kike: implement the ping-pong and QUIT

src/common.c

@@ -961,6 +961,15 @@ poller_timers_find (struct poller_timers *self,
 	return -1;
 }
 
+static ssize_t
+poller_timers_find_by_data (struct poller_timers *self, void *data)
+{
+	for (size_t i = 0; i < self->len; i++)
+		if (self->info[i].user_data == data)
+			return i;
+	return -1;
+}
+
 static void
 poller_timers_add (struct poller_timers *self,
 	poller_timer_func dispatcher, void *data, int timeout_ms)