Provided by: manpages-dev_4.04-2_all bug


       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);

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


       EAGAIN The  specified  nr_events  exceeds the user's limit of available
              events, as defined in /proc/sys/fs/aio-max-nr.

       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.


       The asynchronous I/O system calls first appeared in Linux 2.5.


       io_setup()  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 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.


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


       This  page  is  part of release 4.04 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