diff --git a/common/observable/observable_test.go b/common/observable/observable_test.go
index d965fa3b..67e29341 100644
--- a/common/observable/observable_test.go
+++ b/common/observable/observable_test.go
@@ -1,8 +1,8 @@
 package observable
 
 import (
-	"runtime"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -38,20 +38,20 @@ func TestObservable_MutilSubscribe(t *testing.T) {
 	src := NewObservable(iter)
 	ch1, _ := src.Subscribe()
 	ch2, _ := src.Subscribe()
-	count := 0
+	var count int32
 
 	var wg sync.WaitGroup
 	wg.Add(2)
 	waitCh := func(ch <-chan interface{}) {
 		for range ch {
-			count++
+			atomic.AddInt32(&count, 1)
 		}
 		wg.Done()
 	}
 	go waitCh(ch1)
 	go waitCh(ch2)
 	wg.Wait()
-	assert.Equal(t, count, 10)
+	assert.Equal(t, int32(10), count)
 }
 
 func TestObservable_UnSubscribe(t *testing.T) {
@@ -82,9 +82,6 @@ func TestObservable_UnSubscribeWithNotExistSubscription(t *testing.T) {
 }
 
 func TestObservable_SubscribeGoroutineLeak(t *testing.T) {
-	// waiting for other goroutine recycle
-	time.Sleep(120 * time.Millisecond)
-	init := runtime.NumGoroutine()
 	iter := iterator([]interface{}{1, 2, 3, 4, 5})
 	src := NewObservable(iter)
 	max := 100
@@ -107,6 +104,12 @@ func TestObservable_SubscribeGoroutineLeak(t *testing.T) {
 		go waitCh(ch)
 	}
 	wg.Wait()
-	now := runtime.NumGoroutine()
-	assert.Equal(t, init, now)
+
+	for _, sub := range list {
+		_, more := <-sub
+		assert.False(t, more)
+	}
+
+	_, more := <-list[0]
+	assert.False(t, more)
 }
diff --git a/common/singledo/singledo.go b/common/singledo/singledo.go
index 58a95434..0db56c1f 100644
--- a/common/singledo/singledo.go
+++ b/common/singledo/singledo.go
@@ -44,9 +44,12 @@ func (s *Single) Do(fn func() (interface{}, error)) (v interface{}, err error, s
 	s.mux.Unlock()
 	call.val, call.err = fn()
 	call.wg.Done()
+
+	s.mux.Lock()
 	s.call = nil
 	s.result = &Result{call.val, call.err}
 	s.last = now
+	s.mux.Unlock()
 	return call.val, call.err, false
 }
 
diff --git a/common/singledo/singledo_test.go b/common/singledo/singledo_test.go
index 637557c4..c9c58e58 100644
--- a/common/singledo/singledo_test.go
+++ b/common/singledo/singledo_test.go
@@ -2,6 +2,7 @@ package singledo
 
 import (
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -11,7 +12,7 @@ import (
 func TestBasic(t *testing.T) {
 	single := NewSingle(time.Millisecond * 30)
 	foo := 0
-	shardCount := 0
+	var shardCount int32 = 0
 	call := func() (interface{}, error) {
 		foo++
 		time.Sleep(time.Millisecond * 5)
@@ -25,7 +26,7 @@ func TestBasic(t *testing.T) {
 		go func() {
 			_, _, shard := single.Do(call)
 			if shard {
-				shardCount++
+				atomic.AddInt32(&shardCount, 1)
 			}
 			wg.Done()
 		}()
@@ -33,7 +34,7 @@ func TestBasic(t *testing.T) {
 
 	wg.Wait()
 	assert.Equal(t, 1, foo)
-	assert.Equal(t, 4, shardCount)
+	assert.Equal(t, int32(4), shardCount)
 }
 
 func TestTimer(t *testing.T) {