aio_cancel - cancel an outstanding asynchronous I/O request
#include <aio.h>
int aio_cancel(int fd, struct aiocb *aiocbp);
Link with
-lrt.
The
aio_cancel() function attempts to cancel outstanding asynchronous I/O
requests for the file descriptor
fd. If
aiocbp is NULL, all such
requests are canceled. Otherwise, only the request described by the control
block pointed to by
aiocbp is canceled. (See
aio(7) for a
description of the
aiocb structure.)
Normal asynchronous notification occurs for canceled requests (see
aio(7)
and
sigevent(7)). The request return status (
aio_return(3)) is
set to -1, and the request error status (
aio_error(3)) is set to
ECANCELED. The control block of requests that cannot be canceled is not
changed.
If the request could not be canceled, then it will terminate in the usual way
after performing the I/O operation. (In this case,
aio_error(3) will
return the status
EINPROGRESSS.)
If
aiocbp is not NULL, and
fd differs from the file descriptor
with which the asynchronous operation was initiated, unspecified results
occur.
Which operations are cancelable is implementation-defined.
The
aio_cancel() function returns one of the following values:
- AIO_CANCELED
- All requests were successfully canceled.
- AIO_NOTCANCELED
- At least one of the requests specified was not canceled because it was in
progress. In this case, one may check the status of individual requests
using aio_error(3).
- AIO_ALLDONE
- All requests had already been completed before the call.
- -1
- An error occurred. The cause of the error can be found by inspecting
errno.
- EBADF
- fd is not a valid file descriptor.
- ENOSYS
- aio_cancel() is not implemented.
The
aio_cancel() function is available since glibc 2.1.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| aio_cancel () |
Thread safety |
MT-Safe |
POSIX.1-2001, POSIX.1-2008.
See
aio(7).
aio_error(3),
aio_fsync(3),
aio_read(3),
aio_return(3),
aio_suspend(3),
aio_write(3),
lio_listio(3),
aio(7)