Nest: Keep route ordering during route updates

Put new non-best routes to the end of list instead of the second
position. Put updated routes to their old position. Position is changed
just by best route selection.

1 files changed, 12 insertions, 6 deletions

diff --git a/nest/rt-table.c b/nest/rt-table.c
index ae5a8444..eff25e5c 100644
--- a/nest/rt-table.c
+++ b/nest/rt-table.c
@@ -1133,6 +1133,9 @@ rte_recalculate(struct channel *c, net *net, rte *new, struct rte_src *src)
       before_old = old;
     }
 
+  /* Save the last accessed position */
+  rte **pos = k;
+
   if (!old)
     before_old = NULL;
 
@@ -1229,6 +1232,7 @@ rte_recalculate(struct channel *c, net *net, rte *new, struct rte_src *src)
 
 	  new->next = *k;
 	  *k = new;
+
 	  table->rt_count++;
 	}
     }
@@ -1247,6 +1251,7 @@ rte_recalculate(struct channel *c, net *net, rte *new, struct rte_src *src)
 
 	  new->next = net->routes;
 	  net->routes = new;
+
 	  table->rt_count++;
 	}
       else if (old == old_best)
@@ -1261,8 +1266,9 @@ rte_recalculate(struct channel *c, net *net, rte *new, struct rte_src *src)
 	  /* Add the new route to the list */
 	  if (new)
 	    {
-	      new->next = net->routes;
-	      net->routes = new;
+	      new->next = *pos;
+	      *pos = new;
+
 	      table->rt_count++;
 	    }
 
@@ -1286,11 +1292,11 @@ rte_recalculate(struct channel *c, net *net, rte *new, struct rte_src *src)
 	  /* The third case - the new route is not better than the old
 	     best route (therefore old_best != NULL) and the old best
 	     route was not removed (therefore old_best == net->routes).
-	     We just link the new route after the old best route. */
+	     We just link the new route to the old/last position. */
+
+	  new->next = *pos;
+	  *pos = new;
 
-	  ASSERT(net->routes != NULL);
-	  new->next = net->routes->next;
-	  net->routes->next = new;
 	  table->rt_count++;
 	}
       /* The fourth (empty) case - suboptimal route was removed, nothing to do */