I am creating a Plone product which uses Twisted's nntp module to fetch newsgroup postings and display them within my Plone site. Within a Plone template I call the Plone External Method, XXXnewsreader. The first time I view the page containing this external method it runs fine but the second time it hangs. I've run the python debugger and it appears to be running an infinite loop within the function mainloop within the class PosixReactorBase. Can anyone share some ideas about what I may be doing wrong here or why the reactor appears to be stuck in the mainlop func? Thanks for any assistance in advance. I am running under Windows XP using Twisted 2.5.0 and using Plone 2.1.3, Zope 2.8.7-final, python 2.3.5. Ed def XXXnewsreader(self): print self.REQUEST.form n = XXXNewsGroup('localhost','local.programming') n.run_XXXNewsGroup() return n.result class XXXDefaultNewsGroupPageProcedure(nntp.NNTPClient): def connectionMade(self): #pdb.set_trace() nntp.NNTPClient.connectionMade(self) self.fetchGroup(self.factory.newsgroup) def gotGroup(self, groupInfo): estNumMsgs, first, last, groupName, type, status = groupInfo first = int(first) last = int(last) start = max(first, last-self.factory.headerCount); self.headersToFetch = range(start, last+1) self.headerCount = len(self.headersToFetch) self.fetchNextHeader() def fetchNextHeader(self): if self.headersToFetch: nextHeaderId = self.headersToFetch.pop(0) print "Fetching header %i of %i..." % ( self.headerCount-len(self.headersToFetch), self.headerCount), self.fetchHead(nextHeaderId) else: self.quit() self.factory.deferred.callback(self.factory.headers) def gotHead(self, header): print "OK" self.factory.handleHeader(header) self.fetchNextHeader() def getHeadFailed(self, errorMessage): print errorMessage self.fetchNextHeader() def getGroupFailed(self, errorMessage): self.factory.defered.errback(Exception(errorMessage)) self.quit() self.transport.loseConnection() def connectionLost(self, error): if not self.factory.deferred.called: self.factory.deferred.errback(error) class XXXDefaultNewsGroupPageFactory(protocol.ClientFactory): protocol = XXXDefaultNewsGroupPageProcedure def __init__(self, deferred, newsgroup, headerCount=5): self.newsgroup = newsgroup self.headerCount = headerCount self.headers = [] self.deferred = deferred # defer.Deferred() def handleHeader(self, headerData): header = HeaderParser(Message).parsestr(headerData, True); self.headers.append(header) temail = parseaddr(header['from']) realName, emailAddress = temail class XXXNewsGroup: def __init__(self, nntpserver, newsgroup): self.server = nntpserver self.newsgroup = newsgroup self.deferred = defer.Deferred() self.result = '' def run_XXXNewsGroup(self): #pdb.set_trace() factory = XXXDefaultNewsGroupPageFactory(self.deferred, self.newsgroup) self.deferred.addCallback( self._toHTMLsuccess).addErrback( self.handleError) self.deferred.addCallback( self.handleSuccess).addErrback( self.handleError) reactor.connectTCP(self.server, 119, factory) reactor.run(installSignalHandlers=0) return self.result def _toHTMLsuccess(self, results): str = '<ul>\n' for header in results: temail = parseaddr(header['from']) realName, emailAddress = temail str += ' <ul>\n' str += ' <li>%s</li>\n' % header['subject'] str += ' <li>%s</li>\n' % realName str += ' <li>%s</li>\n' % header['date'] str += ' </ul>\n' str += '</ul>\n' return str def handleSuccess(self, result): self.result = result pdb.set_trace() reactor.stop() def handleError(self, error): self.result = error.getErrorMessage() print self.result reactor.stop()