AIO_CANCEL
Section: POSIX Programmer's Manual (3P)
Updated: 2017
Page Index
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This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
NAME
aio_cancel
--- cancel an asynchronous I/O request
SYNOPSIS
#include <aio.h>
int aio_cancel(int fildes, struct aiocb *aiocbp);
DESCRIPTION
The
aio_cancel()
function shall attempt to cancel one or more asynchronous I/O requests
currently outstanding against file descriptor
fildes.
The
aiocbp
argument points to the asynchronous I/O control block for a particular
request to be canceled. If
aiocbp
is NULL, then all outstanding cancelable asynchronous I/O requests
against
fildes
shall be canceled.
Normal asynchronous notification shall occur for asynchronous I/O
operations that are successfully canceled. If there are requests that
cannot be canceled, then the normal asynchronous completion process
shall take place for those requests when they are completed.
For requested operations that are successfully canceled, the associated
error status shall be set to
[ECANCELED]
and the return status shall be -1. For requested operations that are
not successfully canceled, the
aiocbp
shall not be modified by
aio_cancel().
If
aiocbp
is not NULL, then if
fildes
does not have the same value as the file descriptor with which the
asynchronous operation was initiated, unspecified results occur.
Which operations are cancelable is implementation-defined.
RETURN VALUE
The
aio_cancel()
function shall return the value AIO_CANCELED
if the requested operation(s) were canceled.
The value AIO_NOTCANCELED
shall be returned if at least one of the requested operation(s) cannot
be canceled because it is in progress. In this case, the state of the
other operations, if any, referenced in the call to
aio_cancel()
is not indicated by the return value of
aio_cancel().
The application may determine the state of affairs for these operations
by using
aio_error().
The value AIO_ALLDONE
is returned if all of the operations have already completed.
Otherwise, the function shall return -1 and set
errno
to indicate the error.
ERRORS
The
aio_cancel()
function shall fail if:
- EBADF
-
The
fildes
argument is not a valid file descriptor.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
None.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
aio_read(),
aio_write()
The Base Definitions volume of POSIX.1-2017,
<aio.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
Any typographical or formatting errors that appear
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