Async call with await in HttpClient never returns

by

Check out this answer to my question which seems to be very similar.

Something to try: call ConfigureAwait(false) on the Task returned by GetStreamAsync(). E.g.

var result = await httpClient.GetStreamAsync("weeklyplan")
                             .ConfigureAwait(continueOnCapturedContext:false);

Whether or not this is useful depends on how your code above is being called – in my case calling the async method using Task.GetAwaiter().GetResult() caused the code to hang.

This is because GetResult() blocks the current thread until the Task completes. When the task does complete it attempts to re-enter the thread context in which it was started but cannot because there is already a thread in that context, which is blocked by the call to GetResult()… deadlock!

This MSDN post goes into a bit of detail on how .NET synchronizes parallel threads – and the answer given to my own question gives some best practices.

More Related Contents:

  1. HttpClient.GetAsync(…) never returns when using await/async
  2. Is async HttpClient from .Net 4.5 a bad choice for intensive load applications?
  3. What is the difference between asynchronous programming and multithreading?
  4. WaitAll vs WhenAll
  5. Catch an exception thrown by an async void method
  6. Running multiple async tasks and waiting for them all to complete
  7. Calling async method synchronously
  8. Entity Framework async operation takes ten times as long to complete
  9. Why does this async action hang when I try and access the Result property of my Task?
  10. Task sequencing and re-entracy
  11. Calling async methods from a WCF service
  12. Using async without await
  13. Is async/await suitable for methods that are both IO and CPU bound?
  14. What thread runs the code after the `await` keyword?
  15. Process files concurrently and asynchronously
  16. Why use async and return await, when you can return Task directly?
  17. async await return Task
  18. Executing tasks in parallel
  19. Are you there, asynchronously written value?
  20. Proper way to start and fire-and-forget asynchronous calls?
  21. Use Task.Run() in synchronous method to avoid deadlock waiting on async method?
  22. A pattern for self-cancelling and restarting task
  23. Async always WaitingForActivation
  24. A pattern to pause/resume an async task?
  25. Converting async/await to Task.ContinueWith
  26. How do I create a custom SynchronizationContext so that all continuations can be processed by my own single-threaded event loop?
  27. How do you implement an async action delegate method?
  28. Using async / await with DataReader ? ( without middle buffers!)
  29. HttpClient.SendAsync using the thread-pool instead of async IO?
  30. Timeout pattern on task-based asynchronous method in C#

Leave a Comment