On 4/4/07, Nicola Larosa <nico@teknico.net> wrote:
littlesweetmelon@gmail.com wrote:
Twist requires all user functions to be non-blocked. If reactor calls a blocking function, what will happen? In my mind, reactor maintains a command queue internally (just like windows message queue). The blocking function only postpones the execution of other queued functions, but it does not break the logic of the program. Is that right?
Yes, that's right. The processing of subsequent events will be delayed, but the program will still run correctly, *if* its correctness does not depend on the timing of event processing.
However, I want to stress that technically Twisted is not maintaining a command queue relevant to this situation. Yes, it does have a queue of scheduled calls, but when you're just talking about running some code that blocks, it's not Twisted which is preventing further things from happening, it is the sequential nature of the code itself. There's no need to queue things up when Python itself, when executing "a(); b()", prevents 'b' from executing before 'a' has returned. -- Christopher Armstrong International Man of Twistery http://radix.twistedmatrix.com/ http://twistedmatrix.com/ http://canonical.com/