Mailman 3 May 2007 - Twisted

[Twisted-Python] Re: [Twisted-commits] r20275 - Add blockingCallFromThread, some tests and docs, and use it in web2.wsgi.
by Itamar Shtull-Trauring 14 May '07

14 May '07

I've heard some comments from new users who run the examples and "nothing happens." So it's probably best to always have a reactor.run() in introductory howtos' examples.

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[Twisted-Python] pyramid.twistedmatrix.com (almost) retired
by James Y Knight 14 May '07

14 May '07

If you have a login there, you now have a login on cube.twistedmatrix.com. But if you haven't logged in this year, your login is disabled. If you want it back, ask. Logins to pyramid are permanently disabled. Your user account and mail are migrated, but website isn't quite. Until the website is moved, any personal .twistd websites you may have won't be functioning. Also changes you make to ~/public_html won't appear. If you had a crontab, it's disabled, and put in a file CRONTAB in your home directory. Cube doesn't accept password-based ssh access, so if you don't have an ssh key, you can't login. Other than that, if anything is broken, let me know. James

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[Twisted-Python] Submission for the wiki page ProjectsUsingTwisted
by Ricardo Niederberger Cabral 12 May '07

12 May '07

Hi, I'd like to submit a commercial software I'm working on. It's basically a server-side database capable of easily adding visual search technology for any image-related website. Twisted is used on the web tier (server admin interface), on a services tier (offering a server API using PB, XML-RPC and SOAP) and for remote procedure calls among peers in a server cluster (PB). The software homepage is: http://server.imgseek.net/ Architecture details where Twisted plays a crucial role is at: http://server.imgseek.net/category/documentation/architecture/ Thanks for the great software and best regards, Ricardo. PS. sorry if this was sent more than once.

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Re: [Twisted-Python] A Solution Re: [Stackless] Advice on Stackless/Twisted Problem
by Andrew Francis 12 May '07

12 May '07

Hello Itamar: AF> 2) I modified doSelect to call stackless.schedule(). AF> If the reactor does not call stackless.schedule(), AF> other tasklets will not get an opportunity to run. >Why not just use twisted.internet.task.LoopingCall? I overlooked using task.LoopingCall in conjunction with creating a request handler tasklet. I tried and it works nicely. And LoopingCall is faster too. Sweet! With the possible need to add critical sections to stuff like add/remove reader/write, this means I can leave the reactor alone. This is good. In the past, I used task.LoopingCall to solve an earlier problems. I guess I threw the baby out with the bath water. Thanks alot! Cheers, Andrew ____________________________________________________________________________________Get the free Yahoo! toolbar and rest assured with the added security of spyware protection. http://new.toolbar.yahoo.com/toolbar/features/norton/index.php

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[Twisted-Python] A Solution Re: [Stackless] Advice on Debugging Stackless/Twisted Problem
by Andrew Francis 11 May '07

11 May '07

Hello Colleagues: Earlier I posted that I was having a problem involving the loss of deferred calls in a programme that uses Stackless and Twisted. I found the problem and wrote a solution. I think it interesting. It helped when I started using the Twisted logging facility :-) The immediate reason the deferred were "lost" was because the main reactor loop stopped iterating. What happened was: 1. In the example, Stackless treats Twisted as a tasklet. see: http://www.stackless.com/pipermail/stackless/2007-April/002448.html 2. When the Request Handler is created, it is running as a *part* of the Twisted tasklet. 3. Consequently when the Request Handler blocked on a channel, this blocked the entire reactor! In turn, doIteration() (doSelect) cannot do its work. Twisted grinds to a halt. 4. When the last tasklet (TestTasklet) blocked, all the tasklets became blocked. Consequently the programme ended. The solution was two-fold. 1) To prevent the reactor from blocking, I run the request handler in its own tasklet. This prevents the reactor from blocking for indeterminate periods of time. 2) I modified doSelect to call stackless.schedule(). If the reactor does not call stackless.schedule(), other tasklets will not get an opportunity to run. (When I have time, I will write a proper reactor. This should be a little more than overriding the doIteration() method of selectReactor). Or re-read the Blocking demo : I don't quite understand how it works) With this approach, I 1) Eliminate a OS-Thread (both Stackless and Twisted folks concur that this is wrong, wrong, wrong). 2) Can execute tasklets in parallel with tasklets that are blocked waiting for network I/O like an incoming HTTP request. I think it is neat that the Twisted framework is flexible enough to be contorted in this fashion. Unfortunately this approach is *very* slow. I feel it is wastefully that a tasklet is created for every incoming request. I have to work on this. ~ I understand the subset of Stackless and Twisted users is small. And the philosophies are different. And what I am doing is a bit esoteric and application specific. Hopefully others will be able to build upon this : I don't see why programmers can't get the best of the Stackless and Twisted worlds. Cheers, Andrew ____________________________________________________________________________________Yahoo! oneSearch: Finally, mobile search that gives answers, not web links. http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC

