try: import epoll as select except ImportError: import select import socket import heapq import time import os import sys import weakref from errno import EALREADY, EINPROGRESS, EWOULDBLOCK, ECONNRESET, \ ENOTCONN, ESHUTDOWN, EINTR, EISCONN, errorcode FLAGS = select.POLLIN | select.POLLPRI | select.POLLERR | \ select.POLLHUP | select.POLLNVAL | select.POLLOUT try: socket_map except NameError: socket_map = {} try: pollster except NameError: pollster = select.poll() try: timers except NameError: timers = [] class ExitNow(Exception): pass def ticks(): return os.times()[4] def readwrite(obj, flags): try: if flags & (select.POLLIN | select.POLLPRI): obj.handle_read_event() if flags & select.POLLOUT: obj.handle_write_event() if flags & (select.POLLERR | select.POLLHUP | select.POLLNVAL): obj.handle_expt_event() except ExitNow: raise except: obj.handle_error() def poll(timeout=0.0): timeout = int(timeout*1000) try: nfds = pollster.poll(timeout) except select.error, err: if err[0] != EINTR: raise nfds = [] for fd, flags in nfds: obj = socket_map.get(fd) if obj: readwrite(obj, flags) def loop(timeout=30.0, use_poll=True): maxtimeout = timeout while socket_map: poll(timeout) timeout = process_timers(maxtimeout) class dispatcher: debug = False connected = False accepting = False closing = False addr = None timerref = 0 def __init__(self, sock=None): self.timers = {} if sock: self.set_socket(sock) self.socket.setblocking(0) self.connected = True try: self.addr = sock.getpeername() except socket.error: pass else: self.socket = None def __repr__(self): status = [self.__class__.__module__+"."+self.__class__.__name__] if self.accepting and self.addr: status.append('listening') elif self.connected: status.append('connected') if self.addr is not None: try: status.append('%s:%d' % self.addr) except TypeError: status.append(repr(self.addr)) return '<%s at %s>' % (' '.join(status), id(self)) def add_channel(self): socket_map[self._fileno] = self pollster.register(self._fileno, FLAGS) def del_channel(self): fd = self._fileno if socket_map.has_key(fd): del socket_map[fd] pollster.unregister(fd) self._fileno = None def create_socket(self, family, type): self.family_and_type = family, type self.socket = socket.socket(family, type) self.socket.setblocking(0) self._fileno = self.socket.fileno() self.add_channel() def set_socket(self, sock): self.socket = sock self._fileno = sock.fileno() self.add_channel() def set_reuse_addr(self): try: self.socket.setsockopt( socket.SOL_SOCKET, socket.SO_REUSEADDR, self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR) | 1 ) except socket.error: pass def gettref(self): dispatcher.timerref += 1 return dispatcher.timerref def set_timer(self, pause, msg): tref = self.gettref() stoptime = ticks() + pause objref = weakref.ref(self) heapq.heappush(timers, (stoptime, tref, objref)) self.timers[tref] = (stoptime, msg) return tref def cancel_timer(self, tref): try: del self.timers[tref] except KeyError: pass def listen(self, num): self.accepting = True if os.name == 'nt' and num > 5: num = 1 return self.socket.listen(num) def bind(self, addr): self.addr = addr return self.socket.bind(addr) def async_connect(self, address): self.connected = False err = self.socket.connect_ex(address) # XXX Should interpret Winsock return values if err in (EINPROGRESS, EALREADY, EWOULDBLOCK): return if err in (0, EISCONN): self.addr = address self.connected = True self.handle_connect() else: raise socket.error, (err, errorcode[err]) def accept(self): # XXX can return either an address pair or None try: conn, addr = self.socket.accept() return conn, addr except socket.error, why: if why[0] == EWOULDBLOCK: pass else: raise def async_send(self, data): try: result = self.socket.send(data) return result except socket.error, why: if why[0] == EWOULDBLOCK: return 0 else: raise return 0 def recv(self, buffer_size): try: data = self.socket.recv(buffer_size) if not data: # a closed connection is indicated by signaling # a read condition, and having recv() return 