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Diffstat (limited to 'src/benchmark_runner.cc')
| -rw-r--r-- | src/benchmark_runner.cc | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/src/benchmark_runner.cc b/src/benchmark_runner.cc new file mode 100644 index 0000000..38faeec --- /dev/null +++ b/src/benchmark_runner.cc @@ -0,0 +1,350 @@ +// Copyright 2015 Google Inc. All rights reserved. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +#include "benchmark_runner.h" +#include "benchmark/benchmark.h" +#include "benchmark_api_internal.h" +#include "internal_macros.h" + +#ifndef BENCHMARK_OS_WINDOWS +#ifndef BENCHMARK_OS_FUCHSIA +#include <sys/resource.h> +#endif +#include <sys/time.h> +#include <unistd.h> +#endif + +#include <algorithm> +#include <atomic> +#include <condition_variable> +#include <cstdio> +#include <cstdlib> +#include <fstream> +#include <iostream> +#include <memory> +#include <string> +#include <thread> +#include <utility> + +#include "check.h" +#include "colorprint.h" +#include "commandlineflags.h" +#include "complexity.h" +#include "counter.h" +#include "internal_macros.h" +#include "log.h" +#include "mutex.h" +#include "re.h" +#include "statistics.h" +#include "string_util.h" +#include "thread_manager.h" +#include "thread_timer.h" + +namespace benchmark { + +namespace internal { + +MemoryManager* memory_manager = nullptr; + +namespace { + +static const size_t kMaxIterations = 1000000000; + +BenchmarkReporter::Run CreateRunReport( + const benchmark::internal::BenchmarkInstance& b, + const internal::ThreadManager::Result& results, size_t memory_iterations, + const MemoryManager::Result& memory_result, double seconds) { + // Create report about this benchmark run. + BenchmarkReporter::Run report; + + report.run_name = b.name; + report.error_occurred = results.has_error_; + report.error_message = results.error_message_; + report.report_label = results.report_label_; + // This is the total iterations across all threads. + report.iterations = results.iterations; + report.time_unit = b.time_unit; + + if (!report.error_occurred) { + if (b.use_manual_time) { + report.real_accumulated_time = results.manual_time_used; + } else { + report.real_accumulated_time = results.real_time_used; + } + report.cpu_accumulated_time = results.cpu_time_used; + report.complexity_n = results.complexity_n; + report.complexity = b.complexity; + report.complexity_lambda = b.complexity_lambda; + report.statistics = b.statistics; + report.counters = results.counters; + + if (memory_iterations > 0) { + report.has_memory_result = true; + report.allocs_per_iter = + memory_iterations ? static_cast<double>(memory_result.num_allocs) / + memory_iterations + : 0; + report.max_bytes_used = memory_result.max_bytes_used; + } + + internal::Finish(&report.counters, results.iterations, seconds, b.threads); + } + return report; +} + +// Execute one thread of benchmark b for the specified number of iterations. +// Adds the stats collected for the thread into *total. +void RunInThread(const BenchmarkInstance* b, size_t iters, int thread_id, + ThreadManager* manager) { + internal::ThreadTimer timer; + State st = b->Run(iters, thread_id, &timer, manager); + CHECK(st.iterations() >= st.max_iterations) + << "Benchmark returned before State::KeepRunning() returned false!"; + { + MutexLock l(manager->GetBenchmarkMutex()); + internal::ThreadManager::Result& results = manager->results; + results.iterations += st.iterations(); + results.cpu_time_used += timer.cpu_time_used(); + results.real_time_used += timer.real_time_used(); + results.manual_time_used += timer.manual_time_used(); + results.complexity_n += st.complexity_length_n(); + internal::Increment(&results.counters, st.counters); + } + manager->NotifyThreadComplete(); +} + +class BenchmarkRunner { + public: + BenchmarkRunner(const benchmark::internal::BenchmarkInstance& b_, + std::vector<BenchmarkReporter::Run>* complexity_reports_) + : b(b_), + complexity_reports(*complexity_reports_), + min_time(!IsZero(b.min_time) ? b.min_time : FLAGS_benchmark_min_time), + repeats(b.repetitions != 0 ? b.repetitions + : FLAGS_benchmark_repetitions), + has_explicit_iteration_count(b.iterations != 0), + pool(b.threads - 1), + iters(has_explicit_iteration_count ? b.iterations : 1) { + run_results.display_report_aggregates_only = + (FLAGS_benchmark_report_aggregates_only || + FLAGS_benchmark_display_aggregates_only); + run_results.file_report_aggregates_only = + FLAGS_benchmark_report_aggregates_only; + if (b.aggregation_report_mode != internal::ARM_Unspecified) { + run_results.display_report_aggregates_only = + (b.aggregation_report_mode & + internal::ARM_DisplayReportAggregatesOnly); + run_results.file_report_aggregates_only = + (b.aggregation_report_mode & internal::ARM_FileReportAggregatesOnly); + } + + for (int repetition_num = 0; repetition_num < repeats; repetition_num++) { + const bool is_the_first_repetition = repetition_num == 0; + DoOneRepetition(is_the_first_repetition); + } + + // Calculate additional statistics + run_results.aggregates_only = ComputeStats(run_results.non_aggregates); + + // Maybe calculate complexity report + if ((b.complexity != oNone) && b.last_benchmark_instance) { + auto additional_run_stats = ComputeBigO(complexity_reports); + run_results.aggregates_only.insert(run_results.aggregates_only.end(), + additional_run_stats.begin(), + additional_run_stats.end()); + complexity_reports.clear(); + } + } + + RunResults&& get_results() { return std::move(run_results); } + + private: + RunResults run_results; + + const benchmark::internal::BenchmarkInstance& b; + std::vector<BenchmarkReporter::Run>& complexity_reports; + + const double min_time; + const int repeats; + const bool has_explicit_iteration_count; + + std::vector<std::thread> pool; + + size_t iters; // preserved between repetitions! + // So only the first repetition has to find/calculate it, + // the other repetitions will just use that precomputed iteration count. + + struct IterationResults { + internal::ThreadManager::Result results; + size_t iters; + double seconds; + }; + IterationResults DoNIterations() { + VLOG(2) << "Running " << b.name << " for " << iters << "\n"; + + std::unique_ptr<internal::ThreadManager> manager; + manager.reset(new internal::ThreadManager(b.threads)); + + // Run all but one thread in separate threads + for (std::size_t ti = 0; ti < pool.size(); ++ti) { + pool[ti] = std::thread(&RunInThread, &b, iters, static_cast<int>(ti + 1), + manager.get()); + } + // And run one thread here directly. + // (If we were asked to run just one thread, we don't create new threads.) + // Yes, we need to do this here *after* we start the separate threads. + RunInThread(&b, iters, 0, manager.get()); + + // The main thread has finished. Now let's wait for the other threads. + manager->WaitForAllThreads(); + for (std::thread& thread : pool) thread.join(); + + IterationResults i; + // Acquire the measurements/counters from the manager, UNDER THE LOCK! + { + MutexLock l(manager->GetBenchmarkMutex()); + i.results = manager->results; + } + + // And get rid of the manager. + manager.reset(); + + // Adjust real/manual time stats since they were reported per thread. + i.results.real_time_used /= b.threads; + i.results.manual_time_used /= b.threads; + + VLOG(2) << "Ran in " << i.results.cpu_time_used << "/" + << i.results.real_time_used << "\n"; + + // So for how long were we running? + i.iters = iters; + // Base decisions off of real time if requested by this benchmark. + i.seconds = i.results.cpu_time_used; + if (b.use_manual_time) { + i.seconds = i.results.manual_time_used; + } else if (b.use_real_time) { + i.seconds = i.results.real_time_used; + } + + return i; + } + + size_t PredictNumItersNeeded(const IterationResults& i) const { + // See how much iterations should be increased by. + // Note: Avoid division by zero with max(seconds, 1ns). + double multiplier = min_time * 1.4 / std::max(i.seconds, 1e-9); + // If our last run was at least 10% of FLAGS_benchmark_min_time