electron/lib/common/init.js

'use strict'

const timers = require('timers')
const util = require('util')

process.atomBinding = require('@electron/internal/common/atom-binding-setup')(process.binding, process.type)

// setImmediate and process.nextTick makes use of uv_check and uv_prepare to
// run the callbacks, however since we only run uv loop on requests, the
// callbacks wouldn't be called until something else activated the uv loop,
// which would delay the callbacks for arbitrary long time. So we should
// initiatively activate the uv loop once setImmediate and process.nextTick is
// called.
const wrapWithActivateUvLoop = function (func) {
  return wrap(func, function (func) {
    return function () {
      process.activateUvLoop()
      return func.apply(this, arguments)
    }
  })
}

function wrap (func, wrapper) {
  const wrapped = wrapper(func)
  if (func[util.promisify.custom]) {
    wrapped[util.promisify.custom] = wrapper(func[util.promisify.custom])
  }
  return wrapped
}

process.nextTick = wrapWithActivateUvLoop(process.nextTick)

global.setImmediate = wrapWithActivateUvLoop(timers.setImmediate)
global.clearImmediate = timers.clearImmediate

if (process.type === 'browser') {
  // setTimeout needs to update the polling timeout of the event loop, when
  // called under Chromium's event loop the node's event loop won't get a chance
  // to update the timeout, so we have to force the node's event loop to
  // recalculate the timeout in browser process.
  global.setTimeout = wrapWithActivateUvLoop(timers.setTimeout)
  global.setInterval = wrapWithActivateUvLoop(timers.setInterval)
}

if (process.platform === 'win32') {
  // Always returns EOF for stdin stream.
  const { Readable } = require('stream')
  const stdin = new Readable()
  stdin.push(null)
  process.__defineGetter__('stdin', function () {
    return stdin
  })
}