The Return the Next Valid Zone Identifier routine returns the
    zone identifier of the next valid zone in the heap management
    32-bit database.

    Format

      LIB$FIND_VM_ZONE  context ,zone-id

1 - Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

2 - Arguments

 context

    OpenVMS usage:context
    type:         longword (unsigned)
    access:       modify
    mechanism:    by reference

    Context specifier. The context argument is the address of an
    unsigned longword used to keep the scan context for finding the
    next valid zone. The context argument must be 0 to initialize the
    scan and to start with the first returnable zone identifier.

 zone-id

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

    Zone identifier. The zone-id argument is the address of an
    unsigned longword that receives the zone identifier for the next
    zone.