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JavaScript & Atomics

Atomics 对象提供了一组静态方法对 SharedArrayBuffer 和 ArrayBuffer 对象进行原子操作。

Atomics.add

Adds the provided value to the existing value at the specified index of the array. Returns the old value at that index.

Atomics.load

Returns the value at the specified index of the array.

Atomics.compareExchange

Atomics.exchange

Atomics.isLockFree

Atomics.store

Atomics.or

Atomics.xor

Atomics.sub

demos

const sab = new SharedArrayBuffer(1024);
const ta = new Uint8Array(sab);

ta[0];
// 0
ta[0] = 5;
// 5

Atomics.add(ta, 0, 12); 
// 5

Atomics.load(ta, 0); 
// 17 ✅
// 12 ❌

Atomics.and(ta, 0, 1);
// 17
Atomics.load(ta, 0); 
// 1

Atomics.compareExchange(ta, 0, 5, 12);
// 
Atomics.load(ta, 0);
// 12

Atomics.exchange(ta, 0, 12);
// 
Atomics.load(ta, 0);
// 12

Atomics.isLockFree(1);
// true
Atomics.isLockFree(2);
// true
Atomics.isLockFree(3);
// false
Atomics.isLockFree(4); 
/ true

Atomics.or(ta, 0, 1);
Atomics.load(ta, 0); 
// 5

Atomics.store(ta, 0, 12);
// 12

Atomics.sub(ta, 0, 2);
Atomics.load(ta, 0);
// 3

Atomics.xor(ta, 0, 1);
Atomics.load(ta, 0);
// 4