Mailman 3 September 2006 - Twisted

[Twisted-Python] Twisted Python 0.7.0 Prerelease Testing
by Glyph Lefkowitz 06 Aug '21

06 Aug '21

hi there, folks: I'd really like to release 0.7.0 but I would like it to be at least a little bit tested before I do so. Could those of you with CVS trees check everything out and see if it performs as advertised? Deeper bugs than that will have to wait for the next release, but I'd at least like to know if it works for someone other than me. Thanks. ______ __ __ _____ _ _ | ____ | \_/ |_____] |_____| |_____| |_____ | | | | @ t w i s t e d m a t r i x . c o m http://www.twistedmatrix.com/~glyph/

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[Twisted-Python] Get IP of connecting client in XMLRPC server
by Remy C. Cool 28 Apr '13

28 Apr '13

Hello, On 18 May 2004, the following message was posted to this mailinglist: Jp Calderone exarkun at divmod.com wrote: >Daniel Newton wrote: > > I have a simple XML-PRC server similar to the example below: > > from twisted.web import xmlrpc, server > > class Example(xmlrpc.XMLRPC): > """An example object to be published.""" > > def xmlrpc_add(self, a, b): > """Return sum of arguments.""" > return a + b def xmlrpc_whatIsMyAddress(self): return self.transport.getPeer().host > > if __name__ == '__main__': > from twisted.internet import reactor > r = Example() > reactor.listenTCP(7080, server.Site(r)) > reactor.run() > > I want to be able to get the address of the client that calls the xmlrpc > method can anyone help me with this? This solution didn't work because 'transport' isn't a property of the Example class. I'm currently in the process of changing from a customized SimpleXMLRPCServer to a twisted XMLRPC server solution and I need to insert the client IP into the attributes passed to the called xmlrpc method. Anyone who knows the answer and is willing to share the info? Regards, Remy

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[Twisted-Python] Reconnecting PB Client
by Don Smith 12 Sep '07

12 Sep '07

Does anyone have some example code for building a reconnecting PB client? This is what I have now: from twisted.spread import pb from twisted.internet import reactor from twisted.python import util events = pb.PBClientFactory() reactor.connectTCP("localhost", 8789, events) queue = events.getRootObject()

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[Twisted-Python] Producers / Consumers and more examples tutorials?
by jarrod roberson 13 Mar '07

13 Mar '07

Are there any more concrete examples or tutorials of using Producers and Consumers?

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[Twisted-Python] Support for ICMP ping?
by Nicolas D. Cesar 09 Feb '07

09 Feb '07

I've been googling if there is any 'ICMP ping' support in Twisted. I've encounter ancient replies: http://twistedmatrix.com/pipermail/twisted-python/2003-August/005542.html I wonder if today is any ICMP support. I've tried to search the source tree[1], and doesn't seem. My actual needs is creating a DeferredList with "ping-testers" for different IPs, just to check if there up or not. I know I can end up using twisted.internet.utils.getProcessOutput and calling ping, as I would normally do from command line. For other newbies as me in the same situation please read: http://twistedmatrix.com/users/moshez/talk.html and search for 'getProcessOutput' ;-) Greetings, [1] my search was: -------------------------------------------------------------------- $ grep -C3 -ir icmp * internet/protocol.py- internet/protocol.py- internet/protocol.py-class AbstractDatagramProtocol: internet/protocol.py: """Abstract protocol for datagram-oriented transports, e.g. IP, ICMP, ARP, UDP.""" internet/protocol.py- internet/protocol.py- transport = None internet/protocol.py- numPorts = 0 -- internet/protocol.py- def connectionRefused(self): internet/protocol.py- """Called due to error from write in connected mode. internet/protocol.py- internet/protocol.py: Note this is a result of ICMP message generated by *previous* internet/protocol.py- write. internet/protocol.py- """ internet/protocol.py- -------------------------------------------------------------------- -- Nicolás D. César <ncesar(a)lunix.com.ar> Lunix S.R.L. -[ http://www.lunix.com.ar ]- GnuPG Public Key: gpg --keyserver wwwkeys.pgp.net --recv-key 0x3606F3E6

