在多线程并发场景中，如何实现安全访问同一块共享内存?

Question

在多线程并发场景中，如何实现安全访问同一块共享内存

Answer 1

可以使用共享对象SharedArrayBuffer实现。SharedArrayBuffer对象存储的数据在同时被修改时，需要通过Atomics原子操作保证其同步性，即下个操作开始之前务必需要等到上个操作已经结束。代码示例：

import { MessageEvents, worker } from '@kit.ArkTS'; 
 
let sab = new SharedArrayBuffer(32); 
// int32 buffer view for sab 
let i32a = new Int32Array(sab); 
i32a[0] = 0; 
 
let producer = new worker.ThreadWorker("entry/ets/workers/worker_producer.ts") 
producer.postMessage(sab); 
let consumection = (e: MessageEvents) => { 
  let sab: number = e.data; 
  let i32a = new Int32Array(sab); 
  console.info("Customer: received sab"); 
  while (true) { 
    Atomics.wait(i32a, 0, 0); // blocked here until be waked. 
    let length = i32a.length; 
    for (let i = length - 1; i > 0; i--) { 
      console.info("arraybuffer " + i + " value is " + i32a[i]); 
      i32a[i] = i; 
    } 
  } 
}