Add facility to run callbacks on the window thread

Common/System/Request.cpp

@@ -144,3 +144,9 @@ void System_ShowFileInFolder(const Path &path) {
 void System_BrowseForFolder(RequesterToken token, std::string_view title, const Path &initialPath, RequestCallback callback, RequestFailedCallback failedCallback) {
 	g_requestManager.MakeSystemRequest(SystemRequestType::BROWSE_FOR_FOLDER, token, callback, failedCallback, title, initialPath.ToCString(), 0);
 }
+
+void System_RunCallbackInWndProc(void (*callback)(void *, void *), void *userdata) {
+	int64_t castPtr = (int64_t)callback;
+	int64_t castUserData = (int64_t)userdata;
+	g_requestManager.MakeSystemRequest(SystemRequestType::RUN_CALLBACK_IN_WNDPROC, NO_REQUESTER_TOKEN, nullptr, nullptr, "", "", castPtr, castUserData);
+}

Common/System/Request.h

@@ -176,6 +176,8 @@ inline void System_SendDebugScreenshot(std::string_view data, int height) {
 	g_requestManager.MakeSystemRequest(SystemRequestType::SEND_DEBUG_SCREENSHOT, NO_REQUESTER_TOKEN, nullptr, nullptr, data, "", height);
 }
 
+void System_RunCallbackInWndProc(void (*callback)(void *, void *), void *userdata);
+
 // Non-inline to avoid including Path.h
 void System_CreateGameShortcut(const Path &path, std::string_view title);
 void System_ShowFileInFolder(const Path &path);

Common/System/System.h

@@ -86,6 +86,8 @@ enum class SystemRequestType {
 	GPS_COMMAND,
 	INFRARED_COMMAND,
 	MICROPHONE_COMMAND,
+
+	RUN_CALLBACK_IN_WNDPROC,
 };
 
 // Implementations are supposed to process the request, and post the response to the g_RequestManager (see Message.h).

Windows/MainWindow.cpp

@@ -764,6 +764,13 @@ namespace MainWindow
 			}
 			break;
 
+		case WM_USER_RUN_CALLBACK:
+		{
+			auto callback = reinterpret_cast<void (*)(void *window, void *userdata)>(wParam);
+			void *userdata = reinterpret_cast<void *>(lParam);
+			callback(hWnd, userdata);
+			break;
+		}
 		case WM_USER_GET_BASE_POINTER:
 			Reporting::NotifyDebugger();
 			switch (lParam) {
@@ -1135,4 +1142,8 @@ namespace MainWindow
 		return g_isFullscreen;
 	}
 
+	void RunCallbackInWndProc(void (*callback)(void *, void *), void *userdata) {
+		PostMessage(hwndMain, WM_USER_RUN_CALLBACK, reinterpret_cast<WPARAM>(callback), reinterpret_cast<LPARAM>(userdata));
+	}
+
 }  // namespace

Windows/MainWindow.h

@@ -18,7 +18,8 @@ namespace MainWindow
 		WM_USER_WINDOW_TITLE_CHANGED = WM_USER + 103,
 		WM_USER_TOGGLE_FULLSCREEN = WM_USER + 105,
 		WM_USER_RESTART_EMUTHREAD = WM_USER + 106,
-		WM_USER_SWITCHUMD_UPDATED = WM_USER + 107
+		WM_USER_SWITCHUMD_UPDATED = WM_USER + 107,
+		WM_USER_RUN_CALLBACK = WM_USER + 108,
 	};
 
 	enum {
@@ -79,6 +80,7 @@ namespace MainWindow
 	void ToggleDebugConsoleVisibility();
 	void SetInternalResolution(int res = -1);
 	void SetWindowSize(int zoom);
+	void RunCallbackInWndProc(void (*callback)(void *window, void *userdata), void *userdata);
 }
 
 #endif

Windows/main.cpp

@@ -636,7 +636,13 @@ bool System_MakeRequest(SystemRequestType type, int requestId, const std::string
 	}
 	case SystemRequestType::CREATE_GAME_SHORTCUT:
 		return W32Util::CreateDesktopShortcut(param1, param2);
-
+	case SystemRequestType::RUN_CALLBACK_IN_WNDPROC:
+	{
+		auto func = reinterpret_cast<void (*)(void *window, void *userdata)>(param3);
+		void *userdata = reinterpret_cast<void *>(param4);
+		MainWindow::RunCallbackInWndProc(func, userdata);
+		return true;
+	}
 	default:
 		return false;
 	}