Is this the correct use of await / async?

Question

I am new to async / await and I want to make sure this way to do it right:

public async Task DoHeavyWorkAsync() 
{
    await Task.Run(() => {
        getResponseFromFarawaySlowServerAndDoSomethingWithIt();
    });
}

public async void ConsumeAsync()
{
    Task longRunningTask = DoHeavyWorkAsync();
    // do a lot of other stuffs here that does not depend on DoHeavyWorkAsync()
    await longRunningTask;
}

Is this way of using async / await right, or have I done something wrong?

Answer 1

There are a few things you can do:

• In DoHeavyWorkAsyncyou do not need to create a state machine with await Task.Run, you can simply return Task.Run:

  public Task DoHeavyWorkAsync() 
  {
     return Task.Run(() => getResponseFromFarawaySlowServerAndDoSomethingWithIt());
  }
  

• async voidapplies exclusively to async event handlers . If your async method returns void, it should return Taskinstead:

  public async Task ConsumeAsync()
  

• DoHeavyWorkAsync - -, Task.Run, . await. , . Task.Run, :

  public void DoHeavyWork()
  {
      getResponseFromFarawaySlowServerAndDoSomethingWithIt();  
  }
  

  :

  Task.Run(DoHeavyWork);
  

Answer 2

API, getResponseFromFarawaySlowServerAndDoSomethingWithIt:
 getResponseFromFarawaySlowServer doSomething().
async

:

var response = await getResponseFromFarawaySlowServerAsync();
doSomething(response);

, : getResponseFromFarawaySlowServer . http webservice , . , . , http-

string getResponseFromFarawaySlowServer(){
  string response = new WebClient().DownloadString(uri);
  ...
  return response
}

async Task<string> getResponseFromFarawaySlowServerAsync(){ Task.StartNew..

:

async Task<string> getResponseFromFarawaySlowServerAsync(){
  string response = await new WebClient().DownloadStringAsync(uri);
  ...
  return response;
}