tick on every 50ms

master.html

<script>
let myWorker = new Worker('worker.js');
let prev = Date.now();
myWorker.onmessage = function(e) {
    let now = Date.now();
    console.log(now - prev);
    prev = now;
}
</script>

worker.js

const TICK_INTERVAL = 50;
const START_TIME = performance.now();
let expecting = 0;

let ticker = () => {
    while (true) {
        let curtime = performance.now();
        if (curtime >= expecting) {
            expecting = (Math.floor((curtime - START_TIME) / TICK_INTERVAL) + 1) * TICK_INTERVAL + START_TIME;
            postMessage(1);
            return setTimeout(ticker, TICK_INTERVAL / 8 * 7);
        }
    }
};

ticker();