Mailman 3 April 2009 - Twisted

[Twisted-Python] One of a kind Gucci reps
by Hope Rios 22 Apr '09

22 Apr '09

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[Twisted-Python] _Win32Waker
by Aron Bierbaum 21 Apr '09

21 Apr '09

I have been using a custom Qt4 reactor that derives from PosixReactorBase. As a result it creates a _Win32Waker to allow threads and signals to wake up the IO thread. It seems though that the current implementation only works about half of the time. The other half it exists with : File "...\Lib\python2.6\site-packages\twisted\internet\posixbase.py", line 170, in __init__ ReactorBase.__init__(self) File "...\Lib\python2.6\site-packages\twisted\internet\base.py", line 424, in __init__ self._initThreads() File "...\Lib\python2.6\site-packages\twisted\internet\base.py", line 813, in _initThreads self.installWaker() File "...\Lib\python2.6\site-packages\twisted\internet\posixbase.py", line 206, in installWaker self.waker = _Waker(self) File "...\Lib\python2.6\site-packages\twisted\internet\posixbase.py", line 77, in __init__ client.connect(server.getsockname()) File "<string>", line 1, in connect socket.error: [Errno 10049] The requested address is not valid in its context I have attached a simple test that shows that the following code does not always return "127.0.0.1", but sometimes returns "0.0.0.0" as the IP address. # Following select_trigger (from asyncore)'s example; server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) client = socket.socket(socket.AF_INET, socket.SOCK_STREAM) client.setsockopt(socket.IPPROTO_TCP, 1, 1) server.bind(('127.0.0.1', 0)) server.listen(1) client.connect(server.getsockname()) My current workaround just calls the following instead: client.connect(('127.0.0.1', server.getsockname()[1])) Any ideas on what is really causing the error? If there is not a better solution can this be added to trunk for future releases? Thanks, Aron

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 19 Apr '09

19 Apr '09

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[Twisted-Python] Writing a shutdown command that sends an ACK back
by Rutt, Benjamin 15 Apr '09

15 Apr '09

Is there a good way, in, say, a LineReceiver based server, to implement a bit of code in lineReceived() that, if you receive a line like, let's say, 'shutdown' from a client, you can call: 1) self.transport.write('goodbye\n') # send a goodbye message to the client And then call 2) self.transport.close() # close the client's socket And then 3) reactor.stop() # terminate the server The problem I'm finding is that since I believe self.transport.write() enqueues the writing for later, and self.transport.close() enqueues the closing for later, both to be picked up by the reactor soon after my lineReceived() returns, so then if you stop the reactor in #3, it won't be available anymore to carry out any enqueued tasks for you. At least I think that's what's happening in my code. Is there any good workarounds? E.g., is reactor.callLater(5, reactor.stop) too much of a hack?

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[Twisted-Python] Can't quit a Tkinter application on MacOS X when using Twisted; fix? workaround?
by Russell E. Owen 15 Apr '09

15 Apr '09

I am trying to convert a cross-platform Python/Tkinter application to use Twisted and have run into a problem: at least on MacOS X I can no longer quit the application. I have appended a minimal script showing the problem. This is probably not an issue on unix and WIndows because I find I have to add my own Quit menu item anyway, so I can make it do what I like. But on MacOS X with Aqua Tcl/Tk that item is added by the system and its meaning appears to be hard-wired -- I suspect to it calls "quit" on Tk's mainloop, but I don't know. Any suggestion for a workaround would be most appreciated. Also if this is not a known issue I will file a bug report. -- Russell """Script showing failure-to-quit bug At least on MacOS XO 10.5.6 with twisted 8.2.0, python 2.5.2 (from python.org) and Aqua Tck/Tk 8.4.19 the File>Quit menu has no effect and typing ctrl-Q causes the menu to briefly highlight (as usual) but has no other effect. "" import Tkinter import twisted.internet.tksupport root = Tkinter.Tk() twisted.internet.tksupport.install(root) reactor = twisted.internet.reactor reactor.run()

