Using ConfigureAwait(false) for private async methods?

Question

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?

Stephen Cleary Stephen Cleary · Accepted Answer · 2016-09-15T20:09:07

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).

Using ConfigureAwait(false) for private async methods?

2 Answers