Mailman 3 October 2006 - Twisted

[Twisted-Python] Help with TCPServer and listenTCP
by James Healey Oct. 20, 2006

Oct. 20, 2006

I've been looking over some Twisted arcticles over the past day or 2 and havnt found much help on TCPServer, ive seen server/client exampels which use listenTCP and connectTCP, but then i also find one that uses TCPServer. What are the differences between TCPServer and listenTCP, and what are the parameters to TCPServer? I'm trying to write a server/client app which handles a build system, where the build system has x number of builds it needs to handle. Currently each build is done at a set time during the night, so one build might start at 7pm and then the next build might start at 10pm, each build is dependent on other builds. A user can request a build, which will then go to the server and ask if it can start a build and then start with the first dependancy it needs to build. But my main question is about the TCPServer call and how it differs from listenTCP. Cheers. Jimmy. Send instant messages to your online friends http://uk.messenger.yahoo.com

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RE: [Twisted-Python] Unreliable UDP
by Sven-Erik Tiberg Oct. 20, 2006

Oct. 20, 2006

Interesting! Appreciate any info on semi-reliable UDP Twisted-based projects? Sven-Erik Tiberg. -----Original Message----- From: twisted-python-bounces(a)twistedmatrix.com [mailto:twisted-python-bounces@twistedmatrix.com] On Behalf Of Jean-Paul Calderone Sent: den 19 oktober 2006 05:27 To: Twisted general discussion Subject: Re: [Twisted-Python] Unreliable UDP On Wed, 18 Oct 2006 21:47:51 -0500, Mike Wyatt <mwyatt(a)wi.rr.com> wrote: >Does Twisted provide any support for reliable UDP? I'm looking for a >nice networking library for and real-time (i.e. non-TCP) game development. First, just use TCP, unless you have already implemented the game using TCP, done performance testing and discovered problems tied to TCP which are resolved by UDP. Assuming you have done that, come up with a list of the kind of traffic your game needs to exchange between hosts. Based on that, you may be able to narrow your search (there are lots of kinds of "reliable" UDP) or you may find that existing solutions aren't suitable. Twisted itself doesn't offer any kind of reliability layering on top of UDP, but there are various Twisted-based projects which use UDP for semi-reliable messaging. Whether any of them might be of use to you depends on how closely your message model matches theirs. Most likely, you'll end up implementing something yourself, assuming you actually need a UDP-based solution at all. Jean-Paul _______________________________________________ Twisted-Python mailing list Twisted-Python(a)twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python

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[Twisted-Python] Unreliable UDP
by Mike Wyatt Oct. 20, 2006

Oct. 20, 2006

Does Twisted provide any support for reliable UDP? I'm looking for a nice networking library for and real-time (i.e. non-TCP) game development.

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[Twisted-Python] Re: Chesspark - A twisted based online chess community.
by Ed Suominen Oct. 19, 2006

Oct. 19, 2006

> I would like to announce a twisted based online game called > Chesspark. ... There is also a Windows client in case you don't like > using web applications. ... Of course, this is only the start. There > is much more to come, and hopefully even more games than just Chess. > > I hope you like it, Christopher Zorn Cool! It's great to see Twisted being used in worthy projects like this. I am a fan of chess (sadly stuck at around ELO 1100), Twisted, and Linux. I'm a little disappointed to see that only the first two of the three seem to be addressed here. What are your plans for a Linux version of the client? Best regards, Ed Suominen Occasionally seen on FICS as "edsuom"...

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[Twisted-Python] Chesspark - A twisted based online chess community.
by Christopher Zorn Oct. 19, 2006

Oct. 19, 2006

I would like to announce a twisted based online game called Chesspark. Chesspark is an online chess community. You can chat, play games, meet new friends, do puzzles, and many other things. The whole system is built upon Jabber and uses Twisted for its backend components and bots. In addition, we have built a web client (which also works as a normal Jabber client). Built on top of punjab and the Javascript version of strophe, this client allows you to play games, chat, and pretty much anything the native client can do. It even supports avatars. Punjab is a twisted based http binding mechanism for jabber. There is also a Windows client in case you don't like using web applications. You can visit Chesspark here: http://www.chesspark.com and try the webclient here: http://www.chesspark.com/webclient/client.xhtml Of course, this is only the start. There is much more to come, and hopefully even more games than just Chess. I hope you like it, Christopher Zorn

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[Twisted-Python] finger tutorial: server slow to shutdown
by Brian King Oct. 19, 2006

