Async.Await未捕获任务异常 [英] Async.Await not catching Task exception
问题描述
我有一个不返回任何内容的任务。您无法在此类任务上执行Async.AwaitTask,因此您需要执行Async.AwaitIAsyncTask。不幸的是,这似乎吞没了底层Task抛出的所有异常:-
TaskFactory()。StartNew(Action(fun _ -> failwith oops))
|> Async.AwaitIAsyncResult
|>异步忽略
|> Async.RunSynchronously
// val:unit =()
打开另一方面,AwaitTask正确地级联了该异常:-
TaskFactory()。StartNew(fun _-> failwith oops
5)
|> Async.AwaitTask
|>异步忽略
|> Async.RunSynchronously
// POP!
将常规(非通用)任务视为异步但仍能传播异常的最佳方法是什么?
来自 Xamarin F#衬衫应用程序(我最初从戴夫·托马斯那里借来的):
> [< AutoOpen>]
模块Async =
让内联awaitPlainTask(task:Task)=
//如果出错$ b $,则从先前任务中抛出异常b让continuation(t:Task)=如果t.IsFaulted然后引发t.Exception
task.ContinueWithcontinuation |> Async.AwaitTask
I have a Task that does not return anything. You can't do an Async.AwaitTask on such a Task, so you need to do an Async.AwaitIAsyncTask instead. Unfortunately this seems to just swallow any exceptions that the underlying Task throws out: -
TaskFactory().StartNew(Action(fun _ -> failwith "oops"))
|> Async.AwaitIAsyncResult
|> Async.Ignore
|> Async.RunSynchronously
// val it : unit = ()
On the other hand, AwaitTask correctly cascades the exception: -
TaskFactory().StartNew(fun _ -> failwith "oops"
5)
|> Async.AwaitTask
|> Async.Ignore
|> Async.RunSynchronously
// POP!
What's the best way of treating regular (non-generic) Tasks as Async yet still get propagation of exceptions?
From the Xamarin F# Shirt App (which I originally borrowed from Dave Thomas):
[<AutoOpen>]
module Async =
let inline awaitPlainTask (task: Task) =
// rethrow exception from preceding task if it faulted
let continuation (t : Task) = if t.IsFaulted then raise t.Exception
task.ContinueWith continuation |> Async.AwaitTask
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