SIMPLE SOLUTIONS

IO_CANCEL - reference manual online

Cancel an outstanding asynchronous I/O operation.

Chapter
2013-04-10
IO_CANCEL(2)                        Linux Programmer's Manual                        IO_CANCEL(2)

NAME io_cancel - cancel an outstanding asynchronous I/O operation
SYNOPSIS #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.
DESCRIPTION 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 oper‐ ation 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. For the failure return, see NOTES.
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 The asynchronous I/O system calls first appeared in Linux 2.5.
CONFORMING TO io_cancel() is Linux-specific and should not be used in programs that are intended to be portable.
NOTES 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 pro‐ vided 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 conven‐ tions 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 io_destroy(2), io_getevents(2), io_setup(2), io_submit(2), aio(7)
COLOPHON This page is part of release 4.04 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 http://www.kernel.org/doc/man-pages/.
Linux 2013-04-10 IO_CANCEL(2)
This manual Reference Other manuals
io_cancel(2) referred by aio(7) | io_destroy(2) | io_getevents(2) | io_setup(2) | io_submit(2) | syscalls(2)
refer to aio(7) | io_destroy(2) | io_getevents(2) | io_setup(2) | io_submit(2) | syscall(2)