AsyncQueue example

AsyncQueue.js

export default class AsyncQueue {
  constructor() {
    this.items = [];
    this.receivers = [];
  }
  
  push(value) {
    if(this.receivers.length == 0){
      this.items.push(value);
    }else{
      this.receivers.shift()(value);
    }
  }
  
  pop() {
    return new Promise(resolve =>
      this.items.length == 0
        ? this.receivers.push(resolve)
        : resolve(this.items.shift()));
  }
}

demo.js

const queue = new AsyncQueue();

async function producer(queue){
  let x = 0;
  while(true){
    await delay(Math.random()*1000);
    queue.push(x++)
  }
}

async function consumer(queue){
  while(true){
    await delay(Math.random()*250);
    console.log(await queue.pop());
  }
}

producer(queue);

consumer(queue);
consumer(queue);
consumer(queue);
consumer(queue);

function delay(time){
  return new Promise(r => setTimeout(r, time));
}