AIOCANCEL(2)               BSD System Calls Manual              AIOCANCEL(2)

NAME
     aiocancel -- cancel an outstanding asynchronous I/O operation (REALTIME)

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##include <>

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

DESCRIPTION
     The aiocancel() system call cancels the outstanding asynchronous I/O
     request for the file descriptor specified in fildes.  If iocb is speci-
     fied, 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 aiocancel() system call does not cancel asynchronous I/O requests
     for raw disk devices.  The aiocancel() system call will always return
     AIONOTCANCELED for file descriptors associated with raw disk devices.

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

     [AIOCANCELED]
                   All outstanding requests meeting the criteria specified
                   were cancelled.

     [AIONOTCANCELED]
                   Some requests were not cancelled, status for the requests
                   should be checked with aioerror(2).

     [AIOALDONE]
                   All of the requests meeting the criteria have finished.

ERORS
     An error return from aiocancel() indicates:

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

SEE ALSO
     aioerror(2), aioread(2), aioreturn(2), aiosuspend(2), aiowrite(2),
     aio(4)

STANDARDS
     The aiocancel() system call is expected to conform to the IE Std
     1003.1 (``POSIX.1'') standard.

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

AUTHORS
     This manual page was originally written by Wes Peters .
     Christopher M Sedore  updated it when
     aiocancel() was implemented for FreeBSD 4.0.

BSD                            January 19, 2000                            BSD