diff --git a/_example/example01/main.go b/_example/example01/main.go
index 833eba8..1edd800 100644
--- a/_example/example01/main.go
+++ b/_example/example01/main.go
@@ -21,19 +21,19 @@ func main() {
 	defer q.Release()
 
 	// assign tasks in queue
-	for i := 0; i < taskN; i++ {
-		go func(i int) {
+	for i := range taskN {
+		go func() {
 			if err := q.QueueTask(func(ctx context.Context) error {
 				rets <- fmt.Sprintf("Hi Gopher, handle the job: %02d", +i)
 				return nil
 			}); err != nil {
 				panic(err)
 			}
-		}(i)
+		}()
 	}
 
 	// wait until all tasks done
-	for i := 0; i < taskN; i++ {
+	for range taskN {
 		fmt.Println("message:", <-rets)
 		time.Sleep(20 * time.Millisecond)
 	}
diff --git a/_example/example02/main.go b/_example/example02/main.go
index e117f27..0e82dc7 100644
--- a/_example/example02/main.go
+++ b/_example/example02/main.go
@@ -44,19 +44,19 @@ func main() {
 	defer q.Release()
 
 	// assign tasks in queue
-	for i := 0; i < taskN; i++ {
-		go func(i int) {
+	for i := range taskN {
+		go func() {
 			if err := q.Queue(&job{
 				Name:    "Gopher",
 				Message: fmt.Sprintf("handle the job: %d", i+1),
 			}); err != nil {
 				log.Println(err)
 			}
-		}(i)
+		}()
 	}
 
 	// wait until all tasks done
-	for i := 0; i < taskN; i++ {
+	for range taskN {
 		fmt.Println("message:", <-rets)
 		time.Sleep(20 * time.Millisecond)
 	}
diff --git a/benchmark_test.go b/benchmark_test.go
index d97d9ce..c0bfb3c 100644
--- a/benchmark_test.go
+++ b/benchmark_test.go
@@ -53,13 +53,12 @@ func BenchmarkQueueTask(b *testing.B) {
 		WithLogger(emptyLogger{}),
 	)
 	b.ReportAllocs()
-	b.ResetTimer()
 
 	m := job.NewTask(func(context.Context) error {
 		return nil
 	})
 
-	for n := 0; n < b.N; n++ {
+	for b.Loop() {
 		if err := q.queue(&m); err != nil {
 			b.Fatal(err)
 		}
@@ -73,13 +72,12 @@ func BenchmarkQueue(b *testing.B) {
 		WithLogger(emptyLogger{}),
 	)
 	b.ReportAllocs()
-	b.ResetTimer()
 
 	m := job.NewMessage(&mockMessage{
 		message: testMessageFoo,
 	})
 
-	for n := 0; n < b.N; n++ {
+	for b.Loop() {
 		if err := q.queue(&m); err != nil {
 			b.Fatal(err)
 		}
@@ -129,7 +127,7 @@ func BenchmarkRingWithTask(b *testing.B) {
 		WithLogger(emptyLogger{}),
 	)
 
-	for n := 0; n < b.N; n++ {
+	for b.Loop() {
 		_ = q.run(&task)
 	}
 }
diff --git a/handle_performance_test.go b/handle_performance_test.go
index 33a430c..b60d76a 100644
--- a/handle_performance_test.go
+++ b/handle_performance_test.go
@@ -33,8 +33,7 @@ func BenchmarkHandleRetry(b *testing.B) {
 				},
 			}
 			b.ReportAllocs()
-			b.ResetTimer()
-			for range b.N {
+			for b.Loop() {
 				attempts = 0
 				m.RetryCount = retries
 				if err := q.handle(&m); err != nil {
diff --git a/job/benchmark_test.go b/job/benchmark_test.go
index 68f5714..67caabe 100644
--- a/job/benchmark_test.go
+++ b/job/benchmark_test.go
@@ -8,7 +8,7 @@ import (
 
 func BenchmarkNewTask(b *testing.B) {
 	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		NewTask(func(context.Context) error {
 			return nil
 		},
@@ -23,7 +23,7 @@ func BenchmarkNewTask(b *testing.B) {
 
 func BenchmarkNewMessage(b *testing.B) {
 	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_ = NewMessage(mockMessage{
 			message: "foo",
 		},
@@ -38,7 +38,7 @@ func BenchmarkNewMessage(b *testing.B) {
 
 func BenchmarkNewOption(b *testing.B) {
 	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
+	for b.Loop() {
 		_ = NewOptions(
 			AllowOption{
 				RetryCount: Int64(100),
diff --git a/ring_performance_test.go b/ring_performance_test.go
index 0196286..64fbcab 100644
--- a/ring_performance_test.go
+++ b/ring_performance_test.go
@@ -22,8 +22,7 @@ func BenchmarkRingBoundary(b *testing.B) {
 				}
 			}
 			b.ReportAllocs()
-			b.ResetTimer()
-			for range b.N {
+			for b.Loop() {
 				if err := w.Queue(&m); err != nil {
 					b.Fatal(err)
 				}
diff --git a/ring_test.go b/ring_test.go
index 79ddebb..d4c07eb 100644
--- a/ring_test.go
+++ b/ring_test.go
@@ -636,8 +636,7 @@ func BenchmarkRingQueue(b *testing.B) {
 		w := NewRing()
 		m := mockMessage{message: testMessageTest}
 
-		b.ResetTimer()
-		for i := 0; i < b.N; i++ {
+		for b.Loop() {
 			for range 100 {
 				_ = w.Queue(&m)
 			}
diff --git a/thread_test.go b/thread_test.go
index 7a5b9fe..910df22 100644
--- a/thread_test.go
+++ b/thread_test.go
@@ -9,35 +9,35 @@ import (
 func TestRoutineGroupRun(t *testing.T) {
 	t.Run("execute single function", func(t *testing.T) {
 		g := newRoutineGroup()
-		var counter int32
+		var counter atomic.Int32
 
 		g.Run(func() {
-			atomic.AddInt32(&counter, 1)
+			counter.Add(1)
 		})
 
 		g.Wait()
 
-		if atomic.LoadInt32(&counter) != 1 {
-			t.Errorf("expected counter to be 1, got %d", counter)
+		if counter.Load() != 1 {
+			t.Errorf("expected counter to be 1, got %d", counter.Load())
 		}
 	})
 
 	t.Run("execute multiple functions", func(t *testing.T) {
 		g := newRoutineGroup()
-		var counter int32
+		var counter atomic.Int32
 		numRoutines := 10
 
 		for range numRoutines {
 			g.Run(func() {
-				atomic.AddInt32(&counter, 1)
+				counter.Add(1)
 				time.Sleep(10 * time.Millisecond)
 			})
 		}
 
 		g.Wait()
 
-		if atomic.LoadInt32(&counter) != int32(numRoutines) {
-			t.Errorf("expected counter to be %d, got %d", numRoutines, counter)
+		if counter.Load() != int32(numRoutines) {
+			t.Errorf("expected counter to be %d, got %d", numRoutines, counter.Load())
 		}
 	})
 }