io_setup - create an asynchronous I/O context
#include <linux/aio_abi.h> /* Defines needed types */
int io_setup(unsigned nr_events, aio_context_t *ctx_idp);
: There is no glibc wrapper for this system call; see NOTES.
() 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,
is filled in with the resulting handle.
On success, io_setup
() returns 0. For the failure return, see NOTES.
- The specified nr_events exceeds the user's limit of
available events, as defined in /proc/sys/fs/aio-max-nr.
- An invalid pointer is passed for ctx_idp.
- 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
The asynchronous I/O system calls first appeared in Linux 2.5.
() is Linux-specific and should not be used in programs that are
intended to be portable.
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
() wrapper function provided by libaio
Note that the libaio
wrapper function uses a different type
) for the ctx_idp
argument. Note also that
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
(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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