Re: [Minios-devel] [UNIKRAFT PATCH] lib/nolibc: Fix remaining time in nanosleep

[Florian Schmidt <Florian.Schmidt@xxxxxxxxx>]

Hi Dafna, a few more remarks:

On 08/27/2018 08:42 AM, Dafna Hirschfeld wrote:
> Calculate the remaining time to sleep and update
> the rem parameter if it is given.
> If the remaining time is larger than 0, it means that
> the thread was waken up explicitly and nanosleep returns -1
> to indicate that. Otherwise nanosleep returns 0
>
> Signed-off-by: Dafna Hirschfeld <dafna3@xxxxxxxxx>
> ---
>   lib/nolibc/time.c | 14 +++++++++++---
>   1 file changed, 11 insertions(+), 3 deletions(-)
>
> diff --git a/lib/nolibc/time.c b/lib/nolibc/time.c
> index 1c058ae..0787559 100644
> --- a/lib/nolibc/time.c
> +++ b/lib/nolibc/time.c
> @@ -59,9 +59,11 @@ static void __spin_wait(__nsec nsec)
>   
>   int nanosleep(const struct timespec *req, struct timespec *rem)
>   {
> +       __nsec before, after;
>         __nsec nsec = (__nsec) req->tv_sec * 1000000000L;
>   
>   	nsec += req->tv_nsec;
> +       before = (__nsec) ukplat_monotonic_clock();
ukplat_monotonic_clock() already returns __nsec, right? So you don't 
need this cast.
>   
>   #if CONFIG_HAVE_SCHED
>         uk_sched_thread_sleep(nsec);
> @@ -69,9 +71,15 @@ int nanosleep(const struct timespec *req, struct timespec 
> *rem)
>         __spin_wait(nsec);
>   #endif
>   
> -	if (rem) {
> -               rem->tv_sec = 0;
> -               rem->tv_nsec = 0;
> +       after = (__nsec) ukplat_monotonic_clock();
Same as above

> +       __nsec diff = after-before;
I would declare diff at the top with the others. Also, there should be 
spaces around the minus sign.
> +
> +       if (diff < nsec) {
> +               if (rem) {
> +                       rem->tv_sec = ukarch_time_nsec_to_sec(nsec-diff);
> +                       rem->tv_nsec = ukarch_time_subsec(nsec-diff);
Same as above with regards to the spacing.

> +               }
> +               return -1;
>         }
>         return 0;
>   }
--
Dr. Florian Schmidt
フローリアン・シュミット
Research Scientist,
Systems and Machine Learning Group
NEC Laboratories Europe
Kurfürsten-Anlage 36, D-69115 Heidelberg
Tel.     +49 (0)6221 4342-265
Fax:     +49 (0)6221 4342-155
e-mail:  florian.schmidt@xxxxxxxxx
============================================================
Registered at Amtsgericht Mannheim, Germany, HRB728558

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