Core: Improve ordering of boot

- Smplification of graphics backend startup/shutdown.
- Don't send complete message until CPU is ready to execute.
- Remove redundant stop message.
- Remove OSD message with backend name.

Source/Core/Core/Core.cpp

@@ -241,7 +241,6 @@ bool Init(std::unique_ptr<BootParameters> boot)
 
   // Start the emu thread
   s_emu_thread = std::thread(EmuThread, std::move(boot));
-
   return true;
 }
 
@@ -311,9 +310,13 @@ void UndeclareAsCPUThread()
 // For the CPU Thread only.
 static void CPUSetInitialExecutionState()
 {
-  QueueHostJob([] {
+  // The CPU starts in stepping state, and will wait until a new state is set before executing.
+  // SetState must be called on the host thread, so we defer it for later.
+  QueueHostJob([]() {
     SetState(SConfig::GetInstance().bBootToPause ? State::Paused : State::Running);
+    Host_UpdateDisasmDialog();
     Host_UpdateMainFrame();
+    Host_Message(WM_USER_CREATE);
   });
 }
 
@@ -323,17 +326,10 @@ static void CpuThread(const std::optional<std::string>& savestate_path, bool del
   DeclareAsCPUThread();
 
   const SConfig& _CoreParameter = SConfig::GetInstance();
-
   if (_CoreParameter.bCPUThread)
-  {
     Common::SetCurrentThreadName("CPU thread");
-  }
   else
-  {
     Common::SetCurrentThreadName("CPU-GPU thread");
-    g_video_backend->Video_Prepare();
-    Host_Message(WM_USER_CREATE);
-  }
 
   // This needs to be delayed until after the video backend is ready.
   DolphinAnalytics::Instance()->ReportGameStart();
@@ -341,6 +337,17 @@ static void CpuThread(const std::optional<std::string>& savestate_path, bool del
   if (_CoreParameter.bFastmem)
     EMM::InstallExceptionHandler();  // Let's run under memory watch
 
+#ifdef USE_MEMORYWATCHER
+  MemoryWatcher::Init();
+#endif
+
+  if (savestate_path)
+  {
+    ::State::LoadAs(*savestate_path);
+    if (delete_savestate)
+      File::Delete(*savestate_path);
+  }
+
   s_is_started = true;
   CPUSetInitialExecutionState();
 
@@ -361,25 +368,11 @@ static void CpuThread(const std::optional<std::string>& savestate_path, bool del
   }
 #endif
 
-#ifdef USE_MEMORYWATCHER
-  MemoryWatcher::Init();
-#endif
-
-  if (savestate_path)
-  {
-    ::State::LoadAs(*savestate_path);
-    if (delete_savestate)
-      File::Delete(*savestate_path);
-  }
-
   // Enter CPU run loop. When we leave it - we are done.
   CPU::Run();
 
   s_is_started = false;
 
-  if (!_CoreParameter.bCPUThread)
-    g_video_backend->Video_CleanupShared();
-
   if (_CoreParameter.bFastmem)
     EMM::UninstallExceptionHandler();
 }
@@ -388,18 +381,12 @@ static void FifoPlayerThread(const std::optional<std::string>& savestate_path,
                              bool delete_savestate)
 {
   DeclareAsCPUThread();
-  const SConfig& _CoreParameter = SConfig::GetInstance();
 
+  const SConfig& _CoreParameter = SConfig::GetInstance();
   if (_CoreParameter.bCPUThread)
-  {
     Common::SetCurrentThreadName("FIFO player thread");
-  }
   else
-  {
-    g_video_backend->Video_Prepare();
-    Host_Message(WM_USER_CREATE);
     Common::SetCurrentThreadName("FIFO-GPU thread");
-  }
 
   // Enter CPU run loop. When we leave it - we are done.
   if (auto cpu_core = FifoPlayer::GetInstance().GetCPUCore())
@@ -412,20 +399,15 @@ static void FifoPlayerThread(const std::optional<std::string>& savestate_path,
 
     s_is_started = false;
     PowerPC::InjectExternalCPUCore(nullptr);
+    FifoPlayer::GetInstance().Close();
   }
-  FifoPlayer::GetInstance().Close();
+  else
-
-  // If we did not enter the CPU Run Loop above then run a fake one instead.
-  // We need to be IsRunningAndStarted() for DolphinWX to stop us.
-  if (CPU::GetState() != CPU::State::PowerDown)
   {
-    s_is_started = true;
+    // FIFO log does not contain any frames, cannot continue.
-    Host_Message(WM_USER_STOP);
+    PanicAlert("FIFO file is invalid, cannot playback.");
-    s_is_started = false;
+    FifoPlayer::GetInstance().Close();
+    return;
   }
-
-  if (!_CoreParameter.bCPUThread)
-    g_video_backend->Video_CleanupShared();
 }
 
