1AIO_WRITE(3) Linux Programmer's Manual AIO_WRITE(3)
2
6 aio_write - asynchronous write
7
9 #include <aio.h>
10 int aio_write(struct aiocb *aiocbp);
12 Link with -lrt.
14
16 The aio_write() function queues the I/O request described by the buffer
17 pointed to by aiocbp. This function is the asynchronous analog of
18 write(2). The arguments of the call
19 write(fd, buf, count)
21 correspond (in order) to the fields aio_fildes, aio_buf, and aio_nbytes
23 of the structure pointed to by aiocbp. (See aio(7) for a description
24 of the aiocb structure.)
25 If O_APPEND is not set, the data is written starting at the absolute
27 position aiocbp->aio_offset, regardless of the file offset. If O_AP‐
28 PEND is set, data is written at the end of the file in the same order
29 as aio_write() calls are made. After the call, the value of the file
30 offset is unspecified.
31 The "asynchronous" means that this call returns as soon as the request
33 has been enqueued; the write may or may not have completed when the
34 call returns. One tests for completion using aio_error(3). The return
35 status of a completed I/O operation can be obtained aio_return(3).
36 Asynchronous notification of I/O completion can be obtained by setting
37 aiocbp->aio_sigevent appropriately; see sigevent(7) for details.
38 If _POSIX_PRIORITIZED_IO is defined, and this file supports it, then
40 the asynchronous operation is submitted at a priority equal to that of
41 the calling process minus aiocbp->aio_reqprio.
42 The field aiocbp->aio_lio_opcode is ignored.
44 No data is written to a regular file beyond its maximum offset.
46
48 On success, 0 is returned. On error, the request is not enqueued, -1
49 is returned, and errno is set to indicate the error. If an error is
50 detected only later, it will be reported via aio_return(3) (returns
51 status -1) and aio_error(3) (error status—whatever one would have got‐
52 ten in errno, such as EBADF).
53
55 EAGAIN Out of resources.
56 EBADF aio_fildes is not a valid file descriptor open for writing.
58 EFBIG The file is a regular file, we want to write at least one byte,
60 but the starting position is at or beyond the maximum offset for
61 this file.
62 EINVAL One or more of aio_offset, aio_reqprio, aio_nbytes are invalid.
64 ENOSYS aio_write() is not implemented.
66
68 The aio_write() function is available since glibc 2.1.
69
71 For an explanation of the terms used in this section, see at‐
72 tributes(7).
73 ┌────────────────────────────────────────────┬───────────────┬─────────┐
75 │Interface │ Attribute │ Value │
76 ├────────────────────────────────────────────┼───────────────┼─────────┤
77 │aio_write() │ Thread safety │ MT-Safe │
78 └────────────────────────────────────────────┴───────────────┴─────────┘
79
81 POSIX.1-2001, POSIX.1-2008.
82
84 It is a good idea to zero out the control block before use. The con‐
85 trol block must not be changed while the write operation is in
86 progress. The buffer area being written out must not be accessed dur‐
87 ing the operation or undefined results may occur. The memory areas in‐
88 volved must remain valid.
89 Simultaneous I/O operations specifying the same aiocb structure produce
91 undefined results.
92
94 aio_cancel(3), aio_error(3), aio_fsync(3), aio_read(3), aio_return(3),
95 aio_suspend(3), lio_listio(3), aio(7)
96
98 This page is part of release 5.12 of the Linux man-pages project. A
99 description of the project, information about reporting bugs, and the
100 latest version of this page, can be found at
101 https://www.kernel.org/doc/man-pages/.
102 2021-03-22 AIO_WRITE(3)