Attempt to exit cleanly, without crash (#51)

include/input/cursor.h

@@ -43,6 +43,7 @@ struct kiwmi_cursor {
     struct {
         struct wl_signal button_down;
         struct wl_signal button_up;
+        struct wl_signal destroy;
         struct wl_signal motion;
         struct wl_signal scroll;
     } events;

include/input/keyboard.h

@@ -40,5 +40,6 @@ struct kiwmi_keyboard_key_event {
 
 struct kiwmi_keyboard *
 keyboard_create(struct kiwmi_server *server, struct wlr_input_device *device);
+void keyboard_destroy(struct kiwmi_keyboard *keyboard);
 
 #endif /* KIWMI_INPUT_KEYBOARD_H */

include/server.h

@@ -22,6 +22,10 @@ struct kiwmi_server {
     struct kiwmi_lua *lua;
     struct kiwmi_desktop desktop;
     struct kiwmi_input input;
+
+    struct {
+        struct wl_signal destroy;
+    } events;
 };
 
 bool server_init(struct kiwmi_server *server, char *config_path);

kiwmi/desktop/desktop.c

@@ -85,6 +85,7 @@ void
 desktop_fini(struct kiwmi_desktop *desktop)
 {
     wlr_output_layout_destroy(desktop->output_layout);
+    desktop->output_layout = NULL;
 }
 
 struct kiwmi_output *

kiwmi/desktop/output.c

@@ -264,14 +264,20 @@ output_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
 {
     struct kiwmi_output *output = wl_container_of(listener, output, destroy);
 
-    wlr_output_layout_remove(
+    if (output->desktop->output_layout) {
-        output->desktop->output_layout, output->wlr_output);
+        wlr_output_layout_remove(
+            output->desktop->output_layout, output->wlr_output);
+    }
 
     wl_signal_emit(&output->events.destroy, output);
 
     wl_list_remove(&output->link);
     wl_list_remove(&output->frame.link);
+    wl_list_remove(&output->commit.link);
     wl_list_remove(&output->destroy.link);
+    wl_list_remove(&output->mode.link);
+
+    wl_list_remove(&output->events.destroy.listener_list);
 
     free(output);
 }

kiwmi/desktop/xdg_shell.c

@@ -239,6 +239,10 @@ xdg_surface_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
         view_child_destroy(child);
     }
 
+    if (view->decoration) {
+        view->decoration->view = NULL;
+    }
+
     wl_list_remove(&view->link);
     wl_list_remove(&view->children);
     wl_list_remove(&view->map.link);
@@ -250,6 +254,8 @@ xdg_surface_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
     wl_list_remove(&view->request_move.link);
     wl_list_remove(&view->request_resize.link);
 
+    wl_list_remove(&view->events.unmap.listener_list);
+
     free(view);
 }
 
@@ -509,7 +515,9 @@ xdg_decoration_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
     struct kiwmi_xdg_decoration *decoration =
         wl_container_of(listener, decoration, destroy);
 
-    decoration->view->decoration = NULL;
+    if (decoration->view) {
+        decoration->view->decoration = NULL;
+    }
 
     wl_list_remove(&decoration->destroy.link);
     wl_list_remove(&decoration->request_mode.link);

kiwmi/input/cursor.c

@@ -254,6 +254,7 @@ cursor_create(
 
     wl_signal_init(&cursor->events.button_down);
     wl_signal_init(&cursor->events.button_up);
+    wl_signal_init(&cursor->events.destroy);
     wl_signal_init(&cursor->events.motion);
     wl_signal_init(&cursor->events.scroll);
 
@@ -263,14 +264,12 @@ cursor_create(
 void
 cursor_destroy(struct kiwmi_cursor *cursor)
 {
+    wl_signal_emit(&cursor->events.destroy, cursor);
+
     wlr_cursor_destroy(cursor->cursor);
     wlr_xcursor_manager_destroy(cursor->xcursor_manager);
 
-    wl_list_remove(&cursor->cursor_motion.link);
+    // The wlr_cursor is already destroyed, don't unregister listeners
-    wl_list_remove(&cursor->cursor_motion_absolute.link);
-    wl_list_remove(&cursor->cursor_button.link);
-    wl_list_remove(&cursor->cursor_axis.link);
-    wl_list_remove(&cursor->cursor_frame.link);
 
     free(cursor);
 }

kiwmi/input/input.c

@@ -101,7 +101,7 @@ input_fini(struct kiwmi_input *input)
     struct kiwmi_keyboard *keyboard;
     struct kiwmi_keyboard *tmp;
     wl_list_for_each_safe (keyboard, tmp, &input->keyboards, link) {
-        free(keyboard);
+        keyboard_destroy(keyboard);
     }
 
     seat_destroy(input->seat);

kiwmi/input/keyboard.c

@@ -116,14 +116,7 @@ keyboard_destroy_notify(struct wl_listener *listener, void *UNUSED(data))
     struct kiwmi_keyboard *keyboard =
         wl_container_of(listener, keyboard, device_destroy);
 
