AIO_WRITE
Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
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NAME
aio_write - asynchronous write
SYNOPSIS
#include <aio.h>
int aio_write(struct aiocb *aiocbp);
Link with -lrt.
DESCRIPTION
The
aio_write()
function queues the I/O request described by the buffer pointed to by
aiocbp.
This function is the asynchronous analog of
write(2).
The arguments of the call
write(fd, buf, count)
correspond (in order) to the fields
aio_fildes,
aio_buf,
and
aio_nbytes
of the structure pointed to by
aiocbp.
(See
aio(7)
for a description of the
aiocb
structure.)
If
O_APPEND
is not set, the data is written starting at the
absolute position
aiocbp->aio_offset,
regardless of the file offset.
If
O_APPEND
is set, data is written at the end of the file in the same order as
aio_write()
calls are made.
After the call, the value of the file offset is unspecified.
The "asynchronous" means that this call returns as soon as the
request has been enqueued; the write may or may not have completed
when the call returns.
One tests for completion using
aio_error(3).
The return status of a completed I/O operation can be obtained
aio_return(3).
Asynchronous notification of I/O completion can be obtained by setting
aiocbp->aio_sigevent
appropriately; see
sigevent(7)
for details.
If
_POSIX_PRIORITIZED_IO
is defined, and this file supports it,
then the asynchronous operation is submitted at a priority equal
to that of the calling process minus
aiocbp->aio_reqprio.
The field
aiocbp->aio_lio_opcode
is ignored.
No data is written to a regular file beyond its maximum offset.
RETURN VALUE
On success, 0 is returned.
On error, the request is not enqueued, -1
is returned, and
errno
is set appropriately.
If an error is detected only later, it will
be reported via
aio_return(3)
(returns status -1) and
aio_error(3)
(error status---whatever one would have gotten in
errno,
such as
EBADF).
ERRORS
- EAGAIN
-
Out of resources.
- EBADF
-
aio_fildes
is not a valid file descriptor open for writing.
- EFBIG
-
The file is a regular file, we want to write at least one byte,
but the starting position is at or beyond the maximum offset for this file.
- EINVAL
-
One or more of
aio_offset,
aio_reqprio,
aio_nbytes
are invalid.
- ENOSYS
-
aio_write()
is not implemented.
VERSIONS
The
aio_write()
function is available since glibc 2.1.
ATTRIBUTES
For an explanation of the terms used in this section, see
attributes(7).
| Interface | Attribute | Value
|
|
aio_write()
| Thread safety | MT-Safe
|
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
NOTES
It is a good idea to zero out the control block before use.
The control block must not be changed while the write operation
is in progress.
The buffer area being written out
must not be accessed during the operation or undefined results may occur.
The memory areas involved must remain valid.
Simultaneous I/O operations specifying the same
aiocb
structure produce undefined results.
SEE ALSO
aio_cancel(3),
aio_error(3),
aio_fsync(3),
aio_read(3),
aio_return(3),
aio_suspend(3),
lio_listio(3),
aio(7)
COLOPHON
This page is part of release 4.13 of the Linux
man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
https://www.kernel.org/doc/man-pages/.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- RETURN VALUE
-
- ERRORS
-
- VERSIONS
-
- ATTRIBUTES
-
- CONFORMING TO
-
- NOTES
-
- SEE ALSO
-
- COLOPHON
-
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