ringer: Cancel async libfeedback calls on timeout

If libfeedback has not finished triggering/ending a feedback after one
second we give up and set an error state.

src/calls-ringer.c

@@ -38,6 +38,10 @@
 #include <libfeedback.h>
 
 
+/* cancel lfb operations after reaching the timeout */
+#define LFB_TIMEOUT_MS 1000
+
+
 enum {
   PROP_0,
   PROP_RING_STATE,
@@ -59,6 +63,7 @@ struct _CallsRinger {
   CallsRingState target_state;
 
   gboolean       freeze_state_notify;
+  guint          request_timeout_id;
 };
 
 
@@ -88,6 +93,8 @@ set_ring_state (CallsRinger   *self,
   g_assert (CALLS_IS_RINGER (self));
   g_assert (state >= CALLS_RING_STATE_INACTIVE && state <= CALLS_RING_STATE_ERROR);
 
+  g_clear_handle_id (&self->request_timeout_id, g_source_remove);
+
   if (self->state == state)
     return;
 
@@ -195,6 +202,23 @@ on_feedback_ended (LfbEvent    *event,
 }
 
 
+static gboolean
+request_timed_out (CallsRinger *self)
+{
+  if (!CALLS_IS_RINGER (self))
+    return G_SOURCE_REMOVE;
+
+  g_debug ("Request '%s' timed out, cancelling..",
+           ring_state_to_string (self->target_state));
+
+  g_cancellable_cancel (self->cancel);
+
+  set_ring_state (self, CALLS_RING_STATE_ERROR);
+
+  return G_SOURCE_REMOVE;
+}
+
+
 static LfbEvent *
 get_event_for_state (CallsRinger   *self,
                      CallsRingState state)
@@ -246,6 +270,9 @@ target_state_step (CallsRinger *self)
                                   (GAsyncReadyCallback) on_event_feedback_ended,
                                   self);
   }
+
+  self->request_timeout_id =
+    g_timeout_add (LFB_TIMEOUT_MS, G_SOURCE_FUNC (request_timed_out), self);
 }
 
 
@@ -453,6 +480,8 @@ dispose (GObject *object)
 
   g_signal_handlers_disconnect_by_data (calls_manager_get_default (), self);
 
+  g_clear_handle_id (&self->request_timeout_id, g_source_remove);
+
   g_cancellable_cancel (self->cancel);
   g_clear_object (&self->cancel);