协程

Asynchronous or non-blocking programming is an important part of the development landscape.创建服务器端应用、桌面应用或者移动端应用时，都很重要的一点是，提供的体验不仅是从用户角度看着流畅，而且还能在需要时伸缩（scalable，可扩充/缩减规模）。

Kotlin solves this problem in a flexible way by providing coroutine support at the language level and delegating most of the functionality to libraries.

In addition to opening the doors to asynchronous programming, coroutines also provide a wealth of other possibilities, such as concurrency and actors.