timer: make timer_del() idempotent, add timer_init().

[ccan] / ccan / timer / timer.c

diff --git a/ccan/timer/timer.c b/ccan/timer/timer.c
index c1979fd32d97244a52b930e04ef50bc51733319a..0abf05cd419ee8111312450872e80b53fee1ebb2 100644 (file)
--- a/ccan/timer/timer.c
+++ b/ccan/timer/timer.c
@@ -63,8 +63,20 @@ static void timer_add_raw(struct timers *timers, struct timer *t)
        list_add_tail(l, &t->list);
 }
 
+void timer_init(struct timer *t)
+{
+       list_node_init(&t->list);
+}
+
+static bool list_node_initted(const struct list_node *n)
+{
+       return n->prev == n;
+}
+
 void timer_add(struct timers *timers, struct timer *t, struct timeabs when)
 {
+       assert(list_node_initted(&t->list));
+
        t->time = time_to_grains(when);
 
        /* Added in the past?  Treat it as imminent. */
@@ -79,7 +91,7 @@ void timer_add(struct timers *timers, struct timer *t, struct timeabs when)
 /* FIXME: inline */
 void timer_del(struct timers *timers, struct timer *t)
 {
-       list_del(&t->list);
+       list_del_init(&t->list);
 }
 
 static void timers_far_get(struct timers *timers,
@@ -285,6 +297,8 @@ struct timer *timers_expire(struct timers *timers, struct timeabs expire)
 
                /* This *may* be NULL, if we deleted the first timer */
                t = list_pop(&timers->level[0]->list[off], struct timer, list);
+               if (t)
+                       list_node_init(&t->list);
        } while (!t && update_first(timers));
 
        return t;