_BOUNDARY_    Boundary tags for faster freeing.
           TAGS
                                 Adds a minimum of 8 bytes to each
                                 block.
    1      LIB$M_VM_GET_FILL0    LIB$GET_VM; fill with bytes of 0.
    2      LIB$M_VM_GET_FILL1    LIB$GET_VM; fill with bytes of FF
                                 (hexadecimal).
    3      LIB$M_VM_FREE_FILL0   LIB$FREE_VM; fill with bytes of 0.
    4      LIB$M_VM_FREE_FILL1   LIB$FREE_VM; fill with bytes of FF
                                 (hexadecimal).
    5      LIB$M_VM_EXTEND_      Adds extents to existing areas if
           AREA                  possible.
    6      LIB$M_VM_NO_EXTEND    Prevents zone from being extended
                                 beyond its initial size. If you
                                 specify this flag, you must also
                                 specify an initial-size. The extend-
                                 size argument is not used.
    7      LIB$M_VM_TAIL_LARGE   Adds areas larger than extend-size
                                 areas to the end of the area list.
                                 Allocations that are larger than
                                 extend-size can result in new areas.
                                 These areas are added to the end of
                                 the area list. (This provides better
                                 memory reuse when allocating small
                                 and very large blocks from the same
                                 zone.)

    Bits 8 through 31 are reserved and must be 0.

    This is an optional argument. If flags is omitted, the default of
    0 (no fill and no boundary tags) is used.

 extend-size

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Zone extend size. The extend-size argument is the address of a
    longword integer that contains the number of (512-byte) pages on
    VAX systems or pagelets on Alpha systems to be added to the zone
    each time it is extended.

    The value of extend-size must be greater than or equal to 1.

    This is an optional argument. If extend-size is not specified, a
    default of 16 pages on VAX systems or pagelets on Alpha systems
    is used.

                                   NOTE

       The extend-size argument does not limit the number of blocks
       that can be allocated from the zone. The actual extension
       size is the greater of extend-size and the number of pages
       on VAX systems or pagelets on Alpha systems needed to
       satisfy the LIB$GET_VM call that caused the extension.

 initial-size

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Initial size for the zone. The initial-size argument is the
    address of a longword integer that contains the number of (512-
    byte) pages on VAX systems or pagelets on Alpha systems to be
    allocated for the zone as the zone is created.

    This is an optional argument. If you specify a value for initial-
    size, the value must be greater than or equal to 0; otherwise,
    LIB$_INVARG is returned. If initial-size is not specified or
    is specified as 0, no pages on VAX systems or pagelets on Alpha
    systems are allocated when the zone is created. The first call
    to LIB$GET_VM for the zone allocates extend-size pages on VAX
    systems or pagelets on Alpha systems.

 block-size

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Block size of the zone. The block-size argument is the address of
    a longword integer specifying the allocation quantum (in bytes)
    for the zone. All blocks allocated are rounded up to a multiple
    of block-size.

    The value of block-size must be a power of 2 between 8 and 512.
    This is an optional argument. If block-size is not specified, a
    default of 8 is used.

 alignment

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Block alignment. The alignment argument is the address of a
    longword integer that specifies the required address alignment
    (in bytes) for each block allocated.

    The value of alignment must be a power of 2 between 4 and 512.
    This is an optional argument. If alignment is not specified, a
    default of 8 (quadword alignment) is used.

 page-limit

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Maximum page limit. The page-limit argument is the address of a
    longword integer that specifies the maximum number of (512-byte)
    pages on VAX systems or pagelets on Alpha systems that can be
    allocated for the zone. The value of page-limit must be greater
    than or equal to 0. Note that part of the zone is used for header
    information.

    This is an optional argument. If page-limit is not specified
    or is specified as 0, the only limit is the total process
    virtual address space limit imposed by OpenVMS. If page-limit
    is specified, then initial-size must also be specified.

 smallest-block-size

    OpenVMS usage:longword_signed
    type:         longword integer (signed)
    access:       read only
    mechanism:    by reference

    Smallest block size. The smallest-block-size argument is the
    address of a longword integer that specifies the smallest block
    size (in bytes) that has a lookaside list for the quick fit
    algorithm.

    If smallest-block-size is not specified, the default of block-
    size is used. That is, lookaside lists are provided for the first
    n multiples of block-size.

 zone-name

    OpenVMS usage:char_string
    type:         character string
    access:       read only
    mechanism:    by descriptor

    Name to be associated with the zone being created. The optional
    zone-name argument is the address of a descriptor pointing to the
    zone name. If zone-name is not specified, the zone will not have
    an associated name.

 get-page

    OpenVMS usage:procedure
    type:         procedure value
    access:       read only
    mechanism:    by value

    Routine that allocates memory. The number and type of the
    arguments to this routine must match those of the LIB$GET_VM_
    PAGE routine. If get-page is not specified or is specified as 0,
    the LIB$GET_VM_PAGE routine is used to allocate memory.

 free-page

    OpenVMS usage:procedure
    type:         procedure value
    access:       read only
    mechanism:    by value

    Routine that deallocates memory. The number and type of the
    arguments to this routine must match those of the LIB$FREE_
    VM_PAGE routine. If free-page is not specified or if free-
    page is specified as 0, the LIB$FREE_VM_PAGE routine is used
    to deallocate memory.