[PATCH weston v2 03/11] timespec: Add timespec_to_msec helper

[Pekka Paalanen]

On Wed,  1 Mar 2017 11:34:02 +0000
Daniel Stone <daniels at collabora.com> wrote:

> Paralleling timespec_to_nsec, converts to milliseconds.
> 
> Signed-off-by: Daniel Stone <daniels at collabora.com>
> Reviewed-by: Pekka Paalanen <pekka.paalanen at collabora.co.uk>
> ---
>  libweston/compositor.c |  2 +-
>  shared/timespec-util.h | 11 +++++++++++
>  tests/timespec-test.c  |  9 +++++++++
>  3 files changed, 21 insertions(+), 1 deletion(-)
> 
> v2: No changes.
> 
> diff --git a/libweston/compositor.c b/libweston/compositor.c
> index 813f701..a28738e 100644
> --- a/libweston/compositor.c
> +++ b/libweston/compositor.c
> @@ -2388,7 +2388,7 @@ weston_output_finish_frame(struct weston_output *output,
>  						  output->msc,
>  						  presented_flags);
>  
> -	output->frame_time = stamp->tv_sec * 1000 + stamp->tv_nsec / 1000000;
> +	output->frame_time = timespec_to_msec(stamp);
>  
>  	weston_compositor_read_presentation_clock(compositor, &now);
>  	timespec_sub(&gone, &now, stamp);
> diff --git a/shared/timespec-util.h b/shared/timespec-util.h
> index 13948b1..c8e3cd6 100644
> --- a/shared/timespec-util.h
> +++ b/shared/timespec-util.h
> @@ -93,6 +93,17 @@ timespec_to_nsec(const struct timespec *a)
>  	return (int64_t)a->tv_sec * NSEC_PER_SEC + a->tv_nsec;
>  }
>  
> +/* Convert timespec to milliseconds
> + *
> + * \param a timespec
> + * \return milliseconds

Hi,

might want to note, that this rounds to integer milliseconds towards
zero. It's not round() nor floor(), it's trunc().

Shall I just add that note when merging?


Thanks,
pq

> + */
> +static inline int64_t
> +timespec_to_msec(const struct timespec *a)
> +{
> +	return (int64_t)a->tv_sec * 1000 + a->tv_nsec / 1000000;
> +}
> +
>  /* Convert milli-Hertz to nanoseconds
>   *
>   * \param mhz frequency in mHz, not zero
> diff --git a/tests/timespec-test.c b/tests/timespec-test.c
> index cd3b1c1..712d1ac 100644
> --- a/tests/timespec-test.c
> +++ b/tests/timespec-test.c
> @@ -60,6 +60,15 @@ ZUC_TEST(timespec_test, timespec_to_nsec)
>  	ZUC_ASSERT_EQ(timespec_to_nsec(&a), (NSEC_PER_SEC * 4ULL) + 4);
>  }
>  
> +ZUC_TEST(timespec_test, timespec_to_msec)
> +{
> +	struct timespec a;
> +
> +	a.tv_sec = 4;
> +	a.tv_nsec = 4000000;
> +	ZUC_ASSERT_EQ(timespec_to_msec(&a), (4000ULL) + 4);
> +}
> +
>  ZUC_TEST(timespec_test, millihz_to_nsec)
>  {
>  	ZUC_ASSERT_EQ(millihz_to_nsec(60000), 16666666);

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