Atomics.load()

// Create a SharedArrayBuffer with a size in bytes
const buffer = new SharedArrayBuffer(16);
const uint8 = new Uint8Array(buffer);
uint8[0] = 5;
// 5 + 2 = 7
console.log(Atomics.add(uint8, 0, 2));
// Expected output: 5
console.log(Atomics.load(uint8, 0));
// Expected output: 7

Atomics.load(typedArray, index)

const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);
Atomics.add(ta, 0, 12);
Atomics.load(ta, 0); // 12