code: def process_request(self, request, client_address):
          
          self.collect_children()
          pid = os.fork()  # @UndefinedVariable
          if pid:
              # Parent process
              if self.active_children is None:
                  self.active_children = []
              self.active_children.append(pid)
              self.close_request(request) #close handle in parent process
              return
          else:
              # Child process.
              # This must never return, hence os._exit()!
              try:
                  self.finish_request(request, client_address)
                  self.shutdown_request(request)
                  os._exit(0)
              except:
                  try:
                      self.handle_error(request, client_address)
                      self.shutdown_request(request)
                  finally:
                      os._exit(1)
docs: Fork a new subprocess to process the request.