宏任务(macrotasks): 主js、UI渲染、setTimeout、setInterval、setImmediately、requestAnimationFrame、I/O等
微任务(microtasks):process.nextTick()、promise、Object.observe()等
宏任务(macrotasks): 主js、UI渲染、setTimeout、setInterval、setImmediately、requestAnimationFrame、I/O等
微任务(microtasks):process.nextTick()、promise、Object.observe()等