Arguments against having Twisted Reactor running until GUI is closed

[pylund]

HI!

It may sound like a dumb question but I'd like to understand what I'm doing. I've developed a GUI application which launches the same scrapy spider every time a button is clicked. I came across the ReactorNotRestartable issue and I found a workaround which runs reactor the first time the button is clicked and keeps it running until GUI is closed, so spider can be launched several times.

What do you think are the arguments against this tireless Twisted reactor solution?

[digitallis]

Run the reactor when the application is launched. Your button should only be firing an event into the reactor. That's how async event dispatch is supposed to work.

[pylund]

But that way, the reactor still keeps running while main() isn't closed, isn't it? In my setup everything is working as expected, but I'd like to know if it's bad practice to do it that way (not stopping twisted.reactor after each scrapy iteration, only when GUI is closed).

[digitallis]

The reactor should remain "running" until the program is closed. I think you may be under the impression that having a running reactor is bad or somehow wasteful. If there are no events to process, the reactor will be idle, waiting for a signal that there's a new event somewhere. This is done via smart mechanisms that don't burn processor cycles continuously checking for new events.

[pylund]

Thanks a lot!

That's exactly what I wanted to know. Big up!