1AIO_WRITE(3P) POSIX Programmer's Manual AIO_WRITE(3P)
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6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
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13 aio_write — asynchronous write to a file
14
16 #include <aio.h>
17 int aio_write(struct aiocb *aiocbp);
19
21 The aio_write() function shall write aiocbp->aio_nbytes to the file
22 associated with aiocbp->aio_fildes from the buffer pointed to by
23 aiocbp->aio_buf. The function shall return when the write request has
24 been initiated or, at a minimum, queued to the file or device.
25 If prioritized I/O is supported for this file, then the asynchronous
27 operation shall be submitted at a priority equal to a base scheduling
28 priority minus aiocbp->aio_reqprio. If Thread Execution Scheduling is
29 not supported, then the base scheduling priority is that of the calling
30 process;
31 otherwise, the base scheduling priority is that of the calling thread.
32 The aiocbp argument may be used as an argument to aio_error() and
34 aio_return() in order to determine the error status and return status,
35 respectively, of the asynchronous operation while it is proceeding.
36 The aiocbp argument points to an aiocb structure. If the buffer pointed
38 to by aiocbp->aio_buf or the control block pointed to by aiocbp becomes
39 an illegal address prior to asynchronous I/O completion, then the
40 behavior is undefined.
41 If O_APPEND is not set for the file descriptor aio_fildes, then the
43 requested operation shall take place at the absolute position in the
44 file as given by aio_offset, as if lseek() were called immediately
45 prior to the operation with an offset equal to aio_offset and a whence
46 equal to SEEK_SET. If O_APPEND is set for the file descriptor, or if
47 aio_fildes is associated with a device that is incapable of seeking,
48 write operations append to the file in the same order as the calls were
49 made, except under circumstances described in Section 2.8.2, Asynchro‐
50 nous I/O. After a successful call to enqueue an asynchronous I/O oper‐
51 ation, the value of the file offset for the file is unspecified.
52 The aio_sigevent member specifies the notification which occurs when
54 the request is completed.
55 The aiocbp->aio_lio_opcode field shall be ignored by aio_write().
57 Simultaneous asynchronous operations using the same aiocbp produce
59 undefined results.
60 If synchronized I/O is enabled on the file associated with
62 aiocbp->aio_fildes, the behavior of this function shall be according to
63 the definitions of synchronized I/O data integrity completion, and syn‐
64 chronized I/O file integrity completion.
65 For any system action that changes the process memory space while an
67 asynchronous I/O is outstanding to the address range being changed, the
68 result of that action is undefined.
69 For regular files, no data transfer shall occur past the offset maximum
71 established in the open file description associated with
72 aiocbp->aio_fildes.
73
75 The aio_write() function shall return the value zero if the I/O opera‐
76 tion is successfully queued; otherwise, the function shall return the
77 value −1 and set errno to indicate the error.
78
80 The aio_write() function shall fail if:
81 EAGAIN The requested asynchronous I/O operation was not queued due to
83 system resource limitations.
84 Each of the following conditions may be detected synchronously at the
86 time of the call to aio_write(), or asynchronously. If any of the con‐
87 ditions below are detected synchronously, the aio_write() function
88 shall return −1 and set errno to the corresponding value. If any of the
89 conditions below are detected asynchronously, the return status of the
90 asynchronous operation shall be set to −1, and the error status of the
91 asynchronous operation is set to the corresponding value.
92 EBADF The aiocbp->aio_fildes argument is not a valid file descriptor
94 open for writing.
95 EINVAL The file offset value implied by aiocbp->aio_offset would be
97 invalid,
98 aiocbp->aio_reqprio is not a valid value, or aiocbp->aio_nbytes
99 is an invalid value.
100 In the case that the aio_write() successfully queues the I/O operation,
102 the return status of the asynchronous operation shall be one of the
103 values normally returned by the write() function call. If the operation
104 is successfully queued but is subsequently canceled or encounters an
105 error, the error status for the asynchronous operation contains one of
106 the values normally set by the write() function call, or one of the
107 following:
108 EBADF The aiocbp->aio_fildes argument is not a valid file descriptor
110 open for writing.
111 EINVAL The file offset value implied by aiocbp->aio_offset would be
113 invalid.
114 ECANCELED
116 The requested I/O was canceled before the I/O completed due to
117 an explicit aio_cancel() request.
118 The following condition may be detected synchronously or asyn‐
120 chronously:
121 EFBIG The file is a regular file, aiobcp->aio_nbytes is greater than
123 0, and the starting offset in aiobcp->aio_offset is at or beyond
124 the offset maximum in the open file description associated with
125 aiocbp->aio_fildes.
126 The following sections are informative.
128
130 None.
131
133 None.
134
136 None.
137
139 None.
140
142 Section 2.8.2, Asynchronous I/O, aio_cancel(), aio_error(), aio_read(),
143 aio_return(), close(), exec, exit(), fork(), lio_listio(), lseek(),
144 write()
145 The Base Definitions volume of POSIX.1‐2008, <aio.h>
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149 Portions of this text are reprinted and reproduced in electronic form
150 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
151 -- Portable Operating System Interface (POSIX), The Open Group Base
152 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
153 cal and Electronics Engineers, Inc and The Open Group. (This is
154 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
155 event of any discrepancy between this version and the original IEEE and
156 The Open Group Standard, the original IEEE and The Open Group Standard
157 is the referee document. The original Standard can be obtained online
158 at http://www.unix.org/online.html .
159 Any typographical or formatting errors that appear in this page are
161 most likely to have been introduced during the conversion of the source
162 files to man page format. To report such errors, see https://www.ker‐
163 nel.org/doc/man-pages/reporting_bugs.html .
164IEEE/The Open Group 2013 AIO_WRITE(3P)