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[Twisted-Python] Ldaptor for a simple python LDAP server
by Alex Davies 15 Apr '09

15 Apr '09

Hi, I'm looking to write a very simple LDAP server in Python. I want to hard code the few attributes that I have, and make them available to clients. I am not the worlds most able programmer, but have looked at the code, documentation and talks about Ldaptor and it seems that this can do what I need - but I can't find any examples anywhere! Is there a simple example that shows me what is needed to build a super-simple LDAP server in Python? Any pointers from the more able would be much appreciated! Many thanks, Alex

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[Twisted-Python] ANNOUNCING Tahoe-LAFS v1.4
by zooko 14 Apr '09

14 Apr '09

ANNOUNCING Tahoe, the Least-Authority Filesystem, v1.4 The allmydata.org team is pleased to announce the release of version 1.4.1 of "Tahoe", the Lightweight-Authorization Filesystem. This is the first release of Tahoe-LAFS which was created solely as a labor of love by volunteers -- it is no longer funded by allmydata.com (see [1] for details). Tahoe-LAFS is a secure, decentralized, fault-tolerant cloud storage system. All of the source code is publicly available under Free Software, Open Source licences. This filesystem is distributed over multiple servers in such a way the filesystem continues to operate correctly even when some of the servers are unavailable, malfunctioning, or malicious. Here is the one-page explanation of Tahoe's unique security and fault-tolerance properties: http://allmydata.org/source/tahoe/trunk/docs/about.html This is the successor to Tahoe-LAFS v1.3, which was released February 13, 2009 [2]. This is a major new release, adding garbage collection, improved diagnostics and error-reporting, and fixing a critical performance problem when downloading large (many GB) files. See the NEWS file [3] and the known_issues.txt file [4] for more information. Besides the Tahoe core, a crop of related projects have sprung up, including frontends for Windows and Macintosh, two front-ends written in JavaScript, a Ruby interface, a plugin for duplicity, a plugin for TiddlyWiki, a new backup tool named "GridBackup", CIFS/SMB integration, an iPhone app, and three incomplete frontends for FUSE. See the Related Projects page on the wiki: [5]. COMPATIBILITY Tahoe v1.4 is fully compatible with the version 1 series of Tahoe. Files written by v1.4 clients can be read by clients of all versions back to v1.0. v1.4 clients can read files produced by clients of all versions since v1.0. v1.4 servers can serve clients of all versions back to v1.0 and v1.4 clients can use servers of all versions back to v1.0. This is the fifth release in the version 1 series. The version 1 series of Tahoe will be actively supported and maintained for the forseeable future, and future versions of Tahoe will retain the ability to read files and directories produced by Tahoe v1 for the forseeable future. The version 1 branch of Tahoe is the basis of the consumer backup product from Allmydata, Inc. -- http://allmydata.com . WHAT IS IT GOOD FOR? With Tahoe, you can distribute your filesystem across a set of servers, such that if some of them fail or even turn out to be malicious, the entire filesystem continues to be available. You can share your files with other users, using a simple and flexible access control scheme. Because this software is new, we do not categorically recommend it as the sole repository of data which is extremely confidential or precious. However, we believe that erasure coding, strong encryption, Free/Open Source Software and careful engineering make Tahoe safer than common alternatives, such as RAID, removable