io_cancel(2) — Linux manual page


IO_CANCEL(2)              Linux Programmer's Manual             IO_CANCEL(2)

NAME         top

       io_cancel - cancel an outstanding asynchronous I/O operation

SYNOPSIS         top

       #include <linux/aio_abi.h>          /* Defines needed types */

       int io_cancel(io_context_t ctx_id, struct iocb *iocb,
                     struct io_event *result);

       Note: There is no glibc wrapper for this system call; see NOTES.

DESCRIPTION         top

       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         top

       On success, io_cancel() returns 0.  For the failure return, see

ERRORS         top

       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         top

       The asynchronous I/O system calls first appeared in Linux 2.5.

CONFORMING TO         top

       io_cancel() is Linux-specific and should not be used in programs that
       are intended to be portable.

NOTES         top

       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.

SEE ALSO         top

       io_destroy(2), io_getevents(2), io_setup(2), io_submit(2), aio(7)

COLOPHON         top

       This page is part of release 5.09 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at

Linux                            2020-06-09                     IO_CANCEL(2)

Pages that refer to this page: io_destroy(2)io_getevents(2)io_setup(2)io_submit(2)syscalls(2)aio(7)