ThreadingTCPServer相关源码和RequestHandler相关源码

class BaseServer:
    """Base class for server classes.
    Methods for the caller:
    - __init__(server_address, RequestHandlerClass)
    - serve_forever(poll_interval=0.5)
    - shutdown()
    - handle_request()  # if you do not use serve_forever()
    - fileno() -> int   # for select()
    Methods that may be overridden:
    - server_bind()
    - server_activate()
    - get_request() -> request, client_address
    - handle_timeout()
    - verify_request(request, client_address)
    - server_close()
    - process_request(request, client_address)
    - shutdown_request(request)
    - close_request(request)
    - handle_error()
    Methods for derived classes:
    - finish_request(request, client_address)
    Class variables that may be overridden by derived classes or
    instances:
    - timeout
    - address_family
    - socket_type
    - allow_reuse_address
    Instance variables:
    - RequestHandlerClass
    - socket
    """
    timeout = None
    def __init__(self, server_address, RequestHandlerClass):
        """Constructor.  May be extended, do not override."""
        self.server_address = server_address
        self.RequestHandlerClass = RequestHandlerClass
        self.__is_shut_down = threading.Event()
        self.__shutdown_request = False
    def server_activate(self):
        """Called by constructor to activate the server.
        May be overridden.
        """
        pass
    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:
                # XXX: Consider using another file descriptor or
                # connecting to the socket to wake this up instead of
                # polling. Polling reduces our responsiveness to a
                # shutdown request and wastes cpu at all other times.
                r, w, e = _eintr_retry(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()
    # The distinction between handling, getting, processing and
    # finishing a request is fairly arbitrary.  Remember:
    #
    # - handle_request() is the top-level call.  It calls
    #   select, get_request(), verify_request() and process_request()
    # - get_request() is different for stream or datagram sockets
    # - process_request() is the place that may fork a new process
    #   or create a new thread to finish the request
    # - finish_request() instantiates the request handler class;
    #   this constructor will handle the request all by itself
    def handle_request(self):
        """Handle one request, possibly blocking.
        Respects self.timeout.
        """
        # Support people who used socket.settimeout() to escape
        # handle_request before self.timeout was available.
        timeout = self.socket.gettimeout()
        if timeout is None:
            timeout = self.timeout
        elif self.timeout is not None:
            timeout = min(timeout, self.timeout)
        fd_sets = _eintr_retry(select.select, [self], [], [], timeout)
        if not fd_sets[0]:
            self.handle_timeout()
            return
        self._handle_request_noblock()
    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.shutdown_request(request)
    def handle_timeout(self):
        """Called if no new request arrives within self.timeout.
        Overridden by ForkingMixIn.
        """
        pass
    def verify_request(self, request, client_address):
        """Verify the request.  May be overridden.
        Return True if we should proceed with this request.
        """
        return True
    def process_request(self, request, client_address):
        """Call finish_request.
        Overridden by ForkingMixIn and ThreadingMixIn.
        """
        self.finish_request(request, client_address)
        self.shutdown_request(request)
    def server_close(self):
        """Called to clean-up the server.
        May be overridden.
        """
        pass
    def finish_request(self, request, client_address):
        """Finish one request by instantiating RequestHandlerClass."""
        self.RequestHandlerClass(request, client_address, self)
    def shutdown_request(self, request):
        """Called to shutdown and close an individual request."""
        self.close_request(request)
    def close_request(self, request):
        """Called to clean up an individual request."""
        pass
    def handle_error(self, request, client_address):
        """Handle an error gracefully.  May be overridden.
        The default is to print a traceback and continue.
        """
        print '-'*40
        print 'Exception happened during processing of request from',
        print client_address
        import traceback
        traceback.print_exc() # XXX But this goes to stderr!
        print '-'*40

