NAME
aio_cancel - cancel an outstanding asynchronous I/O operation (REALTIME)
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <aio.h>
int
aio_cancel(int fildes, struct aiocb *iocb);
DESCRIPTION
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.
RESTRICTIONS
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.
RETURN VALUES
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.
ERRORS
An error return from aio_cancel() indicates:
[EBADF] The fildes argument is an invalid file descriptor.
SEE ALSO
aio_error(2), aio_read(2), aio_return(2), aio_suspend(2), aio_write(2),
aio(4)
STANDARDS
The aio_cancel() system call is expected to conform to the IEEE Std
1003.1 (“POSIX.1”) standard.
HISTORY
The aio_cancel() system call first appeared in FreeBSD 3.0. The first
functional implementation of aio_cancel() appeared in FreeBSD 4.0.
AUTHORS
This manual page was originally written by Wes Peters 〈wes@softweyr.com〉.
Christopher M Sedore 〈cmsedore@maxwell.syr.edu〉 updated it when
aio_cancel() was implemented for FreeBSD 4.0.