fix: avoid loader-lock work in DllMain detach

src/Utils/FileWatcher.h

@@ -4,7 +4,7 @@
 #include <string>
 #include <vector>
 
-namespace FileWatcher {
-    void Start(const std::vector<std::string>& directories);
-    void Stop();
-}
+namespace FileWatcher {
+    void Start(const std::vector<std::string>& directories);
+    void Stop();
+}

src/dllmain.cpp

@@ -1,97 +1,105 @@
-#include "dllmain.h"
-#include "Hook/HookManager.h"
-#include "Utils/FileWatcher.h"
-#include "Utils/IPCLoader.h"
-#include "Utils/PatternLoader.h"
-#include "Utils/SteamDiagnostics.h"
-
-// prepare key runtime paths.
-bool InitializeSteamComponents()
-{
-    if (!GetCurrentDirectoryA(MAX_PATH, SteamInstallPath)) {
-        return false;
-    }
-    sprintf_s(SteamclientPath, MAX_PATH, "%s\\steamclient64.dll",  SteamInstallPath);
-    sprintf_s(SteamUIPath,     MAX_PATH, "%s\\steamui.dll",        SteamInstallPath);
-    sprintf_s(DiversionPath,   MAX_PATH, "%s\\bin\\diversion.dll", SteamInstallPath);
-    sprintf_s(LuaDir,          MAX_PATH, "%s\\config\\lua",        SteamInstallPath);
-    sprintf_s(ConfigPath,      MAX_PATH, "%s\\opensteamtool.toml", SteamInstallPath);
-
-    client_hModule = LoadLibraryA(SteamclientPath);
-    if (!client_hModule) {
-        LOG_ERROR("LoadLibraryA failed: {} (err={})", SteamclientPath, GetLastError());
-        return false;
-    }
-    LOG_INFO("Loaded diversion.dll from {}", SteamclientPath);
-
-    ui_hModule = GetModuleHandleA("steamui.dll");
-    if(!ui_hModule) {
-        LOG_ERROR("GetModuleHandleA failed for steamui.dll: err={}", GetLastError());
-        return false;
-    }
-    return true;
-}
-
-// All initialisation that touches the filesystem, calls LoadLibrary, scans
-// memory, or installs detours runs here on a worker thread — we MUST NOT do
-// any of that from inside DllMain (loader lock).
-static DWORD WINAPI InitThread(LPVOID param) {
-    HMODULE selfModule = static_cast<HMODULE>(param);
-    Log::Init(selfModule);
-    LOG_INFO("OpenSteamTool init thread started");
-
-    if (!InitializeSteamComponents()) {
-        LOG_ERROR("InitializeSteamComponents failed");
-        return 1;
-    }
-
-    Config::Load(ConfigPath);
-    Log::InitModules();
-    SteamDiagnostics::Initialize(SteamclientPath, SteamUIPath);
-
-    // Load pattern files for steamclient64.dll and steamui.dll.
-    // Each call computes the SHA-256 of the DLL on disk, checks the local
-    // cache, and downloads from GitHub if needed.  Both calls are synchronous
-    // but run on this worker thread, never under the loader lock.
-    PatternLoader::Load(ui_hModule, SteamUIPath, "steamui");
-    PatternLoader::Load(client_hModule, SteamclientPath, "steamclient");
-
-    // IPC method metadata (funcHash, fencepost, argc, ...)
-    IPCLoader::Load(SteamclientPath);
-
-    std::vector<std::string> watchDirs = Config::luaPaths;
-    watchDirs.push_back(std::string(LuaDir));
-    for (const auto& dir : watchDirs)
-        LuaConfig::ParseDirectory(dir);
-
-    FileWatcher::Start(watchDirs);
-
-    SteamUI::CoreHook();
-    SteamClient::CoreHook();
-
-    // Surface any functions that FindPattern() could not locate.
-    PatternLoader::ReportMissingFunctions();
-
-    LOG_INFO("OpenSteamTool init complete");
-    return 0;
-}
-
-BOOL APIENTRY DllMain(HMODULE hModule, DWORD dwReason, PVOID pvReserved)
-{
-    if (dwReason == DLL_PROCESS_ATTACH)
-    {
-        DisableThreadLibraryCalls(hModule);
-        // Hand off all real work to a worker thread to avoid running file I/O,
-        // LoadLibrary, and detour transactions under the loader lock.
-        HANDLE h = CreateThread(nullptr, 0, InitThread, hModule, 0, nullptr);
-        if (h) CloseHandle(h);
-    }
-    else if (dwReason == DLL_PROCESS_DETACH)
-    {
-        FileWatcher::Stop();
-        SteamUI::CoreUnhook();
-        SteamClient::CoreUnhook();
-    }
-
-    return TRUE;
-}
+#include "dllmain.h"
+#include "Hook/HookManager.h"
+#include "Utils/FileWatcher.h"