drive, tape, "on-line storage" or "Cloud storage" systems. This software comes with extensive tests, and there are no known security flaws which would compromise confidentiality or data integrity. (For all currently known issues please see the known_issues.txt file [3].) This release of Tahoe is suitable for the "friendnet" use case [6] -- it is easy to create a filesystem spread over the computers of you and your friends so that you can share disk space and files. LICENCE You may use this package under the GNU General Public License, version 2 or, at your option, any later version. See the file "COPYING.GPL" [7] for the terms of the GNU General Public License, version 2. You may use this package under the Transitive Grace Period Public Licence, version 1 or, at your option, any later version. (The Transitive Grace Period Public Licence has requirements similar to the GPL except that it allows you to wait for up to twelve months after you redistribute a derived work before releasing the source code of your derived work.) See the file "COPYING.TGPPL.html" [8] for the terms of the Transitive Grace Period Public Licence, version 1. (You may choose to use this package under the terms of either licence, at your option.) INSTALLATION Tahoe works on Linux, Mac OS X, Windows, Cygwin, and Solaris, and probably most other systems. Start with "docs/install.html" [9]. HACKING AND COMMUNITY Please join us on the mailing list [10]. Patches are gratefully accepted -- the RoadMap page [11] shows the next improvements that we plan to make and CREDITS [12] lists the names of people who've contributed to the project. The wiki Dev page [13] contains resources for hackers. SPONSORSHIP Tahoe was originally developed thanks to the sponsorship of Allmydata, Inc. [14], a provider of commercial backup services. Allmydata, Inc. created the Tahoe project, and contributed hardware, software, ideas, bug reports, suggestions, demands, and money (employing several Tahoe hackers and instructing them to spend part of their work time on this Free Software project). Also they awarded customized t-shirts to hackers who find security flaws in Tahoe (see http://hacktahoe.org ). After discontinuing funding of Tahoe R&D in early 2009, Allmydata, Inc. has continued to provide servers, co-lo space and bandwidth to the open source project. Thank you to Allmydata, Inc. for their generous and public-spirited support. Zooko Wilcox-O'Hearn on behalf of the allmydata.org team Special acknowledgment goes to Brian Warner, whose superb engineering skills and dedication are primarily responsible for the Tahoe implementation, and significantly responsible for the Tahoe design as well, not to mention most of the docs and tests and many other things besides. April 13, 2009 Boulder, Colorado, USA [1] http://allmydata.org/pipermail/tahoe-dev/2009-March/001461.html [2] http://allmydata.org/trac/tahoe/browser/relnotes.txt?rev=3620 [3] http://allmydata.org/trac/tahoe/browser/NEWS?rev=3835 [4] http://allmydata.org/trac/tahoe/browser/docs/known_issues.txt [5] http://allmydata.org/trac/tahoe/wiki/RelatedProjects [6] http://allmydata.org/trac/tahoe/wiki/UseCases [7] http://allmydata.org/trac/tahoe/browser/COPYING.GPL [8] http://allmydata.org/source/tahoe/trunk/COPYING.TGPPL.html [9] http://allmydata.org/source/tahoe/trunk/docs/install.html [10] http://allmydata.org/cgi-bin/mailman/listinfo/tahoe-dev [11] http://allmydata.org/trac/tahoe/roadmap [12] http://allmydata.org/trac/tahoe/browser/CREDITS?rev=3758 [13] http://allmydata.org/trac/tahoe/wiki/Dev [14] http://allmydata.com --- Tahoe, the Least-Authority Filesystem -- http://allmydata.org store your data: $10/month -- http://allmydata.com/?tracking=zsig I am available for work -- http://zooko.com/résumé.html

