Merge d5114e7191 into 8ee64a84c7

Source/Core/Core/Config/MainSettings.cpp

@@ -45,6 +45,7 @@ const Info<bool> MAIN_ACCURATE_CPU_CACHE{{System::Main, "Core", "AccurateCPUCach
 const Info<bool> MAIN_DSP_HLE{{System::Main, "Core", "DSPHLE"}, true};
 const Info<int> MAIN_MAX_FALLBACK{{System::Main, "Core", "MaxFallback"}, 100};
 const Info<int> MAIN_TIMING_VARIANCE{{System::Main, "Core", "TimingVariance"}, 40};
+const Info<bool> MAIN_CORRECT_TIME_DRIFT{{System::Main, "Core", "CorrectTimeDrift"}, false};
 const Info<bool> MAIN_CPU_THREAD{{System::Main, "Core", "CPUThread"}, true};
 const Info<bool> MAIN_SYNC_ON_SKIP_IDLE{{System::Main, "Core", "SyncOnSkipIdle"}, true};
 const Info<std::string> MAIN_DEFAULT_ISO{{System::Main, "Core", "DefaultISO"}, ""};

Source/Core/Core/Config/MainSettings.h

@@ -63,6 +63,7 @@ extern const Info<bool> MAIN_ACCURATE_CPU_CACHE;
 extern const Info<bool> MAIN_DSP_HLE;
 extern const Info<int> MAIN_MAX_FALLBACK;
 extern const Info<int> MAIN_TIMING_VARIANCE;
+extern const Info<bool> MAIN_CORRECT_TIME_DRIFT;
 extern const Info<bool> MAIN_CPU_THREAD;
 extern const Info<bool> MAIN_SYNC_ON_SKIP_IDLE;
 extern const Info<std::string> MAIN_DEFAULT_ISO;

Source/Core/Core/CoreTiming.cpp

@@ -81,12 +81,6 @@ void CoreTimingManager::UnregisterAllEvents()
 
 void CoreTimingManager::Init()
 {
-  m_registered_config_callback_id =
-      CPUThreadConfigCallback::AddConfigChangedCallback([this]() { RefreshConfig(); });
-  RefreshConfig();
-
-  m_last_oc_factor = m_config_oc_factor;
-  m_globals.last_OC_factor_inverted = m_config_oc_inv_factor;
   m_system.GetPPCState().downcount = CyclesToDowncount(MAX_SLICE_LENGTH);
   m_globals.slice_length = MAX_SLICE_LENGTH;
   m_globals.global_timer = 0;
@@ -103,6 +97,13 @@ void CoreTimingManager::Init()
 
   m_event_fifo_id = 0;
   m_ev_lost = RegisterEvent("_lost_event", &EmptyTimedCallback);
+
+  m_registered_config_callback_id =
+      CPUThreadConfigCallback::AddConfigChangedCallback([this]() { RefreshConfig(); });
+  RefreshConfig();
+
+  m_last_oc_factor = m_config_oc_factor;
+  m_globals.last_OC_factor_inverted = m_config_oc_inv_factor;
 }
 
 void CoreTimingManager::Shutdown()
@@ -127,16 +128,17 @@ void CoreTimingManager::RefreshConfig()
 
   m_max_variance = std::chrono::duration_cast<DT>(DT_ms(Config::Get(Config::MAIN_TIMING_VARIANCE)));
 
+  m_correct_time_drift = Config::Get(Config::MAIN_CORRECT_TIME_DRIFT);
+
   if (AchievementManager::GetInstance().IsHardcoreModeActive() &&
       Config::Get(Config::MAIN_EMULATION_SPEED) < 1.0f &&
       Config::Get(Config::MAIN_EMULATION_SPEED) > 0.0f)
   {
     Config::SetCurrent(Config::MAIN_EMULATION_SPEED, 1.0f);
-    m_emulation_speed = 1.0f;
     OSD::AddMessage("Minimum speed is 100% in Hardcore Mode");
   }
 
-  m_emulation_speed = Config::Get(Config::MAIN_EMULATION_SPEED);
+  UpdateSpeedLimit(GetTicks(), Config::Get(Config::MAIN_EMULATION_SPEED));
 
   m_use_precision_timer = Config::Get(Config::MAIN_PRECISION_FRAME_TIMING);
 }
@@ -197,13 +199,14 @@ void CoreTimingManager::DoState(PointerWrap& p)
     // The exact layout of the heap in memory is implementation defined, therefore it is platform
     // and library version specific.
     std::ranges::make_heap(m_event_queue, std::ranges::greater{});
-
-    // The stave state has changed the time, so our previous Throttle targets are invalid.
-    // Especially when global_time goes down; So we create a fake throttle update.
-    ResetThrottle(m_globals.global_timer);
   }
 }
 
+void CoreTimingManager::Resume()
+{
+  ResetThrottle(m_globals.global_timer);
+}
+
 // This should only be called from the CPU thread. If you are calling
 // it from any other thread, you are doing something evil
 u64 CoreTimingManager::GetTicks() const
@@ -355,20 +358,24 @@ void CoreTimingManager::Advance()
   power_pc.CheckExternalExceptions();
 }
 
