PerformWork

PerformWork rendering process

Render rendering process entry

Function declaration

function performWork(deadline: IdleDeadline);

PerformWork is registered to the background collaborative task queue by the requestIdleCallback function, and the functions in the queue are executed when the JS thread is idle.

Function realization

function performWork(deadline: IdleDeadline) {
  // 内部循环迭代workInProgress
  workLoop(deadline);

  // 如果workInProgress为空了，表示当前渲染任务执行完毕，查看updateQueue是否为空
  // 如果不为空则再请求一次后台协同任务
  if (workInProgress || updateQueue.length) {
    requestIdleCallback(performWork);
  }
}