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[Twisted-Python] Basic factory question
by Ted Pederson 13 Apr '09

13 Apr '09

Coming from C++ to python/twisted. Looking at samples, created a simple server and want to create a tester file that will create many clients to connect to and exercise my server. All very nice and easy and like this a lot so far. The one thing that looks strange to me is that the samples instantiate a ClientFactory to then connect to the server via reactor.connectTCP(). I copied this pattern, worried that a factory would be created for every one of my clients, and this is indeed what happened. Isn't the point of a factory to generate all of the clients? I'd like to keep some aggregate info in 1 factory, and have the factory contain the dbpools, etc.. How to do this?

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[Twisted-Python] Documentation overviews
by Cary Hull 13 Apr '09

13 Apr '09

Hi folks, One of the goals for the Pycon sprint was to develop user oriented overviews for existing documentation. These would ideally guide users through everything they would need to read in order to accomplish a desired goal with Twisted. I've formulated the following 'track' suggestions based on a conversation in the sprint room a few nights ago. Feedback would be greatly appreciated. --- Overviews # The basics of event driven applications (beginner) # No hand holding, just the facts (advanced, already familiar with concepts involved) # Testing Twisted applications # Driving processes (interactively or otherwise) # Custom protocols # When it makes sense to use threads # Persisting application data (Would cover various options including Axiom) # Task scheduling (Would cover various options including Axiom) # Web clients # Web applications using just Twisted # Web applications using WSGI (Maybe show how to run Django) # Mail clients # Mail servers # SSH clients # SSH servers # XMPP (Jabber) clients # XMPP (Jabber) servers # Multiple servers in a single application # GUI applications (non web) # Networked video games

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[Twisted-Python] adapt from more than one interface
by Esteve Fernandez 13 Apr '09

13 Apr '09

Hi all. I have a bunch of services, which implement a set of interfaces, and I use a bunch of adapters to turn them into factories, making those services protocol-independent. The interface/adapter stuff works great and I'm able to expose those services to several protocols, without changing a single line in them. However, some of the protocols need some extra information to be passed, so I have to do this: factory = IFooFactory(myService) factory.bar = "some value" it works, but I'd rather use this: factory = IFooFactory(myService, configurationObject) which would take a second argument, an object implementing another interface (e.g. IConfigurationDescriptor), containing all the necessary information for that adapter. I don't want to put that information in the service, as it's only useful to the protocol and would tie the service to a particular protocol. In order to implement this, registerAdapter would have to be able to take a tuple of interfaces, like this: components.registerAdapter( AdaptToFactory, (IFooService, IConfigurationDescriptor), IFooFactory) would that feature make sense? If so, I'll file an issue right now :-) Cheers.

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Re: [Twisted-Python] Giving inlineCallbacks-wrapped functions access to the deferred their wrapper will return
by Terry Jones 12 Apr '09

12 Apr '09

>>>>> "glyph" == glyph <glyph(a)divmod.com> writes: glyph> When I write functions that take a Deferred I typically have them glyph> return a Deferred as well, to avoid this, and other syntactic glyph> nuisances. Would you consider the following more elegant? Yes. And thanks for the rule of thumb. In any case, I realized that my original idea wont work. _inlineCallbacks returns the deferred to the caller of the wrapped function early. The caller could add callbacks to it before the wrapped function does, which makes the whole idea unworkable. Terry

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 12 Apr '09

12 Apr '09

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[Twisted-Python] Giving inlineCallbacks-wrapped functions access to the deferred their wrapper will return
by Terry Jones 12 Apr '09

12 Apr '09

This will probably fall into the too-weird or too-infrequent to be worth implementing category, but I think it's worth mentioning. (BTW, none of the following code has been run.) When you write a normal function that returns a deferred, it (of course) has access to the deferred it's going to return: def func(): d = defer.Deferred() d.addCallback(...).addErrback(...) callSomethingElse(d) return d Apart from operating on the deferred itself, func can pass the deferred to some other function that might add more callbacks (as in the call to callSomethingElse). That's all very nice and convenient. But if I write this: @defer.inlineCallbacks def func(): # do some stuff to calculate a result. defer.returnValue(result) func never has its hands on the deferred that will be returned (by _inlineCallbacks) to the caller of its wrapper. I can get around this in ways that are less elegant: @defer.inlineCallbacks def func(): # do some stuff d = defer.Deferred() callSomethingElse(d) d.callback(result) newResult = yield d defer.returnValue(newResult) But I don't really like doing it that way: it's a slightly different coding style, it's much more manual, the above is just one simple example - actual usage could be more involved, and it doesn't feel as natural as the kind of code I can write when I'm not using inlineCallbacks. A way around this (which maybe will generate howls of protest) would be to have _inlineCallbacks do something this: def unwindGenerator(*args, **kwargs): assert '_inlineCallbacksDeferred' not in kwargs d = Deferred() return _inlineCallbacks(None, f(*args, **kwargs, _inlineCallbacksDeferred=d), d) return mergeFunctionMetadata(f, unwindGenerator) While I don't like this implementation much, it does manage to simply put the deferred that _inlineCallbacks will eventually return, into the hands of f (i.e., func above). func can then pass the deferred around, add callbacks to it etc. exactly as a normal (non-inlineCallbacks) function would. Maybe there's a cleaner way to implement this? I ran into this asymmetry today, when I wanted a function to pass its deferred off to another function but realized that because mine was an inlineCallbacks-decorated function I couldn't do it in the same way I would otherwise. Comments? Terry

