[PATCH v2] time: Add TIME_MONOTONIC, TIME_ACTIVE, and TIME_THREAD_ACTIVE

[Paul Eggert]

On 2025-11-24 10:29, Adhemerval Zanella wrote:
> +* The ISO C23 optimal time base TIME_MONOTONIC, TIME_ACTIVE, and
> +  TIME_THREAD_ACTIVE have been added.

I assume you meant "optional" not "optimal"?

Also, shouldn't this new feature be documented in the manual?

> +  clockid_t clockid = clock_from_timebase (base);
> +  if (clockid < 0)
> +    return 0;
> +  return __clock_gettime64 (clockid, ts) == 0 ? base : 0;

Wouldn't it be a bit faster, and even a bit future-proofier, to do this?

    return __clock_gettime64 (clockid - 1, ts) == 0 ? base : 0;

Speed can matter in clock routines....


>  int
>  __timespec_getres (struct timespec *ts, int base)
>  {
> -  int ret;
>    struct __timespec64 tp64;
>  
> -  ret = __timespec_getres64 (&tp64, base);
> +  if (__timespec_getres64 (&tp64, base) != 0 && ts != NULL)
> +    {
> +      *ts = valid_timespec64_to_timespec (tp64);
> +      return base;
> +    }
>  
> -  if (ret == TIME_UTC && ts != NULL)
> -    *ts = valid_timespec64_to_timespec (tp64);
> -
> -  return ret;
> +  return 0;

Why change from the old way of doing "return ret;"? In other words, why 
not do something like this?

   struct __timespec64 tp64;
   int ret = __timespec_getres64 (&tp64, base);
   if (ret != 0 && ts != NULL)
     *ts = valid_timespec64_to_timespec (tp64);
   return ret;

This way, the compiler doesn't need to save and restore BASE so the code 
can be a tiny bit smaller and faster.