使用Play.async会产生什么效果，因为Play使用的是非阻塞性Netty

Since Netty is a non-blocking server, what effect does changing an action to using .async?def index = Action { ... }versusdef index = Action.async { ... }I understand that with .async you will get a Future[SimpleResult]. But since Netty is non-blocking, will Play do something similar under the covers anyway?What effect will this have on throughput/scalability? Is this a hard question to answer where it depends on other factors?The reason I am asking is, I have my own custom Action and I wanted to reset the cookie timeout for every page request so I am doing this which is a async call:object MyAction extends ActionBuilder[abc123] { def invokeBlock[A](request: Request[A], block: (abc123[A]) => Future[SimpleResult]) = { ... val result: Future[SimpleResult] = block(new abc123(..., result)) result.map(_.withCookies(...)) }}The take away from the above snippet is I am using a Future[SimpleResult], is this similar to calling Action.async but this is inside of my Action itself?I want to understand what effect this will have on my application design. It seems like just for the ability to set my cookie on a per request basis I have changed from blocking to non-blocking. But I am confused since Netty is non-blocking, maybe I haven't really changed anything in reality as it was already async? Or have I simply created another async call embedded in another one?Hoping someone can clarify this with some details and how or what effect this will have in performance/throughput. 解决方案 def index = Action { ... } is non-blocking you are right.The purpose of Action.async is simply to make it easier to work with Futures in your actions.For example:def index = Action.async { val allOptionsFuture: Future[List[UserOption]] = optionService.findAll() allOptionFuture map { options => Ok(views.html.main(options)) }}Here my service returns a Future, and to avoid dealing with extracting the result I just map it to a Future[SimpleResult] and Action.async takes care of the rest.If my service was returning List[UserOption] directly I could just use Action.apply, but under the hood it would still be non-blocking.If you look at Action source code, you can even see that apply eventually calls async:https://github.com/playframework/playframework/blob/2.3.x/framework/src/play/src/main/scala/play/api/mvc/Action.scala#L432 这篇关于使用Play.async会产生什么效果，因为Play使用的是非阻塞性Netty的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！