Mailman 3 May 2011 - Twisted

[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 22 May '11

22 May '11

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[Twisted-Python] 100% CPU on high opened descriptors
by Juan Antonio Ibañez Santorum 19 May '11

19 May '11

Hello! I have a Linux box serving my twisted app. All works ok except after some days running (where I can see my CPU going to 100%). I saw that CPU goes 100% usage when the app reaches to 1024 opened descriptors (sockets). It seems TM isn't closing some connections when clients loose connection to the server. I have no more than 200 simultaneous clients, each of then using a single connection. Any idea why those connections remain open? Regards

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[Twisted-Python] Is it possible to know what kind of methods are thread safe?
by gelin yan 16 May '11

16 May '11

Hi all I notice the core doc mentions that "Most code in Twisted is not thread-safe. For example, writing data to a transport from a protocol is not thread-safe. " I want to know whether there is a way to know what methods are thread safe besides of reading source codes? Or I use reacator.callFromThread for all related methods from threads other than reactor thread? Thanks dfgqq (gelin yan)

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[Twisted-Python] a problem about iocp and callInThread
by Dfgqq Dfgqq 15 May '11

15 May '11

Hi all I just encountered a problem about iocp reactor & callInThread. I paste the code following: from twisted.internet import iocpreactor iocpreactor.install() from twisted.internet import reactor class ThreadTest: def __init__(self,name): self.count = 0 self.max = 5 self.wait = 1 self.name = name def __call__(self): self.Execute() def Execute(self): print self.name, time.time() self.count += 1 if self.count <self.max: reactor.callLater(self.wait, reactor.callInThread, self.Execute) else: print self.name, "stop" reactor.callInThread(ThreadTest("test")) the problem is every time the print method was invoked, i noticed that the difference between current invoke and previous invoke was 2 seconds. In theory ,it should be one second. When i used the plain reactor (which means no iocpreactor), the difference was one second which is a correct value. I want to know what makes callInThread so special with iocpreactor? BTW: i used windows 7 & window s2008. Regards gelin yan

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 15 May '11

15 May '11

1 0

[Twisted-Python] Some "spread" objects and comparison semantics
by Facundo Batista 12 May '11

12 May '11

I'm analysing the code in twisted/spread/flavors.py and twisted/spread/pb.py, trying to remove the __cmp__ and cmp() in RemoteCache, RemoteCacheMethod and RemoteCacheObserver classes. They all have __cmp__ methods, but as there is not any test for these, and it's not specified in the documentation, I don't know if the comparison method is to compare by equality, or for these objects to be orderable. Yes, I could replace __cmp__ with the full rich comparison battery, but it's not worth it if the semantic of these objects will not use it. Thanks! -- . Facundo Blog: http://www.taniquetil.com.ar/plog/ PyAr: http://www.python.org/ar/

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[Twisted-Python] test if thread is reactor's thread
by Alessandro Dentella 11 May '11

11 May '11

Hi, is there a way to test if the thread a function is called is the reactor's thread? I have a function that can be called from the main thread or from the reactor's thread and should behave differently... thanks sandro *:-) -- Sandro Dentella *:-) http://www.reteisi.org Soluzioni libere per le scuole http://sqlkit.argolinux.org SQLkit home page - PyGTK/python/sqlalchemy

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[Twisted-Python] EuroPython 2011 early bird ends in 2 days
by Valentino Volonghi 11 May '11

11 May '11

Hi everyone, this is just a gentle reminder that EuroPython 2011 early bird ends in 2 days, some core Twisted developers will be there and there will be at least one tutorial about Twisted. EuroPython is the official European conference about the Python programming language. It is aimed at everyone in the Python community, of all skill levels, both users and programmers. It will be held in Florence from June 20th-24th for the conference and June 25th-26th for sprint days. More information available at: http://ep2011.europython.eu/ The schedule of the conference is available at http://ep2011.europython.eu/p3/schedule/ep2011/ For those of you that are not living in Italy we will give you the opportunity to buy a cheap pre-paid voice/data enabled SIM for your smartphone or computer (it has tethering enabled) so that you don't have to pay for expensive international calls and you will be able to use your phone, more details here http://ep2011.europython.eu/p3/mobile/ And for all of you who have a family it's possible to have them come with you and while you're at the conference they will be able to visit Tuscany's amazing locations thanks to our partner program, more details at http://ep2011.europython.eu/partner-program We want the Python Community to embrace and support diversity, for this reason Google is offering a special Diversity Grant reserved for female computer scientists, more information here http://ep2011.europython.eu/google-diversity-grant And we are also working to create a special grant for students and unemployed (but searching for a job) programmers that, thanks to those speakers who decided to pay the full conference price, will enable us to offer 3 free tickets for students and 3 free tickets for unemployed, details will be ready soon on EuroPython 2011 blog: http://ep2011.europython.eu/blog/ See you all in Florence! -- Valentino Volonghi EuroPython 2011 Organization

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[Twisted-Python] Question about using the adbapi
by Albert Brandl 10 May '11

10 May '11

Hi! In the application I'm currently working on, we gather data from different sources and store them in a database, but only if the values have changed. One example is GPS information. We don't want to store hundreds of identical values that are sent by the receiver, so we have to compare the last written row with the current latitude / longitude pair. I use a subclass of NMEARreceiver class to determine the current latitude and longitude. Then I query the database using a ConnectionPool instance to get the previous values for latitude and longitude. If the result differs from the current values, a new entry is stored, again using the ConnectionPool. The problem is: How do I "connect" the current latitude and longitude to the database query? The query returns a Deferred object, but this expects a callback with only one argument, the result of the query. Storing them as instance variables of NMEAReceiver does not seem to be the right way, since I don't know how long it takes to query the database - the relevant GPS information might be overwritten by a new NMEA telegram when the connection pool finally triggers the callback One workaround I've found is to add this information to the SQL query, but this seems quite weird to me (and doesn't work in the case that the query does not return a result). A different approach would be to implement a callback with three arguments (result, latitude and longitude), and wrap it in a lambda function that fills latitude and longitude with the current values. Would this would be a better way to handle this requirement? How would you implement this? Thanks & 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] Weekly Bug Summary
by exarkun＠twistedmatrix.com 08 May '11

08 May '11

1 0

Twisted May 2011