lio_listio(2)lio_listio(2)NAMElio_listio() - start a list of asynchronous I/O operations
SYNOPSISDESCRIPTION
The function allows the calling process to request a list of asynchro‐
nous I/O operations with a single function call. The function call
returns when all operation requests have been enqueued for processing.
At this point, processing of the operations may proceed concurrently
with execution of the calling process or thread.
The argument is an array of pointers to structures. Each in is treated
as if it were being handled in a separate call to or depending on the
value of its When is the is treated as though it had been referenced in
a call to and the and fields are interpreted accordingly. When is the
is treated as though it had been referenced in a call to and the and
fields are interpreted accordingly. If is nothing is enqueued.
If an error condition is detected that prevents the list from being
processed, returns and sets to indicate the cause of the failure. If
any requests are enqueued by the call to and is then the function
returns only after all enqueued operation requests have completed. The
sig argument of the call is ignored. If is the function returns as
soon as all requests are enqueued. The action specified by sig is per‐
formed after all enqueued requests have completed.
Once the requested operations have been successfully enqueued, an and
function referencing the corresponding from must be used to determine
their status and any error conditions, including those normally
reported by or as appropriate. Requests remain enqueued and consume
process and system resources until is called for each one.
Re-using or deallocating memory referred to by the or any referenced in
the while an asynchronous I/O operation is outstanding (i.e. before has
been called) may produce unpredictable results.
To use this function, link in the realtime library by specifying on the
compiler or linker command line.
RETURN VALUE
When is set, returns the following values:
Success. All of the non-empty operations, if any, were
successfully enqueued.
Failure or partial success.
At least one requested operation was either not
enqueued or completed with an error before the
function call returned. is set to indicate the
error.
When is set, returns the following values:
Success. All of the non-empty operations, if any, were
successfully enqueued and completed.
Failure or partial success.
At least one requested operation was either not
enqueued or completed with an error. is set to
indicate the error.
The three values and are the only ones associated with partial success.
and must be used to determine the outcomes of individual requests.
ERRORS
If detects one of the following error conditions, is set to the indi‐
cated value:
[EAGAIN] At least one request could not be queued either
because of a resource shortage or because the
per-process or system-wide limit on asynchronous
I/O operations or asynchronous threads would have
been exceeded.
[EINVAL] The specified by sig is not valid.
[EINVAL] The argument is neither nor
[EINVAL] The value of the argument is negative or greater
than the maximum value allowed. The maximum value
allowed can be obtained using the call with the
argument
[EINTR] The argument was and a signal was delivered while
waiting for the requested operations to complete.
This signal may result from completion of one or
more of the requested operations and other
requests may still be pending or completed.
Once an operation has been enqueued by the following errors, in addi‐
tion to all of the errors normally reported by the appropriate or func‐
tion, may be reported asynchronously by a subsequent call to or refer‐
encing its
[EBADF] The was not a valid file descriptor open for
reading or writing as appropriate to the
[EINVAL] The value of is not valid, or the value of is
invalid, or the file offset implied by or is not
valid.
[EIO] One or more of the enqueued operations did not
complete successfully.
EXAMPLE
The following code sequence and call to starts two asynchronous write
operations and one asynchronous read operation and waits for all opera‐
tions to complete.
SEE ALSOaio_cancel(2), aio_error(2), aio_fsync(2), aio_read(2), aio_return(2),
aio_suspend(2), aio_write(2), read(2), write(2), aio(5).
STANDARDS CONFORMANCElio_listio(2)