class TCPServer(BaseServer):
    """Base class for various socket-based server classes.
    Defaults to synchronous IP stream (i.e., TCP).
    Methods for the caller:
    - __init__(server_address, RequestHandlerClass, bind_and_activate=True)
    - serve_forever(poll_interval=0.5)
    - shutdown()
    - handle_request()  # if you don't use serve_forever()
    - fileno() -> int   # for select()
    Methods that may be overridden:
    - server_bind()
    - server_activate()
    - get_request() -> request, client_address
    - handle_timeout()
    - verify_request(request, client_address)
    - process_request(request, client_address)
    - shutdown_request(request)
    - close_request(request)
    - handle_error()
    Methods for derived classes:
    - finish_request(request, client_address)
    Class variables that may be overridden by derived classes or
    instances:
    - timeout
    - address_family
    - socket_type
    - request_queue_size (only for stream sockets)
    - allow_reuse_address
    Instance variables:
    - server_address
    - RequestHandlerClass
    - socket
    """
    address_family = socket.AF_INET
    socket_type = socket.SOCK_STREAM
    request_queue_size = 5
    allow_reuse_address = False
    def __init__(self, server_address, RequestHandlerClass, bind_and_activate=True):
        """Constructor.  May be extended, do not override."""
        BaseServer.__init__(self, server_address, RequestHandlerClass)
        self.socket = socket.socket(self.address_family,
                                    self.socket_type)
        if bind_and_activate:
            try:
                self.server_bind()
                self.server_activate()
            except:
                self.server_close()
                raise
    def server_bind(self):
        """Called by constructor to bind the socket.
        May be overridden.
        """
        if self.allow_reuse_address:
            self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.socket.bind(self.server_address)
        self.server_address = self.socket.getsockname()
    def server_activate(self):
        """Called by constructor to activate the server.
        May be overridden.
        """
        self.socket.listen(self.request_queue_size)
    def server_close(self):
        """Called to clean-up the server.
        May be overridden.
        """
        self.socket.close()
    def fileno(self):
        """Return socket file number.
        Interface required by select().
        """
        return self.socket.fileno()
    def get_request(self):
        """Get the request and client address from the socket.
        May be overridden.
        """
        return self.socket.accept()
    def shutdown_request(self, request):
        """Called to shutdown and close an individual request."""
        try:
            #explicitly shutdown.  socket.close() merely releases
            #the socket and waits for GC to perform the actual close.
            request.shutdown(socket.SHUT_WR)
        except socket.error:
            pass #some platforms may raise ENOTCONN here
        self.close_request(request)
    def close_request(self, request):
        """Called to clean up an individual request."""
        request.close()

class ThreadingMixIn:
    """Mix-in class to handle each request in a new thread."""
    # Decides how threads will act upon termination of the
    # main process
    daemon_threads = False
    def process_request_thread(self, request, client_address):
        """Same as in BaseServer but as a thread.
        In addition, exception handling is done here.
        """
        try:
            self.finish_request(request, client_address)
            self.shutdown_request(request)
        except:
            self.handle_error(request, client_address)
            self.shutdown_request(request)
    def process_request(self, request, client_address):
        """Start a new thread to process the request."""
        t = threading.Thread(target = self.process_request_thread,
                             args = (request, client_address))
        t.daemon = self.daemon_threads
        t.start()

class BaseRequestHandler:
    """Base class for request handler classes.
    This class is instantiated for each request to be handled.  The
    constructor sets the instance variables request, client_address
    and server, and then calls the handle() method.  To implement a
    specific service, all you need to do is to derive a class which
    defines a handle() method.
    The handle() method can find the request as self.request, the
    client address as self.client_address, and the server (in case it
    needs access to per-server information) as self.server.  Since a
    separate instance is created for each request, the handle() method
    can define arbitrary other instance variariables.
    """
    def __init__(self, request, client_address, server):
        self.request = request
        self.client_address = client_address
        self.server = server
        self.setup()
        try:
            self.handle()
        finally:
            self.finish()
    def setup(self):
        pass
    def handle(self):
        pass
    def finish(self):
        pass