suyu/src/core/perf_stats.cpp
Lioncash 4a587b81b2 core/core: Replace includes with forward declarations where applicable
The follow-up to e2457418da, which
replaces most of the includes in the core header with forward declarations.

This makes it so that if any of the headers the core header was
previously including change, then no one will need to rebuild the bulk
of the core, due to core.h being quite a prevalent inclusion.

This should make turnaround for changes much faster for developers.
2018-08-31 16:30:14 -04:00

114 lines
3.9 KiB
C++

// Copyright 2017 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <chrono>
#include <mutex>
#include <thread>
#include "common/math_util.h"
#include "core/perf_stats.h"
#include "core/settings.h"
using namespace std::chrono_literals;
using DoubleSecs = std::chrono::duration<double, std::chrono::seconds::period>;
using std::chrono::duration_cast;
using std::chrono::microseconds;
namespace Core {
void PerfStats::BeginSystemFrame() {
std::lock_guard<std::mutex> lock(object_mutex);
frame_begin = Clock::now();
}
void PerfStats::EndSystemFrame() {
std::lock_guard<std::mutex> lock(object_mutex);
auto frame_end = Clock::now();
accumulated_frametime += frame_end - frame_begin;
system_frames += 1;
previous_frame_length = frame_end - previous_frame_end;
previous_frame_end = frame_end;
}
void PerfStats::EndGameFrame() {
std::lock_guard<std::mutex> lock(object_mutex);
game_frames += 1;
}
PerfStatsResults PerfStats::GetAndResetStats(microseconds current_system_time_us) {
std::lock_guard<std::mutex> lock(object_mutex);
const auto now = Clock::now();
// Walltime elapsed since stats were reset
const auto interval = duration_cast<DoubleSecs>(now - reset_point).count();
const auto system_us_per_second = (current_system_time_us - reset_point_system_us) / interval;
PerfStatsResults results{};
results.system_fps = static_cast<double>(system_frames) / interval;
results.game_fps = static_cast<double>(game_frames) / interval;
results.frametime = duration_cast<DoubleSecs>(accumulated_frametime).count() /
static_cast<double>(system_frames);
results.emulation_speed = system_us_per_second.count() / 1'000'000.0;
// Reset counters
reset_point = now;
reset_point_system_us = current_system_time_us;
accumulated_frametime = Clock::duration::zero();
system_frames = 0;
game_frames = 0;
return results;
}
double PerfStats::GetLastFrameTimeScale() {
std::lock_guard<std::mutex> lock(object_mutex);
constexpr double FRAME_LENGTH = 1.0 / 60;
return duration_cast<DoubleSecs>(previous_frame_length).count() / FRAME_LENGTH;
}
void FrameLimiter::DoFrameLimiting(microseconds current_system_time_us) {
// Max lag caused by slow frames. Can be adjusted to compensate for too many slow frames. Higher
// values increase the time needed to recover and limit framerate again after spikes.
constexpr microseconds MAX_LAG_TIME_US = 25000us;
if (!Settings::values.use_frame_limit) {
return;
}
auto now = Clock::now();
const double sleep_scale = Settings::values.frame_limit / 100.0;
// Max lag caused by slow frames. Shouldn't be more than the length of a frame at the current
// speed percent or it will clamp too much and prevent this from properly limiting to that
// percent. High values means it'll take longer after a slow frame to recover and start
// limiting
const microseconds max_lag_time_us = duration_cast<microseconds>(
std::chrono::duration<double, std::chrono::microseconds::period>(25ms / sleep_scale));
frame_limiting_delta_err += duration_cast<microseconds>(
std::chrono::duration<double, std::chrono::microseconds::period>(
(current_system_time_us - previous_system_time_us) / sleep_scale));
frame_limiting_delta_err -= duration_cast<microseconds>(now - previous_walltime);
frame_limiting_delta_err =
std::clamp(frame_limiting_delta_err, -max_lag_time_us, max_lag_time_us);
if (frame_limiting_delta_err > microseconds::zero()) {
std::this_thread::sleep_for(frame_limiting_delta_err);
auto now_after_sleep = Clock::now();
frame_limiting_delta_err -= duration_cast<microseconds>(now_after_sleep - now);
now = now_after_sleep;
}
previous_system_time_us = current_system_time_us;
previous_walltime = now;
}
} // namespace Core