Understanding async / await in C#

by

I recommend you start out with my intro to async/await and follow-up with the official Microsoft documentation on TAP.

As I mention in my intro blog post, there are several Task members that are holdovers from the TPL and have no use in pure async code. new Task and Task.Start should be replaced with Task.Run (or TaskFactory.StartNew). Similarly, Thread.Sleep should be replaced with Task.Delay.

Finally, I recommend that you do not use Task.WaitAll; your Console app should just Wait on a single Task which uses Task.WhenAll. With all these changes, your code would look like:

class Program
{
    static void Main(string[] args)
    {
        MainAsync().Wait();
    }

    public static async Task MainAsync()
    {
        Task task1 = Task1();
        Task task2 = Task2();

        await Task.WhenAll(task1, task2);

        Debug.WriteLine("Finished main method");
    }

    public static async Task Task1()
    {
        await Task.Delay(5000);
        Debug.WriteLine("Finished Task1");
    }

    public static async Task Task2()
    {
        await Task.Delay(10000);
        Debug.WriteLine("Finished Task2");
    }
}

More Related Contents:

  1. ‘await’ works, but calling task.Result hangs/deadlocks
  2. What is the difference between asynchronous programming and multithreading?
  3. Catch an exception thrown by an async void method
  4. Is Task.Result the same as .GetAwaiter.GetResult()?
  5. TAP global exception handler
  6. At the end of an async method, should I return or await?
  7. Fire and Forget approach
  8. How can I use Async with ForEach?
  9. Task sequencing and re-entracy
  10. Calling async methods from a WCF service
  11. Is Async await keyword equivalent to a ContinueWith lambda?
  12. Is async/await suitable for methods that are both IO and CPU bound?
  13. Async threadsafe Get from MemoryCache
  14. Task.Yield – real usages?
  15. What thread runs the code after the `await` keyword?
  16. Entity Framework Queryable async
  17. Process files concurrently and asynchronously
  18. Are you there, asynchronously written value?
  19. Get current method name from async function?
  20. Async always WaitingForActivation
  21. The lack of non-capturing Task.Yield forces me to use Task.Run, why follow that?
  22. Await vs Task.Result in an Async Method [duplicate]
  23. What’s the difference between InvokeAsync and BeginInvoke for WPF Dispatcher
  24. Task.WhenAny – What happens with remaining running tasks?
  25. Warning message in async method saying that it lacks await operators
  26. Async and Await with For Loop [duplicate]
  27. When is the best place to use Task.Result instead of awaiting Task
  28. Why does Console.In.ReadLineAsync block?
  29. Entity Framework SaveChanges() vs. SaveChangesAsync() and Find() vs. FindAsync()
  30. How can I run both of these methods ‘at the same time’ in .NET 4.5?

Leave a Comment