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io_setup

Section: System Calls (2)
Updated: 202-0-11
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NAME

io_setup - create an asynchronous I/O context

LIBRARY

Standard C library (libc,~-lc)

SYNOPSIS

#include <linux/aio_abi.h>
#include <sys/syscall.h>    /* Definition of SYS_* constants */
#include <unistd.h>
long~syscall(SYS_io_setup, unsigned int n, aio_context_t *ctx_idp);

DESCRIPTION

Note: you probably want to use the io_setup(3) wrapper function provided by libaio; see VERSIONS. The io_setup() system call creates an asynchronous I/O context suitable for concurrently processing n 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.

RETURN VALUE

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

ERRORS

EAGAIN: The specified n exceeds the limit of available events, as defined in /proc/sys/fs/aio-max-nr (see proc_sys_fs(5)).
EFAULT: An invalid pointer is passed for ctx_idp.
EINVAL: *ctx_idp is not initialized to 0.
EINVAL: The specified n exceeds internal limits. n should be greater than 0.
ENOMEM: Insufficient kernel resources are available.
ENOSYS: io_setup() 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.