Merge branch 'main' into refactor-integrated-test

inotify.go

@@ -69,12 +69,15 @@ func (w *Watcher) isClosed() bool {
 
 // Close removes all watches and closes the events channel.
 func (w *Watcher) Close() error {
+	w.mu.Lock()
 	if w.isClosed() {
+		w.mu.Unlock()
 		return nil
 	}
 
 	// Send 'close' signal to goroutine, and set the Watcher to closed.
 	close(w.done)
+	w.mu.Unlock()
 
 	// Causes any blocking reads to return with an error, provided the file still supports deadline operations
 	err := w.inotifyFile.Close()

integration_test.go

@@ -521,3 +521,18 @@ func TestRemove(t *testing.T) {
 		}
 	})
 }
+
+// Make sure Close() doesn't race; hard to write a good reproducible test for
+// this, but running it 150 times seems to reproduce it in ~75% of cases and
+// isn't too slow (~0.06s on my system).
+func TestCloseRace(t *testing.T) {
+	for i := 0; i < 150; i++ {
+		w, err := NewWatcher()
+		if err != nil {
+			t.Fatal(err)
+		}
+		go w.Close()
+		go w.Close()
+		go w.Close()
+	}
+}

windows.go

@@ -51,10 +51,13 @@ func NewWatcher() (*Watcher, error) {
 
 // Close removes all watches and closes the events channel.
 func (w *Watcher) Close() error {
+	w.mu.Lock()
 	if w.isClosed {
+		w.mu.Unlock()
 		return nil
 	}
 	w.isClosed = true
+	w.mu.Unlock()
 
 	// Send "quit" message to the reader goroutine
 	ch := make(chan error)
@@ -67,9 +70,12 @@ func (w *Watcher) Close() error {
 
 // Add starts watching the named file or directory (non-recursively).
 func (w *Watcher) Add(name string) error {
+	w.mu.Lock()
 	if w.isClosed {
+		w.mu.Unlock()
 		return errors.New("watcher already closed")
 	}
+	w.mu.Unlock()
 	in := &input{
 		op:    opAddWatch,
 		path:  filepath.Clean(name),