Callback Loop Balancing in JavaScript

cloop-balancer.js

const cores = navigator.hardwareConcurrency || 2;

let frameCount = 0;
let last_time = performance.now();
const render = now_time => {
  const delta = now_time - last_time;
  frameCount++;
  last_time = now_time;

  const FPS = Math.round(1000 / delta);

  if (FPS < 50)
    if ((frameCount % cores) === 0) hard_worker();
  else hard_worker();
  
  requestAnimationFrame(render);
};

requestAnimationFrame(render);

function hard_worker() {
  // code...
}