REST - HttpClient - Server, C#, with await or without // What are the advantages and disadvantages?

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REST - HttpClient - Server, C#, with await or without // What are the advantages and disadvantages?

Markus Freitag 3,791

Hello,

HttpResponseMessage response = client.GetAsync("Api/valuesGET").Result;

HttpResponseMessage response2 = await client.GetAsync("Api/valuesGET");

Do you ever have an example to see the difference?

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Answer 1

Hi @Markus Freitag,

It looks like you want to understand the difference between synchronous and asynchronous programming. As already mentioned, asynchronous allows multiple tasks to run simultaneously without blocking the main program. The pros and cons based on your question will determine their usage scenarios are different:

Because asynchrony allows multiple operations to occur simultaneously, it can improve overall program concurrency and performance utilization.
Synchronous code is generally easier to read and write because it follows a more linear flow of execution, making debugging code more straightforward than asynchronous code. This reflects the certain complexity of asynchronous code.

And the code (network communication) you provided belongs to an I/O-Bound task, and it doesn't require maintaining a specific order of execution, so I think it will be more efficient to use asynchronous.

Additionally, I think you can simply refer to this document to recognize CPU-bound and I/O-bound work, as well as examples of using asynchronous programming in other scenarios.

Best regards,

Xudong Peng

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Answer 2

Please read the following Micorosoft document:

Async Programming : Introduction to Async/Await on ASP.NET

See Figure 2 A and Figure 3 in the above document.

HttpResponseMessage response = client.GetAsync("Api/valuesGET").Result;

will result in the situation shown in "Figure 2 A Two-Threaded Server Receiving Three Requests" - "the first two requests are assigned threads from the thread pool. Each of these requests calls an external resource, blocking their threads."

HttpResponseMessage response2 = await client.GetAsync("Api/valuesGET");

will result in the situation shown in "Figure 3 Waiting Asynchronously for an External Resource" - "the request thread has been returned to the thread pool while the asynchronous call is in progress."

Therefore,

"Now, if three requests were to come in, the server could cope easily. Because the threads are released to the thread pool whenever the request has asynchronous work it’s waiting for, they’re free to handle new requests, as well as existing ones. Asynchronous requests allow a smaller number of threads to handle a larger number of requests. Hence, the primary benefit of asynchronous code on ASP.NET is scalability."

Answer 3

Bruce (SqlWork.com) 78,006 Volunteer Moderator

the first blocks the thread until the request completes. the second frees the thread to do more work.

with asp.net (especially core), the thread could be processing another request while waiting for the request. thus using .Result reduces scaling. (how fast and how many concurrent requests)

note: using .Result with async calls may lead to deadlocked threads.

so in general with asp.net MVC and asp.net core you should always use async.

Markus Freitag 3,791 Reputation points

2023-10-23T14:32:20.17+00:00

so in general with asp.net MVC and asp.net core you should always use async.

I need a server to test my interface. The client is a C# desktop (WPF or WinForms) application.

The idea is that I deliver this test compilation. Then I switch to the customer system and continue testing.

Here I am looking for a suitable solution. The customer cannot supply a test system, the main problem. ASP.NET is quite difficult. Which variant would you take for C# WPF Desktop? Did you understand my problems? Maybe it is better to create a server via PostMan. Which returns a response to Get, Post, Put.

Do you know a good tutorial? How can I simulate a good answer and a bad answer? I would have to create a script on PostMan? Do you know a tutorial for this also.

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REST - HttpClient - Server, C#, with await or without // What are the advantages and disadvantages?

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