diff --git a/service/testtimer.lua b/service/testtimer.lua
index c6d64f36..776aa0de 100644
--- a/service/testtimer.lua
+++ b/service/testtimer.lua
@@ -11,7 +11,17 @@ local function wakeup(co)
 	end
 end
 
+local function test()
+	skynet.timeout(10, function() print("test timeout 10") end)
+	for i=1,10 do
+		print("test sleep",i,skynet.now())
+		skynet.sleep(1)
+	end
+end
+
 skynet.start(function()
+	test()
+
 	skynet.fork(wakeup, coroutine.running())
 	skynet.timeout(300, function() timeout "Hello World" end)
 	for i = 1, 10 do
@@ -20,4 +30,5 @@ skynet.start(function()
 	end
 	skynet.exit()
 	print("Test timer exit")
+
 end)
diff --git a/skynet-src/skynet_timer.c b/skynet-src/skynet_timer.c
index 96084ec1..faa27ced 100644
--- a/skynet-src/skynet_timer.c
+++ b/skynet-src/skynet_timer.c
@@ -102,16 +102,36 @@ timer_add(struct timer *T,void *arg,size_t sz,int time)
 	__sync_lock_release(&T->lock);
 }
 
-static void 
-timer_execute(struct timer *T)
-{
-	while (__sync_lock_test_and_set(&T->lock,1)) {};
-	int idx=T->time & TIME_NEAR_MASK;
-	struct timer_node *current;
-	int mask,i,time;
+static void
+timer_shift(struct timer *T) {
+	int mask = TIME_NEAR;
+	int time = (++T->time) >> TIME_NEAR_SHIFT;
+	int i=0;
+	
+	while ((T->time & (mask-1))==0) {
+		int idx=time & TIME_LEVEL_MASK;
+		if (idx!=0) {
+			--idx;
+			struct timer_node *current = link_clear(&T->t[i][idx]);
+			while (current) {
+				struct timer_node *temp=current->next;
+				add_node(T,current);
+				current=temp;
+			}
+			break;				
+		}
+		mask <<= TIME_LEVEL_SHIFT;
+		time >>= TIME_LEVEL_SHIFT;
+		++i;
+	}	
+}
+
+static inline void
+timer_execute(struct timer *T) {
+	int idx = T->time & TIME_NEAR_MASK;
 	
 	while (T->near[idx].head.next) {
-		current=link_clear(&T->near[idx]);
+		struct timer_node *current = link_clear(&T->near[idx]);
 		
 		do {
 			struct timer_event * event = (struct timer_event *)(current+1);
@@ -128,29 +148,20 @@ timer_execute(struct timer *T)
 			free(temp);	
 		} while (current);
 	}
-	
-	++T->time;
-	
-	mask = TIME_NEAR;
-	time = T->time >> TIME_NEAR_SHIFT;
-	i=0;
-	
-	while ((T->time & (mask-1))==0) {
-		idx=time & TIME_LEVEL_MASK;
-		if (idx!=0) {
-			--idx;
-			current=link_clear(&T->t[i][idx]);
-			while (current) {
-				struct timer_node *temp=current->next;
-				add_node(T,current);
-				current=temp;
-			}
-			break;				
-		}
-		mask <<= TIME_LEVEL_SHIFT;
-		time >>= TIME_LEVEL_SHIFT;
-		++i;
-	}	
+}
+
+static void 
+timer_update(struct timer *T)
+{
+	while (__sync_lock_test_and_set(&T->lock,1)) {};
+
+	// try to dispatch timeout 0 (rare condition)
+	timer_execute(T);
+
+	// shift time first, and then dispatch timer message
+	timer_shift(T);
+	timer_execute(T);
+
 	__sync_lock_release(&T->lock);
 }
 
@@ -225,7 +236,7 @@ skynet_updatetime(void) {
 		TI->current = ct;
 		int i;
 		for (i=0;i<diff;i++) {
-			timer_execute(TI);
+			timer_update(TI);
 		}
 	}
 }