io_setup - create an asynchronous I/O context
#include <linux/aio_abi.h> /* Defines needed types */ long io_setup(unsigned nr_events, aio_context_t *ctx_idp);
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_idp argument. See NOTES.
The io_setup() system call creates an asynchronous I/O context suitable for concurrently processing
nr_events operations. The
ctx_idp argument must not point to an AIO context that already exists, and must be initialized to 0 prior to the call. On successful creation of the AIO context,
*ctx_idp is filled in with the resulting handle.
On success, io_setup() returns 0. For the failure return, see NOTES.
nr_events exceeds the limit of available events, as defined in
/proc/sys/fs/aio-max-nr (see proc(5)).
An invalid pointer is passed for
ctx_idp is not initialized, or the specified
nr_events exceeds internal limits.
nr_events should be greater than 0.
Insufficient kernel resources are available.
io_setup() is not implemented on this architecture.
The asynchronous I/O system calls first appeared in Linux 2.5.
Note that the
libaio wrapper function uses a different type (
io_context_t *) for the
ctx_idp 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.
This page is part of release 5.10 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 https://www.kernel.org/doc/man-pages/.