Index: Doc/library/asyncore.rst =================================================================== --- Doc/library/asyncore.rst (revisione 84998) +++ Doc/library/asyncore.rst (copia locale) @@ -210,10 +210,13 @@ .. method:: accept() Accept a connection. The socket must be bound to an address and listening - for connections. The return value is a pair ``(conn, address)`` where - *conn* is a *new* socket object usable to send and receive data on the - connection, and *address* is the address bound to the socket on the other - end of the connection. + for connections. The return value can be either ``None`` or a pair + ``(conn, address)`` where *conn* is a *new* socket object usable to send + and receive data on the connection, and *address* is the address bound to + the socket on the other end of the connection. + When ``None`` is returned it means the connection didn't take place, hence + the server should just ignore this event and keep listening for further + incoming connections. .. method:: close() @@ -223,6 +226,12 @@ flushed). Sockets are automatically closed when they are garbage-collected. +.. class:: dispatcher_with_send() + + A :class:`dispatcher` subclass which adds simple buffered output capability, + useful for simple clients. For more sophisticated usage use + :class:`asynchat.async_chat`. + .. class:: file_dispatcher() A file_dispatcher takes a file descriptor or :term:`file object` along @@ -239,7 +248,7 @@ socket for use by the :class:`file_dispatcher` class. Availability: UNIX. -.. _asyncore-example: +.. _asyncore-example-1: asyncore Example basic HTTP client ---------------------------------- @@ -249,7 +258,7 @@ import asyncore, socket - class http_client(asyncore.dispatcher): + class HTTPClient(asyncore.dispatcher): def __init__(self, host, path): asyncore.dispatcher.__init__(self) @@ -273,6 +282,44 @@ sent = self.send(self.buffer) self.buffer = self.buffer[sent:] - c = http_client('www.python.org', '/') - + client = HTTPClient('www.python.org', '/') asyncore.loop() + +.. _asyncore-example-2: + +asyncore Example basic echo server +---------------------------------- + +Here is abasic echo server that uses the :class:`dispatcher` class to accept +connections and dispatches the incoming connections to a handler:: + + import asyncore + import socket + + class EchoHandler(asyncore.dispatcher_with_send): + + def handle_read(self): + data = self.recv(8192) + self.send(data) + + class EchoServer(asyncore.dispatcher): + + def __init__(self, host, port): + asyncore.dispatcher.__init__(self) + self.create_socket(socket.AF_INET, socket.SOCK_STREAM) + self.set_reuse_addr() + self.bind((host, port)) + self.listen(5) + + def handle_accept(self): + conn = self.accept() + if conn is None: + return + else: + sock, addr = conn + print('Incoming connection from %s' % repr(addr)) + handler = EchoHandler(sock) + + server = EchoServer('localhost', 8080) + asyncore.loop() + Index: Lib/smtpd.py =================================================================== --- Lib/smtpd.py (revisione 84998) +++ Lib/smtpd.py (copia locale) @@ -422,22 +422,13 @@ localaddr, remoteaddr), file=DEBUGSTREAM) def handle_accept(self): - try: - conn, addr = self.accept() - except TypeError: - # sometimes accept() might return None - return - except socket.error as err: - # ECONNABORTED might be thrown - if err.args[0] != errno.ECONNABORTED: - raise + conn = self.accept() + if conn is None: return else: - # sometimes addr == None instead of (ip, port) - if addr == None: - return + sock, addr = conn print('Incoming connection from %s' % repr(addr), file=DEBUGSTREAM) - channel = self.channel_class(self, conn, addr) + channel = self.channel_class(self, sock, addr) # API for "doing something useful with the message" def process_message(self, peer, mailfrom, rcpttos, data): Index: Lib/asyncore.py =================================================================== --- Lib/asyncore.py (revisione 84998) +++ Lib/asyncore.py (copia locale) @@ -352,12 +352,15 @@ # XXX can return either an address pair or None try: conn, addr = self.socket.accept() - return conn, addr except socket.error as why: - if why.args[0] == EWOULDBLOCK: - pass + if why.args[0] in (EWOULDBLOCK, ECONNABORTED): + return None else: raise + else: + if addr is None: + return None + return conn, addr def send(self, data): try: