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>    /* 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         top

       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.

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

       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 5.13 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                          2021-03-22                   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)