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[Twisted-Python] Plugin startup and shutdown actions
by luper rouch 12 Apr '09

12 Apr '09

I would like to port my Application API based services to the twistd plugin interface, to be able to retrieve command line options. In the existing services, I reimplemented t.a.s.MultiService startService() and stopService() to do some actions at startup and shutdown. How can I do this in a plugin ? -- Lup

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Re: [Twisted-Python] Plugin startup and shutdown actions
by Terry Jones 11 Apr '09

11 Apr '09

Hi Luper >>>>> "luper" == luper rouch <luper.rouch(a)gmail.com> writes: luper> I have a last question, I put my plugins in a 'twisted/plugins' luper> subfolder of my project, and running them from the command line luper> works fine. How can I invoke them in unit tests (I need to be able luper> to start and stop them), since the plugin files are not in a luper> package? I suspect some will answer "Uh, you probably shouldn't be doing that"... But something like this will work: from twisted.plugin import getPlugins from twisted.application.service import IServiceMaker def getPlugin(name): for plugin in getPlugins(IServiceMaker): if hasattr(plugin, 'tapname'): if plugin.tapname == name: return plugin return None Terry

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[Twisted-Python] Two-way telnet client problem
by Greg Taylor 11 Apr '09

11 Apr '09

Hello all, I'm still pretty new with Twisted, so the documentation is a little bit cryptic and strange to wade through. I'm writing a MUD server that I'd like to add InterMUD Protocol (IMC) to. This basically allows any of the games running the MUD server to connect to an IMC server that lets players from other games talk to one another. I'm thinking I'll create another thread and run the IMC client from there so as to not block the main server thread. I've started tinkering with how to get the IMC client connected and able to send and receive, but I'm hitting a problem. If you look at my pasted example at http://python.pastebin.com/m155730ed you will see at the end that once the reactor is running, I _think_ this blocks things up for this thread. This is just fine, I assumed it'd be the case. However, let's go back to my main MUD server's thread for a moment. How would I tell the IMC client to send a line of text now? I assume it'd be something to do with the factory or reactor objects, but I'm just not sure. I've seen mention of something like: p = reactor.buildProtocol() p.sendLine('blah\n') But can't quite seem to piece it together. I'd really love to figure this out, as it'd do a lot for my game. I may be doing this horribly wrong, any direction would be great. Greg

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Re: [Twisted-Python] Fork/Spawn children to accept connections on the same port.
by Eric York 11 Apr '09

11 Apr '09

> > From: Jean-Paul Calderone <exarkun(a)divmod.com> > Date: April 10, 2009 8:57:19 AM PDT > To: Twisted general discussion <twisted-python(a)twistedmatrix.com> > Subject: Re: [Twisted-Python] Fork/Spawn children to accept > connections on the same port. > Reply-To: Twisted general discussion <twisted- > python(a)twistedmatrix.com> > > > On Mon, 6 Apr 2009 15:25:39 -0700, Eric York <eyork(a)apple.com> wrote: >> I am trying to get the highest level of performance using all of >> the processors cores on a server. >> >> In the past, a unix app would bind/listen to a socket and then fork >> or spawn children to accept connections on that socket. I can’t see >> how to do that in Twisted. Can someone point me in the right >> direction? >> >> The solution of using a single process to accept connections and >> then farm out work to child processes, while a workable solution, >> isn’t at the same level of performance as children processes that >> are doing their own accepts. > It's also possible to bind a port in one process and then send it > over a UNIX socket to another process; this comes closer to the bind/ > fork > approach, but accomplishes the resource sharing explicitly via fd > passing > rather than through fork. This is the path that I would like to follow. I can see how to spawn a child process and pass the fd in Twisted. What I can't see how to do in Twisted is to have a parent process just bind and listen to a socket and have a child process accept on that socket. In twisted/ internet/tcp.py in the class Port, there is a function startListening which does bind/listen/startReading all in this one function. It seems that a small refactoring would allow the parent to bind and a child to do startReading, if the call to startReading was moved out of startListening. The reactor calls would also need a small refactoring to allow this type of setup. How does that sound? Eric

