public ValueTask<FlushResult> FlushAsync(CancellationToken cancellationToken)
{
if (cancellationToken.IsCancellationRequested)
{
return new ValueTask<FlushResult>(Task.FromCanceled<FlushResult>(cancellationToken));
}
lock (_dataWriterLock)
{
ThrowIfSuffixSentOrCompleted();
if (_streamCompleted)
{
return default;
}
if (_startedWritingDataFrames)
{
// If there's already been response data written to the stream, just wait for that. Any header
// should be in front of the data frames in the connection pipe. Trailers could change things.
return _flusher.FlushAsync(this, cancellationToken);
}
else
{
// Flushing the connection pipe ensures headers already in the pipe are flushed even if no data
// frames have been written.
return _frameWriter.FlushAsync(this, cancellationToken);
}
}
}