Manual Pages  — AIO_CANCEL

aio_cancel – cancel an outstanding asynchronous I/O operation (REALTIME)

LIBRARY SYNOPSIS DESCRIPTION RESTRICTIONS RETURN VALUES ERRORS SEE ALSO STANDARDS HISTORY AUTHORS

Standard C Library (libc, -lc)

#include <aio.h>

int
aio_cancel(int fildes, struct aiocb *iocb);

The aio_cancel() system call cancels the outstanding asynchronous I/O request for the file descriptor specified in fildes. If iocb is specified, only that specific asynchronous I/O request is cancelled.

Normal asynchronous notification occurs for cancelled requests. Requests complete with an error result of ECANCELED.

The aio_cancel() system call does not cancel asynchronous I/O requests for raw disk devices. The aio_cancel() system call will always return AIO_NOTCANCELED for file descriptors associated with raw disk devices.

The aio_cancel() system call returns -1 to indicate an error, or one of the following:

[ AIO_CANCELED]
	All outstanding requests meeting the criteria specified were cancelled.
[ AIO_NOTCANCELED]
	Some requests were not cancelled, status for the requests should be checked with aio_error(2).
[ AIO_ALLDONE]
	All of the requests meeting the criteria have finished.

An error return from aio_cancel() indicates:

[EBADF]
	The fildes argument is an invalid file descriptor.

The aio_cancel() system call is expected to conform to the IEEE Std 1003.1 ("POSIX.1") standard.

The aio_cancel() system call first appeared in FreeBSD 3.0 . The first functional implementation of aio_cancel() appeared in FreeBSD 4.0 .

This manual page was originally written by Wes Peters <Mt wes@softweyr.com>. Christopher M Sedore <Mt cmsedore@maxwell.syr.edu> updated it when aio_cancel() was implemented for FreeBSD 4.0 .