Re: [PATCH v2] eal/windows: resolve conversion and truncation warnings

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Mar 07, 2024 at 10:34:42AM -0800, Tyler Retzlaff wrote:
> * Initialize const int NS_PER_SEC with an integer literal instead of
>   double thereby avoiding implicit conversion from double to int.
> 
> * Cast the result of the expression assigned to timespec.tv_nsec to long.
> 
> Signed-off-by: Tyler Retzlaff <roretzla@linux.microsoft.com>
> Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>
> ---
> 
> v2:
>   * update commit message to correct misspelled timspec -> timespec,
>     remove remarks about casting to long they were unnecessary.
> 
>  lib/eal/windows/include/rte_os_shim.h | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/lib/eal/windows/include/rte_os_shim.h b/lib/eal/windows/include/rte_os_shim.h
> index eda8113..19b12e9 100644
> --- a/lib/eal/windows/include/rte_os_shim.h
> +++ b/lib/eal/windows/include/rte_os_shim.h
> @@ -87,7 +87,7 @@
>  static inline int
>  rte_clock_gettime(clockid_t clock_id, struct timespec *tp)
>  {
> -	const int NS_PER_SEC = 1E9;
> +	const int NS_PER_SEC = 1000000000;

Just for readability, and the immediate visibility of errors, could this be
rewritten as (1000 * 1000 * 1000). That avoids us having to count the zeros
to know that the number is correct.

BTW: is "int" still the best type to use for this value? Would it be better
as a #define?

/Bruce

>  	LARGE_INTEGER pf, pc;
>  	LONGLONG nsec;
>  
> @@ -102,7 +102,7 @@
>  
>  		nsec = pc.QuadPart * NS_PER_SEC / pf.QuadPart;
>  		tp->tv_sec = nsec / NS_PER_SEC;
> -		tp->tv_nsec = nsec - tp->tv_sec * NS_PER_SEC;
> +		tp->tv_nsec = (long)(nsec - tp->tv_sec * NS_PER_SEC);
>  		return 0;
>  	default:
>  		return -1;
> -- 
> 1.8.3.1
>