AIO_WRITE(3) Linux Programmer's Manual AIO_WRITE(3)NAMEaio_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
file offset aiocbp->aio_offset, regardless of the current 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
current 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.
CONFORMING TO
POSIX.1-2001, POSIX.1-2008.
NOTES
It is a good idea to zero out the control block before use. The con‐
trol block must not be changed while the write operation is in
progress. The buffer area being written out must not be accessed dur‐
ing 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 ALSOaio_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 3.53 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/man-pages/.
2012-05-08 AIO_WRITE(3)
