plucky (2) io_setup.2.gz

NAME

       io_setup - create an asynchronous I/O context

LIBRARY

       Standard C library (libc, -lc)

       Alternatively, Asynchronous I/O library (libaio, -laio); see VERSIONS.

SYNOPSIS

       #include <linux/aio_abi.h>          /* Defines needed types */

       long io_setup(unsigned int nr_events, aio_context_t *ctx_idp);

       Note: There is no glibc wrapper for this system call; see VERSIONS.

DESCRIPTION

       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 VERSIONS.

       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.

RETURN VALUE

       On success, io_setup() returns 0.  For the failure return, see VERSIONS.

ERRORS

       EAGAIN The   specified   nr_events   exceeds   the   limit   of   available   events,   as   defined   in
              /proc/sys/fs/aio-max-nr (see proc(5)).

       EFAULT An invalid pointer is passed for ctx_idp.

       EINVAL ctx_idp is not initialized, or the specified nr_events exceeds internal limits.  nr_events  should
              be greater than 0.

       ENOMEM Insufficient kernel resources are available.

       ENOSYS io_setup() is not implemented on this architecture.

VERSIONS

       glibc  does  not  provide  a  wrapper  for  this system call.  You could invoke it using syscall(2).  But
       instead, you probably want to use the io_setup() wrapper function provided by libaio.

       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.

STANDARDS

       Linux.

HISTORY

       Linux 2.5.

SEE ALSO

       io_cancel(2), io_destroy(2), io_getevents(2), io_submit(2), aio(7)