convert to Writer field

colorable_windows.go

@@ -95,6 +95,7 @@ type Writer struct {
 	oldattr   word
 	oldpos    coord
 	rest      bytes.Buffer
+	mutex     sync.Mutex
 }
 
 // NewColorable returns new instance of Writer which handles escape sequence from File.
@@ -432,14 +433,10 @@ func atoiWithDefault(s string, def int) (int, error) {
 	return strconv.Atoi(s)
 }
 
-var (
-	writeMutex sync.Mutex
-)
-
 // Write writes data on console
 func (w *Writer) Write(data []byte) (n int, err error) {
-	writeMutex.Lock()
-	defer writeMutex.Unlock()
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
 	var csbi consoleScreenBufferInfo
 	procGetConsoleScreenBufferInfo.Call(uintptr(w.handle), uintptr(unsafe.Pointer(&csbi)))