[Twisted-Python] does setTcpNoDelay() not work?

Jean-Paul Calderone exarkun at divmod.com
Mon Aug 11 13:30:04 EDT 2008

On Mon, 11 Aug 2008 19:13:56 +0200, Gabriel Rossetti <gabriel.rossetti at arimaz.com> wrote:
>Gabriel Rossetti wrote:
>>I'm needing to send small packets to update a progress bar. My update msgs 
>>were all being sent in big packets, so I tried setting setTcpNoDelay() in 
>>connectionMade() but it doesn't change anything, is it broken?
>>Thank you,
>I an using code that I wrote using threads.deferToThread(), I wondered if it 
>was blocking the reactor maybe, so I tried just using a plain 
>deferToThread() call. Here's the code (without all the protocol stuff, it's 
>executed when data come in.
>    def loop(self):
>        import time
>        m = utils.createMessage("toto", "hello")
>        while(True):
>            print "Sending %s" % m.toXml()
>            self.sendMessage(m)
>            print "Sent!"
>            time.sleep(2)
>the TCP no delay option is turned on like I said before, the weird thing is 
>that I have the same thing, all my msgs get sent in big blocks. Either the 
>TCP no delay doesn't work, or the reactor is getting tied up. I don' t get 
>it since I'm running the blocking code in a thread, the reactor should have 
>nothing to do.

Since you didn't include the definition of `sendMessage´, it's hard to say
what's really going on here.  However, my guess is that you're calling the
transport.write method in a non-reactor thread, which is not allowed.

If this isn't the case, including a full, minimal example in your next
message would be a good idea. :)


More information about the Twisted-Python mailing list