HP 3000 Manuals HP 3000 Manuals
IO[DONT]WAIT
Initiates completion operations for a nowait I/O request.
Syntax
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| fnum := IO[DONT]WAIT ([ filenum][, target][, tcount][, cstation])|
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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.
cstation (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.
If a nowait IPCSEND, IPCRECVCN, or IPCRECV request is issued, the data
and flags parameters (if specified) must exist when IOWAIT or IODONTWAIT
is called. In other words, these parameters must be global to both the
IPC intrinsic that initiates the request and theIO[DONT]WAIT that
attempts to complete the I/O.
All parameters are optional (option variable). In general, the condition
codes returned by IOWAIT/IODONTWAIT for socket I/O have the following
meanings:
* CCE--Succeeded.
* CCL--Failed.
* CCG--The operation succeeded but a noncritical error occurred (for
example, the flags parameter was out of bounds).
IOWAIT and IODONTWAIT can be called in split stack mode.