text: #define _POSIX_C_SOURCE 200112L
  #include <stdlib.h>
  #include <time.h>
  #include <wlr/types/wlr_surface.h>
  #include "sway/server.h"
  #include "sway/surface.h"
  
  void handle_destroy(struct wl_listener *listener, void *data) {
  	struct sway_surface *surface = wl_container_of(listener, surface, destroy);
  
  	surface->wlr_surface->data = NULL;
  	wl_list_remove(&surface->destroy.link);
  
  	if (surface->frame_done_timer) {
  		wl_event_source_remove(surface->frame_done_timer);
  	}
  
  	free(surface);
  }
  
  static int surface_frame_done_timer_handler(void *data) {
  	struct sway_surface *surface = data;
  
  	struct timespec now;
  	clock_gettime(CLOCK_MONOTONIC, &now);
  	wlr_surface_send_frame_done(surface->wlr_surface, &now);
  
  	return 0;
  }
  
  void handle_compositor_new_surface(struct wl_listener *listener, void *data) {
  	struct wlr_surface *wlr_surface = data;
  
  	struct sway_surface *surface = calloc(1, sizeof(struct sway_surface));
  	surface->wlr_surface = wlr_surface;
  	wlr_surface->data = surface;
  
  	surface->destroy.notify = handle_destroy;
  	wl_signal_add(&wlr_surface->events.destroy, &surface->destroy);
  
  	surface->frame_done_timer = wl_event_loop_add_timer(server.wl_event_loop,
  		surface_frame_done_timer_handler, surface);
  	if (!surface->frame_done_timer) {
  		wl_resource_post_no_memory(wlr_surface->resource);
  	}
  }
  