And same for a Playlist.

cmd/dwelling-radio/main.go

@@ -123,6 +123,8 @@ func main() {
 			}
 			return
 		case syscall.SIGHUP:
+			plylst.Lock()
+			defer plylst.Unlock()
 			if err := plylst.Reload(); err != nil {
 				log.Println(err)
 			}

internal/http/dj_handlers.go

@@ -69,7 +69,9 @@ const defaultTitleTagNoArtist = "[And no title tag either! Pffft]"
 
 func (dj *DJHandlers) PlaylistNext(w http.ResponseWriter, _ *http.Request) {
 	w.Header().Add("Content-Type", "text/plain")
+	dj.playlist.Lock()
 	nxt := dj.playlist.Next()
+	dj.playlist.Unlock()
 	if nxt == "" {
 		log.Println("the end of a playlist has been reached")
 		if nxt = dj.fallbackSong; nxt == "" {

internal/radio/playlist.go

@@ -10,7 +10,7 @@ import (
 
 // Playlist holds a list of paths to a song files.
 type Playlist struct {
-	mutex    sync.Mutex
+	sync.Mutex
 	filePath string
 	playlist []string
 	cur      int
@@ -27,8 +27,6 @@ func NewPlaylist(filePath string, repeat bool) (*Playlist, error) {
 // Next returns the next song to play. Returns an empty string if repeat is
 // false and the end of a playlist was reached.
 func (p *Playlist) Next() (song string) {
-	p.mutex.Lock()
-	defer p.mutex.Unlock()
 	if p.cur == len(p.playlist) {
 		// If the end of a playlist was reached and repeat is set to true,
 		// then go back to the head of it, thus repeating it. Return an empty
@@ -55,10 +53,8 @@ func (p *Playlist) load() error {
 		return errors.New("a playlist file is empty. Did not update")
 	}
 
-	p.mutex.Lock()
 	p.playlist = strings.Split(string(data), "\n")
 	p.cur = 0
-	p.mutex.Unlock()
 
 	return nil
 }