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[Twisted-Python] PBClientFactory and getRootObject
by Fabrizio Mancini 10 Apr '09

10 Apr '09

Hi everyone, I'm writing a server and a client using Perspective Broker with no Avatar and no auth. The server accumulates some data using a DeferredQueue. The clients using a remote call retrieve one item per time from the queue and elaborates it making some changes on a database using adbapi. What i want to know is: 1) how can i recursively call the remote method to retrieve the items from the server? 2) can i defer the database operations to a thread so every client can elaborates multiple requests per time? The code i'm using is this: from twisted.internet import reactor, defer, pb from twisted.enterprise import adbapi from twisted.python import log import os globalConfigurationFile=os.path.abspath('conf' + os.sep + 'configuration.ini') class DataBasePreparerClient(object): ''' DataBasePreparerClient() ''' def __init__(self, globalConfigurationFile): self._gcf = globalConfigurationFile self.data = {} self._parseConfig() self._createDbPool() self.d = defer.Deferred() self.clientfactory = pb.PBClientFactory() def _createDbPool(self): self.dbpool = adbapi.ConnectionPool('cx_Oracle', self.data['db_username'], self.data['db_password'], self.data['db_tns']) def connect(self): reactor.connectTCP(self.data['server_ip'], self.data['server_port'], self.clientfactory) self.d = self.clientfactory.getRootObject() self.dbpool.connect() self.d.addCallbacks(self.get_item, self._eb) def _eb(self, reason): print "Failure: ", reason.getErrorMessage() def get_item(self, result): d = result.callRemote("get_item") d.addCallback(self.got_item) def got_item(self, item): query = "update table where ..." res = self.dbpool.runOperation(query) res.addErrback(self._eb) self.d = self.clientfactory.getRootObject() self.d.addCallbacks(self.get_item, self._eb) if __name__ == "__main__": DataBasePreparerClient(globalConfigurationFile).connect() reactor.run() To call recursively the remote object in function connect i call clientfactory.getRootObject() and addCallback() for the first time, and the i recall always self.clientfactory.getRootObject() and self.d.addCallback when the db query has completed. Is this correct? Do I have to always call self.clientfactory.getRootObject() every time i have to call a remote method? Can i deferToThread the function got_item or self.dbpool.runOperation(query)? Thanks in advance Fabrizio

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[Twisted-Python] adbapi and long-running transactions
by Wolfgang Powisch (privat) 10 Apr '09

10 Apr '09

Hi, I'm using twisted.enterprise.adbapi for non-blocking database interaction with a postgres database. Currently I'm only using runQuery or runOperation for running single queries or some own little helper methods "runQueries" or "runOperations" for running multiple queries within one Transaction (using runInteraction). What I need now is to start a Transaction and access this Transaction from multiple callbacks within my application-code in the main-thread. In the last callback (and/or errback) I will then either commit or rollback the transaction. Any ideas how to acomplish that, didn't find a working solution yet. The two options I tested are: 1.) running my code within the adbapi thread using runInteraction: -> this is really not what I want and will screw up my code 2.) create a transaction and pass it as an argument to a function called with connectionpool._deferToThread -> this doesn't work, because I seem to end up in the wrong thread and another (or no) transaction. thx in advance for your help regards, Wolfgang

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[Twisted-Python] RE: Question about Descriptors and SelectReactor
by Andrew Francis 10 Apr '09

