Use Atomic Bool variable instead of using mutex lock and unlock

Signed-off-by: kennyaz <115052215+kennyaz@users.noreply.github.com>

Author: kennyaz

pkg/fswatcher/fswatcher.go

@@ -22,6 +22,7 @@ import (
 	"path"
 	"path/filepath"
 	"sync"
+	"sync/atomic"
 
 	"github.com/fsnotify/fsnotify"
 	"go.uber.org/zap"
@@ -34,7 +35,7 @@ type FSWatcher struct {
 	onChange           func()
 	mu                 sync.RWMutex
 	stop               chan struct{}
-	isClosed           bool
+	isClosed           atomic.Bool //default value is False
 	wg                 sync.WaitGroup
 }
 
@@ -71,7 +72,6 @@ func New(filepaths []string, onChange func(), logger *zap.Logger) (*FSWatcher, e
 		fileHashContentMap: make(map[string]string),
 		onChange:           onChange,
 		stop:               make(chan struct{}),
-		isClosed:           false,
 	}
 
 	if err = w.setupWatchedPaths(filepaths); err != nil {
@@ -148,13 +148,9 @@ func (w *FSWatcher) watch() {
 
 // Close closes the watcher and stops the background go routine of FSWatcher.
 func (w *FSWatcher) Close() error {
-	w.mu.Lock()
-	defer w.mu.Unlock()
-
-	if !w.isClosed {
+	if w.isClosed.CompareAndSwap(false, true) {
 		close(w.stop)
 		w.wg.Wait()
-		w.isClosed = true
 	}
 
 	return w.watcher.Close()