Is.GetAwaiter().GetResult(); 一般用途安全吗？

Question

I read in a few places that .GetAwaiter().GetResult(); could cause deadlocks and that we should use async / await instead. But I see many code samples where this is used. Is it ok to use it? Which are the cases where it can deadlock? Is there something else I should use, like Task.Wait ?

Answer 1

As I describe on my blog, GetAwaiter().GetResult() can deadlock when it's used in a one-thread-at-a-time context . This is most commonly seen when called on the UI thread or in an ASP.NET context (for pre-Core ASP.NET).

Wait has the same problems. The appropriate fix is to use await , and make the calling code asynchronous.

Note that the Main method in Console apps is an exception to this rule; it is perfectly appropriate to use there. Many code samples use it in this way.

Answer 2

When considering these kinds of things, it always helps to look at the official documentation . In the remarks section you will find this:

This method is intended for compiler use; do not use it directly in your code.

I think that gives a fairly strong steer on this. It basically gives the developers of.Net a licence to change how it works in the future. They may never do so, but I wouldn't be confident myself. As for what else you should be using it would depend upon the context, but async/await is the most likely alternative.