// 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