catch2/benchmark/catch_chronometer.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_CHRONOMETER_HPP_INCLUDED
0011 #define CATCH_CHRONOMETER_HPP_INCLUDED
0012
0013 #include <catch2/benchmark/catch_clock.hpp>
0014 #include <catch2/benchmark/catch_optimizer.hpp>
0015 #include <catch2/internal/catch_meta.hpp>
0016 #include <catch2/internal/catch_move_and_forward.hpp>
0017
0018 namespace Catch {
0019     namespace Benchmark {
0020         namespace Detail {
0021             struct ChronometerConcept {
0022                 virtual void start() = 0;
0023                 virtual void finish() = 0;
0024                 virtual ~ChronometerConcept(); // = default;
0025
0026                 ChronometerConcept() = default;
0027                 ChronometerConcept(ChronometerConcept const&) = default;
0028                 ChronometerConcept& operator=(ChronometerConcept const&) = default;
0029             };
0030             template <typename Clock>
0031             struct ChronometerModel final : public ChronometerConcept {
0032                 void start() override { started = Clock::now(); }
0033                 void finish() override { finished = Clock::now(); }
0034
0035                 IDuration elapsed() const {
0036                     return std::chrono::duration_cast<std::chrono::nanoseconds>(
0037                         finished - started );
0038                 }
0039
0040                 TimePoint<Clock> started;
0041                 TimePoint<Clock> finished;
0042             };
0043         } // namespace Detail
0044
0045         struct Chronometer {
0046         public:
0047             template <typename Fun>
0048             void measure(Fun&& fun) { measure(CATCH_FORWARD(fun), is_callable<Fun(int)>()); }
0049
0050             int runs() const { return repeats; }
0051
0052             Chronometer(Detail::ChronometerConcept& meter, int repeats_)
0053                 : impl(&meter)
0054                 , repeats(repeats_) {}
0055
0056         private:
0057             template <typename Fun>
0058             void measure(Fun&& fun, std::false_type) {
0059                 measure([&fun](int) { return fun(); }, std::true_type());
0060             }
0061
0062             template <typename Fun>
0063             void measure(Fun&& fun, std::true_type) {
0064                 Detail::optimizer_barrier();
0065                 impl->start();
0066                 for (int i = 0; i < repeats; ++i) invoke_deoptimized(fun, i);
0067                 impl->finish();
0068                 Detail::optimizer_barrier();
0069             }
0070
0071             Detail::ChronometerConcept* impl;
0072             int repeats;
0073         };
0074     } // namespace Benchmark
0075 } // namespace Catch
0076
0077 #endif // CATCH_CHRONOMETER_HPP_INCLUDED