* Use the new _PyTime_FromSeconds() function to set the timeout to -1 second
  for socket.settimeout(None). It avoids a special case in internal_select()
  because of a rounding issue: -1 nanosecond is rounded to 0 millisecond which
  means non-blocking, instead of blocking.
* Check if the interval the negative in sock_call_ex() instead of doing the
  check in internal_select(). sock_call_ex() remembers if the socket has a
  timeout or not, which avoids a race condition if the timeout is modified in a
  different thread.