Core: Remove RunAsCPUThread

It's a fine function, but CPUThreadGuard is more vogue. Also, its potential for being confused with RunOnCPUThread will not be missed.

Source/Android/jni/MainAndroid.cpp

@@ -515,7 +515,6 @@ Java_org_dolphinemu_dolphinemu_NativeLibrary_UpdateGCAdapterScanThread(JNIEnv*,
 
 JNIEXPORT void JNICALL Java_org_dolphinemu_dolphinemu_NativeLibrary_Initialize(JNIEnv*, jclass)
 {
-  // InitControllers ends up calling config code, and some config callbacks use RunAsCPUThread
   HostThreadLock guard;
 
   UICommon::CreateDirectories();

Source/Core/Core/AchievementManager.cpp

@@ -689,7 +689,7 @@ void AchievementManager::DoFrame()
   time_t current_time = std::time(nullptr);
   if (difftime(current_time, m_last_ping_time) > 120)
   {
-    GenerateRichPresence();
+    GenerateRichPresence(Core::CPUThreadGuard{*m_system});
     m_queue.EmplaceItem([this] { PingRichPresence(m_rich_presence); });
     m_last_ping_time = current_time;
     m_update_callback();
@@ -1341,9 +1341,8 @@ void AchievementManager::ActivateDeactivateAchievement(AchievementId id, bool en
     rc_runtime_deactivate_achievement(&m_runtime, id);
 }
 
-void AchievementManager::GenerateRichPresence()
+void AchievementManager::GenerateRichPresence(const Core::CPUThreadGuard& guard)
 {
-  Core::RunAsCPUThread([&] {
   std::lock_guard lg{m_lock};
   rc_runtime_get_richpresence(
       &m_runtime, m_rich_presence.data(), RP_SIZE,
@@ -1351,7 +1350,6 @@ void AchievementManager::GenerateRichPresence()
         return static_cast<AchievementManager*>(ud)->MemoryPeeker(address, num_bytes, ud);
       },
       this, nullptr);
-  });
 }
 
 AchievementManager::ResponseType AchievementManager::AwardAchievement(AchievementId achievement_id)

Source/Core/Core/AchievementManager.h

@@ -23,8 +23,9 @@
 
 namespace Core
 {
+class CPUThreadGuard;
 class System;
-}
+}  // namespace Core
 
 namespace OSD
 {
@@ -180,7 +181,7 @@ private:
   std::unique_ptr<DiscIO::Volume>& GetLoadingVolume() { return m_loading_volume; };
 
   void ActivateDeactivateAchievement(AchievementId id, bool enabled, bool unofficial, bool encore);
-  void GenerateRichPresence();
+  void GenerateRichPresence(const Core::CPUThreadGuard& guard);
 
   ResponseType AwardAchievement(AchievementId achievement_id);
   ResponseType SubmitLeaderboard(AchievementId leaderboard_id, int value);

Source/Core/Core/Core.cpp

@@ -788,14 +788,14 @@ static std::string GenerateScreenshotName()
 
 void SaveScreenShot()
 {
-  Core::RunAsCPUThread([] { g_frame_dumper->SaveScreenshot(GenerateScreenshotName()); });
+  const Core::CPUThreadGuard guard(Core::System::GetInstance());
+  g_frame_dumper->SaveScreenshot(GenerateScreenshotName());
 }
 
 void SaveScreenShot(std::string_view name)
 {
-  Core::RunAsCPUThread([&name] {
+  const Core::CPUThreadGuard guard(Core::System::GetInstance());
   g_frame_dumper->SaveScreenshot(fmt::format("{}{}.png", GenerateScreenshotFolderPath(), name));
-  });
 }
 
 static bool PauseAndLock(Core::System& system, bool do_lock, bool unpause_on_unlock)
@@ -837,20 +837,6 @@ static bool PauseAndLock(Core::System& system, bool do_lock, bool unpause_on_unl
   return was_unpaused;
 }
 
-void RunAsCPUThread(std::function<void()> function)
-{
-  auto& system = Core::System::GetInstance();
-  const bool is_cpu_thread = IsCPUThread();
-  bool was_unpaused = false;
-  if (!is_cpu_thread)
-    was_unpaused = PauseAndLock(system, true, true);
-
-  function();
-
-  if (!is_cpu_thread)
-    PauseAndLock(system, false, was_unpaused);
-}
-
 void RunOnCPUThread(std::function<void()> function, bool wait_for_completion)
 {
   // If the CPU thread is not running, assume there is no active CPU thread we can race against.

Source/Core/Core/Core.h

@@ -94,13 +94,10 @@ enum class ConsoleType : u32
   ReservedTDEVSystem = 0x20000007,
 };
 
-// Run a function as the CPU thread. This is an RAII alternative to the RunAsCPUThread function.
-//
-// If constructed from the Host thread, the CPU thread is paused and the current thread temporarily
-// becomes the CPU thread.
-// If constructed from the CPU thread, nothing special happens.
-//
-// This should only be constructed from the CPU thread or the host thread.
+// This is an RAII alternative to using PauseAndLock. If constructed from the host thread, the CPU
+// thread is paused, and the current thread temporarily becomes the CPU thread. If constructed from
+// the CPU thread, nothing special happens. This should only be constructed on the CPU thread or the
+// host thread.
 //
 // Some functions use a parameter of this type to indicate that the function should only be called
 // from the CPU thread. If the parameter is a pointer, the function has a fallback for being called
@@ -158,15 +155,6 @@ void DisplayMessage(std::string message, int time_in_ms);
 void FrameUpdateOnCPUThread();
 void OnFrameEnd(Core::System& system);
 
-// Run a function as the CPU thread.
-//
-// If called from the Host thread, the CPU thread is paused and the current thread temporarily
-// becomes the CPU thread while running the function.
-// If called from the CPU thread, the function will be run directly.
-//
-// This should only be called from the CPU thread or the host thread.
-void RunAsCPUThread(std::function<void()> function);
-
 // Run a function on the CPU thread, asynchronously.
 // This is only valid to call from the host thread, since it uses PauseAndLock() internally.
 void RunOnCPUThread(std::function<void()> function, bool wait_for_completion);

Source/Core/Core/HW/Wiimote.cpp

@@ -50,7 +50,8 @@ void OnSourceChanged(unsigned int index, WiimoteSource source)
 
   WiimoteReal::HandleWiimoteSourceChange(index);
 
-  Core::RunAsCPUThread([index] { WiimoteCommon::UpdateSource(index); });
+  const Core::CPUThreadGuard guard(Core::System::GetInstance());
+  WiimoteCommon::UpdateSource(index);
 }
 
 void RefreshConfig()

Source/Core/Core/HW/WiimoteReal/WiimoteReal.cpp

@@ -947,10 +947,11 @@ static bool TryToConnectWiimoteToSlot(std::unique_ptr<Wiimote>& wm, unsigned int
   led_report.leds = u8(1 << (i % WIIMOTE_BALANCE_BOARD));
   wm->QueueReport(led_report);
 
-  Core::RunAsCPUThread([i, &wm] {
+  {
+    const Core::CPUThreadGuard guard(Core::System::GetInstance());
     g_wiimotes[i] = std::move(wm);
     WiimoteCommon::UpdateSource(i);
-  });
+  }
 
   NOTICE_LOG_FMT(WIIMOTE, "Connected real wiimote to slot {}.", i + 1);
 
@@ -967,12 +968,11 @@ static void TryToConnectBalanceBoard(std::unique_ptr<Wiimote> wm)
 
 static void HandleWiimoteDisconnect(int index)
 {
-  Core::RunAsCPUThread([index] {
+  const Core::CPUThreadGuard guard(Core::System::GetInstance());
   // The Wii Remote object must exist through the call to UpdateSource
   // to prevent WiimoteDevice from having a dangling HIDWiimote pointer.
   const auto temp_real_wiimote = std::move(g_wiimotes[index]);
   WiimoteCommon::UpdateSource(index);
-  });
 }
 
 // This is called from the GUI thread
@@ -1004,10 +1004,11 @@ void HandleWiimoteSourceChange(unsigned int index)
 {
   std::lock_guard wm_lk(g_wiimotes_mutex);
 