Oct. 19, 2006

I was working my way through the tutorial, running each version of the server and testing it out with "telnet localhost 1079". When I got to this ( http://twistedmatrix.com/projects/core/documentation/howto/tutorial/intro.h…) version of the server, I noticed that the server was not shutting down immediately when I pressed ctrl-c. The script I'm running is a verbatim copy of the tutorial code. I see the following behavior: 1. If immediately after receiving a response from a "finger" query I press ctrl-c to stop the server, the server shuts down: a) after about 20 seconds, if there is no activity on port 1079, or b) as soon as a connection is attempted on port 1079 (e.g. "telnet localhost 1079"). 2. If after having waited some time (e.g. 30 seconds) after the last query I press ctrl-c to stop the server, it shuts down only after the next connection attempt on port 1079. 3. If no connections have been made to the server, ctrl-c shuts it down immediately. For the case 1) above: Running "netstat -tn" after having pressed ctrl-c and before the server shuts down gives the following output: Active Internet connections Proto Recv-Q Send-Q Local Address Foreign Address (state) tcp4 0 0 127.0.0.1.1079 127.0.0.1.57791 TIME_WAIT ... (nothing indicating an open connection to the queried web server) For the case 2) above, there is no mention of port 1079 in the output from "netstat -tn". I've spent some time trying to understand why it doesn't shut down immediately in cases 1 and 2, but haven't figured it out. Can anybody shed some light on what is going on? What would I have to do to get it to shutdown quickly? Environment info: freebsd 6.1 release python 2.4.3 twisted 2.4.0 Thanks, Brian

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[Twisted-Python] Newbie question on how to send "complex" objects over the wire
by Franz Zieher Oct. 18, 2006

Oct. 18, 2006

Can anybody provide a an example on how I would best send a data structure (i.e. an ElemenTree from elementtree) over from a server to a client process. I followed somewhat the example in the documentation and used the perspective broker "pb" to send an "simple" structure (some class with simple members) When I changed to a more complex class definition, I obviously got an InsecureJelly exception. I'm sure this question must have come up a number of times. I'm new in using twisted and not everything is so obvious at the beginning to me :-( Many thanks for the help Franz Attached is the sample code I used: sending test1 --> OK sending test2 --> InsecureJelly exception ------ pbsimple.py (server) ------- from twisted.spread import pb, jelly from twisted.internet import reactor class test: def __init__(self): x = 3. y = 4. class Bag: def setContent(self,content): self.content = content def printContent(self): print "My data is", self.content class CopyBag(Bag, pb.Copyable): pass class Sender(pb.Root): def __init__(self, bag): self.bag = bag def remote_sendBag(self, remote): self.remote = remote d = remote.callRemote("takeBag", self.bag) d.addCallback(self.ok).addErrback(self.notOk) def ok(self, response): print "info: %s" % response d = self.remote.callRemote("finishTransfer") d.addErrback(self.notOk) return None def notOk(self, failure): if failure.type == jelly.InsecureJelly: print "error: InsecureJelly" elif failure.type == pb.PBConnectionLost: print "info: data transfer finished" else: print failure return None def main(): from pbsimple import CopyBag icae = iCAEconfig() bag = CopyBag() bag.setContent('simple data') # --> OK #bag.setContent(test()) # --> InsecureJelly sender = Sender(bag) factory = pb.PBServerFactory(sender) reactor.listenTCP(8789, factory) reactor.run() if __name__ == '__main__': main() ----------------------------- ------------ pbsimleclient.py ----------------- from twisted.spread import pb from twisted.internet import reactor from twisted.python import util from pbsimple import Bag, CopyBag class ReceiverBag(Bag,pb.RemoteCopy): pass pb.setUnjellyableForClass(CopyBag, ReceiverBag) class Receiver(pb.Referenceable): def remote_takeBag(self, bag): self.bag = bag return "data arrived safe and sound" # positive acknowledgement def remote_finishTransfer(self): print "got bag:", self.bag reactor.stop() def requestBag(self,remote): print "asking server for sending the data bag" remote.callRemote("sendBag",self) def getContentFromServer(): receiver = Receiver() factory = pb.PBClientFactory() reactor.connectTCP("localhost", 8789, factory,30) d = factory.getRootObject() d.addCallback(receiver.requestBag) reactor.run() return receiver.bag.content if __name__ == '__main__': print getContentFromServer() ---------------------------------------------------------

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[Twisted-Python] Error? twisted/internet/tcp.py:216: exceptions.UserWarning: SSL connection shutdown possibly unreliable, please upgrade to ver 0.XX
by Chaz. Oct. 18, 2006

Oct. 18, 2006

I just recently started getting the message from the my application : [HTTPChannel,0,127.0.0.1] /usr/lib/python2.4/site-packages/twisted/internet/tcp.py:216: exceptions.UserWarning: SSL connection shutdown possibly unreliable, please upgrade to ver 0.XX Can someone tell me what I need to upgrade? Thanks, Chuck Wegrzyn

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Re: [Twisted-Python] Twisted - reactor activated by reciving UDP-package.
by glyph＠divmod.com Oct. 17, 2006

Oct. 17, 2006

On 09:05 am, sven-erik.tiberg(a)ltu.se wrote: >My Q. can a Twisted script be activated from an arrival of a UDP or TCP >package? Yes. That is what Twisted _is_. Have you looked at the "finger" tutorial? http://twistedmatrix.com/projects/core/documentation/howto/tutorial/index.h…

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[Twisted-Python] Perspective Broker and keeping track of connected clients
by Yi Qiang Oct. 17, 2006

Oct. 17, 2006

Hi, I am using PB to expose some methods and objects remotely. However, I need to keep track of the people who are connected to the PB server via IP address (I've thought about using authentication, but I would like anonymous access as well). My requirement is that at any given moment, I need to know which ip's are connected to the server. Is this possible using PB/Twisted? If so how? I have the Twisted book and have looked for tutorials on the web, but neither seem to address this issue. Thanks, Yi

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