From a442239ac1bc8f334b48e104345ee0fbb9b8fec3 Mon Sep 17 00:00:00 2001
From: narzoul <narzoul@users.noreply.github.com>
Date: Sat, 29 Jun 2024 23:22:07 +0200
Subject: [PATCH] Fixed a potential deadlock in resetMouseHook

Fixes a sporadic deadlock when alt-tabbing in Star Trek: Armada with the
config overlay open.
---
 DDrawCompat/Gdi/GuiThread.cpp | 12 ++++++++
 DDrawCompat/Gdi/GuiThread.h   |  1 +
 DDrawCompat/Input/Input.cpp   | 52 ++++++++++++++++++-----------------
 3 files changed, 40 insertions(+), 25 deletions(-)

diff --git a/DDrawCompat/Gdi/GuiThread.cpp b/DDrawCompat/Gdi/GuiThread.cpp
index eae3d1a..a7c1974 100644
--- a/DDrawCompat/Gdi/GuiThread.cpp
+++ b/DDrawCompat/Gdi/GuiThread.cpp
@@ -20,6 +20,7 @@
 namespace
 {
 	const UINT WM_USER_EXECUTE = WM_USER;
+	const UINT WM_USER_EXECUTE_ASYNC = WM_USER + 1;
 
 	struct EnumWindowsArgs
 	{
@@ -185,6 +186,12 @@ namespace
 			func();
 			return 0;
 		}
+		if (WM_USER_EXECUTE_ASYNC == uMsg)
+		{
+			auto func = reinterpret_cast<void(*)()>(lParam);
+			func();
+			return 0;
+		}
 		return CALL_ORIG_FUNC(DefWindowProc)(hwnd, uMsg, wParam, lParam);
 	}
 
@@ -277,6 +284,11 @@ namespace Gdi
 			PostMessage(hwnd, WM_CLOSE, 0, 0);
 		}
 
+		void executeAsyncFunc(void(*func)())
+		{
+			PostMessage(g_messageWindow, WM_USER_EXECUTE_ASYNC, 0, reinterpret_cast<LPARAM>(func));
+		}
+
 		void executeFunc(const std::function<void()>& func)
 		{
 			DWORD_PTR result = 0;
diff --git a/DDrawCompat/Gdi/GuiThread.h b/DDrawCompat/Gdi/GuiThread.h
index 67489bb..9220007 100644
--- a/DDrawCompat/Gdi/GuiThread.h
+++ b/DDrawCompat/Gdi/GuiThread.h
@@ -27,6 +27,7 @@ namespace Gdi
 
 		template <typename Func>
 		void execute(const Func& func) { executeFunc(std::cref(func)); }
+		void executeAsyncFunc(void(*func)());
 		void executeFunc(const std::function<void()>& func);
 
 		bool isGuiThreadWindow(HWND hwnd);
diff --git a/DDrawCompat/Input/Input.cpp b/DDrawCompat/Input/Input.cpp
index f46c117..2bb5fad 100644
--- a/DDrawCompat/Input/Input.cpp
+++ b/DDrawCompat/Input/Input.cpp
@@ -268,33 +268,35 @@ namespace
 			});
 	}
 
+	void resetMouseHookFunc()
+	{
+		if (g_mouseHook)
+		{
+			UnhookWindowsHookEx(g_mouseHook);
+		}
+
+		g_origCursorPos = { MAXLONG, MAXLONG };
+		g_mouseHook = CALL_ORIG_FUNC(SetWindowsHookExA)(
+			WH_MOUSE_LL, &lowLevelMouseProc, Dll::g_origDDrawModule, 0);
+
+		if (g_mouseHook)
+		{
+			INPUT inputs[2] = {};
+			inputs[0].mi.dy = 1;
+			inputs[0].mi.dwFlags = MOUSEEVENTF_MOVE;
+			inputs[1].mi.dx = 1;
+			inputs[1].mi.dwFlags = MOUSEEVENTF_MOVE;
+			SendInput(2, inputs, sizeof(INPUT));
+		}
+		else
+		{
+			LOG_ONCE("ERROR: Failed to install low level mouse hook, error code: " << GetLastError());
+		}
+	}
+
 	void resetMouseHook()
 	{
-		Gdi::GuiThread::execute([]()
-			{
-				if (g_mouseHook)
-				{
-					UnhookWindowsHookEx(g_mouseHook);
-				}
-
-				g_origCursorPos = { MAXLONG, MAXLONG };
-				g_mouseHook = CALL_ORIG_FUNC(SetWindowsHookExA)(
-					WH_MOUSE_LL, &lowLevelMouseProc, Dll::g_origDDrawModule, 0);
-
-				if (g_mouseHook)
-				{
-					INPUT inputs[2] = {};
-					inputs[0].mi.dy = 1;
-					inputs[0].mi.dwFlags = MOUSEEVENTF_MOVE;
-					inputs[1].mi.dx = 1;
-					inputs[1].mi.dwFlags = MOUSEEVENTF_MOVE;
-					SendInput(2, inputs, sizeof(INPUT));
-				}
-				else
-				{
-					LOG_ONCE("ERROR: Failed to install low level mouse hook, error code: " << GetLastError());
-				}
-			});
+		Gdi::GuiThread::executeAsyncFunc(resetMouseHookFunc);
 	}
 
 	BOOL WINAPI setCursorPos(int X, int Y)