Merge pull request #3335 from geniusgogo/fixed_timerlist_search

[src/timer.c]fixed rt_timer_list_next_timeout multi-task safe

src/timer.c

@@ -108,14 +108,23 @@ static void _rt_timer_init(rt_timer_t timer,
 static rt_tick_t rt_timer_list_next_timeout(rt_list_t timer_list[])
 {
     struct rt_timer *timer;
+    register rt_base_t level;
+    rt_tick_t timeout_tick = RT_TICK_MAX;
 
-    if (rt_list_isempty(&timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1]))
-        return RT_TICK_MAX;
+    /* disable interrupt */
+    level = rt_hw_interrupt_disable();
 
-    timer = rt_list_entry(timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1].next,
-                          struct rt_timer, row[RT_TIMER_SKIP_LIST_LEVEL - 1]);
+    if (!rt_list_isempty(&timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1]))
+    {
+        timer = rt_list_entry(timer_list[RT_TIMER_SKIP_LIST_LEVEL - 1].next,
+                              struct rt_timer, row[RT_TIMER_SKIP_LIST_LEVEL - 1]);
+        timeout_tick = timer->timeout_tick;
+    }
+
+    /* enable interrupt */
+    rt_hw_interrupt_enable(level);
 
-    return timer->timeout_tick;
+    return timeout_tick;
 }
 
 rt_inline void _rt_timer_remove(rt_timer_t timer)