+TimePoint CoreTimingManager::CalculateTargetHostTimeInternal(s64 target_cycle)
+{
+  const s64 elapsed_cycles = target_cycle - m_throttle_reference_cycle;
+  return m_throttle_reference_time +
+         Clock::duration{std::chrono::seconds{elapsed_cycles}} / m_throttle_adj_clock_per_sec;
+}
+
+bool CoreTimingManager::IsSpeedUnlimited() const
+{
+  return m_throttle_adj_clock_per_sec == 0 || Core::GetIsThrottlerTempDisabled();
+}
+
 TimePoint CoreTimingManager::GetTargetHostTime(s64 target_cycle)
 {
-  const double speed = Core::GetIsThrottlerTempDisabled() ? 0.0 : m_emulation_speed;
-
-  if (speed > 0)
-  {
-    const s64 cycles = target_cycle - m_throttle_last_cycle;
-    return m_throttle_deadline + std::chrono::duration_cast<DT>(
-                                     DT_s(cycles) / (m_emulation_speed * m_throttle_clock_per_sec));
-  }
-  else
-  {
+  if (IsSpeedUnlimited())
     return Clock::now();
-  }
+
+  return CalculateTargetHostTimeInternal(target_cycle);
 }
 
 void CoreTimingManager::SleepUntil(TimePoint time_point)
@@ -399,44 +406,78 @@ void CoreTimingManager::SleepUntil(TimePoint time_point)
 
 void CoreTimingManager::Throttle(const s64 target_cycle)
 {
-  // Based on number of cycles and emulation speed, increase the target deadline
-  const s64 cycles = target_cycle - m_throttle_last_cycle;
-  m_throttle_last_cycle = target_cycle;
+  if (IsSpeedUnlimited())
+  {
+    ResetThrottle(target_cycle);
+    m_throttle_disable_vi_int = false;
+    return;
+  }
 
-  const double speed = Core::GetIsThrottlerTempDisabled() ? 0.0 : m_emulation_speed;
+  // Push throttle reference values forward by exact seconds.
+  // This avoids drifting from cumulative rounding errors.
+  {
+    const s64 sec_adj = (target_cycle - m_throttle_reference_cycle) / m_throttle_adj_clock_per_sec;
+    const s64 cycle_adj = sec_adj * m_throttle_adj_clock_per_sec;
 
-  if (0.0 < speed)
-    m_throttle_deadline +=
-        std::chrono::duration_cast<DT>(DT_s(cycles) / (speed * m_throttle_clock_per_sec));
+    m_throttle_reference_cycle += cycle_adj;
+    m_throttle_reference_time += std::chrono::seconds{sec_adj};
+  }
+
+  TimePoint target_time = CalculateTargetHostTimeInternal(target_cycle);
 
   const TimePoint time = Clock::now();
-  const TimePoint min_deadline = time - m_max_fallback;
-  const TimePoint max_deadline = time + m_max_fallback;
 
-  if (m_throttle_deadline > max_deadline)
+  // "Correct Time Drift" setting prevents the timing relaxing.
+  const TimePoint min_target = m_correct_time_drift ? target_time : (time - m_max_fallback);
+  if (target_time < min_target)
   {
-    m_throttle_deadline = max_deadline;
-  }
-  else if (m_throttle_deadline < min_deadline)
-  {
-    DEBUG_LOG_FMT(COMMON, "System can not to keep up with timings! [relaxing timings by {} us]",
-                  DT_us(min_deadline - m_throttle_deadline).count());
-    m_throttle_deadline = min_deadline;
+    // Core is running too slow.. i.e. CPU bottleneck.
+    const DT adjustment = min_target - target_time;
+    DEBUG_LOG_FMT(CORE, "Core can not keep up with timings! [relaxing timings by {} us]",
+                  DT_us(adjustment).count());
+
+    m_throttle_reference_time += adjustment;
+    target_time += adjustment;
   }
 
-  const TimePoint vi_deadline = time - std::min(m_max_fallback, m_max_variance) / 2;
+  UpdateVISkip(time, target_time);
 
-  // Skip the VI interrupt if the CPU is lagging by a certain amount.
-  // It doesn't matter what amount of lag we skip VI at, as long as it's constant.
-  m_throttle_disable_vi_int = 0.0 < speed && m_throttle_deadline < vi_deadline;
+  SleepUntil(target_time);
+}
 
