Re: [PATCH] timerfd_create.2: Included return value 0

["Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>]

Hello Devi,

On 3/18/20 3:04 PM, devi R.K wrote:
> Added a return value 0 for timerfd_read which happens when there is a
> bigger backward time drift*.*
> 
> Signed-off-by: DEVI RK <devi.feb27@gmail.com>

Can you say some more please about how you verified this and/or
point me at the relevant kernel source code? At a simple attempt,
I can't replicate the behavior you describe.

Thanks,

Michael

> ---
>  man2/timerfd_create.2 | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/man2/timerfd_create.2 b/man2/timerfd_create.2
> index 066e0be..ccced98 100644
> --- a/man2/timerfd_create.2
> +++ b/man2/timerfd_create.2
> @@ -317,6 +317,10 @@ fails with the error
>  if the real-time clock undergoes a discontinuous change.
>  (This allows the reading application to discover
>  such discontinuous changes to the clock.)
> +.IP
> +A
> +.BR read (2)
> +may return 0 if the system clock undergoes a discontinuous change.
>  .TP
>  .BR poll "(2), " select "(2) (and similar)"
>  The file descriptor is readable
> 


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/