public async ValueTask <string> GetHeaderValueAsync(HttpMessage message, bool async)
{
bool getTokenFromCredential;
TaskCompletionSource <HeaderValueInfo> headerValueTcs;
TaskCompletionSource <HeaderValueInfo>?backgroundUpdateTcs;
(headerValueTcs, backgroundUpdateTcs, getTokenFromCredential) = GetTaskCompletionSources();
if (getTokenFromCredential)
{
if (backgroundUpdateTcs != null)
{
#pragma warning disable AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
HeaderValueInfo info = headerValueTcs.Task.EnsureCompleted();
#pragma warning restore AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
_ = Task.Run(() => GetHeaderValueFromCredentialInBackgroundAsync(backgroundUpdateTcs, info, message, async));
return(info.HeaderValue);
}
try
{
HeaderValueInfo info = await GetHeaderValueFromCredentialAsync(message, async, message.CancellationToken).ConfigureAwait(false);
headerValueTcs.SetResult(info);
}
catch (OperationCanceledException)
{
headerValueTcs.SetCanceled();
throw;
}
catch (Exception exception)
{
headerValueTcs.SetException(exception);
throw;
}
}
var headerValueTask = headerValueTcs.Task;
if (!headerValueTask.IsCompleted)
{
if (async)
{
await headerValueTask.AwaitWithCancellation(message.CancellationToken);
}
else
{
try
{
headerValueTask.Wait(message.CancellationToken);
}
catch (AggregateException) { } // ignore exception here to rethrow it with EnsureCompleted
}
}
#pragma warning disable AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
return(headerValueTcs.Task.EnsureCompleted().HeaderValue);
#pragma warning restore AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
}
public async ValueTask <string> GetHeaderValueAsync(HttpMessage message, bool async)
{
bool getTokenFromCredential;
TaskCompletionSource <HeaderValueInfo> headerValueTcs;
TaskCompletionSource <HeaderValueInfo>?backgroundUpdateTcs;
int maxCancellationRetries = 3;
while (true)
{
(headerValueTcs, backgroundUpdateTcs, getTokenFromCredential) = GetTaskCompletionSources();
if (getTokenFromCredential)
{
if (backgroundUpdateTcs != null)
{
#pragma warning disable AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
HeaderValueInfo info = headerValueTcs.Task.EnsureCompleted();
#pragma warning restore AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
_ = Task.Run(() => GetHeaderValueFromCredentialInBackgroundAsync(backgroundUpdateTcs, info, message, async));
return(info.HeaderValue);
}
try
{
HeaderValueInfo info = await GetHeaderValueFromCredentialAsync(message, async, message.CancellationToken).ConfigureAwait(false);
headerValueTcs.SetResult(info);
}
catch (OperationCanceledException)
{
headerValueTcs.SetCanceled();
}
#pragma warning disable CA1031 // Catch more specific allowed exception type, or rethrow the exception
catch (Exception exception)
#pragma warning restore CA1031 // Catch more specific allowed exception type, or rethrow the exception
{
headerValueTcs.SetException(exception);
// The exception will be thrown on the next lines when we touch the result of
// headerValueTcs.Task, this approach will prevent later runtime UnobservedTaskException
}
}
var headerValueTask = headerValueTcs.Task;
try
{
if (!headerValueTask.IsCompleted)
{
if (async)
{
await headerValueTask.AwaitWithCancellation(message.CancellationToken);
}
else
{
try
{
headerValueTask.Wait(message.CancellationToken);
}
catch (AggregateException) { } // ignore exception here to rethrow it with EnsureCompleted
}
}
#pragma warning disable AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
return(headerValueTcs.Task.EnsureCompleted().HeaderValue);
#pragma warning restore AZC0111 // DO NOT use EnsureCompleted in possibly asynchronous scope.
}
catch (TaskCanceledException) when(!message.CancellationToken.IsCancellationRequested)
{
maxCancellationRetries--;
// If the current message has no CancellationToken and we have tried this 3 times, throw.
if (!message.CancellationToken.CanBeCanceled && maxCancellationRetries <= 0)
{
throw;
}
// We were waiting on a previous headerValueTcs operation which was canceled.
//Retry the call to GetTaskCompletionSources.
continue;
}
}
}
