man3/aio_suspend.3

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  25 .TH AIO_SUSPEND 3 2017-09-15  "" "Linux Programmer's Manual"
  26 .SH NAME
  27 aio_suspend \- wait for asynchronous I/O operation or timeout
  28 .SH SYNOPSIS
  29 .nf
  30 .PP
  31 .B "#include <aio.h>"
  32 .PP
  33 .BI "int aio_suspend(const struct aiocb * const " aiocb_list [],
  34 .BI "                int " nitems ", const struct timespec *" timeout );
  35 .PP
  36 Link with \fI\-lrt\fP.
  37 .fi
  38 .SH DESCRIPTION
  39 The
  40 .BR aio_suspend ()
  41 function suspends the calling thread until one of the following occurs:
  42 .IP * 3
  43 One or more of the asynchronous I/O requests in the list
  44 .I aiocb_list
  45 has completed.
  46 .IP *
  47 A signal is delivered.
  48 .IP *
  49 .I timeout
  50 is not NULL and the specified time interval has passed.
  51 (For details of the
  52 .I timespec
  53 structure, see
  54 .BR nanosleep (2).)
  55 .PP
  56 The
  57 .I nitems
  58 argument specifies the number of items in
  59 .IR aiocb_list .
  60 Each item in the list pointed to by
  61 .I aiocb_list
  62 must be either NULL (and then is ignored),
  63 or a pointer to a control block on which I/O was initiated using
  64 .BR aio_read (3),
  65 .BR aio_write (3),
  66 or
  67 .BR lio_listio (3).
  68 (See
  69 .BR aio (7)
  70 for a description of the
  71 .I aiocb
  72 structure.)
  73 .PP
  74 If
  75 .B CLOCK_MONOTONIC
  76 is supported, this clock is used to measure
  77 the timeout interval (see
  78 .BR clock_gettime (3)).
  79 .SH RETURN VALUE
  80 If this function returns after completion of one of the I/O
  81 requests specified in
  82 .IR aiocb_list ,
  83 0 is returned.
  84 Otherwise, \-1 is returned, and
  85 .I errno
  86 is set to indicate the error.
  87 .SH ERRORS
  88 .TP
  89 .B EAGAIN
  90 The call timed out before any of the indicated operations
  91 had completed.
  92 .TP
  93 .B EINTR
  94 The call was ended by signal
  95 (possibly the completion signal of one of the operations we were
  96 waiting for); see
  97 .BR signal (7).
  98 .TP
  99 .B ENOSYS
 100 .BR aio_suspend ()
 101 is not implemented.
 102 .SH VERSIONS
 103 The
 104 .BR aio_suspend ()
 105 function is available since glibc 2.1.
 106 .SH ATTRIBUTES
 107 For an explanation of the terms used in this section, see
 108 .BR attributes (7).
 109 .TS
 110 allbox;
 111 lb lb lb
 112 l l l.
 113 Interface       Attribute       Value
 114 T{
 115 .BR aio_suspend ()
 116 T}      Thread safety   MT-Safe
 117 .TE
 118 .SH CONFORMING TO
 119 POSIX.1-2001, POSIX.1-2008.
 120 .SH NOTES
 121 One can achieve polling by using a non-NULL
 122 .I timeout
 123 that specifies a zero time interval.
 124 .PP
 125 If one or more of the asynchronous I/O operations specified in
 126 .IR aiocb_list
 127 has already completed at the time of the call to
 128 .BR aio_suspend (),
 129 then the call returns immediately.
 130 .PP
 131 To determine which I/O operations have completed
 132 after a successful return from
 133 .BR aio_suspend (),
 134 use
 135 .BR aio_error (3)
 136 to scan the list of
 137 .I aiocb
 138 structures pointed to by
 139 .IR aiocb_list .
 140 .SH BUGS
 141 The glibc implementation of
 142 .BR aio_suspend ()
 143 is not async-signal-safe,
 144 .\" FIXME . https://sourceware.org/bugzilla/show_bug.cgi?id=13172
 145 in violation of the requirements of POSIX.1.
 146 .SH SEE ALSO
 147 .BR aio_cancel (3),
 148 .BR aio_error (3),
 149 .BR aio_fsync (3),
 150 .BR aio_read (3),
 151 .BR aio_return (3),
 152 .BR aio_write (3),
 153 .BR lio_listio (3),
 154 .BR aio (7),
 155 .BR time (7)