Code caching in development period


I make such test: I have created new RoR-project and have made one controller and on ruby library: app/controllers/test_controller.rb lib/test.rb

I have tested my simple project on 3 web-servers:: thin, mongrel, apache + passenger in development-environment.

On all 3 web-servers I see changes in my controller without web-server restarting. But changes in test.rb I can see only after web-server restarting. I understand, why i don't see changes. But I have such questions:

1. Is it possible to configure my web-server or rails so, that require caching (code caching) for my rb-files was turned off? 2. Can I by ruby-code reload cached rb-libraries? 3. Can I configure, that web-server doesn't cache all rb-scripts, except some of them?