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NM and CM callable. Initiates completion operations for an I/O request. Syntax | |
I16 I16V UDS I16 U16
fnum:=IODONTWAIT(filenum,buffer,length,cstation)
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Functional Return | |
- fnum
16-bit signed integer (assigned functional return) The file number for which the completion occurred.
If no completion occurred, zero is returned.
Parameters | |
- filenum
16-bit signed integer by value (required) The file number for which there is a pending I/O request.
If you specify 0, the IODONTWAIT intrinsic checks for any
I/O completion.
- buffer
user-defined structure (optional) Passes an input buffer. This buffer must be large enough to contain
the input record. It should be the same buffer specified in
the original I/O request if that was a read request.
This allows for a proper recognition of EOF where applicable.
The buffer parameter is required if not in priviledged mode, or
the buffer parameter can be ommitted if the GETPRIVMODE intrinsic is
called first.
- length
16-bit signed integer by reference (optional) Returns the length of the received or transmitted record.
If the original request specified a byte count, the integer represents
bytes; if the request specified half words, the integer
represents half words. This parameter is pertinent only if the
original I/O request was a read request. The FREAD intrinsic
always returns zero as its functional return if you specify nowait I/O.
In this case, the actual record length is returned in the length
parameter of IODONTWAIT.
- cstation
16-bit unsigned integer by reference (optional) Returns the number of the calling station when completed (used for
distributed systems). (ASC) Not used for asynchronous devices.
Operation Notes | |
The IODONTWAIT intrinsic operates the same as IOWAIT with one
exception: if you call IOWAIT and no I/O has completed,
then the calling process is suspended until some I/O completes;
if you call IODONTWAIT and no I/O has completed,
then control is returned to the calling process.
(CCE (2) is returned and the result of IODONTWAIT is zero.) Condition Codes | |
- CCE (2)
Request granted. If the functional return is not zero, then
I/O completion occurred with no errors. If the functional return is zero,
no I/O has completed. - CCG (0)
An end-of-file was encountered. - CCL (1)
Request denied. Normal I/O completion did not occur; there were
no I/O requests pending, a parameter error occurred, or an abnormal
I/O completion occurred.
Related Information | |
- Intrinsics
None - Commands
None - Manuals
Interprocess Communication Programmer's Guide (32650-90019)
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