NetIPC 3000/XL Programmer's Reference Manual (5958-8600)

60 Chapter3
NetIPC Intrinsics
Common Parameters
Common Parameters
The flags , opt , data , and result parameters are common to many
NetIPC intrinsics. Remote Process Management intrinsics also use
these parameters, with the exception of the
data parameter. The
following discussion of these parameters may help to clarify the more
condensed information given under each intrinsic.
Flags Parameter
The flags parameter is a bit representation, 32 bits long, of various
options. Normally an option is invoked if the appropriate bit is on (that
is, set equal to 1). Borrowing Pascal-type syntax, we shall use
flags [0]
to refer to the high order bit in the parameter,
flags [31] to refer to the
low order bit, and a similar designation to refer to each of the bits in
between. Bits which are not defined for a given intrinsic must be off
(zero).
Opt Parameter
The opt parameter, which denotes various options, contains an integer
code for each option along with associated information. It is not
necessary to know the internal structure of this parameter in order to
use it. Several
opt parameter manipulation intrinsics have been
provided to enable you to add option information without concerning
yourself with the parameter’s structure. However, a knowledge of the
structure of the
opt parameter can help you to determine an
appropriate size for the array.
The opt parameter must be defined as a byte array or as a record
structured in the manner described below. If your program is written in
a language which supports dynamically allocated arrays, the
OPTOVERHEAD intrinsic may be used to determine the size of the array.
The
opt parameter consists of these fields as shown in Figure 3-1.
• length, in bytes, of option entries and data (2-byte integer);
• number of entries (2-byte integer);
• option entries (8 bytes per option entry). Each 8-byte option entry,
in turn, consists of the following fields:
— option code (2-byte integer);
— offset (2-byte integer) byte offset relative to the base address of
the
opt parameter indicating the location of the data for this
option entry;
— data length, in bytes(2-byte integer);