aio_waitn(3c)

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

6       aio_waitn - wait for completion of asynchronous I/O operations
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SYNOPSIS

9       #include <aio.h>
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11       int aio_waitn(struct aiocb *list[], uint_t nent,
12            uint_t *nwait, const struct timespec *timeout);
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DESCRIPTION

16       The aio_waitn() function suspends the calling thread until at least the
17       number of requests specified by nwait have completed,  until  a  signal
18       interrupts  the  function,  or  if  timeout is not NULL, until the time
19       interval specified by timeout has passed.
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22       To effect a poll, the timeout argument should be non-zero, pointing  to
23       a zero-valued timespec structure.
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26       The  list  argument  is  an array of uninitialized I/O completion block
27       pointers to be filled in by the system before aio_waitn() returns.  The
28       nent  argument  indicates  the  maximum  number of elements that can be
29       placed in list[] and is limited to _AIO_LISTIO_MAX = 4096.
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32       The nwait argument points to the minimum number of requests aio_waitn()
33       should  wait  for.  Upon  returning, the content of nwait is set to the
34       actual number of requests in the aiocb list, which can be greater  than
35       the initial value specified in nwait. The aio_waitn() function attempts
36       to return as many requests as possible, up to the number of outstanding
37       asynchronous  I/Os  but  less than or equal to the maximum specified by
38       the nent argument. As soon as the number  of  outstanding  asynchronous
39       I/O  requests  becomes  0, aio_waitn() returns with the current list of
40       completed requests.
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43       The aiocb structures returned will have  been  used  in  initiating  an
44       asynchronous   I/O   request  from  any  thread  in  the  process  with
45       aio_read(3C), aio_write(3C), or lio_listio(3C).
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48       If the time interval expires before the expected number of  I/O  opera‐
49       tions  specified by nwait are completed, aio_waitn() returns the number
50       of completed requests and the content of the nwait pointer  is  updated
51       with that number.
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54       If  aio_waitn()  is interrupted by a signal, nwait is set to the number
55       of completed requests.
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58       The application can determine the status of the completed  asynchronous
59       I/O   by   checking  the  associated  error  and  return  status  using
60       aio_error(3C) and aio_return(3C), respectively.
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RETURN VALUES

63       Upon  successful  completion,  aio_waitn()  returns  0.  Otherwise,  it
64       returns -1 and sets errno to indicate the error.
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ERRORS

67       The aio_waitn() function will fail if:
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69       EAGAIN    There are no outstanding asynchronous I/O requests.
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72       EFAULT    The  list[],  nwait, or timeout argument points to an address
73                 outside the address space of the process. The errno  variable
74                 is  set  to  EFAULT only if this condition is detected by the
75                 application process.
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78       EINTR     The execution of aio_waitn() was interrupted by a signal.
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81       EINVAL    The timeout element tv_sec or tv_nsec is < 0, nent is set  to
82                 0  or  > _AIO_LISTIO_MAX, or nwait is either set to 0 or is >
83                 nent.
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86       ENOMEM    There is currently not enough available memory. The  applica‐
87                 tion can try again later.
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90       ETIME     The  time  interval expired before nwait outstanding requests
91                 have completed.
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USAGE

95       The aio_waitn() function has a transitional interface for  64-bit  file
96       offsets.  See lf64(5).
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ATTRIBUTES

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