C#•2d ago

Where i should use async await?

I have two methods. One of these will be used from "public async Task<int?> SomeASPNETControllerPostMethodAsync()". Should i use await async everywhere or only in Controllers? Which one is the best for performance?

8 Replies

Angius•2d ago

$rulesofasync

MODiX•2d ago

TLDR on async/await: * every .net API that is suffixed with Async (eg: .Read() and .ReadAsync()) => use the Async version * if the API name ends with Async => await it * if the API returns a Task => await it * if you have to await in a method: * that method must have the async keyword (you could even suffix your function name with Async, up to you) * if it was returning T (eg:string) => it should now return Task<T> (eg: Task<string>) * APIs to ban and associated fix:

var r = t.Result;                   /* ===> */ var r = await t;
t.Wait();                           /* ===> */ await t;
var r = t.GetAwaiter().GetResult(); /* ===> */ var r = await t;
Task.WaitAll(t1, t2);               /* ===> */ await Task.WhenAll(t1, t2);

var r = t.Result;                   /* ===> */ var r = await t;
t.Wait();                           /* ===> */ await t;
var r = t.GetAwaiter().GetResult(); /* ===> */ var r = await t;
Task.WaitAll(t1, t2);               /* ===> */ await Task.WhenAll(t1, t2);

Angius•2d ago

Speaking of your code in particular, the use of .ContinueWith() makes the code look like shit, as you can see So just await what needs to be awaited

WeeWeeLeninOP•2d ago

Thank you!

Angius•2d ago

As a side note, don't use .AddAsync(), .RemoveAsync() and so on with EF They're there for some edge cases Since .Add(), .Update() and similar only touch the change tracker, not the db, they don't need to be async

WeeWeeLeninOP•2d ago

But i must use SaveChangesAsync()?

Angius•2d ago

Yes Since that actually calls the database

WeeWeeLeninOP•2d ago

Thanks

Gaming

Programming

Where i should use async await?