Function sleep

interview/limit.js:45–53

(n,name='test')

}
async function sleep(n,name='test'){
  return new Promise(resolve=>{
    console.log(n,name,'start')
    setTimeout(()=>{
      console.log(n,name,'end','-------------')
      resolve({n,name})
    },n*1000)
  })
}

async function start(){
  let runner = limit(2) //并发量是3