有没有一种方法可以同步运行异步lambda? [英] Is there a way to run async lambda synchronously?

问题描述

有没有一种方法可以同步运行异步lambda?不允许修改lambda表达式，必须将其保留原样.

Is there a way to run async lambda synchronously? It is not allowed to modify lambda expression, it must be leaved as is.

复制/粘贴示例(是抽象的):

Copy/paste example(it's an abstraction):

var loopCnt = 1000000;

Action<List<int>> aslambda = async (l) =>
{
    Thread.Sleep(100);
    await Task.Run(() => { });
    for (int i = 0; i < loopCnt; i++) { l.Add(i); }
};

var lst = new List<int>();
aslambda(lst); //This runs asynchronously 
if (lst.Count < loopCnt-100) { ; }

解决方案:

接受一个答案对我来说是一个真正的难题.我已经尝试使用NuGet软件包尝试了 Stephen Cleary 的解决方案-效果很好，适用范围很广，但是 dvorn 对这个问题的回答(因为它是提法的；)是容易得多.

Solution:

It is really a dilemma for me to accept one answer. I have tried out the solution from Stephen Cleary with NuGet package - works brilliant and is broad applicable, but an answer from dvorn to the question(as it's formulated ;)) is much easier.

dvorn 是否更改了lambda的签名?否，是;)

Has dvorn changed the signature of lambda? No and Yes ;)

请注意，lambda表达式本身没有类型，因为 普通类型系统没有"lambda"的内在概念 表达."但是，有时非正式发言很方便 lambda表达式的类型".在这些情况下，类型是指 到lambda表达式所代表的委托类型或表达式类型 被转换.

Note that lambda expressions in themselves do not have a type because the common type system has no intrinsic concept of "lambda expression." However, it is sometimes convenient to speak informally of the "type" of a lambda expression. In these cases the type refers to the delegate type or Expression type to which the lambda expression is converted.

因此，两者都收到 +1 并由 Stephen Cleary

So both receive +1 and accepted answer by Stephen Cleary

推荐答案

有没有一种方法可以同步运行异步[void] lambda?

Is there a way to run async [void] lambda synchronously?

是的，但是像所有同步/异步黑客一样，这很危险，并且不适用于所有lambda.

Yes, but like all sync-over-async hacks, it's dangerous and won't work for all lambdas.

您必须具有自定义SynchronizationContext才能检测到方法(或lambda).这很简单，但是您可以使用我的 AsyncContext (可在NuGet软件包Nito.AsyncEx.Context中找到):

You must have a custom SynchronizationContext to detect the completion of an async void method (or lambda). This is non-trivial, but you can use my AsyncContext (available in the NuGet package Nito.AsyncEx.Context):

AsyncContext.Run(() => aslambda(lst));

这篇关于有没有一种方法可以同步运行异步lambda?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IT屋！