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
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
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,
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
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
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.
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