Embedded a sync.Mutex to a ListenerCounter.

internal/radio/listener_counter.go

@@ -10,7 +10,7 @@ import (
 
 // ListenerCounter stores the current and peak numbers of listeners.
 type ListenerCounter struct {
-	mut           sync.Mutex
+	sync.Mutex
 	current, peak int
 }
 
@@ -21,22 +21,22 @@ func NewListenerCounter() *ListenerCounter {
 
 // Current returns a number of current listeners.
 func (l *ListenerCounter) Current() int {
-	l.mut.Lock()
+	l.Lock()
-	defer l.mut.Unlock()
+	defer l.Unlock()
 	return l.current
 }
 
 // Current returns a number of peak listeners.
 func (l *ListenerCounter) Peak() int {
-	l.mut.Lock()
+	l.Lock()
-	defer l.mut.Unlock()
+	defer l.Unlock()
 	return l.peak
 }
 
 // Inc increments by 1 a current number of listeners and updates a peak number.
 func (l *ListenerCounter) Inc() int {
-	l.mut.Lock()
+	l.Lock()
-	defer l.mut.Unlock()
+	defer l.Unlock()
 	if l.current == math.MaxInt {
 		// We panic here because if this will ever happen, then something's going certainly wrong.
 		panic(fmt.Sprint("a current number of listeners exceeded MaxInt which is", math.MaxInt))
@@ -51,8 +51,8 @@ func (l *ListenerCounter) Inc() int {
 // Dec decrements by 1 a current number of listeners. An error will occur if
 // a resulting number is less than 0.
 func (l *ListenerCounter) Dec() (int, error) {
-	l.mut.Lock()
+	l.Lock()
-	defer l.mut.Unlock()
+	defer l.Unlock()
 	if l.current == 0 {
 		return l.current, errors.New("an attempt to decrement a number of current listeners down to less than 0")
 	}
@@ -61,8 +61,8 @@ func (l *ListenerCounter) Dec() (int, error) {
 }
 
 func (l *ListenerCounter) MarshalJSON() ([]byte, error) {
-	l.mut.Lock()
+	l.Lock()
-	defer l.mut.Unlock()
+	defer l.Unlock()
 	return json.Marshal(&struct {
 		Current int `json:"current"`
 		Peak    int `json:"peak"`