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[Twisted-Python] Hacking in Bazaar
by Jonathan Lange 10 May '07

10 May '07

Hey guys, I've got a couple of longish flights coming up and I'd like to spend at least some of the flight time contributing to Twisted. Thing is, I'd like to be able to use some version control while I'm working. Call me crazy. My plan is to branch off the Bazaar import at https://code.launchpad.net/~vcs-imports/twisted/main, make changes, then make SVN branches when I get back to the internet. Sound good? Is there anything related to UQDS or Twisted's processes that I should know now? cheers, jml

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[Twisted-Python] StdIO forwarding server
by Tomas Neme 10 May '07

10 May '07

I need to write a server that receives a command through stdIO and forwards it to all of its clients. So far I've been able to create and mantain a list of clients, but I can't send the message to all of them. This might be confusing, I think I have a completely wrong approach. I used the echoclient.py example from O'Reilly's Network Programming Essentials, and simply changed the ClientFactory to a ServerFactory, added a clients list and changed def dataReceived(self,data): self.output.write(data) to def dataReceived(self,data): for c in self.factory.clients: c.output.write(data) but for some reason this comes out to the server's StdIO instead of the client's can anyone give me some tip? -- |_|0|_| |_|_|0| |0|0|0|

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[Twisted-Python] SSL Server and Client
by Chakkaradeep C C 10 May '07

10 May '07

Hi, I am trying out this example<http://twistedmatrix.com/pipermail/twisted-python/2007-May/015325.html>to start with twisted and ssl I generated my certificate by the command, openssl genrsa -des3 -out server.pem 1024 When I execute the program, I get this error, chaks@chaks-laptop:~/LDMS$ python twisted-ssl.py Enter PEM pass phrase: Traceback (most recent call last): File "twisted-ssl.py", line 17, in <module> theCert = PrivateCertificate.loadPEM(file('server.pem','r').read()) File "/usr/lib/python2.5/site-packages/twisted/internet/_sslverify.py", line 584, in loadPEM crypto.FILETYPE_PEM) File "/usr/lib/python2.5/site-packages/twisted/internet/_sslverify.py", line 561, in load return Class._load(data, format)._setPrivateKey(privateKey) File "/usr/lib/python2.5/site-packages/twisted/internet/_sslverify.py", line 395, in load return Class(crypto.load_certificate(format, requestData), *args) OpenSSL.crypto.Error: [('PEM routines', 'PEM_read_bio', 'no start line')] What am i doing wrong ? Am i missing something here ? Thanks. -- Regards, C.C.Chakkaradeep, http://chakkaradeep.net -- "Sometimes it's better not to ask - or to listen - when people tell you something can't be done. I didnt ask for permission or approval. I just went ahead and did it." - from "Direct from Dell"

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[Twisted-Python] Distinguishing several open Firefox/Opera windows authorized in same realm
by Werner Thie 08 May '07

08 May '07

Can someone advise if it is possible to distinguish two open Firefox/Opera windows authorized for the same realm? Many thanks, Werner

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[Twisted-Python] Getting multiservice from running reactor
by David Pratt 07 May '07

07 May '07

Can someone advise if it possible to obtain a service or multiservice object from the reactor object. I am interested in status of services in multiservice. Many thanks. Regards, David

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