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[Twisted-Python] Problem: spawnProcess() never ending when installSignalHandlers=False
by Matt Feifarek 03 Feb '07

03 Feb '07

Hello. I'm using Twisted 1.3.0 on python2.4 on an Ubuntu-Hoary x86 Linux box. I'm using twisted and spawnProcess() with a Queue structure to chain processes that need to be called (specifically, imagemagick commands). I use the "processEnded" event/method of t.i.p.ProcessProtocol to go from one task to the next. Twisted shares a python process with a multi-threaded web-app-kit (Webware) so it has to be run in a thread. This worked well on other older versions of twisted and older versions of python; also on linux. I've tracked down the problem to be twisted itself (or my incorrect use of it) rather than my code. This example illustrates it: ------------------------------------------------- from twisted.internet import reactor from twisted.internet.protocol import ProcessProtocol class MyProt( ProcessProtocol ): def processEnded(self, reason): print "ended.", reason executable = '/bin/touch' args = ( '/tmp/foo.txt', ) args = (executable,) + tuple(args) reactor.spawnProcess( MyProt(), executable, args ) reactor.callLater( 5, reactor.stop ) #reactor.run() reactor.run(installSignalHandlers=False) ------------------------------------------------- As is, this code never runs the "processEnded()" method of MyProt(). If I change the reactor.run() parameter to leave the signal handlers on, it works. Note that I need to leave the signal handlers turned off because I can't run the reactor in the main thread; Webware needs that. I also know that the subprocess is giving up its file descriptors; I can see that if I put more print statements into MyProt(). And I know that the subprocess is working; /tmp/foo.txt is there. It seems that somehow the reactor is using signals to notice when a process has ended; this makes a certain ammount of sense intuitively, though I don't understand the nitty-gritty of processes and signals at all. And more importantly, this has worked before on other combinations of twisted/python. Is this a bug? If so, has it been fixed? If not, what should I do to detect when a spawned process is finished? Thanks very much. Twisted rocks.

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[Twisted-Python] Twisted & Qt
by Ed Suominen 09 Oct '06

09 Oct '06

I'm using the qtreactor in a GPL-but-unreleased PyQt 4.1 application of my own, and have not found any problems whatsoever with the integration of the Qt Twisted event loops. It's really a pretty slick combination. As an example and a contribution, I offer the following (GPL'd) module: http://deadbeefbabe.org/paste/1996 (syntax-highlighted version), http://foss.eepatents.com/misc/qt-twisted-dialog.py (source). It allows you to construct a non-blocking modal dialog, immediately obtaining a deferred to the user's eventual input. As an aside, I would be interested in people's viewpoints about whether the Qt reactor is suitable for Twisted's MIT-style license, given that it doesn't actually import any Qt code itself. It leaves that step up to the user with the installation of a reactor into the Qt application object. As every Qt user probably knows, the Qt library itself is dual-licensed under either the GPL or Trolltech's proprietary license. Best regards, Ed

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[Twisted-Python] _dumbwin32proc and PIPE_NOWAIT
by Manlio Perillo 08 Oct '06

08 Oct '06

From the msdn: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ipc/base/s… """PIPE_NOWAIT 0x00000001 Nonblocking mode is enabled. In this mode, ReadFile, WriteFile, and ConnectNamedPipe always return immediately. Note that nonblocking mode is supported for compatibility with Microsoft® LAN Manager version 2.0 and should not be used to achieve asynchronous input and output (I/O) with named pipes. """ P.S. I really can't believe that win32 support for asynchronous I/O works with named pipes but not with anonymous pipes... By the way, instead of using a polling, why not to use a separate thread that puts data into a DeferredQueue? P.S.2: From: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ipc/base/a… """Anonymous pipes are implemented using a named pipe with a unique name. Therefore, you can often pass a handle to an anonymous pipe to a function that requires a handle to a named pipe. """ And from: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/ba… """A child process can inherit [...] * Open handles returned by the CreateFile function. This includes handles to files, console input buffers, console screen buffers, named pipes, serial communication devices, and mailslots. * Open handles to process, thread, mutex, event, semaphore, named-pipe, anonymous-pipe, and file-mapping objects. These are returned by the CreateProcess, CreateThread, CreateMutex, CreateEvent, CreateSemaphore, CreateNamedPipe, CreatePipe, and CreateFileMapping functions, respectively. """ So, why not to create a named pipe with an unique name, know to both the parent and the child process, as an example using an enviroment variable? I think that using named pipes can simplify the _dumbwin32proc. Moreover polling a named pipe is not an efficient operation (reading the author of "Windows System Programming"). Lastly, the parent process, after creating a named pipe instance, can wait for a client connection using ConnectNamedPipe. Regards Manlio Perillo