-  SleepUntil(m_throttle_deadline);
+void CoreTimingManager::UpdateSpeedLimit(s64 cycle, double new_speed)
+{
+  m_emulation_speed = new_speed;
+
+  const u32 new_clock_per_sec =
+      std::lround(m_system.GetSystemTimers().GetTicksPerSecond() * new_speed);
+
+  const bool was_limited = m_throttle_adj_clock_per_sec != 0;
+  if (was_limited)
+  {
+    // Adjust throttle reference for graceful clock speed transition.
+    const s64 ticks = cycle - m_throttle_reference_cycle;
+    const s64 new_ticks = ticks * new_clock_per_sec / m_throttle_adj_clock_per_sec;
+    m_throttle_reference_cycle = cycle - new_ticks;
+  }
+
+  m_throttle_adj_clock_per_sec = new_clock_per_sec;
 }
 
 void CoreTimingManager::ResetThrottle(s64 cycle)
 {
-  m_throttle_last_cycle = cycle;
-  m_throttle_deadline = Clock::now();
+  m_throttle_reference_cycle = cycle;
+  m_throttle_reference_time = Clock::now();
+}
+
+void CoreTimingManager::UpdateVISkip(TimePoint current_time, TimePoint target_time)
+{
+  const DT vi_fallback = std::min(m_max_variance, m_max_fallback);
+
+  // Skip the VI interrupt if the CPU is lagging by a certain amount.
+  // It doesn't matter what amount of lag we skip VI at, as long as it's constant.
+  const TimePoint vi_target = current_time - vi_fallback / 2;
+  m_throttle_disable_vi_int = target_time < vi_target;
 }
 
 bool CoreTimingManager::GetVISkip() const
@@ -465,12 +506,14 @@ void CoreTimingManager::AdjustEventQueueTimes(u32 new_ppc_clock, u32 old_ppc_clo
 {
   g_perf_metrics.AdjustClockSpeed(m_globals.global_timer, new_ppc_clock, old_ppc_clock);
 
-  m_throttle_clock_per_sec = new_ppc_clock;
+  const s64 ticks = m_globals.global_timer;
+
+  UpdateSpeedLimit(ticks, m_emulation_speed);
 
   for (Event& ev : m_event_queue)
   {
-    const s64 ticks = (ev.time - m_globals.global_timer) * new_ppc_clock / old_ppc_clock;
-    ev.time = m_globals.global_timer + ticks;
+    const s64 ev_ticks = (ev.time - ticks) * new_ppc_clock / old_ppc_clock;
+    ev.time = ticks + ev_ticks;
   }
 }
 

Source/Core/Core/CoreTiming.h

@@ -95,6 +95,10 @@ public:
   void Init();
   void Shutdown();
 
+  // Needed when the host-time changes from the guest's perspective.
+  // e.g. state-load or resume-from-pause
+  void Resume();
+
   // This should only be called from the CPU thread, if you are calling it any other thread, you are
   // doing something evil
   u64 GetTicks() const;
@@ -202,16 +206,21 @@ private:
   float m_config_oc_inv_factor = 0.0f;
   bool m_config_sync_on_skip_idle = false;
 
-  s64 m_throttle_last_cycle = 0;
-  TimePoint m_throttle_deadline = Clock::now();
-  s64 m_throttle_clock_per_sec = 0;
+  s64 m_throttle_reference_cycle = 0;
+  TimePoint m_throttle_reference_time = Clock::now();
+  u32 m_throttle_adj_clock_per_sec = 0;
   bool m_throttle_disable_vi_int = false;
 
   DT m_max_fallback = {};
   DT m_max_variance = {};
+  bool m_correct_time_drift = false;
   double m_emulation_speed = 1.0;
 
+  bool IsSpeedUnlimited() const;
+  void UpdateSpeedLimit(s64 cycle, double new_speed);
   void ResetThrottle(s64 cycle);
+  TimePoint CalculateTargetHostTimeInternal(s64 target_cycle);
+  void UpdateVISkip(TimePoint current_time, TimePoint target_time);
 
   int DowncountToCycles(int downcount) const;
   int CyclesToDowncount(int cycles) const;

Source/Core/Core/PowerPC/PowerPC.cpp

@@ -382,6 +382,7 @@ void PowerPCManager::SingleStep()
 
 void PowerPCManager::RunLoop()
 {
+  m_system.GetCoreTiming().Resume();
   m_cpu_core_base->Run();
   Host_UpdateDisasmDialog();
 }

Source/Core/DolphinQt/Settings/AdvancedPane.cpp

@@ -88,6 +88,18 @@ void AdvancedPane::CreateLayout()
          "needed.<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>"));
   cpu_options_group_layout->addWidget(m_accurate_cpu_cache_checkbox);
 
+  auto* const timing_group = new QGroupBox(tr("Timing"));
+  main_layout->addWidget(timing_group);
+  auto* timing_group_layout = new QVBoxLayout{timing_group};
+  auto* const correct_time_drift =
+      new ConfigBool{tr("Correct Time Drift"), Config::MAIN_CORRECT_TIME_DRIFT};
+  correct_time_drift->SetDescription(
+      tr("Allow the emulated console to run fast after stutters,"
+         "<br>pursuing accurate overall elapsed time unless paused or speed-adjusted."
+         "<br><br>This may be useful for internet play."
+         "<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>"));
+  timing_group_layout->addWidget(correct_time_drift);
+
   auto* clock_override = new QGroupBox(tr("Clock Override"));
   auto* clock_override_layout = new QVBoxLayout();
   clock_override->setLayout(clock_override_layout);