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.
aio_cancel — cancel an asynchronous I/O request
int aio_cancel(int fildes, struct aiocb *aiocbp);
() function shall attempt to cancel one or more
asynchronous I/O requests currently outstanding against file descriptor
. The aiocbp
argument points to the asynchronous I/O
control block for a particular request to be canceled. If aiocbp
NULL, then all outstanding cancelable asynchronous I/O requests against
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
shall not be modified by aio_cancel
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.
() 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
indicate the error.
() function shall fail if:
The following sections are informative.
- The fildes argument is not a valid file
The Base Definitions volume of POSIX.1‐2008, <aio.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
7, Copyright (C) 2013 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013
Technical Corrigendum 1 applied.) 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.unix.org/online.html .
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