LP13 LP13 - 2 months ago 32
C# Question

Using ConfigureAwait(false) for private async methods?

I have public

async
method which calls 3 different APIs to get some data and then post the response to the next API. Now based on Stephen cleary's article here to avoid deadlock :


1.In your “library” async methods, use ConfigureAwait(false) wherever possible.

2.Don’t block on Tasks; use async all the way down.


I wanted to know if same is true for private async methods? Do I need to use
ConfigureAwait(false)
when I am calling
private
async method as well? So something along the line

public async Task<int> ProcessAsync(ServiceTaskArgument arg)
{
// do i need to use ConfigureAwait here while calling private async method?
var response1 = await GetAPI1().ConfigureAwait(false);

// do i need to use ConfigureAwait here while calling private async method?
var response2= await PostAPI2(response1).ConfigureAwait(false);

// do i need to use ConfigureAwait here while calling private async method?
await PostAPI3(response2).ConfigureAwait(false);

return 1;
}

private async Task<string> GetAPI1()
{
var httpResponse = await _httpClient.GetAsync("api1").ConfigureAwait(false);

// do i need to use ConfigureAwait here while calling private async method?
await EnsureHttpResponseIsOk(httpResponse).ConfigureAwait(false);

return await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
}

private async Task<string> PostAPI2(string data)
{
var stringContent = new StringContent(data, Encoding.UTF8, "application/json");
var httpResponse = await _httpClient.PostAsync("api2", stringContent).ConfigureAwait(false);

// do i need to use ConfigureAwait here while calling private async method?
await EnsureHttpResponseIsOk(httpResponse).ConfigureAwait(false);

return await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
}

private async Task<string> PostAPI3(string data)
{
var stringContent = new StringContent(data, Encoding.UTF8, "application/json");
var httpResponse = await _httpClient.PostAsync("api3", stringContent).ConfigureAwait(false);

// do i need to use ConfigureAwait here while calling private async method?
await EnsureHttpResponseIsOk(httpResponse).ConfigureAwait(false);

return await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
}

private async Task EnsureHttpResponseIsOk(HttpResponseMessage httpResponse)
{
if (!httpResponse.IsSuccessStatusCode)
{
var content = await httpResponse.Content.ReadAsStringAsync().ConfigureAwait(false);
throw new MyHttpClientException("Unexpected error has occurred while invoking http client.", content, httpResponse.Headers);
}
}


Update1

Also I have gone through SO post here, but answer suggesting to use custom NoSynchronizationContextScope.

I wanted to know if I need to use ConfigureAwait(false) on private methods or not?

Answer

I wanted to know if I need to use ConfigureAwait(false) on private methods or not?

As a general rule, yes. ConfigureAwait(false) should be used for every await unless the method needs its context.

However, if you use NoSynchronizationContextScope, then that removes the need for ConfigureAwait(false).