NAME

io_cancel - cancel an outstanding asynchronous I/O operation

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#include <linux/aio_abi.h>    /* Definition of needed types */
#include <sys/syscall.h>      /* Definition of SYS_* constants */
#include <unistd.h>

int syscall(SYS_io_cancel, aio_context_t ctx_id, struct iocb *iocb,
            struct io_event *result);

DESCRIPTION

Note: you probably want to use the io_getevents(3) wrapper function provided by libaio; see VERSIONS.

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.

RETURN VALUE

On success, io_cancel() returns 0. On error, -1 is returned, and errno is set to indicate the error.

ERRORS

EAGAIN: The iocb specified was not canceled.
EFAULT: One of the data structures points to invalid data.
EINVAL: The AIO context specified by ctx_id is invalid.
ENOSYS: io_cancel() is not implemented on this architecture.

VERSIONS

libaio provides a wrapper function with the same name, but different prototype and return value. You probably want to use that wrapper.

STANDARDS

Linux.

HISTORY

Linux 2.5.