then we + // use the multiplier directly. + // Otherwise we use at most 10 times expansion. + // NOTE: When the last run was at least 10% of the min time the max + // expansion should be 14x. + bool is_significant = (i.seconds / min_time) > 0.1; + multiplier = is_significant ? multiplier : std::min(10.0, multiplier); + if (multiplier <= 1.0) multiplier = 2.0; + + // So what seems to be the sufficiently-large iteration count? Round up. + const size_t max_next_iters = + 0.5 + std::max(multiplier * i.iters, i.iters + 1.0); + // But we do have *some* sanity limits though.. + const size_t next_iters = std::min(max_next_iters, kMaxIterations); + + VLOG(3) << "Next iters: " << next_iters << ", " << multiplier << "\n"; + return next_iters; // round up before conversion to integer. + } + + bool ShouldReportIterationResults(const IterationResults& i) const { + // Determine if this run should be reported; + // Either it has run for a sufficient amount of time + // or because an error was reported. + return i.results.has_error_ || + i.iters >= kMaxIterations || // Too many iterations already. + i.seconds >= min_time || // The elapsed time is large enough. + // CPU time is specified but the elapsed real time greatly exceeds + // the minimum time. + // Note that user provided timers are except from this sanity check. + ((i.results.real_time_used >= 5 * min_time) && !b.use_manual_time); + } + + void DoOneRepetition(bool is_the_first_repetition) { + IterationResults i; + + // We *may* be gradually increasing the length (iteration count) + // of the benchmark until we decide the results are significant. + // And once we do, we report those last results and exit. + // Please do note that the if there are repetitions, the iteration count + // is *only* calculated for the *first* repetition, and other repetitions + // simply use that precomputed iteration count. + for (;;) { + i = DoNIterations(); + + // Do we consider the results to be significant? + // If we are doing repetitions, and the first repetition was already done, + // it has calculated the correct iteration time, so we have run that very + // iteration count just now. No need to calculate anything. Just report. + // Else, the normal rules apply. + const bool results_are_significant = !is_the_first_repetition || + has_explicit_iteration_count || + ShouldReportIterationResults(i); + + if (results_are_significant) break; // Good, let's report them! + + // Nope, bad iteration. Let's re-estimate the hopefully-sufficient + // iteration count, and run the benchmark again... + + iters = PredictNumItersNeeded(i); + assert(iters > i.iters && + "if we did more iterations than we want to do the next time, " + "then we should have accepted the current iteration run."); + } + + // Oh, one last thing, we need to also produce the 'memory measurements'.. + MemoryManager::Result memory_result; + size_t memory_iterations = 0; + if (memory_manager != nullptr) { + // Only run a few iterations to reduce the impact of one-time + // allocations in benchmarks that are not properly managed. + memory_iterations = std::min<size_t>(16, iters); + memory_manager->Start(); + std::unique_ptr<internal::ThreadManager> manager; + manager.reset(new internal::ThreadManager(1)); + RunInThread(&b, memory_iterations, 0, manager.get()); + manager->WaitForAllThreads(); + manager.reset(); + + memory_manager->Stop(&memory_result); + } + + // Ok, now actualy report. + BenchmarkReporter::Run report = CreateRunReport( + b, i.results, memory_iterations, memory_result, i.seconds); + + if (!report.error_occurred && b.complexity != oNone) + complexity_reports.push_back(report); + + run_results.non_aggregates.push_back(report); + } +}; + +} // end namespace + +RunResults RunBenchmark( + const benchmark::internal::BenchmarkInstance& b, + std::vector<BenchmarkReporter::Run>* complexity_reports) { + internal::BenchmarkRunner r(b, complexity_reports); + return r.get_results(); +} + +} // end namespace internal + +} // end namespace benchmark |