深入理解JS中的Promise.race控制并发量

class ConcurrencyTask {
    // 回调
    callBack = ()=>{}
    // 任务
    task = ()=>{}
    // 异步任务
    promse = null
    constructor(task,callBack){
        this.task = task
        this.callBack = callBack
    }
    // 开始进行任务
    beginExecuteTask(){
        this.promse = new Promise((resolve, reject)=>{
            this.task(resolve,reject)
        })
        return this.promse
    }
    // 类方法初始化
    static SimulationTask(time){
        return new ConcurrencyTask((resolve, _)=>{
                console.log('开始执行延时任务：' + (time / 1000) + '秒！')
                setTimeout(()=>{
                    resolve('延时任务完成：' + (time / 1000) + '秒！')
                },time)
            },(res)=>{
                console.log(res)
        })
    }
}
class ConcurrencyQueue {
    // 最大并发数
    maxConcurrencyNum = 1
    // 并发任务集合
    concurrencyTasks = []
    // 正在进行的任务
    executionTasks = []
    constructor(maxConcurrencyNum,...concurrencyTasks){
        this.maxConcurrencyNum = maxConcurrencyNum
        concurrencyTasks.forEach((task)=>{
            this.concurrencyTasks.push(task)
        })
    }
    // 开始执行
    async beginExecuteTasks(){
        // 当前执行任务
        this.executionTasks = []
        // 全部任务
        let allExecutionTasks = []
        for(let index = 0;index < this.concurrencyTasks.length;index ++){
            let task = this.concurrencyTasks[index]
            // 开始并进行后续追踪
            task.beginExecuteTask().then((res)=>{
                this.executionTasks.splice(this.executionTasks.indexOf(task),1)
                if(task.callBack){
                    task.callBack(res)
                }
            })
            // 不足直接添加
            if(this.executionTasks.length < this.maxConcurrencyNum){
                //待执行任务集合添加
                this.executionTasks.push(task)
                //全任务执行集合添加
                allExecutionTasks.push(task)
                if((this.concurrencyTasks.length - 1) == index || this.executionTasks.length >= this.maxConcurrencyNum){
                    // 满足直接运行
                    await Promise.race(this.executionTasks.map((task)=>{ return task.promse }))
                }
            }
        }
        //全部任务完成
        await Promise.all(allExecutionTasks.map((task)=>{ return task.promse }))
        console.log('任务全部完成')
    }
}
export { ConcurrencyTask ,ConcurrencyQueue }

<script type="module">
    import { ConcurrencyTask ,ConcurrencyQueue } from "./concurrencyTask.js"
    //添加任务
    let concurrencyQueue = new ConcurrencyQueue(3,ConcurrencyTask.SimulationTask(1000),ConcurrencyTask.SimulationTask(6000),ConcurrencyTask.SimulationTask(5000),ConcurrencyTask.SimulationTask(4000),ConcurrencyTask.SimulationTask(2000),ConcurrencyTask.SimulationTask(3000))
    //开始执行任务
    concurrencyQueue.beginExecuteTasks()
</script>