io_cancel - cancel an outstanding asynchronous I/O operation
#include <linux/aio_abi.h> /* Defines needed types */
int io_cancel(aio_context_t ctx_id, struct iocb *iocb,
struct io_event *result);
Note
: There is no glibc wrapper for this system call; see
NOTES.
Note
: this page describes the raw Linux system call
interface. The wrapper function provided by libaio
uses a
different type for the ctx_id
argument. See NOTES.
The io_cancel() system call attempts to cancel an
asynchronous I/O operation previously submitted with
io_submit(2). The iocb
argument describes the
operation to be canceled and the ctx_id
argument is the AIO
context to which the operation was submitted. If the operation is
successfully canceled, the event will be copied into the memory pointed
to by result
without being placed into the completion
queue.
On success, io_cancel() returns 0. For the failure return, see NOTES.
The iocb
specified was not canceled.
One of the data structures points to invalid data.
The AIO context specified by ctx_id
is invalid.
io_cancel() is not implemented on this architecture.
The asynchronous I/O system calls first appeared in Linux 2.5.
io_cancel() is Linux-specific and should not be used in programs that are intended to be portable.
Glibc does not provide a wrapper function for this system call. You
could invoke it using syscall(2). But instead, you
probably want to use the io_cancel() wrapper function
provided by libaio
.
Note that the libaio
wrapper function uses a different type
(io_context_t
) for the ctx_id
argument. Note also that
the libaio
wrapper does not follow the usual C library
conventions for indicating errors: on error it returns a negated error
number (the negative of one of the values listed in ERRORS). If the
system call is invoked via syscall(2), then the return
value follows the usual conventions for indicating an error: -1, with
errno
set to a (positive) value that indicates the error.
io_destroy(2), io_getevents(2), io_setup(2), io_submit(2), aio(7)
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