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

128 Chapter3
NetIPC Intrinsics
IO[DONT]WAIT
IO[DONT]WAIT
Initiates completion operations for a nowait I/O request.
Syntax
fnum := IO[DONT]WAIT ([ filenum ][, target ][, tcount ][, cstation ])
Parameters
fnum (returned function value)
16-bit integer. The socket/VC socket descriptor for
which an I/O request has completed. Zero indicates no
completion. If there are any nowait file access requests
outstanding, and if the
filenum parameter is zero, the
returned function value may be an actual file number.
filenum (input)
16-bit integer, by value. The call/VC socket
descriptor indicating the socket or connection (that is,
call or VC socket) for which the nowait I/O request was
issued. If omitted, or if the value is zero, any nowait
NetIPC or file request issued by the calling process may
be completed by this intrinsic call.
target
Array of 16-bit values, by reference. Not used by
NetIPC.
tcount (output)
16-bit integer, by reference. Returns the amount of
data received after a nowait IPCRECV call. The actual
data will be in the IPCRECV data parameter.
station (output)
16-bit integer (unsigned), by reference. Bit one is
returned on if the completed request was a send, off if it
was a receive. All other bits will be off.
Description
Either IOWAIT or IODONTWAIT is needed to complete a NetIPC nowait
send or receive request. IOWAIT waits until a request can be completed;
IODONTWAIT checks to see if a request can be completed and then
immediately returns control to the calling process.