sway

commit 1d483c340d39ca75996729cfc6d5bb2b33cff2be
parent aa8fe584215d29e31ae5af43afa81db03b997f85
Author: Manuel Stoeckl <code@mstoeckl.com>
Date:   Mon, 23 Dec 2019 19:17:06 -0500

desktop/surface: Fix crash when timer is NULL

When many surfaces are created, sway can run out of file descriptors,
making wl_event_loop_add_timer (which creates a timerfd) fail and
return NULL. This patch posts a "no memory" error when that is the case,
and only removes the timer if it was created.

(Why "no memory"? It is not easy to distinguish between failures due to
running out of memory and failures due to running out of file
descriptors. Also, using the newer `wl_client_post_implementation_error`
function would lead to an increased version requirement for the
libwayland-server dependency.)

Diffstat:
M
sway/desktop/surface.c
 | 
7
++++++-

1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/sway/desktop/surface.c b/sway/desktop/surface.c
@@ -11,7 +11,9 @@ void handle_destroy(struct wl_listener *listener, void *data) {
 	surface->wlr_surface->data = NULL;
 	wl_list_remove(&surface->destroy.link);
 
-	wl_event_source_remove(surface->frame_done_timer);
+	if (surface->frame_done_timer) {
+		wl_event_source_remove(surface->frame_done_timer);
+	}
 
 	free(surface);
 }
@@ -38,4 +40,7 @@ void handle_compositor_new_surface(struct wl_listener *listener, void *data) {
 
 	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);
+	}
 }