发送connreset错误重试之前，是否有必要重新使用铬检查套接字？

Question

Chromium在发送重试请求之前检查了套接字是否已重用，我想知道为什么有必要发生ECONNRESET错误，如果服务器未在端口上处理，则会收到ECONNREFUSED错误，因此也许每次运行时我们都可以重试进入ECONNRESET错误。

https://cs.chromium.org/chromium/src/net/http/http_network_transaction.cc?g=0&l=1646

bool HttpNetworkTransaction::ShouldResendRequest() const {
  bool connection_is_proven = stream_->IsConnectionReused();
  bool has_received_headers = GetResponseHeaders() != nullptr;

  // NOTE: we resend a request only if we reused a keep-alive connection.
  // This automatically prevents an infinite resend loop because we'll run
  // out of the cached keep-alive connections eventually.
  if (connection_is_proven && !has_received_headers)
    return true;
  return false;
}

switch (error) {
    // If we try to reuse a connection that the server is in the process of
    // closing, we may end up successfully writing out our request (or a
    // portion of our request) only to find a connection error when we try to
    // read from (or finish writing to) the socket.
    case ERR_CONNECTION_RESET:
    case ERR_CONNECTION_CLOSED:
    case ERR_CONNECTION_ABORTED:
    // There can be a race between the socket pool checking checking whether a
    // socket is still connected, receiving the FIN, and sending/reading data
    // on a reused socket.  If we receive the FIN between the connectedness
    // check and writing/reading from the socket, we may first learn the socket
    // is disconnected when we get a ERR_SOCKET_NOT_CONNECTED.  This will most
    // likely happen when trying to retrieve its IP address.
    // See http://crbug.com/105824 for more details.
    case ERR_SOCKET_NOT_CONNECTED:
    // If a socket is closed on its initial request, HttpStreamParser returns
    // ERR_EMPTY_RESPONSE. This may still be close/reuse race if the socket was
    // preconnected but failed to be used before the server timed it out.
    case ERR_EMPTY_RESPONSE:
      if (ShouldResendRequest()) {
        net_log_.AddEventWithNetErrorCode(
            NetLogEventType::HTTP_TRANSACTION_RESTART_AFTER_ERROR, error);
        ResetConnectionAndRequestForResend();
        error = OK;
      }
      break;