Should I rewrite my code from ground up with async/await, or can I just use Task.FromAsync and TaskComplitionSource to wrap higher level classes?

Question

I have class that uses HttpWebRequest asynchroniously inside it and provides interface like this:

StartAsyncOperation(Action<TResult> onSuccess, Action<Exception> onError)

What profit will I get if I'll rewrite this class using HttpWebRequest.GetResponseAsync iside it, or I just can use TaskComplitionSource like here Using the Task Parallel Library on an event-based asynchronous pattern, and it will be ok?

Does your class use `Begin*()` / `End*()` (APM) or just the threadpool? — SLaks, Jun 25 '13 at 13:53

score 2 · Accepted Answer · answered Jun 25 '13 at 13:55

Assuming your StartAsyncOperation does in fact use asynchronous operations (e.g., BeginGetResponse/EndGetResponse), then there's not a huge benefit in rewriting it.

Doing a TaskCompletionSource wrapper for now is fine. Eventually you'll probably want to rewrite it to use async because years down the road the onSuccess/onError pattern is going to look very strange to developers who are used to async.

score 0 · Answer 2 · answered Jun 25 '13 at 23:31

If your code follows the APM pattern (BeginMethod / EndMethod), then go ahead and use TaskFactory.FromAsync right away.

I would recommend not consuming TaskFactory.FromAsync but wrapping it in Async suffixed method that can have its implementation replaced in the future by async/await. This way you can refactor your code as needed and not just for the sake of async/await.

Should I rewrite my code from ground up with async/await, or can I just use Task.FromAsync and TaskComplitionSource to wrap higher level classes?

2 Answers2