renepay: bugfix assertion htlc_total<=known_max

Make knowledge update and removal of pending HTLCs atomic
to avoid race conditions.

Changelog-EXPERIMENTAL: renepay: fixed: make knowledge update and removal of pending HTLCs atomic to avoid race conditions.

Signed-off-by: Lagrang3 <[email protected]>

plugins/renepay/routetracker.c

@@ -87,16 +87,15 @@ static void routetracker_add_to_final(struct routetracker *routetracker,
 	}
 }
 
-static void route_success_register(struct routetracker *routetracker,
-				   struct route *route)
+static void route_success_update_knowledge(struct route *route,
+					   struct uncertainty *uncertainty)
 {
-	if(route->hops){
-		uncertainty_route_success(pay_plugin->uncertainty, route);
-	}
-	routetracker_add_to_final(routetracker, route);
+	if (route->hops)
+		uncertainty_route_success(uncertainty, route);
 }
-void route_failure_register(struct routetracker *routetracker,
-			    struct route *route)
+
+static void route_failure_update_knowledge(struct route *route,
+					   struct uncertainty *uncertainty)
 {
 	struct payment_result *result = route->result;
 	assert(result);
@@ -135,6 +134,24 @@ void route_failure_register(struct routetracker *routetracker,
 			    route->hops[last_good_channel + 1].direction);
 		}
 	}
+}
+
+static void route_success_register(struct routetracker *routetracker,
+				   struct route *route)
+{
+	/* Delay the knowledge update to destruction so that updating the
+	 * knowledge and htlc removal happens atomically. */
+	tal_add_destructor2(route, route_success_update_knowledge,
+			    pay_plugin->uncertainty);
+	routetracker_add_to_final(routetracker, route);
+}
+void route_failure_register(struct routetracker *routetracker,
+			    struct route *route)
+{
+	/* Delay the knowledge update to destruction so that updating the
+	 * knowledge and htlc removal happens atomically. */
+	tal_add_destructor2(route, route_failure_update_knowledge,
+			    pay_plugin->uncertainty);
 	routetracker_add_to_final(routetracker, route);
 }