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NAME

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

SYNOPSIS

       #include <linux/time.h>
       #include <libaio.h>

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

       Link with -laio.

DESCRIPTION

       io_getevents()  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.  timeout 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, August
       2002.

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.

       The  wrapper  provided in libaio for io_getevents() 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_setup(2), io_submit(2), time(7)

COLOPHON

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