bench: prefer a steady clock if the resolution is no worse

This commit is contained in:
Cory Fields 2017-10-25 17:54:05 -04:00
parent c515d266ec
commit 24a0bddf4a

View file

@ -37,8 +37,15 @@ BENCHMARK(CODE_TO_TIME);
*/ */
namespace benchmark { namespace benchmark {
// On many systems, the high_resolution_clock offers no better resolution than the steady_clock.
using clock = std::chrono::high_resolution_clock; // If that's the case, prefer the steady_clock.
struct best_clock {
using hi_res_clock = std::chrono::high_resolution_clock;
using steady_clock = std::chrono::steady_clock;
static constexpr bool steady_is_high_res = std::ratio_less_equal<steady_clock::period, hi_res_clock::period>::value;
using type = std::conditional<steady_is_high_res, steady_clock, hi_res_clock>::type;
};
using clock = best_clock::type;
using time_point = clock::time_point; using time_point = clock::time_point;
using duration = clock::duration; using duration = clock::duration;