worker.receiveMessageOnPort(port)

• port <MessagePort>

• 返回: <Object> | <undefined>

从给定的 MessagePort 接收消息。 如果没有消息可用，则返回 undefined，否则返回具有单个 message 属性的对象，其中包含消息有效负载，对应于 MessagePort 队列中最旧的消息。

const { MessageChannel, receiveMessageOnPort } = require('worker_threads');
const { port1, port2 } = new MessageChannel();
port1.postMessage({ hello: 'world' });

console.log(receiveMessageOnPort(port2));
// 打印: { message: { hello: 'world' } }
console.log(receiveMessageOnPort(port2));
// 打印: undefined

当使用此函数时，不会触发 'message' 事件，也不会调用 onmessage 监听器。

• port <MessagePort>

• Returns: <Object> | <undefined>

Receive a single message from a given MessagePort. If no message is available, undefined is returned, otherwise an object with a single message property that contains the message payload, corresponding to the oldest message in the MessagePort’s queue.

const { MessageChannel, receiveMessageOnPort } = require('worker_threads');
const { port1, port2 } = new MessageChannel();
port1.postMessage({ hello: 'world' });

console.log(receiveMessageOnPort(port2));
// Prints: { message: { hello: 'world' } }
console.log(receiveMessageOnPort(port2));
// Prints: undefined

When this function is used, no 'message' event will be emitted and the onmessage listener will not be invoked.