add GetRunningTimer

a8/xtimer.cc

@@ -228,6 +228,9 @@ namespace a8
 
     void XTimer::DeleteTimer(xtimer_list* timer)
     {
+        if (!timer) {
+            abort();
+        }
         if (base_->running_timer == timer) {
             base_->running_timer = nullptr;
         }
@@ -256,6 +259,11 @@ namespace a8
         return timer->param;
     }
 
+    xtimer_list* XTimer::GetRunningTimer()
+    {
+        return base_->running_timer;
+    }
+
     void XTimer::UpdateTimer()
     {
         struct xtvec_base *base = base_;

a8/xtimer.h

@@ -41,6 +41,7 @@ namespace a8
         //通过关联的list_head获取定时器对象
         xtimer_list* GetTimerByAttach(list_head* attach_entry);
         a8::XParams& GetTimerXParams(xtimer_list* timer);
+        xtimer_list* GetRunningTimer();
 
     private:
         void UpdateTimer();