How to Implement a Shutdown Method in SocketServer.TCPServer for Python 2.5

Prior to Python 2.6, the SocketServer.TCPServer doesn't have a shutdown method. The SocketServer.TCPServer.serve_forever() also blocks. Here is a TCPServer implementation that works in Python 2.5, implements a shutdown method, and support non-blocking request. The implementation here is based on the TCPServer implementation in Python 2.6.

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class Py25TCPServer(SocketServer.ThreadingTCPServer):    def __init__(self, address_tuple, handler):       SocketServer.ThreadingTCPServer.__init__(self, address_tuple, handler)       self.__is_shut_down = threading.Event()       self.__shutdown_request = False      def serve_forever(self, poll_interval=0.5):       """Handle one request at a time until shutdown.            Polls for shutdown every poll_interval seconds. Ignores          self.timeout. If you need to do periodic tasks, do them in          another thread.       """       self.__is_shut_down.clear()       try:          while not self.__shutdown_request:             r, w, e = select.select([self], [], [], poll_interval)             if self in r:                self._handle_request_noblock()       finally:          self.__shutdown_request = False          self.__is_shut_down.set()      def shutdown(self):       """Stops the serve_forever loop.            Blocks until the loop has finished. This must be called while          serve_forever() is running in another thread, or it will          deadlock.       """       self.__shutdown_request = True       self.__is_shut_down.wait()      def _handle_request_noblock(self):       """Handle one request, without blocking.            I assume that select.select has returned that the socket is          readable before this function was called, so there should be          no risk of blocking in get_request().       """       try:          request, client_address = self.get_request()       except socket.error:          return       if self.verify_request(request, client_address):          try:             self.process_request(request, client_address)          except:             self.handle_error(request, client_address)             self.close_request(request)

To make our program work in both Python 2.5 and 2.6+, we can do something like this.

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import sys   python_version = sys.version_info server = None if python_version[1] < 6:     server = Py25TCPServer((self.host, self.port), MyHandler) else:     server = SocketServer.TCPServer((self.host, self.port), MyHandler) server.server_forever()