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.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved
.TH "AIO_FSYNC" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" aio_fsync
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.SH NAME
aio_fsync \- asynchronous file synchronization (\fBREALTIME\fP)
.SH SYNOPSIS
.LP
\fB#include <aio.h>
.br
.sp
int aio_fsync(int\fP \fIop\fP\fB, struct aiocb *\fP\fIaiocbp\fP\fB);
\fP
\fB
.br
\fP
.SH DESCRIPTION
.LP
The \fIaio_fsync\fP() function shall asynchronously force all I/O
operations associated with the file indicated by the file
descriptor \fIaio_fildes\fP member of the \fBaiocb\fP structure referenced
by the \fIaiocbp\fP argument and queued at the time
of the call to \fIaio_fsync\fP() to the synchronized I/O completion
state. The function call shall return when the synchronization
request has been initiated or queued to the file or device (even when
the data cannot be synchronized immediately).
.LP
If \fIop\fP is O_DSYNC, all currently queued I/O operations shall
be completed as if by a call to \fIfdatasync\fP(); that is, as defined
for synchronized I/O data integrity completion. If
\fIop\fP is O_SYNC, all currently queued I/O operations shall be completed
as if by a call to \fIfsync\fP(); that is, as defined for synchronized
I/O file integrity completion. If the
\fIaio_fsync\fP() function fails, or if the operation queued by \fIaio_fsync\fP()
fails, then, as for \fIfsync\fP() and \fIfdatasync\fP(), outstanding
I/O
operations are not guaranteed to have been completed.
.LP
If \fIaio_fsync\fP() succeeds, then it is only the I/O that was queued
at the time of the call to \fIaio_fsync\fP() 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.
.LP
The \fIaiocbp\fP argument refers to an asynchronous I/O control block.
The \fIaiocbp\fP value may be used as an argument to \fIaio_error\fP()
and \fIaio_return\fP() 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 shall be reset to reflect the success or failure of the operation.
If the operation does not complete successfully, the
error status for the operation shall be set to indicate the error.
The \fIaio_sigevent\fP member determines the asynchronous
notification to occur as specified in \fISignal Generation and Delivery\fP
when all
operations have achieved synchronized I/O completion. All other members
of the structure referenced by \fIaiocbp\fP are ignored.
If the control block referenced by \fIaiocbp\fP becomes an illegal
address prior to asynchronous I/O completion, then the behavior
is undefined.
.LP
If the \fIaio_fsync\fP() function fails or \fIaiocbp\fP indicates
an error condition, data is not guaranteed to have been
successfully transferred.
.SH RETURN VALUE
.LP
The \fIaio_fsync\fP() function shall return the value 0 to the calling
process if the I/O operation is successfully queued;
otherwise, the function shall return the value -1 and set \fIerrno\fP
to indicate the error.
.SH ERRORS
.LP
The \fIaio_fsync\fP() function shall fail if:
.TP 7
.B EAGAIN
The requested asynchronous operation was not queued due to temporary
resource limitations.
.TP 7
.B EBADF
The \fIaio_fildes\fP member of the \fBaiocb\fP structure referenced
by the \fIaiocbp\fP argument is not a valid file
descriptor open for writing.
.TP 7
.B EINVAL
This implementation does not support synchronized I/O for this file.
.TP 7
.B EINVAL
A value of \fIop\fP other than O_DSYNC or O_SYNC was specified.
.sp
.LP
In the event that any of the queued I/O operations fail, \fIaio_fsync\fP()
shall return the error condition defined for \fIread\fP() and \fIwrite\fP().
The error is returned in
the error status for the asynchronous \fIfsync\fP() operation, which
can be retrieved using
\fIaio_error\fP().
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
The \fIaio_fsync\fP() function is part of the Asynchronous Input and
Output option and need not be available on all
implementations.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIfcntl\fP(), \fIfdatasync\fP(), \fIfsync\fP(), \fIopen\fP(),
\fIread\fP(), \fIwrite\fP(), the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
\fI<aio.h>\fP
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
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