aio_write(3)

1AIO_WRITE(3)               Linux Programmer's Manual              AIO_WRITE(3)
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NAME

6       aio_write - asynchronous write
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SYNOPSIS

9       #include <aio.h>
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11       int aio_write(struct aiocb *aiocbp);
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13       Link with -lrt.
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DESCRIPTION

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
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20           write(fd, buf, count)
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22       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.)
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26       If  O_APPEND  is  not set, the data is written starting at the absolute
27       file offset aiocbp->aio_offset, regardless of the current file  offset.
28       If  O_APPEND is set, data is written at the end of the file in the same
29       order as aio_write() calls are made.  After the call, the value of  the
30       current file offset is unspecified.
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32       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.
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39       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.
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43       The field aiocbp->aio_lio_opcode is ignored.
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45       No data is written to a regular file beyond its maximum offset.
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RETURN VALUE

48       On success, 0 is returned.  On error the request is not enqueued, -1 is
49       returned, and errno is set appropriately.  If an error is detected only
50       later, it will be reported via aio_return(3) (returns  status  -1)  and
51       aio_error(3)  (error  status—whatever  one  would have gotten in errno,
52       such as EBADF).
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ERRORS

55       EAGAIN Out of resources.
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57       EBADF  aio_fildes is not a valid file descriptor open for writing.
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59       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.
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63       EINVAL One or more of aio_offset, aio_reqprio, aio_nbytes are invalid.
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65       ENOSYS aio_write() is not implemented.
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VERSIONS

68       The aio_write() function is available since glibc 2.1.
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CONFORMING TO

71       POSIX.1-2001, POSIX.1-2008.
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NOTES

74       It is a good idea to zero out the control block before use.   The  con‐
75       trol  block  must  not  be  changed  while  the  write  operation is in
76       progress.  The buffer area being written out must not be accessed  dur‐
77       ing  the  operation  or  undefined results may occur.  The memory areas
78       involved must remain valid.
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80       Simultaneous I/O operations specifying the same aiocb structure produce
81       undefined results.
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COLOPHON

88       This page is part of release 3.53 of the Linux  man-pages  project.   A
89       description  of  the project, and information about reporting bugs, can
90       be found at http://www.kernel.org/doc/man-pages/.
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94                                  2012-05-08                      AIO_WRITE(3)