Question

I have 1 static class and 1 field and 2 methods within it:

 static class MyClass{

       private static HttpClient client = new HttpClient();
       private static string SendRequestToServer(int id)
       {
          Task<HttpResponseMessage> response = client.GetAsync("some string");
          responseTask.ContinueWith(x => PrintResult(x));
          return "some new value";
        }

        private static void Print(Task<HttpResponseMessage> task)
        {
            Task<string> r = task.Result.Content.ReadAsStringAsync();
            r.ContinueWith(resultTask => Console.WriteLine("result is: " + resultTask.Result));
        }
 }

The question is, if many threads start using MyClass and its methods, would it cause some problems?

Answer 1

All the resources accessed through these methods need to be thread-safe. In your case, they are not. If you look at the HttpClient documentation, it states:

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

You’re calling an instance method (client.GetAsync), which is not be guaranteed to be thread-safe, so that could potentially cause problems for you.

To mitigate this, you could:

• create a new (local) HttpClient on each call.
• synchronize access to client (e.g. using a lock).

Also, I can’t tell you if PrintResult will be thread-safe, but Console.WriteLine should be thread-safe.