From 7930ed22f2371ba3405f9644f427bec9554d2a15 Mon Sep 17 00:00:00 2001 From: Thom Nichols Date: Wed, 2 Jun 2010 12:39:54 -0400 Subject: overhauled state machine. Now allows for atomic transitions. Next step: atomic function calls (and maybe 'handlers') on state transition. --- sleekxmpp/xmlstream/xmlstream.py | 90 +++++++++++++++------------------------- 1 file changed, 33 insertions(+), 57 deletions(-) (limited to 'sleekxmpp/xmlstream/xmlstream.py') diff --git a/sleekxmpp/xmlstream/xmlstream.py b/sleekxmpp/xmlstream/xmlstream.py index fd307a5c..3bcb3412 100644 --- a/sleekxmpp/xmlstream/xmlstream.py +++ b/sleekxmpp/xmlstream/xmlstream.py @@ -53,8 +53,9 @@ class XMLStream(object): global ssl_support self.ssl_support = ssl_support self.escape_quotes = escape_quotes - self.state = statemachine.StateMachine() - self.state.addStates({'connected':False, 'is client':False, 'ssl':False, 'tls':False, 'reconnect':True, 'processing':False}) #set initial states + self.state = statemachine.StateMachine(('disconnected','connecting', + 'connected')) + self.should_reconnect = True self.setSocket(socket) self.address = (host, int(port)) @@ -86,21 +87,21 @@ class XMLStream(object): def setSocket(self, socket): "Set the socket" self.socket = socket - if socket is not None: + if socket is not None and self.state.transition('disconnected','connecting'): self.filesocket = socket.makefile('rb', 0) # ElementTree.iterparse requires a file. 0 buffer files have to be binary - self.state.set('connected', True) - + self.state.transition('connecting','connected') def setFileSocket(self, filesocket): self.filesocket = filesocket - def connect(self, host='', port=0, use_ssl=False, use_tls=True): + def connect(self, host='', port=0, use_ssl=None, use_tls=None): "Link to connectTCP" - return self.connectTCP(host, port, use_ssl, use_tls) + if self.state.transition('disconnected', 'connecting'): + return self.connectTCP(host, port, use_ssl, use_tls) def connectTCP(self, host='', port=0, use_ssl=None, use_tls=None, reattempt=True): "Connect and create socket" - while reattempt and not self.state['connected']: + while reattempt and not self.state['connected']: # the self.state part is redundant. logging.debug('connecting....') try: if host and port: @@ -122,7 +123,8 @@ class XMLStream(object): try: self.socket.connect(self.address) self.filesocket = self.socket.makefile('rb', 0) - self.state.set('connected', True) + if not self.state.transition('connecting','connected'): + logging.error( "State transition error!!!! Shouldn't have happened" ) logging.debug('connect complete.') return True except socket.error as serr: @@ -182,7 +184,7 @@ class XMLStream(object): "Start processing the socket." logging.debug('Process thread starting...') while self.run: - self.state.set('processing', True) + if not self.state.ensure('connected',wait=2): continue try: self.sendRaw(self.stream_header) while self.run and self.__readXML(): pass @@ -196,38 +198,16 @@ class XMLStream(object): logging.debug("Restarting stream...") continue # DON'T re-initialize the stream -- this exception is sent # specifically when we've initialized TLS and need to re-send the header. - except KeyboardInterrupt: - logging.debug("Keyboard Escape Detected") - self.state.set('processing', False) - self.state.set('reconnect', False) - self.disconnect() - # TODO this is probably not necessary... - self.eventqueue.put(('quit', None, None)) - return - except SystemExit: - # TODO shouldn't this be the same as KeyboardInterrupt???? + except (KeyboardInterrupt, SystemExit): + logging.debug("System interrupt detected") + self.shutdown() self.eventqueue.put(('quit', None, None)) - return except: logging.exception('Unexpected error in RCV thread') - if not self.state.reconnect: - return - else: - logging.debug('reconnecting...') - self.state.set('processing', False) + if self.should_reconnect: self.disconnect(reconnect=True) - # TODO the individual exception handlers above already handle reconnect! - # Why are we attempting to do it again down here??? -# if self.state['reconnect']: -# self.state.set('connected', False) - self.state.set('processing', False) -# self.reconnect() -# else: -# TODO I think this is getting queued, and when the eventRunner comes back online after -# reconnect, it immediately processes a 'quit' event and exits again, meanwhile the -# rest of the client is just starting to connect and process the incoming event stream!!! -# self.eventqueue.put(('quit', None, None)) - logging.debug('Quitting Process thread') + + logging.debug('Quitting Process thread') def __readXML(self): "Parses the incoming stream, adding to xmlin queue as it goes" @@ -246,7 +226,6 @@ class XMLStream(object): edepth += -1 if edepth == 0 and event == b'end': # what is this case exactly? Premature EOF? - #self.disconnect(reconnect=self.state['reconnect']) logging.debug("Ending readXML loop") return False elif edepth == 1: @@ -261,9 +240,8 @@ class XMLStream(object): def _sendThread(self): logging.debug('send thread starting...') while self.run: - if not self.state['connected']: - logging.warning("Not connected yet...") - time.sleep(1) + if not self.state.ensure('connected',wait=2): continue + data = None try: data = self.sendqueue.get(True,10) @@ -272,7 +250,7 @@ class XMLStream(object): except queue.Empty: logging.debug('nothing on send queue') except socket.timeout: - # this is to prevent hanging + # this is to prevent a thread blocked indefinitely logging.debug('timeout sending packet data') except: logging.warning("Failed to send %s" % data) @@ -282,9 +260,7 @@ class XMLStream(object): # the same thing concurrently. Oops! The safer option would be to throw # some sort of event that could be handled by a common thread or the reader # thread to perform reconnect and then re-initialize the handler threads as well. - if self.state.reconnect: - logging.debug('Reconnecting...') - traceback.print_exc() + if self.should_reconnect: self.disconnect(reconnect=True) def sendRaw(self, data): @@ -292,8 +268,7 @@ class XMLStream(object): return True def disconnect(self, reconnect=False): - self.state.set('reconnect', reconnect) - if not self.state['connected']: + if not self.state.transition('connected','disconnected'): logging.warning("Already disconnected.") return logging.debug("Disconnecting...") @@ -301,10 +276,7 @@ class XMLStream(object): time.sleep(5) #send end of stream #wait for end of stream back - self.run = False - self.scheduler.run = False try: - self.state.set('connected',False) # self.socket.shutdown(socket.SHUT_RDWR) self.socket.close() except socket.error as (errno,strerror): @@ -312,13 +284,17 @@ class XMLStream(object): try: self.filesocket.close() except socket.error as (errno,strerror): - logging.exception("Error closing filesocket.") + logging.exception("Error closing filesocket.") + + if reconnect: self.connect() - def reconnect(self): - self.state.set('tls',False) - self.state.set('ssl',False) - time.sleep(1) - self.connect() + def shutdown(self): + ''' + Disconnects and shuts down all event threads. + ''' + self.disconnect() + self.run = False + self.scheduler.run = False def incoming_filter(self, xmlobj): return xmlobj -- cgit v1.2.3