linux man page for io_setup

IO_SETUP(2)						     Linux Programmer's Manual						       IO_SETUP(2)

NAME
       io_setup - create an asynchronous I/O context

SYNOPSIS
       #include <libaio.h>

       int io_setup(unsigned nr_events, aio_context_t *ctxp);

       Link with -laio.

DESCRIPTION
       io_setup() creates an asynchronous I/O context capable of receiving at least nr_events.	ctxp 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, *ctxp is filled in with  the  resulting
       handle.

RETURN VALUE
       On success, io_setup() returns 0.  For the failure return, see NOTES.

ERRORS
       EAGAIN The specified nr_events exceeds the user's limit of available events.

       EFAULT An invalid pointer is passed for ctxp.

       EINVAL ctxp 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
       The asynchronous I/O system calls first appeared in Linux 2.5, August 2002.

CONFORMING TO
       io_setup() is Linux-specific and should not be used in programs that are intended to be portable.

NOTES
       Glibc does not provide a wrapper function for this system call.

       The  wrapper  provided in libaio for io_setup() does not follow the usual C library conventions for indicating error: 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.

SEE ALSO
       io_cancel(2), io_destroy(2), io_getevents(2), io_submit(2)

COLOPHON
       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2008-06-18							       IO_SETUP(2)