Node.js MessageChannel.close() 方法

MessageChannel.close()方法是worker_threads模块中Worker 类的内置应用程序编程接口，用于禁用消息端口对象以发送进一步的消息。

句法：

const MessageChannel.close()

参数：此方法不接受任何参数。

返回值：此方法不返回任何值。

示例 1：文件名：index.js

javascript

// Node.js program to demonstrate the
// MessageChannel.close() method
 
// Importing worker_thread module
const { MessageChannel, receiveMessageOnPort }
        = require('worker_threads');
 
// Creating and initializing the MessageChannel
const { port1, port2} = new MessageChannel();
 
// Posting data in port1
port1.postMessage({ hello: 'world1' });
 
// Posting data in port2
port2.postMessage({ hello: 'world2' });
 
/// Display the result
console.log("received data in port1 : ");
console.log( receiveMessageOnPort(port1));
console.log("received data in port2 : ");
console.log( receiveMessageOnPort(port2));
 
// Closing the ports
port1.close();
port2.close();

使用以下命令运行index.js文件：

node index.js

输出：

received data in port1 :
{ message: { hello: 'world2' } }
received data in port2 :
{ message: { hello: 'world1' } }

示例 2：文件名：index.js

javascript

// Node.js program to demonstrate the
// MessageChannel.close() Method
 
// Importing worker_thread module
const { MessageChannel, receiveMessageOnPort }
        = require('worker_threads');
 
// Creating and initializing the MessageChannel
const { port1, port2} = new MessageChannel();
 
// Catching the event message
port2.on('message', (message) => console.log(message));
 
// Catching the event close
port2.on('close', () => console.log('closed!'));
 
// Sending message to port2
port1.postMessage('GFG');
 
// Closing port by using close() method
port1.close();

使用以下命令运行index.js文件：

node index.js

输出：

GFG
closed!

参考： https://nodejs.org/dist/latest-v12.x/docs/api/worker_threads.html#worker_threads_port_close