10 Apr '09

Hi Alec and Drew: Thanks for answering my question. From reading an excerpt of Steven's "UNIX Network Programming," it implies that the FD_SETSIZE is defined in the kernel. If you want a bigger FD_SETSIZE, you need to recompile the kernel. At least that is the case in BSD 4.4 UNIX. However I am using Linux. The Twisted documentation is recommending that it may be better to use pollreactor. Cheers, Andrew --- On Tue, 4/7/09, twisted-python-request(a)twistedmatrix.com <twisted-python-request(a)twistedmatrix.com> wrote: > From: twisted-python-request(a)twistedmatrix.com <twisted-python-request(a)twistedmatrix.com> > Subject: Twisted-Python Digest, Vol 61, Issue 10 > To: twisted-python(a)twistedmatrix.com > Date: Tuesday, April 7, 2009, 9:00 AM > Send Twisted-Python mailing list > submissions to > twisted-python(a)twistedmatrix.com > > To subscribe or unsubscribe via the World Wide Web, visit > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python > or, via email, send a message with subject or body 'help' > to > twisted-python-request(a)twistedmatrix.com > > You can reach the person managing the list at > twisted-python-owner(a)twistedmatrix.com > > When replying, please edit your Subject line so it is more > specific > than "Re: Contents of Twisted-Python digest..." > > > Today's Topics: > > 1. RE: Question about Descriptors and > SelectReactor (Alec Matusis) > 2. trac server error (Johann Borck) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 6 Apr 2009 18:25:45 -0700 > From: "Alec Matusis" <matusis(a)yahoo.com> > Subject: RE: [Twisted-Python] Question about Descriptors > and > SelectReactor > To: "'Twisted general discussion'" <twisted-python(a)twistedmatrix.com> > Message-ID: <009701c9b71f$ca82aac0$5f880040$@com> > Content-Type: text/plain; > charset="utf-8" > > > I would say a function of the operating system - or > specifically > > ulimit on a *nix system. > > I do not think this is correct, on linux: ulimit -n is the > number of fds that can be written/read by a process, but the > 1024 limit on select is actually hard-compiled into the > kernel and can be changed only in the headers with kernel > recompilation. > > > -----Original Message----- > > From: twisted-python-bounces(a)twistedmatrix.com > [mailto:twisted-python- > > bounces(a)twistedmatrix.com] > On Behalf Of Drew Smathers > > Sent: Monday, April 06, 2009 8:40 AM > > To: Twisted general discussion > > Subject: Re: [Twisted-Python] Question about > Descriptors and > > SelectReactor > > > > On Sat, Apr 4, 2009 at 6:04 PM, Andrew Francis <andrewfr_ice(a)yahoo.com> > > wrote: > > > > > > Hi: > > > > > > Perhaps this question has been asked before but > is there a limit to > > the number of descriptors the SelectReactor can > handle? Is this a > > function of the operating system? > > > > > > > I would say a function of the operating system - or > specifically > > ulimit on a *nix system. > > > > -Drew > > > > _______________________________________________ > > Twisted-Python mailing list > > Twisted-Python(a)twistedmatrix.com > > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python

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[Twisted-Python] trac server error
by Johann Borck 10 Apr '09

