This is a question about MT safe on jruby on rails.
I just want to confirm that there is no MT safe issue to use controller instance variable.
In fact, the same question is that for each http request, rails will spawn a controller instance to process it or rails will reuse the same controller instance with different threads(just like servlet instance)?
I.E.,If one controller instance for one http request, then controller instance variable has NO MT safe issue,
If more than one thread share one controller instance, then controller instance variable has MT safe issue
Another similar questions is Thread-safe Rails controller actions - setting instance variables?