aio_suspend(3)

1aio_suspend(3)             Library Functions Manual             aio_suspend(3)
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NAME

6       aio_suspend - wait for asynchronous I/O operation or timeout
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LIBRARY

9       Real-time library (librt, -lrt)
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SYNOPSIS

12       #include <aio.h>
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14       int aio_suspend(const struct aiocb *const aiocb_list[], int nitems,
15                       const struct timespec *restrict timeout);
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DESCRIPTION

18       The aio_suspend() function suspends the calling thread until one of the
19       following occurs:
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21       •  One or more of the asynchronous I/O requests in the list  aiocb_list
22          has completed.
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24       •  A signal is delivered.
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26       •  timeout  is  not  NULL  and  the specified time interval has passed.
27          (For details of the timespec structure, see nanosleep(2).)
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29       The nitems argument specifies the number of items in aiocb_list.   Each
30       item in the list pointed to by aiocb_list must be either NULL (and then
31       is ignored), or a pointer to a control block on which I/O was initiated
32       using  aio_read(3),  aio_write(3), or lio_listio(3).  (See aio(7) for a
33       description of the aiocb structure.)
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35       If CLOCK_MONOTONIC is supported, this clock  is  used  to  measure  the
36       timeout interval (see clock_gettime(2)).
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RETURN VALUE

39       If  this  function  returns after completion of one of the I/O requests
40       specified in aiocb_list, 0 is returned.  Otherwise, -1 is returned, and
41       errno is set to indicate the error.
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ERRORS

44       EAGAIN The  call  timed  out before any of the indicated operations had
45              completed.
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47       EINTR  The call was ended by signal (possibly the completion signal  of
48              one of the operations we were waiting for); see signal(7).
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50       ENOSYS aio_suspend() is not implemented.
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ATTRIBUTES

53       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
54       tributes(7).
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56       ┌────────────────────────────────────────────┬───────────────┬─────────┐
57       │Interface                                   │ Attribute     │ Value   │
58       ├────────────────────────────────────────────┼───────────────┼─────────┤
59       │aio_suspend()                               │ Thread safety │ MT-Safe │
60       └────────────────────────────────────────────┴───────────────┴─────────┘
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STANDARDS

63       POSIX.1-2008.
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HISTORY

66       glibc 2.1.  POSIX.1-2001.
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68       POSIX doesn't specify the parameters to be restrict; that  is  specific
69       to glibc.
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NOTES

72       One  can  achieve  polling by using a non-NULL timeout that specifies a
73       zero time interval.
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75       If one  or  more  of  the  asynchronous  I/O  operations  specified  in
76       aiocb_list  has  already  completed at the time of the call to aio_sus‐
77       pend(), then the call returns immediately.
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79       To determine which I/O operations have completed after a successful re‐
80       turn  from  aio_suspend(),  use  aio_error(3) to scan the list of aiocb
81       structures pointed to by aiocb_list.
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BUGS

84       The glibc implementation of aio_suspend() is not async-signal-safe,  in
85       violation of the requirements of POSIX.1.
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