xinput1_3: Hold module reference while the hid thread is running.

We have no means of stopping the thread from DllMain on DLL_PROCESS_DETACH without having a race condition - waiting on the thread itself is not an option due to the loader lock. The best we can do is just never unload the DLL as long as the thread is active which is forever. This fixes crashes in Mighty Switch Force! Collection while controllers are unplugged - the game loads and frees xinput in a loop.

xinput1_3: Hold module reference while the hid thread is running.
10a0a8ea · Arkadiusz Hiler · Alexandre Julliard · 7128a659 · 10a0a8ea
Commit 10a0a8ea authored Oct 10, 2023 by Arkadiusz Hiler Committed by Alexandre Julliard Oct 11, 2023
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Showing with 13 additions and 37 deletions

main.c dlls/xinput1_3/main.c +13 -37

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--- a/dlls/xinput1_3/main.c
+++ b/dlls/xinput1_3/main.c
@@ -121,8 +121,6 @@ static struct xinput_controller controllers[XUSER_MAX_COUNT] =

 static HMODULE xinput_instance;
 static HANDLE start_event;
-static HANDLE stop_event;
-static HANDLE done_event;
 static HANDLE update_event;

 static BOOL find_opened_device(const WCHAR *device_path, int *free_slot)
@@ -547,21 +545,6 @@ static void controller_destroy(struct xinput_controller *controller, BOOL alread
    LeaveCriticalSection(&controller->crit);
 }

-static void stop_update_thread(void)
-{
-    int i;
-
-    SetEvent(stop_event);
-    WaitForSingleObject(done_event, INFINITE);
-
-    CloseHandle(start_event);
-    CloseHandle(stop_event);
-    CloseHandle(done_event);
-    CloseHandle(update_event);
-
-    for (i = 0; i < XUSER_MAX_COUNT; i++) controller_destroy(&controllers[i], FALSE);
-}
-
 static LONG sign_extend(ULONG value, const HIDP_VALUE_CAPS *caps)
 {
    UINT sign = 1 << (caps->BitSize - 1);
@@ -687,9 +670,9 @@ static LRESULT CALLBACK xinput_devnotify_wndproc(HWND hwnd, UINT msg, WPARAM wpa

 static DWORD WINAPI hid_update_thread_proc(void *param)
 {
-    struct xinput_controller *devices[XUSER_MAX_COUNT + 2];
-    HANDLE events[XUSER_MAX_COUNT + 2];
-    DWORD i, count = 2, ret = WAIT_TIMEOUT;
+    struct xinput_controller *devices[XUSER_MAX_COUNT + 1];
+    HANDLE events[XUSER_MAX_COUNT + 1];
+    DWORD i, count = 1, ret = WAIT_TIMEOUT;
    DEV_BROADCAST_DEVICEINTERFACE_W filter =
    {
        .dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE_W),
@@ -721,7 +704,7 @@ static DWORD WINAPI hid_update_thread_proc(void *param)
    {
        if (ret == count) while (PeekMessageW(&msg, hwnd, 0, 0, PM_REMOVE)) DispatchMessageW(&msg);
        if (ret == WAIT_TIMEOUT) update_controller_list();
-        if (ret < count - 2) read_controller_state(devices[ret]);
+        if (ret < count - 1) read_controller_state(devices[ret]);

        count = 0;
        for (i = 0; i < XUSER_MAX_COUNT; ++i)
@@ -737,33 +720,30 @@ static DWORD WINAPI hid_update_thread_proc(void *param)
            LeaveCriticalSection(&controllers[i].crit);
        }
        events[count++] = update_event;
-        events[count++] = stop_event;
    }
-    while ((ret = MsgWaitForMultipleObjectsEx(count, events, 2000, QS_ALLINPUT, MWMO_ALERTABLE)) < count - 1 ||
-            ret == count || ret == WAIT_TIMEOUT);
+    while ((ret = MsgWaitForMultipleObjectsEx(count, events, 2000, QS_ALLINPUT, MWMO_ALERTABLE)) <= count ||
+            ret == WAIT_TIMEOUT);
+
+    ERR("wait failed in the update thread, ret %lu, error %lu\n", ret, GetLastError());

    UnregisterDeviceNotification(notif);
    DestroyWindow(hwnd);
    UnregisterClassW(cls.lpszClassName, xinput_instance);

-    if (ret != count - 1) ERR("update thread exited unexpectedly, ret %lu\n", ret);
-    SetEvent(done_event);
-    return ret;
+    FreeLibraryAndExitThread(xinput_instance, ret);
 }

 static BOOL WINAPI start_update_thread_once( INIT_ONCE *once, void *param, void **context )
 {
    HANDLE thread;
+    HMODULE module;
+
+    if (!GetModuleHandleExW(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS, (void*)hid_update_thread_proc, &module))
+        WARN("Failed to increase module's reference count, error: %lu\n", GetLastError());

    start_event = CreateEventA(NULL, FALSE, FALSE, NULL);
    if (!start_event) ERR("failed to create start event, error %lu\n", GetLastError());

-    stop_event = CreateEventA(NULL, FALSE, FALSE, NULL);
-    if (!stop_event) ERR("failed to create stop event, error %lu\n", GetLastError());
-
-    done_event = CreateEventA(NULL, FALSE, FALSE, NULL);
-    if (!done_event) ERR("failed to create done event, error %lu\n", GetLastError());
-
    update_event = CreateEventA(NULL, FALSE, FALSE, NULL);
    if (!update_event) ERR("failed to create update event, error %lu\n", GetLastError());

@@ -811,10 +791,6 @@ BOOL WINAPI DllMain(HINSTANCE inst, DWORD reason, LPVOID reserved)
        xinput_instance = inst;
        DisableThreadLibraryCalls(inst);
        break;
-    case DLL_PROCESS_DETACH:
-        if (reserved) break;
-        stop_update_thread();
-        break;
    }
    return TRUE;
 }