On Tue, May 19, 2009 at 11:48 AM, Pet <petshm...@googlemail.com> wrote: > On Tue, May 19, 2009 at 10:59 AM, <gl...@divmod.com> wrote: >> On 07:51 am, petshm...@googlemail.com wrote: >>>after playing with reactor, factory and protocol, I'm trying to >>>implement XML-RPC server, but it seems that it is not able to handle >>>several clients in parallel. If I call the slow function with first >>>client and then with second client a fast function, second client >>>will receiver the results after slow function returned. There is no >>>factory for clients in server.Site() like in Protokoll? What is the >>>way to do that for XML-RPC? >> >> Whenever you perform some blocking work in a Twisted program, the >> reactor will block and no processing will occur in parallel. This is >> not specific to XML-RPC. server.Site() *is* a Factory for clients, >> exactly the same as any other protocol. You can see its place in the >> inheritance hierarchy: > > Thank you for explanations! > > I still have some questions :( > if server.Site() is Factory clients, what object is created for each > connection? > How can I ensure, that each client gets answer belonging to him and > not for other "slow" client? How can I close connection to a client?
deferToThread or db.runInteraction seems to be the solution for me. The "only" thing I don't know how to do is, logging requests *after* response was send to the client. Obviously, it should happens after a xmlrpc_method returns, but how can accomplish this? Thanks for any help! > > >> >> http://twistedmatrix.com/documents/8.2.0/api/classIndex.html#twisted.web.server.Site >>> def xmlrpc_addslow(self, a, b): >>> """ >>> Return sum of arguments. takes time >>> """ >>> sleep(20) >>> return a + b >> >> The Twisted equivalent way to spell this is to return a Deferred which >> fires later from your xmlrpc_addslow method: >> >> from twisted.internet.task import deferLater >> from twisted.internet import reactor >> # ... >> def xmlrpc_addslow(self, a, b): >> return deferLater(reactor, 20, lambda : a + b) >> >> However, if your "sleep(20)" is intended to simulate 20 seconds of work >> in a blocking API you can't control, you might want to return a Deferred >> that does the work in a thread instead: >> >> from time import sleep >> from twisted.internet.threads import deferToThread >> # ... >> def xmlrpc_addslow(self, a, b): >> def hardWork(): >> sleep(20) >> return a + b >> return deferToThread(hardWork) > > this should be ok for me. > >> >> As with all Python programs, if you truly want CPU parallelism, then you >> will need to put the work into a subprocess instead. You might want to >> look at the "ampoule" process-pool project: >> https://launchpad.net/ampoule >> >> For many applications though, you shouldn't need to worry about >> parallelism this much. Since Twisted's XMLRPC server support allows you >> to replace any method's return value with a Deferred without changing >> the externally observable behavior of XML-RPC server, you can add >> parallelism incrementally as you actually require it. In other words, >> you probably don't need to worry about it as much as you think :). >> >> Hope this helped! >> >> _______________________________________________ >> Twisted-Python mailing list >> Twisted-Python@twistedmatrix.com >> http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python >> > _______________________________________________ Twisted-Python mailing list Twisted-Python@twistedmatrix.com http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python
