debian man page for io_getevents

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

NAME
       io_getevents - read asynchronous I/O events from the completion queue

SYNOPSIS
       #include <linux/aio_abi.h>	  /* Defines needed types */
       #include <linux/time.h>		  /* Defines 'struct timespec' */

       int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
			struct io_event *events, struct timespec *timeout);

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

DESCRIPTION
       The  io_getevents()  system  call  attempts to read at least min_nr events and up to nr events from the completion queue of the AIO context
       specified by ctx_id.  The timeout argument specifies the amount of time to wait for events, where a  NULL  timeout  waits  until  at  least
       min_nr events have been seen.  Note that timeout is relative and will be updated if not NULL and the operation blocks.

RETURN VALUE
       On success, io_getevents() returns the number of events read: 0 if no events are available, or less than min_nr if the timeout has elapsed.
       For the failure return, see NOTES.

ERRORS
       EFAULT Either events or timeout is an invalid pointer.

       EINVAL ctx_id is invalid.  min_nr is out of range or nr is out of range.

       EINTR  Interrupted by a signal handler; see signal(7).

       ENOSYS io_getevents() is not implemented on this architecture.

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

CONFORMING TO
       io_getevents() 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.	You could invoke it using syscall(2).  But instead, you probably  want	to
       use the io_getevents() wrapper function provided by libaio.

       Note that the libaio wrapper function uses a different type (io_context_t) for the ctx_id 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.

SEE ALSO
       io_cancel(2), io_destroy(2), io_setup(2), io_submit(2), aio(7), time(7)

COLOPHON
       This page is part of release 3.44 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								    2012-07-13							   IO_GETEVENTS(2)