HarmonyOS emitter相关

不会覆盖，参考示例如下：

import taskpool from '@ohos.taskpool';
import emitter from '@ohos.events.emitter';

@Concurrent
function imageProcessing(dataSlice: ArrayBuffer): ArrayBuffer {
  // 步骤1: 具体的图像处理操作及其他耗时操作
  return dataSlice;
}

let event: emitter.InnerEvent = {
  eventId: 1
};

let callback = (eventData: emitter.EventData): void => {
  console.log('event callback:' + JSON.stringify(eventData.data?.content))

};

function histogramStatistic(pixelBuffer: ArrayBuffer): void {
  // 步骤2: 分成三段并发调度
  let number: number = pixelBuffer.byteLength / 3;
  let buffer1: ArrayBuffer = pixelBuffer.slice(0, number);
  let buffer2: ArrayBuffer = pixelBuffer.slice(number, number * 2);
  let buffer3: ArrayBuffer = pixelBuffer.slice(number * 2);

  taskpool.execute(imageProcessing, buffer1).then(() => {
    console.log("111")
    let eventData: emitter.EventData = {
      data: {
        content: 'a',
        id: 1,
        isEmpty: false
      }
    };
    emitter.emit(event, eventData);
  })
  taskpool.execute(imageProcessing, buffer2).then(() => {
    let eventData: emitter.EventData = {
      data: {
        content: 'b',
        id: 1,
        isEmpty: false
      }
    };
    console.log("222")
    emitter.emit(event, eventData);
  })
  taskpool.execute(imageProcessing, buffer3).then(() => {
    let eventData: emitter.EventData = {
      data: {
        content: 'c',
        id: 1,
        isEmpty: false
      }
    };
    console.log("333")
    emitter.emit(event, eventData);
  })

}

@Entry
@Component
struct Index {
  @State message: string = '发送请求'

  build() {
    Row() {
      Column() {
        Button("订阅事件").onClick(() => {
          emitter.on(event, callback);
        })
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
          .onClick(() => {
            let buffer: ArrayBuffer = new ArrayBuffer(24);
            histogramStatistic(buffer);
          })
      }
      .width('100%')
    }
    .height('100%')
  }
}
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log 输出：

08-15 14:03:21.263   2772-2772     A03d00/JSAPP                    com.xxx  I     111
08-15 14:03:21.264   2772-2772     A03d00/JSAPP                    com.xxx  I     222
08-15 14:03:21.264   2772-2772     A03d00/JSAPP                    com.xxx  I     333
08-15 14:03:21.264   2772-2772     A03d00/JSAPP                    com.xxx  I     event callback:"a"
08-15 14:03:21.264   2772-2772     A03d00/JSAPP                    com.xxx  I     event callback:"b"
08-15 14:03:21.264   2772-2772     A03d00/JSAPP                    com.xxx  I     event callback:"c"
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