10 Apr '09

there seems to be some serious problem with http://twistedmatrix.com/trac/ this is what the browser shows me on about one third of the requests: Traceback (most recent call last): File "/srv/trac/.local/lib/python2.4/site-packages/trac/web/api.py", line 382, in send_error 'text/html') File "/srv/trac/.local/lib/python2.4/site-packages/trac/web/chrome.py", line 475, in render_template return stream.render(method, doctype=doctype) File "/srv/trac/.local/lib/python2.4/site-packages/genshi/core.py", line 146, in render output = u''.join(list(generator)) File "/srv/trac/.local/lib/python2.4/site-packages/genshi/output.py", line 200, in __call__ for kind, data, pos in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/output.py", line 486, in __call__ for kind, data, pos in chain(stream, [(None, None, None)]): File "/srv/trac/.local/lib/python2.4/site-packages/genshi/output.py", line 436, in __call__ for kind, data, pos in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/core.py", line 207, in _ensure for event in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/core.py", line 207, in _ensure for event in stream: File "/srv/trac/.local/lib/python2.4/site-packages/trac/web/chrome.py", line 478, in _strip_accesskeys for kind, data, pos in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/filters.py", line 313, in __call__ for kind, data, pos in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/template.py", line 1145, in _match content = list(content) File "/srv/trac/.local/lib/python2.4/site-packages/genshi/filters.py", line 313, in __call__ for kind, data, pos in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/template.py", line 1120, in _match for event in stream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/template.py", line 1109, in _strip event = stream.next() File "/srv/trac/.local/lib/python2.4/site-packages/genshi/template.py", line 941, in _eval for event in substream: File "/srv/trac/.local/lib/python2.4/site-packages/genshi/template.py", line 920, in _eval ctxt): File "/srv/trac/.local/lib/python2.4/site-packages/genshi/template.py", line 930, in _eval result = data.evaluate(ctxt) File "/srv/trac/.local/lib/python2.4/site-packages/genshi/eval.py", line 101, in evaluate {'data': data}) File "/home/trac/.local/share/trac/templates/error.html", line 36, in <Expression u"get_reporter_id(req)"> <input type="hidden" name="reporter" value="${get_reporter_id(req)}" /> File "/srv/trac/.local/lib/python2.4/site-packages/trac/util/__init__.py", line 50, in get_reporter_id name = req.session.get('name', None) AttributeError: 'NoneType' object has no attribute 'get'

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[Twisted-Python] Fork/Spawn children to accept connections on the same port.
by Eric York 10 Apr '09

10 Apr '09

I am trying to get the highest level of performance using all of the processors cores on a server. In the past, a unix app would bind/listen to a socket and then fork or spawn children to accept connections on that socket. I can’t see how to do that in Twisted. Can someone point me in the right direction? The solution of using a single process to accept connections and then farm out work to child processes, while a workable solution, isn’t at the same level of performance as children processes that are doing their own accepts. Eric

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[Twisted-Python] HTTP Proxy client?
by Alec Flett 10 Apr '09

10 Apr '09

Is there any way to make twisted.web.client talk through an HTTP proxy? I don't know enough about http to know if its as simple as opening the connection to the proxy and just including the full URL in the GET line? Alec

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[Twisted-Python] ZeroC Ice + Twisted?
by Einar S. Idsø 09 Apr '09

09 Apr '09

Dear listmembers, I have a project that requires me to use ZeroC Ice for communicating with a server application. I would very much like to use Twisted for this project, and am therefore wondering if anyone has any experience with using Twisted with ZeroC Ice? Previous posts on this list have mentioned that ZeroC Ice has asynchronous operations and therefore should be easily twistable, but its Python bindings and type system are unpythonic (Stephen Waterbury, May 30th 2006) . But I haven't found any posts by people that have actually used Ice with Twisted, and whether it is possible to achieve proper twistified asynchronous behaviour. Any tales of experience, code snippets or anything else that could help me get started using Ice with Twisted and avoid *not* using Twisted would be greatly appreciated :) Cheers, Einar S. Idsø

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[Twisted-Python] How to hook at StandardIO factory to a twistd app
by akrherz＠iastate.edu 08 Apr '09

08 Apr '09

Hi Twisted! Could a kind soul provide me an example of how to connect my StandardIO factory to a twistd app? Here is an overview of my code class MyProtocol(basic.LineReceiver): # Blah Blah class MyFactory( stdio.StandardIO ): def __init__(self, protocol): self.protocol = protocol # then by .tac has application = service.Application("Ingestor") serviceCollection = service.IServiceCollection(application) proto = MyProtocol() factory = MyFactory( proto ) It is not clear to me how to connect my factory to the application, I do this many other times for network related factories by connecting via a TCPServer or TCPClient . Sorry for what I suspect is an embarrassingly simple question. :( thank you! daryl

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