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.

Debian                                          January 19, 2000                                   AIO_CANCEL(2)