man3/aio_cancel.3

   1 .\" Copyright (c) 2003 Andries Brouwer (aeb@cwi.nl)
   2 .\"
   3 .\" SPDX-License-Identifier: GPL-2.0-or-later
   4 .\"
   5 .TH aio_cancel 3 (date) "Linux man-pages (unreleased)"
   6 .SH NAME
   7 aio_cancel \- cancel an outstanding asynchronous I/O request
   8 .SH LIBRARY
   9 Real-time library
  10 .RI ( librt ", " \-lrt )
  11 .SH SYNOPSIS
  12 .nf
  13 .B "#include <aio.h>"
  14 .PP
  15 .BI "int aio_cancel(int " fd ", struct aiocb *" aiocbp );
  16 .fi
  17 .SH DESCRIPTION
  18 The
  19 .BR aio_cancel ()
  20 function attempts to cancel outstanding asynchronous I/O requests
  21 for the file descriptor
  22 .IR fd .
  23 If
  24 .I aiocbp
  25 is NULL, all such requests are canceled.
  26 Otherwise, only the request
  27 described by the control block pointed to by
  28 .I aiocbp
  29 is canceled.
  30 (See
  31 .BR aio (7)
  32 for a description of the
  33 .I aiocb
  34 structure.)
  35 .PP
  36 Normal asynchronous notification occurs for canceled requests (see
  37 .BR aio (7)
  38 and
  39 .BR sigevent (7)).
  40 The request return status
  41 .RB ( aio_return (3))
  42 is set to \-1, and the request error status
  43 .RB ( aio_error (3))
  44 is set to
  45 .BR ECANCELED .
  46 The control block of requests that cannot be canceled is not changed.
  47 .PP
  48 If the request could not be canceled,
  49 then it will terminate in the usual way after performing the I/O operation.
  50 (In this case,
  51 .BR aio_error (3)
  52 will return the status
  53 .BR EINPROGRESSS .)
  54 .PP
  55 If
  56 .I aiocbp
  57 is not NULL, and
  58 .I fd
  59 differs from the file descriptor with which the asynchronous operation
  60 was initiated, unspecified results occur.
  61 .PP
  62 Which operations are cancelable is implementation-defined.
  63 .\" FreeBSD: not those on raw disk devices.
  64 .SH RETURN VALUE
  65 The
  66 .BR aio_cancel ()
  67 function returns one of the following values:
  68 .TP
  69 .B AIO_CANCELED
  70 All requests were successfully canceled.
  71 .TP
  72 .B AIO_NOTCANCELED
  73 At least one of the
  74 requests specified was not canceled because it was in progress.
  75 In this case, one may check the status of individual requests using
  76 .BR aio_error (3).
  77 .TP
  78 .B AIO_ALLDONE
  79 All requests had already been completed before the call.
  80 .TP
  81 \-1
  82 An error occurred.
  83 The cause of the error can be found by inspecting
  84 .IR errno .
  85 .SH ERRORS
  86 .TP
  87 .B EBADF
  88 .I fd
  89 is not a valid file descriptor.
  90 .TP
  91 .B ENOSYS
  92 .BR aio_cancel ()
  93 is not implemented.
  94 .SH VERSIONS
  95 The
  96 .BR aio_cancel ()
  97 function is available since glibc 2.1.
  98 .SH ATTRIBUTES
  99 For an explanation of the terms used in this section, see
 100 .BR attributes (7).
 101 .ad l
 102 .nh
 103 .TS
 104 allbox;
 105 lbx lb lb
 106 l l l.
 107 Interface       Attribute       Value
 108 T{
 109 .BR aio_cancel ()
 110 T}      Thread safety   MT-Safe
 111 .TE
 112 .hy
 113 .ad
 114 .sp 1
 115 .SH STANDARDS
 116 POSIX.1-2001, POSIX.1-2008.
 117 .SH EXAMPLES
 118 See
 119 .BR aio (7).
 120 .SH SEE ALSO
 121 .BR aio_error (3),
 122 .BR aio_fsync (3),
 123 .BR aio_read (3),
 124 .BR aio_return (3),
 125 .BR aio_suspend (3),
 126 .BR aio_write (3),
 127 .BR lio_listio (3),
 128 .BR aio (7)