[Twisted-Python] writing back to the connection is blocking my code

[coder_gus]

Hi,
I have a server that tries to write back to several clients after it 
processed some that. I keep a hash with the currently connected clients 
(protocol instances) and write back to those as soon as the workers 
finish their job. The thing is I don't know where to call that 
instance.writeDataToClient() to not block my code. (I have tried in 
buildProtocol, but of course, it waits that another connection to be 
made until it writes back).

Thanks for All your help.