Mailman 3 September 2005 - Twisted

Re: [Twisted-Python] Re: GUI responsiveness
by Brian Warner Sept. 25, 2005

Sept. 25, 2005

> Is there a good place to read more about NewPB? Or is it just a matter > of searching the maillist archives and SVN repository? For now, the SVN code and docs are the best source of information: svn://svn.twistedmatrix.com/svn/Twisted/branches/warner/newpb You'll want to look in doc/pb/* and twisted/pb/* . There is a surprising quantity of documentation for newpb, I tried to document everything before implementing it. I've got a few more things to get implemented first, but I'll … [View More]

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Re: [Twisted-Python] jelly tracebacks
by Brian Warner Sept. 24, 2005

Sept. 24, 2005

> I just had a grueling experience debugging some > unjellying problem. I wonder, why not make jelly > tracebacks more useful by adding the details of the PB > message that gave rise to them (i.e. which method of > which object was called with which arguments). Any > thoughts? Good idea. I've incorporated this into newpb, where any problem during serialization or unserialization is reported via an exception that has a .where attribute. This .where string reports the location … [View More]

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Re: [Twisted-Python] unsafe tracebacks in PB
by Brian Warner Sept. 24, 2005

Sept. 24, 2005

> Just wondering, why is it possible to turn on unsafe > tracebacks only at the server and not at the client? > PB being symmetrical, this discrimination makes it > arbitrarily difficuly to debug PB applications > sometimes. Hey, sorry for the slow response. It *is* possible to set the 'unsafeTracebacks' flag on both ends of the wire. PBServerFactory() takes a constructor argument to set this flag, while PBClientFactory() does not, but you can always set it after the fact: f =… [View More] PBClientFactory() f.unsafeTracebacks = True I'm more inclined to resolve the asymmetry by removing the argument from PBServerFactory rather than adding it to PBClientFactory. As a debugging thing, I feel it isn't entirely appropriate to have as a constructor argument. However, I don't really feel that strongly about it either way. For the record, I'll describe a little bit more about what exactly this flag does, because there *is* a sense in which unsafe tracebacks can only be enabled on the "server" side of a given method call. The important thing to remember is that there are two different ways to divide the connection into "client" and "server" ends. Suppose you have program A, which has a pb.Referenceable named Alice that implements remote_foo. Likewise, you have program B, which contains a pb.Referenceable named Bob that implements remote_bar. Let us further suppose that program B used PBServerFactory and reactor.listenTCP to make the object Bob available to the world. Program A then used PBClientFactory and reactor.connectTCP to obtain a RemoteReference to Bob (and somehow passed a reference to Alice over to program B at the same time, so that both programs have a RemoteReference to the other's Referenceable). Now, the setting of this "unsafe tracebacks" flag on side A only affects tracebacks being sent *from* side A: that is, for exceptions that occur on side A, during a remote method invocation that was requested by side B. If you consider any given method call to have a "client side" (which requests the call by doing rref.callRemote("foo", args)), and a "server side" (which implements the method remote_foo(self, args)), then the unsafe-tracebacks flag is only relevant for the "server side". In our example, when B does alice.callRemote("foo"), B is the "client" side and A is the "server" side. If an exception occurs inside Alice's remote_foo method, it is the setting of A's clientfactory.unsafeTracebacks flag that determines whether's A's internal state will be exposed to B. On the other hand, when A does bob.callRemote("bar"), B is the "server" side, so it is B's serverfactory.unsafeTracebacks flag that matters. The important point is that the requesting side for any particular method call does not get to ask for an "unsafe traceback": only the owner of the sensitive information (in this case, the stack frames leading up to the exception, and the globals/locals that are in those stack frames) gets to decide whether or not to share it with the outside world. The second usage of the terms "client" and "server" here has to do with which side initiated the TCP connection and which side accepted it. This is how the PBClientFactory and PBServerFactory classes use these terms. Both of these classes have an 'unsafeTracebacks' flag, and if you set it to something non-zero, then any exception-raising methods invoked on that side will send back a full traceback to the other side. The minor asymmetry here (constructor argument versus set-the-flag-later) is just an oversight in the API. hope that's useful, -Brian [View Less]