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[Twisted-Python] twistd save state does not work
by Remi Cool 02 Oct '06

02 Oct '06

Hello, I've readied my app for use with twistd, the daemonizing works, but a tap file is not saved upon exit (kill 'cat twisted.pid'). How can I enable the save state option? BTW I'm not using the -o option with twistd ;) Second ... is it possible to disable the twisted logging if you use twistd to start the app? Or is it possible to set a log level so that only warnings and errors are shown and my log is not flooded with (TCPServer) connection messages. - Remi -

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[Twisted-Python] Removing _wait from Trial
by Jonathan Lange 01 Oct '06

01 Oct '06

So, I would like to remove _wait() from Trial and make it work like a regular Twisted application. I've had all this stuff on my brain, and have decided to dump it here for feedback. Here's how the plan looks at the moment[1]: 1. Deprecate the use of reactor-spinning things within tests. (Twisted 2.5) We've already done a great deal of work on this. spinWhile, spinUntil and util.wait have alll been deprecated and removed. #2090 (ready for review) actually issues deprecation warnings when the reactor is iterated, crashed or stopped within a test. Unfortunately, some of Trial's cleanup code spins the reactor (see t.trial.util._Janitor.do_cleanPending). This has to go. 2. Tighten test cleanup errors. (Twisted 2.5) #2091 (ready for review) fulfils a long-standing promise. The "reactor unclean" warnings have been turned into errors. It doesn't help us remove _wait, but To remove _wait, we'll also have to remove the two calls to reactor.iterate() from _Janitor (see #2092). That means that many tests that *thought* they were cleaning up the reactor properly will find out that they weren't. We can reduce the number of errors by simulating reactor.iterate() using callLater. However, experiments show that even with this bandaid, there will still be new errors in the Twisted suite. That means we will have to either: a) surprise our users with new errors in their tests b) find some way to introduce this gradually. Obviously everyone[2] would prefer b). I've filed #2124 explaining how that might work. 3. Introduce asynchronous APIs to Trial (Twisted 2.6) Currently TestCase.run() is a blocking call. I wish it could remain a blocking call, but it can't. The branch for #1781 makes a SyncTestCase and an AsyncTestCase. run() works in SyncTestCase and doesn't work in AsyncTestCase. For AsyncTestCase, one uses runDeferred(). Although the branch for #1781 will need to be abandoned, these new classes should be brought in for Twisted 2.6 (without breaking run()). Naturally, this affects many, many tests in Trial. We might even add runDeferred to TestSuite at this point. 4. Deprecate TestSuite.run and TestCase.run. (Twisted 2.6) Neither of these will work without wait[3] and they are both public APIs. Also remove the calls to iterate() from _Janitor at this point. 5. Actually remove _wait. (Twisted 2.7) Add runDeferred() to TestSuite, make run() raise NotImplementedErrors for TestCase and TestSuite. Alter TrialSuite to start and stop the reactor. I can't find a theory to explain why this change will break unexpected tests in the Twisted suite. However, it will certainly happen. That means that some tests in user code will probably break as well. I don't know how we could make this any smoother. Questions: - What should I do with the ticket #1781? - What should I do with the branch for #1781? - What more can we do to reduce the number of tests that will break when _wait is removed? - Thoughts? thanks for getting this far :), jml [1] Incidentally, all of this would be superfluous if reactors were restartable. [2] Well, almost everyone [3] ... or restartable reactors.

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Twisted September 2006