HarmonyOS ArkTS符合线程安全的单例代码示例

参考demo如下：

TestData.ets

import { ArkTSUtils } from '@kit.ArkTS';
// 声明当前模块为共享模块，只能导出可Sendable数据
"use shared"
// 共享模块，TestData全局唯一
@Sendable
export class TestData {
  private keyHandle: string = '0';
  private count_: number = 0;
  lock_: ArkTSUtils.locks.AsyncLock = new ArkTSUtils.locks.AsyncLock()
  private static instance: TestData ;
  private constructor() {}
  public static getInstance(): TestData {
    if (TestData.instance == null) {
      TestData.instance = new TestData();
      console.debug('getInstance  new  ')
    }
    return TestData.instance ;
  }
  initData() {
    this.keyHandle = '100';
  }
  async getKeyHandle(): Promise<string> {
    return this.lock_.lockAsync(() => {
      return this.keyHandle;
    })
  }
  async setKeyHandle(keyHandle:string) {
    await this.lock_.lockAsync(() => {
      this.keyHandle = keyHandle;
    })
  }
  public async  getCount():Promise<number>  {
    return this.lock_.lockAsync(() => {
      return this.count_;
    })
  }
  public async increaseCount() {
    await this.lock_.lockAsync(() => {
      this.count_++;
    })
  }
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Index.ets

import { TestData } from '../common/TestData';
import { taskpool } from '@kit.ArkTS';
@Concurrent
async function increaseCount() {
  TestData.getInstance().increaseCount();
  console.info("TestData: count is:" + await TestData.getInstance().getCount());
}
@Concurrent
async function printCount() {
  console.info("TestData: count is:" + await TestData.getInstance().getCount());
}
@Concurrent
async function increaseKeyHandle() {
  TestData.getInstance().setKeyHandle('test');
  console.info("TestData: count is:" + await TestData.getInstance().getKeyHandle());
}
@Concurrent
async function printKeyHandle() {
  console.info("TestData: KeyHandle is:" + await TestData.getInstance().getKeyHandle());
}
@Entry
@Component
struct Index {
  @Styles ButtonStyle(){
    .width(180).height(45).margin({ top: 20 })
  }
  build() {
    Row() {
      Column() {
        Button("MainThread print count").ButtonStyle()
          .onClick(async () => {
            await printCount()
          })
        Button("Taskpool print count").ButtonStyle()
          .onClick(async () => {
            await taskpool.execute(printCount);
          })
        Button("MainThread increase count").ButtonStyle()
          .onClick(async () => {
            await increaseCount()
          })
        Button("Taskpool increase count").ButtonStyle()
          .onClick(async () => {
            await taskpool.execute(increaseCount);
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
}
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