JS现在支持多线程了吗？

Question

我正在仔细阅读一些答案，但它们已经很旧了。有人知道这方面的最新进展吗

还有，JS在不久的将来有可能变成多线程吗？

相关问题：- 链接

Answer 1

我知道如何访问单独线程的唯一方法是使用 Web Workers。

您可以为工作人员创建一个文件：

/////////////////////////////////////////// Main (main.js)
const worker = new Worker('worker.js')


// Set up a listener for messages from the worker
worker.onmessage = (message) => {
  // This is where you receive your worker response
}

// Error handling
worker.onerror = console.error


// This message will be passed to the worker
worker.postMessage('hello worker')



/////////////////////////////////////////// Web workers (worker.js)

self.onmessage = (message) => {
  // message.data is where your passed parameter is stored
  const data = message.data
  
  // Execute some code
  
  // Send back a response to the main thread (main.js)
  postMessage(data)
}

或者您实际上可以创建一个动态工作人员：

// main.js


// This function will be passed into the worker
function test(message) {
  const data = message.data
 
  // Response
  postMessage(data)
}

// Dynamic creation of a worker
const bytes = new TextEncoder().encode(`self.onmessage = ${test.toString()}`)
const blob = new Blob([bytes], {type: 'application/javascript'})
const url = URL.createObjectURL(blob)
const worker = new Worker(url)


// Set up a listener for messages from the worker
worker.onmessage = (message) => {
  // This is where you receive your worker response
}

// Error handling
worker.onerror = console.error

// This message will be passed to the worker
worker.postMessage('hello')

第三个变体是使用我自己的 npm 库

@a4tur/threads.js

API 易于使用。

import Threads from '@a4tur/threads.js'

// Creating new threads
const threads = new Threads(4)

// Task to execute on separated threads 
function test(param) {
  param = param ?? 0
  // Note that passed message is directly accessible. So no `message.data` 
  
  // Execute some code
  
  // Just a regular return to get the message
  return param + 10
}

// @param task: Function to execute
// @param message?: Parameter value of the function
// Chainable
threads.push(test, 20).push(test, 10).push(test)



// Execution
// You will get all responses in the same order you pushed tasks
const result = await threads.execute()