@Override
 protected void drawPixels(
     long pointer,
     int[] pixels,
     int w,
     int h,
     int stride,
     double[] i2u,
     double alpha,
     int interpolation) {
   try {
     lock();
     super.drawPixels(pointer, pixels, w, h, stride, i2u, alpha, interpolation);
   } finally {
     unlock();
   }
 }