aio_fsync(3c)

1aio_fsync(3C)            Standard C Library Functions            aio_fsync(3C)
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NAME

6       aio_fsync - asynchronous file synchronization
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SYNOPSIS

9       #include <aio.h>
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11       int aio_fsync(int op, struct aiocb *aiocbp);
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DESCRIPTION

15       The aio_fsync() function asynchronously forces all I/O operations asso‐
16       ciated with the file indicated by the file descriptor aio_fildes member
17       of  the aiocb structure referenced by the aiocbp argument and queued at
18       the time of the call to aio_fsync() to the synchronized I/O  completion
19       state.  The  function call returns when the synchronization request has
20       been initiated or queued to the file or device (even when the data can‐
21       not be synchronized immediately).
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24       If  op is O_DSYNC, all currently queued I/O operations are completed as
25       if by a call to fdatasync(3C); that is, as defined for synchronized I/O
26       data  integrity  completion.  If op is O_SYNC, all currently queued I/O
27       operations are completed as if by a call  to  fsync(3C);  that  is,  as
28       defined   for  synchronized  I/O  file  integrity  completion.  If  the
29       aio_fsync() function fails, or if the operation queued  by  aio_fsync()
30       fails, then, as for fsync(3C) and fdatasync(3C), outstanding I/O opera‐
31       tions are not guaranteed to have been completed.
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34       If aio_fsync() succeeds, then it is only the I/O that was queued at the
35       time  of the call to aio_fsync() that is guaranteed to be forced to the
36       relevant completion state. The completion of subsequent I/O on the file
37       descriptor is not guaranteed to be completed in a synchronized fashion.
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40       The  aiocbp  argument  refers to an asynchronous I/O control block. The
41       aiocbp  value  may  be  used  as  an  argument  to  aio_error(3C)   and
42       aio_return(3C)  in  order to determine the error status and return sta‐
43       tus, respectively, of the asynchronous operation while it  is  proceed‐
44       ing.  When the request is queued, the error status for the operation is
45       EINPROGRESS. When all data has been successfully transferred, the error
46       status  will  be  reset to reflect the success or failure of the opera‐
47       tion. If the operation does not complete successfully, the error status
48       for  the  operation will be set to indicate the error. The aio_sigevent
49       member determines the asynchronous notification to occur when all oper‐
50       ations have achieved synchronized I/O completion (see signal.h(3HEAD)).
51       All other members of the structure referenced by aiocbp are ignored. If
52       the control block referenced by aiocbp becomes an illegal address prior
53       to asynchronous I/O completion, then the behavior is undefined.
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56       If the aio_fsync() function fails or the aiocbp indicates an error con‐
57       dition, data is not guaranteed to have been successfully transferred.
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60       If  aiocbp is NULL, then no status is returned in aiocbp, and no signal
61       is generated upon completion of the operation.
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RETURN VALUES

64       The aio_fsync() function returns 0 to the calling process  if  the  I/O
65       operation  is  successfully  queued; otherwise, the function returns −1
66       and sets errno to indicate the error.
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ERRORS

69       The aio_fsync() function will fail if:
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71       EAGAIN    The requested asynchronous operation was not  queued  due  to
72                 temporary resource limitations.
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75       EBADF     The  aio_fildes  member  of the aiocb structure referenced by
76                 the aiocbp argument is not a valid file descriptor  open  for
77                 writing.
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80       EINVAL    The system does not support synchronized I/O for this file.
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83       EINVAL    A value of op other than O_DSYNC or O_SYNC was specified.
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87       In  the  event  that any of the queued I/O operations fail, aio_fsync()
88       returns the error condition defined for read(2) and write(2). The error
89       will  be  returned  in  the error status for the asynchronous fsync(3C)
90       operation, which can be retrieved using aio_error(3C).
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USAGE

93       The aio_fsync() function has a transitional interface for  64-bit  file
94       offsets.  See lf64(5).
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ATTRIBUTES

97       See attributes(5) for descriptions of the following attributes:
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102       ┌─────────────────────────────┬─────────────────────────────┐
103       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
104       ├─────────────────────────────┼─────────────────────────────┤
105       │Interface Stability          │Committed                    │
106       ├─────────────────────────────┼─────────────────────────────┤
107       │MT-Level                     │MT-Safe                      │
108       ├─────────────────────────────┼─────────────────────────────┤
109       │Standard                     │See standards(5).            │
110       └─────────────────────────────┴─────────────────────────────┘
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