benchmark/detail/catch_run_for_at_least.hpp

0001
0002 //              Copyright Catch2 Authors
0003 // Distributed under the Boost Software License, Version 1.0.
0004 //   (See accompanying file LICENSE.txt or copy at
0005 //        https://www.boost.org/LICENSE_1_0.txt)
0006
0007 // SPDX-License-Identifier: BSL-1.0
0008 // Adapted from donated nonius code.
0009
0010 #ifndef CATCH_RUN_FOR_AT_LEAST_HPP_INCLUDED
0011 #define CATCH_RUN_FOR_AT_LEAST_HPP_INCLUDED
0012
0013 #include <catch2/benchmark/catch_clock.hpp>
0014 #include <catch2/benchmark/catch_chronometer.hpp>
0015 #include <catch2/benchmark/detail/catch_measure.hpp>
0016 #include <catch2/benchmark/detail/catch_complete_invoke.hpp>
0017 #include <catch2/benchmark/detail/catch_timing.hpp>
0018 #include <catch2/internal/catch_meta.hpp>
0019 #include <catch2/internal/catch_move_and_forward.hpp>
0020
0021 #include <type_traits>
0022
0023 namespace Catch {
0024     namespace Benchmark {
0025         namespace Detail {
0026             template <typename Clock, typename Fun>
0027             TimingOf<Clock, Fun, int> measure_one(Fun&& fun, int iters, std::false_type) {
0028                 return Detail::measure<Clock>(fun, iters);
0029             }
0030             template <typename Clock, typename Fun>
0031             TimingOf<Clock, Fun, Chronometer> measure_one(Fun&& fun, int iters, std::true_type) {
0032                 Detail::ChronometerModel<Clock> meter;
0033                 auto&& result = Detail::complete_invoke(fun, Chronometer(meter, iters));
0034
0035                 return { meter.elapsed(), CATCH_MOVE(result), iters };
0036             }
0037
0038             template <typename Clock, typename Fun>
0039             using run_for_at_least_argument_t = std::conditional_t<is_callable<Fun(Chronometer)>::value, Chronometer, int>;
0040
0041
0042             [[noreturn]]
0043             void throw_optimized_away_error();
0044
0045             template <typename Clock, typename Fun>
0046             TimingOf<Clock, Fun, run_for_at_least_argument_t<Clock, Fun>>
0047                 run_for_at_least(ClockDuration<Clock> how_long,
0048                                  const int initial_iterations,
0049                                  Fun&& fun) {
0050                 auto iters = initial_iterations;
0051                 while (iters < (1 << 30)) {
0052                     auto&& Timing = measure_one<Clock>(fun, iters, is_callable<Fun(Chronometer)>());
0053
0054                     if (Timing.elapsed >= how_long) {
0055                         return { Timing.elapsed, CATCH_MOVE(Timing.result), iters };
0056                     }
0057                     iters *= 2;
0058                 }
0059                 throw_optimized_away_error();
0060             }
0061         } // namespace Detail
0062     } // namespace Benchmark
0063 } // namespace Catch
0064
0065 #endif // CATCH_RUN_FOR_AT_LEAST_HPP_INCLUDED