Common HttpClient Blocks for Asynchronous Requests

Question

I have a problem with HttpClient and async requests. Basically, I have an async method that creates asynchronous requests with a common HttpClient that is initialized in ctor.

My problem is that it seems that HttpClient is blocking my method asynchronously when called.

Here is my code:

var tasks = trips.Select(u => api.Animals.GetAsync(u * 100, 100).ContinueWith(t => { lock (animals) { if (t.Result != null) { foreach (var a in t.Result) { animals.Add(a); } } } })); await Task.WhenAll(tasks); 

Here is a method that blocks a common HttpClient:

  //HttpClient blocks on each request var uri = String.Format("animals?take={0}&from={1}", take, from); var resourceSegmentUri = new Uri(uri, UriKind.Relative); var response = await _client.GetAsync(resourceSegmentUri); if (response.IsSuccessStatusCode) { var content = await response.Content.ReadAsStringAsync(); var animals = JsonConvert.DeserializeObject<T>(content); return animals; } 

This fragment is not blocked when using the client for each request:

 using (var client = new HttpClient(){BaseAddress = new Uri(_config.BaseUrl)}) { var uri = String.Format("animals?take={0}&from={1}", take, from); var resourceSegmentUri = new Uri(uri, UriKind.Relative); var response = await client.GetAsync(resourceSegmentUri); if (response.IsSuccessStatusCode) { var content = await response.Content.ReadAsStringAsync(); var animals = JsonConvert.DeserializeObject<T>(content); return animals; } } 

Is generic HttpClient and not? Or can I use it in some other way?

Answer 1

Using a generic HttpClient .

See my answer, why - What are the overheads of creating a new HttpClient for each call in the WebAPI client?