async all the way down issue

Question

I have an async asp.net controller. This controller calls an async method. The method that actually performs the async IO work is deep down in my application. The series of

Answer 1

Yes. There is a penalty (though not a huge one), and if you don't need to be async don't be. This pattern is often called "return await" where you can almost always remove both the async and the await. Simply return the task you already have that represents the asynchronous operations:

private Task C_Async(int id)
{
    // This method executes very fast
    var idTemp = paddID(id);
    return D_Async(idTemp);
}

private Task D_Async(string id)
{
    // This method executes very fast
    return E_Async(id);
}

In this specific case Index will only await the tasks that E_Async returns. That means that after all the I/O is done the next line of code will directly be return View();. C_Async and D_Async already ran and finished in the synchronous call.