Mailman 3 February 2011 - Twisted

[Twisted-Python] DeferredSemaphore - action on acquire and release
by Jason Heeris 08 Feb '11

08 Feb '11

I'm using a DeferredSemaphore with a token count of 1 to control access to a serial port. I also have a GTK object for which I'd like the "in-use" property to change (and notify listeners) when the resource is in use. So far, I have something like this: ---- class SerialResource(gobject): # Property defs, etc def _acquire(self): # The "in-use" property is actually stored in self.taken self.taken = True self.notify('in-use') def _release(self, res): self.taken = False self.notify('in-use') return res def run(self, func, *args, **kargs): def wrapper(): self._acquire() res = func(*args, **kargs) return res d = self.sem.run(wrapper) d.addBoth(self._release) return d ---- I feel like there might be a simpler way to do this, but I just can't see it. Or is this as simple as I can make it? — Jason

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[Twisted-Python] ipv6 support
by Thomas Vander Stichele 08 Feb '11

08 Feb '11

Hi everyone, For Flumotion we would like to be able to add IPv6 support. This is not yet in Twisted, but there's a ticket open for it: http://twistedmatrix.com/trac/ticket/3014 We are considering sponsoring a developer to finish and integrate this patch, but I wanted to check first if there are any willing and able developers to take on the job if we go ahead ? Thanks Thomas -- The blood before me makes me open up my heart again And I feel it coming over like a storm again -- GStreamer - bringing multimedia to your desktop http://gstreamer.freedesktop.org/

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[Twisted-Python] Change to ticket workflow
by exarkun＠twistedmatrix.com 07 Feb '11

07 Feb '11

Hi all, Last weekend I changed the default owner for all components in the issue tracker to be nobody. I also installed the "DefaultCC" plugin which lets us configure a list of users to be added to the cc list of tickets on a per-component basis. The motivation for this change is basically the fact that when people see a ticket with an owner, they think that owner is either working on the ticket or will be upset if someone else starts working on it. This has really never been the case with Twisted's development process. Beyond this change, I think it may also be a good idea to remove owners from most old tickets as well. This will probably happen sometime in the coming week, so don't be surprised when you look at your ticket list and find it empty. After this, if you actually want to work on a ticket, there's no reason not to assign it to yourself. The goal here is just to eliminate accidental/careless ownership. Jean-Paul

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[Twisted-Python] Boston Mini-Sprint: February Edition
by Tenth 07 Feb '11

07 Feb '11

We'll be holding another Boston-area Twisted Mini-Sprint on Sunday, February 13th at my place in Somerville, MA... I've sent out invitations to the attendees from last time, plus a few other people who've expressed interest, but if you weren't invited yet, and want to be, let me know! Thanks, - Dave

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[Twisted-Python] Task-based documentation started
by Tom Davis 06 Feb '11

06 Feb '11

I have the beginnings of some task-based documentation available in twisted-docs (https://github.com/tdavis/twisted-docs) now. You can find the built version in the usual place (http://docs.recursivedream.com/twisted/) -- just remember to bust the cache. I chose serving web content as a starting point because it seems as common a task as any. I took some examples from the existing howto ( http://twistedmatrix.com/documents/current/web/howto/using-twistedweb.html), as well as added some examples of further learning and glossary entries to make the point. Obviously there's nothing completely usable here yet; it's primarily an exercise in showing how I'd like to split up sprawling, semi-random docs like *using-twistedweb* into more coherent, digestible, stackable pieces. A document to talk about core concepts (Site Objects, Resources, etc.), sections for supplementary features like Sessions, Virtual Hosts, etc. Another advantage of this style is that we can effortlessly stitch together our own tutorials (were that ever a goal) just by linking in step-wise fashion to ever-advanced tutorials which themselves wrap back around to core concepts like, in this case, Applications and the IService stack. It should be up to the user how deep into the rabbit hole they want to go; right now I have to slog through two sections to get to a part that tells me how to just serve a directory of HTML. Thoughts?

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 06 Feb '11

06 Feb '11

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[Twisted-Python] ClientFactory: implementing Request/Response with a persistent connection
by Wolfgang Powisch 05 Feb '11

05 Feb '11

Hello, I need to talk to a Line-based TCP service from a Twisted Application. The remote server will accept requests and send a response. I do NOT want to open a NEW TCP-Connection for each request. Are there any examples how to send concurrent requests over a single conenction ? .. so that my module takes care of sending the next request when the previous response has been received Here a simple (pseudo-)example of how I would like to use my client-module: ------------------------- xyclient = yield XyClient('127.0.0.1',1234).connect() d1 = xyclient.send_request('GET 1') # returns a deferred d2 = xyclient.send_request('GET 2') # returns a deferred d1.addCallback(print) d2.addCallback(print) "Response 1" "Response 2" ------------------------- Later I need to enhance this to manage a Pool of connections and dispatch requests across this pool. Does there exist something "out of the box" for ConnectionPools ? regards, powo

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[Twisted-Python] SerialPort testing on the Twisted build slaves
by Michael Thompson 04 Feb '11

04 Feb '11

Hi, Ticket http://twistedmatrix.com/trac/ticket/3690 is adding some serial port testing. The patch adds code to discover serial ports on Windows and Posix and the test uses the first serial port that is discovered. Will this approach work for the build slaves, or is it better to use an environment variable that can be set for each build slave? Do any of the build slaves have serial ports or are they all VMs? Michael

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[Twisted-Python] Using SerialPort with t.a.s.Application
by Albert Brandl 04 Feb '11

04 Feb '11

Hi! In our project, we accumulate data from various sources. Some of them are connected via serial line (e.g. a GPS receiver and a weather station). I'd like to run the application with twistd. But it looks as if SerialPort does not really fit into this framework. It does not implement IService, so `my_serial_port.setServiceParent(collection)` does not work. Is there any technical reason that SerialPort does not implement IService? Could you suggest a workaround for this problem (other than dumping t.a.s.Application ;-))? Best regards, Albert -- Albert Brandl Weiermayer Solutions GmbH | Abteistraße 12, A-4813 Altmünster phone: +43 (0) 720 70 30 14 | fax: +43 (0) 7612 20 3 56 web: http://www.weiermayer.com

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[Twisted-Python] design of twisted application
by Kurt Spindler 02 Feb '11

02 Feb '11

Hey, I am trying to design a twisted application, (I'm pretty new to twisted and networking in general) and I feel like I'm not approaching it quite the right way and would appreciate your feedback. First part, is that I am trying to couple twisted with an existing graphics-type application, that already has it's own main loop, etc. Meaning, I need to be running other python code while I have the reactor running. Is the solution threading? f = MyFactory() reactor.connectTCP("localhost",22223,f) t = threading.Thread(target=reactor.run) t.run() runOtherCodeConcurrently() Is there a better solution? Second question is that, in that other bunch of code, I need to be able to write things to the socket. How can I access the instance of my protocol subclass that is used by the factory, so I can make protocolInstance.transport.write type calls? Or am I thinking about this is a completely wrong way? Thank you very much for your help! Kurt

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Twisted February 2011