SOURCE

requestIdleCallback(myNonEssentialWork, { timeout: 2000 });


const tasks = [
 () => {
   console.log("第一个任务");
 },
 () => {
   console.log("第二个任务");
 },
 () => {
   console.log("第三个任务");
 },
];

function myNonEssentialWork (deadline) {

 while ((deadline.timeRemaining() > 0 || deadline.didTimeout) && tasks.length > 0) {
   work();
 }

 if (tasks.length > 0)
   requestIdleCallback(myNonEssentialWork);
 }

function work () {
 tasks.shift()();
 console.log('执行任务');
}