Taskcompletionsource<Tresult> without a type parameter

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The class TaskCompletionSource<TResult> needs a type TResult. That way, when I need to use this class without having a return type (void), I have to do something like:

var tcs = new TaskCompletionSource<object>();
// ...
tcs.TrySetResult(null);

I don’t know if this is the best way to do when the return of a function is only one Task, of no kind. It seems to me.

There is no TaskCompletionSource without the type parameter? There is another output?

c# .net asynchronous task

2 answers

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IS by-design. I saw in the Soen that there is a microsoft document, written by Stephen Toub, "The Task-based Asynchronous Pattern", which says:

There is no non-generic Counterpart to TaskCompletionSource<TResult>. However, Task<TResult> derives from Task, and Thus the Generic TaskCompletionSource<TResult> can be used for I/O-bound methods that Simply Return a Task by Utilizing a source with a dummy TResult (bool is a good default Choice, and if a Developer is concerned about a Consumer of the Task downcasting it to Task<TResult>, a private TResult type may be used)

Ali says to use a boolean on the guy, but Stephen Cleary doesn’t recommend it, since object with the value null takes away meaning, and a value true or false leaves some meaning in the value returned. Anyway, matter of semantics.

1


There is no better form today. There is no TaskCompletionSource without a result to be defined.

What may be a gain, but I have doubts is to return a type by value and not object to avoid allocation in heap. but it will be a very small gain and I do not know if it will generate any consequences in other parts.

If you want to learn all about asynchrony and . NET tasks this is the guy to follow.

  • I already knew Stephen by Soen, but I didn’t know that it was a reference of asynchrony in .NET. I will read some of his things.

  • 1

    He’s an expert. Of course there’s Jon Skeet and others. There’s people from the team. NET as Jared Parsons, had the compiler’s Eric Lippert who talks a lot about the more conceptual part and how the compiler deals with it. Joe Duffy was the guy who created all the homework.

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