-    wl_list_remove(&keyboard->link);
+    keyboard_destroy(keyboard);
-    wl_list_remove(&keyboard->modifiers.link);
-    wl_list_remove(&keyboard->key.link);
-    wl_list_remove(&keyboard->device_destroy.link);
-
-    wl_signal_emit(&keyboard->events.destroy, keyboard);
-
-    free(keyboard);
 }
 
 struct kiwmi_keyboard *
@@ -167,3 +160,19 @@ keyboard_create(struct kiwmi_server *server, struct wlr_input_device *device)
 
     return keyboard;
 }
+
+void
+keyboard_destroy(struct kiwmi_keyboard *keyboard)
+{
+    wl_list_remove(&keyboard->modifiers.link);
+    wl_list_remove(&keyboard->key.link);
+    wl_list_remove(&keyboard->device_destroy.link);
+
+    wl_signal_emit(&keyboard->events.destroy, keyboard);
+
+    wl_list_remove(&keyboard->link);
+
+    wl_list_remove(&keyboard->events.destroy.listener_list);
+
+    free(keyboard);
+}

kiwmi/luak/kiwmi_cursor.c

@@ -309,7 +309,8 @@ luaK_kiwmi_cursor_new(lua_State *L)
     struct kiwmi_lua *lua       = lua_touserdata(L, 1);
     struct kiwmi_cursor *cursor = lua_touserdata(L, 2);
 
-    struct kiwmi_object *obj = luaK_get_kiwmi_object(lua, cursor, NULL);
+    struct kiwmi_object *obj =
+        luaK_get_kiwmi_object(lua, cursor, &cursor->events.destroy);
 
     struct kiwmi_object **cursor_ud = lua_newuserdata(L, sizeof(*cursor_ud));
     luaL_getmetatable(L, "kiwmi_cursor");

kiwmi/luak/kiwmi_server.c

@@ -574,7 +574,8 @@ luaK_kiwmi_server_new(lua_State *L)
     struct kiwmi_lua *lua       = lua_touserdata(L, 1);
     struct kiwmi_server *server = lua_touserdata(L, 2);
 
-    struct kiwmi_object *obj = luaK_get_kiwmi_object(lua, server, NULL);
+    struct kiwmi_object *obj =
+        luaK_get_kiwmi_object(lua, server, &server->events.destroy);
 
     struct kiwmi_object **server_ud = lua_newuserdata(L, sizeof(*server_ud));
     luaL_getmetatable(L, "kiwmi_server");

kiwmi/luak/luak.c

@@ -39,6 +39,15 @@ luaK_toudata(lua_State *L, int ud, const char *tname)
     return NULL;
 }
 
+static void
+kiwmi_object_destroy(struct kiwmi_object *obj)
+{
+    wl_list_remove(&obj->destroy.link);
+    wl_list_remove(&obj->events.destroy.listener_list);
+
+    free(obj);
+}
+
 int
 luaK_kiwmi_object_gc(lua_State *L)
 {
@@ -47,7 +56,7 @@ luaK_kiwmi_object_gc(lua_State *L)
     --obj->refcount;
 
     if (obj->refcount == 0 && wl_list_empty(&obj->callbacks)) {
-        free(obj);
+        kiwmi_object_destroy(obj);
     }
 
     return 0;
@@ -71,8 +80,6 @@ kiwmi_object_destroy_notify(struct wl_listener *listener, void *data)
         free(lc);
     }
 
-    wl_list_remove(&obj->destroy.link);
-
     lua_State *L = obj->lua->L;
 
     lua_rawgeti(L, LUA_REGISTRYINDEX, obj->lua->objects);
@@ -84,7 +91,7 @@ kiwmi_object_destroy_notify(struct wl_listener *listener, void *data)
     obj->valid = false;
 
     if (obj->refcount == 0) {
-        free(obj);
+        kiwmi_object_destroy(obj);
     }
 }
 
@@ -123,10 +130,12 @@ luaK_get_kiwmi_object(
     if (destroy) {
         obj->destroy.notify = kiwmi_object_destroy_notify;
         wl_signal_add(destroy, &obj->destroy);
-
+    } else {
-        wl_signal_init(&obj->events.destroy);
+        wl_list_init(&obj->destroy.link);
     }
 
+    wl_signal_init(&obj->events.destroy);
+
     wl_list_init(&obj->callbacks);
 
     lua_rawgeti(L, LUA_REGISTRYINDEX, lua->objects);

kiwmi/server.c

@@ -46,6 +46,8 @@ server_init(struct kiwmi_server *server, char *config_path)
     struct wlr_renderer *renderer = wlr_backend_get_renderer(server->backend);
     wlr_renderer_init_wl_display(renderer, server->wl_display);
 
+    wl_signal_init(&server->events.destroy);
+
     if (!desktop_init(&server->desktop, renderer)) {
         wlr_log(WLR_ERROR, "Failed to initialize desktop");
         wl_display_destroy(server->wl_display);
@@ -132,12 +134,15 @@ server_fini(struct kiwmi_server *server)
 {
     wlr_log(WLR_DEBUG, "Shutting down Wayland server");
 
+    wl_signal_emit(&server->events.destroy, server);
+
     wl_display_destroy_clients(server->wl_display);
-    wl_display_destroy(server->wl_display);
 
     desktop_fini(&server->desktop);
     input_fini(&server->input);
 
+    wl_display_destroy(server->wl_display);
+
     luaK_destroy(server->lua);
 
     free(server->config_path);