+#include "Utils/IPCLoader.h"
+#include "Utils/PatternLoader.h"
+#include "Utils/SteamDiagnostics.h"
+
+// prepare key runtime paths.
+bool InitializeSteamComponents()
+{
+    if (!GetCurrentDirectoryA(MAX_PATH, SteamInstallPath)) {
+        return false;
+    }
+    sprintf_s(SteamclientPath, MAX_PATH, "%s\\steamclient64.dll",  SteamInstallPath);
+    sprintf_s(SteamUIPath,     MAX_PATH, "%s\\steamui.dll",        SteamInstallPath);
+    sprintf_s(DiversionPath,   MAX_PATH, "%s\\bin\\diversion.dll", SteamInstallPath);
+    sprintf_s(LuaDir,          MAX_PATH, "%s\\config\\lua",        SteamInstallPath);
+    sprintf_s(ConfigPath,      MAX_PATH, "%s\\opensteamtool.toml", SteamInstallPath);
+
+    client_hModule = LoadLibraryA(SteamclientPath);
+    if (!client_hModule) {
+        LOG_ERROR("LoadLibraryA failed: {} (err={})", SteamclientPath, GetLastError());
+        return false;
+    }
+    LOG_INFO("Loaded diversion.dll from {}", SteamclientPath);
+
+    ui_hModule = GetModuleHandleA("steamui.dll");
+    if(!ui_hModule) {
+        LOG_ERROR("GetModuleHandleA failed for steamui.dll: err={}", GetLastError());
+        return false;
+    }
+    return true;
+}
+
+// All initialisation that touches the filesystem, calls LoadLibrary, scans
+// memory, or installs detours runs here on a worker thread — we MUST NOT do
+// any of that from inside DllMain (loader lock).
+static DWORD WINAPI InitThread(LPVOID param) {
+    HMODULE selfModule = static_cast<HMODULE>(param);
+    Log::Init(selfModule);
+    LOG_INFO("OpenSteamTool init thread started");
+
+    if (!InitializeSteamComponents()) {
+        LOG_ERROR("InitializeSteamComponents failed");
+        return 1;
+    }
+
+    Config::Load(ConfigPath);
+    Log::InitModules();
+    SteamDiagnostics::Initialize(SteamclientPath, SteamUIPath);
+
+    // Load pattern files for steamclient64.dll and steamui.dll.
+    // Each call computes the SHA-256 of the DLL on disk, checks the local
+    // cache, and downloads from GitHub if needed.  Both calls are synchronous
+    // but run on this worker thread, never under the loader lock.
+    PatternLoader::Load(ui_hModule, SteamUIPath, "steamui");
+    PatternLoader::Load(client_hModule, SteamclientPath, "steamclient");
+
+    // IPC method metadata (funcHash, fencepost, argc, ...)
+    IPCLoader::Load(SteamclientPath);
+
+    std::vector<std::string> watchDirs = Config::luaPaths;
+    watchDirs.push_back(std::string(LuaDir));
+    for (const auto& dir : watchDirs)
+        LuaConfig::ParseDirectory(dir);
+
+    FileWatcher::Start(watchDirs);
+
+    SteamUI::CoreHook();
+    SteamClient::CoreHook();
+
+    // Surface any functions that FindPattern() could not locate.
+    PatternLoader::ReportMissingFunctions();
+
+    LOG_INFO("OpenSteamTool init complete");
+    return 0;
+}
+
+BOOL APIENTRY DllMain(HMODULE hModule, DWORD dwReason, PVOID pvReserved)
+{
+    if (dwReason == DLL_PROCESS_ATTACH)
+    {
+        DisableThreadLibraryCalls(hModule);
+        // Keep this module pinned so explicit FreeLibrary cannot unload code
+        // while hooks and worker threads may still reference it.
+        HMODULE pinnedModule = nullptr;
+        GetModuleHandleExA(
+            GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS | GET_MODULE_HANDLE_EX_FLAG_PIN,
+            reinterpret_cast<LPCSTR>(&DllMain), &pinnedModule);
+        // Hand off all real work to a worker thread to avoid running file I/O,
+        // LoadLibrary, and detour transactions under the loader lock.
+        HANDLE h = CreateThread(nullptr, 0, InitThread, hModule, 0, nullptr);
+        if (h) CloseHandle(h);
+    }
+    else if (dwReason == DLL_PROCESS_DETACH)
+    {
+        // During process termination, join watcher thread object so CRT static
+        // teardown does not hit std::thread's joinable-guard terminate.
+        if (pvReserved != nullptr) {
+            FileWatcher::Stop();
+        }
+    }
+
+    return TRUE;
+}