0. self.handle_close() return '' else: return data except socket.error, why: # winsock sometimes throws ENOTCONN if why[0] in [ECONNRESET, ENOTCONN, ESHUTDOWN]: self.handle_close() return '' else: raise def close(self): self.del_channel() self.timers = {} self.socket.close() # cheap inheritance, used to pass all other attribute # references to the underlying socket object. def __getattr__(self, attr): return getattr(self.socket, attr) # log and log_info may be overridden to provide more sophisticated # logging and warning methods. In general, log is for 'hit' logging # and 'log_info' is for informational, warning and error logging. def log(self, message): sys.stderr.write('log: %s\n' % str(message)) def log_info(self, message, type='info'): if __debug__ or type != 'info': print '%s: %s' % (type, message) def handle_read_event(self): if self.accepting: # for an accepting socket, getting a read implies # that we are connected if not self.connected: self.connected = True self.handle_accept() elif not self.connected: self.handle_connect() self.connected = True self.handle_read() else: self.handle_read() def handle_write_event(self): # getting a write implies that we are connected if not self.connected: self.handle_connect() self.connected = True self.handle_write() def handle_expt_event(self): self.handle_expt() def handle_timer_event(self, tref): msg = self.timers.pop(tref)[1] self.handle_timer(tref, msg) def handle_error(self): nil, t, v, tbinfo = compact_traceback() # sometimes a user repr method will crash. try: self_repr = repr(self) except: self_repr = '<__repr__(self) failed for object at %0x>' % id(self) self.log_info( 'uncaptured python exception, closing channel %s (%s:%s %s)' % ( self_repr, t, v, tbinfo ), 'error' ) self.close() def handle_expt(self): self.log_info('unhandled exception', 'warning') self.close() def handle_read(self): self.log_info('unhandled read event', 'warning') def handle_write(self): self.log_info('unhandled write event', 'warning') def handle_connect(self): self.log_info('unhandled connect event', 'warning') def handle_accept(self): self.log_info('unhandled accept event', 'warning') def handle_close(self): self.log_info('unhandled close event', 'warning') self.close() def handle_timer(self, tref, msg): self.log_info('unhandled timer event', 'warning') class dispatcher_with_send(dispatcher): def __init__(self, sock=None): dispatcher.__init__(self, sock) self.out_buffer = '' self.buf_limit = 'unlimited' def handle_write(self): num_sent = dispatcher.async_send(self, self.out_buffer) self.out_buffer = self.out_buffer[num_sent:] if len(self.out_buffer) > self.buf_limit: # If the buffer size is more than buf_limit, we # generate an exception event. It is much # better to close the connection than to have # gigabytes of swamped memory. self.handle_expt() elif not self.out_buffer: pollster.register(self._fileno, FLAGS ^ select.POLLOUT) def async_send(self, data): if self.debug: self.log_info('sending %s' % repr(data)) self.out_buffer += data if self.out_buffer: pollster.register(self._fileno, FLAGS) # --------------------------------------------------------------------------- # timers processing # --------------------------------------------------------------------------- PRECISION = 0.01 def process_timers(maxtimeout): while timers: delta = timers[0][0] - ticks() if delta <= PRECISION: stoptime, tref, objref = heapq.heappop(timers) obj = objref() if obj and obj.timers.has_key(tref): try: obj.handle_timer_event(tref) except ExitNow: raise except: obj.handle_error() else: return delta return maxtimeout def compact_traceback(): t, v, tb = sys.exc_info() tbinfo = [] assert tb # Must have a traceback while tb: tbinfo.append(( tb.tb_frame.f_code.co_filename, tb.tb_frame.f_code.co_name, str(tb.tb_lineno) )) tb = tb.tb_next # just to be safe del tb file, function, line = tbinfo[-1] info = ' '.join(['[%s|%s|%s]' % x for x in tbinfo]) return (file, function, line), t, v, info def close_all(): for obj in socket_map.values(): obj.close()