 // Initialize and create emulation thread
@@ -449,9 +431,6 @@ static void EmuThread(std::unique_ptr<BootParameters> boot)
     INFO_LOG(CONSOLE, "Stop\t\t---- Shutdown complete ----");
   }};
 
-  // Prevent the UI from getting stuck whenever an error occurs.
-  Common::ScopeGuard stop_message_guard{[] { Host_Message(WM_USER_STOP); }};
-
   Common::SetCurrentThreadName("Emuthread - Starting");
 
   // For a time this acts as the CPU thread...
@@ -485,9 +464,11 @@ static void EmuThread(std::unique_ptr<BootParameters> boot)
     PanicAlert("Failed to initialize video backend!");
     return;
   }
-  Common::ScopeGuard video_guard{[] { g_video_backend->Shutdown(); }};
+  g_video_backend->Video_Prepare();
-
+  Common::ScopeGuard video_guard{[] {
-  OSD::AddMessage("Dolphin " + g_video_backend->GetName() + " Video Backend.", 5000);
+    g_video_backend->Video_Cleanup();
+    g_video_backend->Shutdown();
+  }};
 
   if (cpu_info.HTT)
     SConfig::GetInstance().bDSPThread = cpu_info.num_cores > 4;
@@ -568,9 +549,6 @@ static void EmuThread(std::unique_ptr<BootParameters> boot)
   // This adds the SyncGPU handler to CoreTiming, so now CoreTiming::Advance might block.
   Fifo::Prepare();
 
-  // Thread is no longer acting as CPU Thread
-  UndeclareAsCPUThread();
-
   // Setup our core, but can't use dynarec if we are compare server
   if (core_parameter.iCPUCore != PowerPC::CORE_INTERPRETER &&
       (!core_parameter.bRunCompareServer || core_parameter.bRunCompareClient))
@@ -582,21 +560,15 @@ static void EmuThread(std::unique_ptr<BootParameters> boot)
     PowerPC::SetMode(PowerPC::CoreMode::Interpreter);
   }
 
-  // Update the window again because all stuff is initialized
-  Host_UpdateDisasmDialog();
-  Host_UpdateMainFrame();
-
   // ENTER THE VIDEO THREAD LOOP
   if (core_parameter.bCPUThread)
   {
     // This thread, after creating the EmuWindow, spawns a CPU
     // thread, and then takes over and becomes the video thread
     Common::SetCurrentThreadName("Video thread");
+    UndeclareAsCPUThread();
 
-    g_video_backend->Video_Prepare();
+    // Spawn the CPU thread. The CPU thread will signal the event that boot is complete.
-    Host_Message(WM_USER_CREATE);
-
-    // Spawn the CPU thread
     s_cpu_thread = std::thread(cpuThreadFunc, savestate_path, delete_savestate);
 
     // become the GPU thread
@@ -620,12 +592,6 @@ static void EmuThread(std::unique_ptr<BootParameters> boot)
   gdb_deinit();
   INFO_LOG(CONSOLE, "%s", StopMessage(true, "GDB stopped.").c_str());
 #endif
-
-  if (core_parameter.bCPUThread)
-    g_video_backend->Video_CleanupShared();
-
-  // If we shut down normally, the stop message does not need to be triggered.
-  stop_message_guard.Dismiss();
 }
 
 // Set or get the running state

Source/Core/DolphinNoGUI/MainNoGUI.cpp

@@ -83,10 +83,9 @@ static Common::Event updateMainFrameEvent;
 void Host_Message(int Id)
 {
   if (Id == WM_USER_STOP)
-  {
     s_running.Clear();
+  if (Id == WM_USER_JOB_DISPATCH || Id == WM_USER_STOP)
     updateMainFrameEvent.Set();
-  }
 }
 
 static void* s_window_handle = nullptr;