Python server that shuts itself after some time being idle

Question

What would be the easiest way of creating a Python server (XML-RPC Server) that shuts itself after sometime being idle?

I was thinking to do it like this but I don't know what to do in the todo's:

from SimpleXMLRPCServer import SimpleXMLRPCServer

# my_paths variable
my_paths = []

# Create server
server = SimpleXMLRPCServer(("localhost", 7789))
server.register_introspection_functions()

# TODO: set the timeout
# TODO: set a function to be run on timeout

class MyFunctions:
    def add_path(paths):
        for path in paths:
            my_paths.append(path)
        return "done"

    def _dispatch(self, method, params):
        if method == 'add_path':
            # TODO: reset timeout
            return add_path(*params)
        else:
            raise 'bad method'

server.register_instance(MyFunctions())

# Run the server's main loop
server.serve_forever()

I also tried to explore signal.alarm() following the example here but it won't run under Windows throwing AttributeError: 'module' object has no attribute 'SIGALRM' at me.

Thanks.

Answer 1

You can create your own server class that extends SimpleXMLRPCServer in order to shutdown when idle for sometime.

class MyXMLRPCServer(SimpleXMLRPCServer):
    def __init__(self, addr):
        self.idle_timeout = 5.0 # In seconds
        self.idle_timer = Timer(self.idle_timeout, self.shutdown)
        self.idle_timer.start()
        SimpleXMLRPCServer.__init__(self, addr)

    def process_request(self, request, client_address):
        # Cancel the previous timer and create a new timer
        self.idle_timer.cancel()
        self.idle_timer = Timer(self.idle_timeout, self.shutdown)
        self.idle_timer.start()
        SimpleXMLRPCServer.process_request(self, request, client_address)

Now, you can use this class instead to make your server object.

# Create server
server = MyXMLRPCServer(("localhost", 7789))
server.register_introspection_functions()