-  Core::RunAsCPUThread([index] {
+  {
+    const Core::CPUThreadGuard guard(Core::System::GetInstance());
     if (auto removed_wiimote = std::move(g_wiimotes[index]))
       AddWiimoteToPool(std::move(removed_wiimote));
-  });
+  }
   g_controller_interface.PlatformPopulateDevices([] { ProcessWiimotePool(); });
 }
 

Source/Core/Core/PowerPC/JitInterface.cpp

@@ -160,7 +160,7 @@ void JitInterface::GetProfileResults(Profiler::ProfileStats* prof_stats) const
   prof_stats->timecost_sum = 0;
   prof_stats->block_stats.clear();
 
-  Core::RunAsCPUThread([this, &prof_stats] {
+  const Core::CPUThreadGuard guard(m_system);
   QueryPerformanceFrequency((LARGE_INTEGER*)&prof_stats->countsPerSec);
   m_jit->GetBlockCache()->RunOnBlocks([&prof_stats](const JitBlock& block) {
     const auto& data = block.profile_data;
@@ -175,7 +175,6 @@ void JitInterface::GetProfileResults(Profiler::ProfileStats* prof_stats) const
   });
 
   sort(prof_stats->block_stats.begin(), prof_stats->block_stats.end());
-  });
 }
 
 std::variant<JitInterface::GetHostCodeError, JitInterface::GetHostCodeResult>

Source/Core/DolphinQt/Host.cpp

@@ -112,9 +112,9 @@ static void RunWithGPUThreadInactive(std::function<void()> f)
   }
   else
   {
-    // If we reach here, we can call Core::PauseAndLock (which we do using RunAsCPUThread).
-
-    Core::RunAsCPUThread(std::move(f));
+    // If we reach here, we can call Core::PauseAndLock (which we do using a CPUThreadGuard).
+    const Core::CPUThreadGuard guard(Core::System::GetInstance());
+    f();
   }
 }
 

Source/Core/DolphinQt/Main.cpp

@@ -52,7 +52,7 @@ static bool QtMsgAlertHandler(const char* caption, const char* text, bool yes_no
   std::optional<bool> r = RunOnObject(QApplication::instance(), [&] {
     // If we were called from the CPU/GPU thread, set us as the CPU/GPU thread.
     // This information is used in order to avoid deadlocks when calling e.g.
-    // Host::SetRenderFocus or Core::RunAsCPUThread. (Host::SetRenderFocus
+    // Host::SetRenderFocus or Core::CPUThreadGuard. (Host::SetRenderFocus
     // can get called automatically when a dialog steals the focus.)
 
     Common::ScopeGuard cpu_scope_guard(&Core::UndeclareAsCPUThread);

Source/Core/DolphinQt/MainWindow.cpp

@@ -1932,12 +1932,13 @@ void MainWindow::OnStopRecording()
 
 void MainWindow::OnExportRecording()
 {
-  Core::RunAsCPUThread([this] {
+  auto& system = Core::System::GetInstance();
+  const Core::CPUThreadGuard guard(system);
+
   QString dtm_file = DolphinFileDialog::getSaveFileName(
       this, tr("Save Recording File As"), QString(), tr("Dolphin TAS Movies (*.dtm)"));
   if (!dtm_file.isEmpty())
-      Core::System::GetInstance().GetMovie().SaveRecording(dtm_file.toStdString());
-  });
+    system.GetMovie().SaveRecording(dtm_file.toStdString());
 }
 
 void MainWindow::OnActivateChat()
@@ -1990,13 +1991,12 @@ void MainWindow::ShowTASInput()
 
 void MainWindow::OnConnectWiiRemote(int id)
 {
-  Core::RunAsCPUThread([&] {
+  const Core::CPUThreadGuard guard(Core::System::GetInstance());
   if (const auto bt = WiiUtils::GetBluetoothEmuDevice())
   {
     const auto wm = bt->AccessWiimoteByIndex(id);
     wm->Activate(!wm->IsConnected());
   }
-  });
 }
 
 #ifdef USE_RETRO_ACHIEVEMENTS