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[Twisted-Python] How to send a UDP datagram
by Drake Smith Sept. 24, 2005

Sept. 24, 2005

Can somebody please show me the Twisted way to send a simple UDP datagram? From the examples, I see how to transport.write in response to receiving a datagram or in response to establishing a UDP "connection". But in my application, I'd like to send datagrams blindly, say, to initiate a heartbeat message or to stream audio samples without acknowledgement via an unconnected UDP socket. I'd also like to do this from a function that is not wrapped inside a Twisted protocol class as such, … [View More]

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[Twisted-Python] RE: [Python-Twisted] How to write a simple telnet client?
by Henning.Ramm＠mediapro-gmbh.de Sept. 23, 2005

Sept. 23, 2005

>Please look at my posts from 11.08.2005 - What is wrong with this >instance (topic). I have send there a code of my telnet client. I don't >remember what was wrong, but i solve most of problems, so if >you had any >questions e-mail me. I think that my code is what You need. This is a >very simple client and i have developed him. I played around with your code at http://twistedmatrix.com/pipermail/twisted-python/2005-August/011115.html, even if I don't understand polish. ;-) … [View More]

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[Twisted-Python] Repository for python developers
by Mikhail Kashkin Sept. 23, 2005

Sept. 23, 2005

Moscow, Russia, September 23th, 2005 We are happy to spread good news about `Key Solutions' <http://keysolutions.ru/>`_ new initiative. We have created a new public repository for python developers. The ulitimate goal of this project is to unite companies and people under the umbrella of Russian-speaking-python (Zope/Plone/Zope3/Twisted/etc) open source programmers community, so that we could jointly push forward new programs and technologies in Russia. The repository powered by `… [View More]

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[Twisted-Python] twisted.internet.serialport
by joy ping Sept. 23, 2005

Sept. 23, 2005

hi list, i just did a search for a framwork which would be good for a to be written application which controlls serialports over webinterfaces. i found that twisted would be ideal for this. i started to write some code with mod_phyton but as threading+pyserial+apache didn't worked i had a closer look at twisted. it seems cool cause it's async. no real need for threads here. and with twisted-web and livepages some kind of persistance could be achived. but at the end i found not really much … [View More]

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[Twisted-Python] internet.TimerSevice in twisted.scripts.twistw
by Maciej Szumocki Sept. 22, 2005

Sept. 22, 2005

Hello, Just a question that has been bugging me and i can't figure out the answer on my own. Why is there a line like this in python.scripts._twistw runApp: app.startApplication(internet.TimerService(0.1, lambda:None), 0) while there is no such thing in python.scripts.twistd? Is it some Windows-specific workaround i need to worry about if i run my application without using twistd? Maciej Szumocki

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[Twisted-Python] Re: [Python-Twisted] How to write a simple telnet client?
by Michał Tyde Sept. 22, 2005

Sept. 22, 2005

Please look at my posts from 11.08.2005 - What is wrong with this instance (topic). I have send there a code of my telnet client. I don't remember what was wrong, but i solve most of problems, so if you had any questions e-mail me. I think that my code is what You need. This is a very simple client and i have developed him.

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[Twisted-Python] How to write a simple telnet client?
by Henning.Ramm＠mediapro-gmbh.de Sept. 21, 2005

Sept. 21, 2005

Hi ho! I need to integrate a simple telnet client into one of my programs to execute a command on an other machine and collect the response. Probably I'm blind, because I didn't find out how to use twisted's telnet protocol for such a client (I know how to setup a server). Could someone please give me a kick? Best regards, Henning Hraban Ramm Südkurier Medienhaus / MediaPro Support/Admin/Development Dept.

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