Why is this async / await code NOT deadlocking?

Question

I found the following example in Jon Skeet "C # in depth. 3rd edition":

static async Task<int> GetPageLengthAsync(string url)
{
    using (HttpClient client = new HttpClient())
    {
        Task<string> fetchTextTask = client.GetStringAsync(url);
        int length = (await fetchTextTask).Length;
        return length;
    }
}

public static void Main()
{
    Task<int> lengthTask = GetPageLengthAsync("http://csharpindepth.com");
    Console.WriteLine(lengthTask.Result);
}

I would expect this code to come to a standstill, but it is not.

As I see it, it works as follows:

• MainThe method calls GetPageLengthAsyncsynchronously in the main thread.
• GetPageLengthAsyncmakes an asynchronous request and immediately returns Task<int>to Main, saying "wait a while, I will return you int in a second."
• Maincontinues execution and stumbles upon lengthTask.Result, which causes the main thread to block and wait for completion lengthTask.
• GetStringAsyncshuts down and waits until the main thread becomes available for execution Lengthand continues to continue.

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Answer 1

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PS VS 15.3:

Visual Studio 2017 15.3 Preview 2 (gasp) . :

public static Task Main()
{
    var length = await GetPageLengthAsync("http://csharpindepth.com");
    Console.WriteLine(length);
}