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AIO_WRITE(3P) POSIX Programmer's Manual AIO_WRITE(3P)
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.
aio_write — asynchronous write to a file
#include <aio.h>
int aio_write(struct aiocb *aiocbp);
The aio_write() function shall write aiocbp->aio_nbytes to the file
associated with aiocbp->aio_fildes from the buffer pointed to by
aiocbp->aio_buf. The function shall return when the write request has
been initiated or, at a minimum, queued to the file or device.
If prioritized I/O is supported for this file, then the asynchronous
operation shall be submitted at a priority equal to a base scheduling
priority minus aiocbp->aio_reqprio. If Thread Execution Scheduling is
not supported, then the base scheduling priority is that of the
calling process;
otherwise, the base scheduling priority is that of the calling
thread.
The aiocbp argument may be used as an argument to aio_error() and
aio_return() in order to determine the error status and return
status, respectively, of the asynchronous operation while it is
proceeding.
The aiocbp argument points to an aiocb structure. If the buffer
pointed to by aiocbp->aio_buf or the control block pointed to by
aiocbp becomes an illegal address prior to asynchronous I/O
completion, then the behavior is undefined.
If O_APPEND is not set for the file descriptor aio_fildes, then the
requested operation shall take place at the absolute position in the
file as given by aio_offset, as if lseek() were called immediately
prior to the operation with an offset equal to aio_offset and a
whence equal to SEEK_SET. If O_APPEND is set for the file
descriptor, or if aio_fildes is associated with a device that is
incapable of seeking, write operations append to the file in the same
order as the calls were made, except under circumstances described in
Section 2.8.2, Asynchronous I/O. After a successful call to enqueue
an asynchronous I/O operation, the value of the file offset for the
file is unspecified.
The aio_sigevent member specifies the notification which occurs when
the request is completed.
The aiocbp->aio_lio_opcode field shall be ignored by aio_write().
Simultaneous asynchronous operations using the same aiocbp produce
undefined results.
If synchronized I/O is enabled on the file associated with
aiocbp->aio_fildes, the behavior of this function shall be according
to the definitions of synchronized I/O data integrity completion, and
synchronized I/O file integrity completion.
For any system action that changes the process memory space while an
asynchronous I/O is outstanding to the address range being changed,
the result of that action is undefined.
For regular files, no data transfer shall occur past the offset
maximum established in the open file description associated with
aiocbp->aio_fildes.
The aio_write() function shall return the value zero if the I/O
operation is successfully queued; otherwise, the function shall
return the value −1 and set errno to indicate the error.
The aio_write() function shall fail if:
EAGAIN The requested asynchronous I/O operation was not queued due to
system resource limitations.
Each of the following conditions may be detected synchronously at the
time of the call to aio_write(), or asynchronously. If any of the
conditions below are detected synchronously, the aio_write() function
shall return −1 and set errno to the corresponding value. If any of
the conditions below are detected asynchronously, the return status
of the asynchronous operation shall be set to −1, and the error
status of the asynchronous operation is set to the corresponding
value.
EBADF The aiocbp->aio_fildes argument is not a valid file descriptor
open for writing.
EINVAL The file offset value implied by aiocbp->aio_offset would be
invalid,
aiocbp->aio_reqprio is not a valid value, or
aiocbp->aio_nbytes is an invalid value.
In the case that the aio_write() successfully queues the I/O
operation, the return status of the asynchronous operation shall be
one of the values normally returned by the write() function call. If
the operation is successfully queued but is subsequently canceled or
encounters an error, the error status for the asynchronous operation
contains one of the values normally set by the write() function call,
or one of the following:
EBADF The aiocbp->aio_fildes argument is not a valid file descriptor
open for writing.
EINVAL The file offset value implied by aiocbp->aio_offset would be
invalid.
ECANCELED
The requested I/O was canceled before the I/O completed due to
an explicit aio_cancel() request.
The following condition may be detected synchronously or
asynchronously:
EFBIG The file is a regular file, aiobcp->aio_nbytes is greater than
0, and the starting offset in aiobcp->aio_offset is at or
beyond the offset maximum in the open file description
associated with aiocbp->aio_fildes.
The following sections are informative.
None.
None.
None.
None.
Section 2.8.2, Asynchronous I/O, aio_cancel(3p), aio_error(3p),
aio_read(3p), aio_return(3p), close(3p), exec(1p), exit(3p),
fork(3p), lio_listio(3p), lseek(3p), write(3p)
The Base Definitions volume of POSIX.1‐2008, aio.h(0p)
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 AIO_WRITE(3P)
Pages that refer to this page: aio.h(0p), aio_cancel(3p), aio_error(3p), aio_read(3p), aio_return(3p), aio_suspend(3p), lio_listio(3p)