AIO_CANCEL(2) System Calls Manual AIO_CANCEL(2)

aio_cancelcancel an outstanding asynchronous I/O operation (REALTIME)

Standard C Library (libc, -lc)

#include <aio.h>

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

The () system call cancels the outstanding asynchronous I/O request for the file descriptor specified in fildes. If aiocbp 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 () 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_ALLDONE]
All of the requests meeting the criteria have finished.
[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).

An error return from aio_cancel() indicates:

[]
The fildes argument is not a valid file descriptor.

aio_error(2), aio_read(2), aio_return(2), aio_suspend(2), aio_write(2), aio(4)

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 ⟨wes@softweyr.com⟩. Christopher M Sedore ⟨cmsedore@maxwell.syr.edu⟩ updated it when aio_cancel() was implemented for FreeBSD 4.0.

January 19, 2000 macOS 15.2