diff --git a/f8/timer.cc b/f8/timer.cc
index 6fca259..607ed96 100644
--- a/f8/timer.cc
+++ b/f8/timer.cc
@@ -9,12 +9,15 @@ namespace f8
 
     Attacher::Attacher()
     {
-
+        p_.SetOwner(&f8::Timer::Instance()->xtimer_);
+        if (!f8::Timer::Instance()->Initialized()) {
+            abort();
+        }
     }
 
     void Timer::Init()
     {
-
+        initialized_ = true;
     }
 
     void Timer::UnInit()
@@ -29,78 +32,77 @@ namespace f8
 
     void Timer::Update()
     {
-
+        xtimer_.Update();
     }
 
     void Timer::SetTimeout(int expire_time, a8::TimerCb cb)
     {
-
+        xtimer_.SetTimeout(expire_time, cb);
     }
 
     void Timer::SetTimeoutEx(int expire_time, a8::TimerCb cb, Attacher* attacher)
     {
-
+        xtimer_.SetTimeoutEx(expire_time, cb, &attacher->p_);
     }
 
     TimerWp Timer::SetTimeoutWp(int expire_time, a8::TimerCb cb)
     {
-
+        return TimerWp(xtimer_.SetTimeoutWp(expire_time, cb));
     }
 
     TimerWp Timer::SetTimeoutWpEx(int expire_time, a8::TimerCb cb, Attacher* attacher)
     {
-
+        return TimerWp(xtimer_.SetTimeoutWpEx(expire_time, cb, &attacher->p_));
     }
 
     void Timer::SetInterval(int expire_time, a8::TimerCb cb)
     {
-
+        xtimer_.SetInterval(expire_time, cb);
     }
 
     void Timer::SetIntervalEx(int expire_time, a8::TimerCb cb, Attacher* attacher)
     {
-
+        xtimer_.SetIntervalEx(expire_time, cb, &attacher->p_);
     }
 
     TimerWp Timer::SetIntervalWp(int expire_time, a8::TimerCb cb)
     {
-
+        return TimerWp(xtimer_.SetIntervalWp(expire_time, cb));
     }
 
     TimerWp Timer::SetIntervalWpEx(int expire_time, a8::TimerCb cb, Attacher* attacher)
     {
-
+        return TimerWp(xtimer_.SetIntervalWpEx(expire_time, cb, &attacher->p_));
     }
 
     void Timer::FireEvent(TimerWp& timer_wp, int event, a8::Args* args)
     {
-
+        xtimer_.FireEvent(timer_wp.p_, event, args);
     }
 
     void Timer::ModifyTime(TimerWp& timer_wp, int expire_time)
     {
-
+        xtimer_.ModifyTime(timer_wp.p_, expire_time);
     }
 
     void Timer::Delete(TimerWp& timer_wp)
     {
-
+        xtimer_.Delete(timer_wp.p_);
     }
 
     long long Timer::GetRemainTime(TimerWp& timer_wp)
     {
-
-
+        return xtimer_.GetRemainTime(timer_wp.p_);
     }
 
     void Timer::DeleteCurrentTimer()
     {
-
+        xtimer_.DeleteCurrentTimer();
     }
 
     bool Timer::IsRunning()
     {
-
+        return xtimer_.IsRunning();
     }
 
 }
diff --git a/f8/timer.h b/f8/timer.h
index be215f5..174bcce 100644
--- a/f8/timer.h
+++ b/f8/timer.h
@@ -61,6 +61,8 @@ namespace f8
     private:
         bool initialized_ = false;
         a8::XTimer xtimer_;
+
+        friend class Attacher;
     };
 
 }