AIO_FSYNC(3C) Standard C Library Functions AIO_FSYNC(3C)
NAME
aio_fsync - asynchronous file synchronization
SYNOPSIS
#include <aio.h>
int aio_fsync(
int op,
struct aiocb *aiocbp);
DESCRIPTION
The
aio_fsync() function asynchronously forces all I/O operations
associated with the file indicated by the file descriptor
aio_fildes member of the
aiocb structure referenced by the
aiocbp argument and
queued at the time of the call to
aio_fsync() to the synchronized I/O
completion state. The function call returns when the synchronization
request has been initiated or queued to the file or device (even when the
data cannot be synchronized immediately).
If
op is
O_DSYNC, all currently queued I/O operations are completed as if
by a call to
fdatasync(3C); that is, as defined for synchronized I/O data
integrity completion. If
op is
O_SYNC, all currently queued I/O
operations are completed as if by a call to
fsync(3C); that is, as
defined for synchronized I/O file integrity completion. If the
aio_fsync() function fails, or if the operation queued by
aio_fsync() fails, then, as for
fsync(3C) and
fdatasync(3C), outstanding I/O
operations are not guaranteed to have been completed.
If
aio_fsync() succeeds, then it is only the I/O that was queued at the
time of the call to
aio_fsync() that is guaranteed to be forced to the
relevant completion state. The completion of subsequent I/O on the file
descriptor is not guaranteed to be completed in a synchronized fashion.
The
aiocbp argument refers to an asynchronous I/O control block. The
aiocbp value may be used as an argument to
aio_error(3C) and
aio_return(3C) in order to determine the error status and return status,
respectively, of the asynchronous operation while it is proceeding. When
the request is queued, the error status for the operation is
EINPROGRESS. When all data has been successfully transferred, the error status will be
reset to reflect the success or failure of the operation. If the
operation does not complete successfully, the error status for the
operation will be set to indicate the error. The
aio_sigevent member
determines the asynchronous notification to occur when all operations
have achieved synchronized I/O completion (see
signal.h(3HEAD)). All
other members of the structure referenced by
aiocbp are ignored. If the
control block referenced by
aiocbp becomes an illegal address prior to
asynchronous I/O completion, then the behavior is undefined.
If the
aio_fsync() function fails or the
aiocbp indicates an error
condition, data is not guaranteed to have been successfully transferred.
If
aiocbp is
NULL, then no status is returned in
aiocbp, and no signal is
generated upon completion of the operation.
RETURN VALUES
The
aio_fsync() function returns
0 to the calling process if the I/O
operation is successfully queued; otherwise, the function returns
-1 and
sets
errno to indicate the error.
ERRORS
The
aio_fsync() function will fail if:
EAGAIN The requested asynchronous operation was not queued due to
temporary resource limitations.
EBADF The
aio_fildes member of the
aiocb structure referenced by the
aiocbp argument is not a valid file descriptor open for
writing.
EINVAL The system does not support synchronized I/O for this file.
EINVAL A value of
op other than
O_DSYNC or
O_SYNC was specified.
In the event that any of the queued I/O operations fail,
aio_fsync() returns the error condition defined for
read(2) and
write(2). The error
will be returned in the error status for the asynchronous
fsync(3C) operation, which can be retrieved using
aio_error(3C).
USAGE
The
aio_fsync() function has a transitional interface for 64-bit file
offsets. See
lf64(7).
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-------------------+
|Interface Stability | Committed |
+--------------------+-------------------+
|MT-Level | MT-Safe |
+--------------------+-------------------+
|Standard | See
standards(7). |
+--------------------+-------------------+
SEE ALSO
fcntl(2),
open(2),
read(2),
write(2),
aio_error(3C),
aio_return(3C),
fdatasync(3C),
fsync(3C),
aio.h(3HEAD),
fcntl.h(3HEAD),
signal.h(3HEAD),
attributes(7),
lf64(7),
standards(7) February 5, 2008
AIO_FSYNC(3C)