On Dec 16, 4:12 am, Vikrant Chaudhary <[email protected]> wrote: > Hi, I just wanted some clarification on this. > > In production mode, while I know that object instance variables are > local to the object and so to the request, but is this same with class > variables and class instance variables or are they shared between > requests? > > I have this question, because I know that classes are cached in > production mode. But what does this mean? Like, classes are > initialised and cached at the start of the server (and so are class > variables and class level instance variables) and are persistent in > the memory throughout, or it's like, just class definitions are cached > (so they are not read every time from the disk), and they are re- > initialised for every request, so that every request has its own set?
I believe that the classes actually do stay around, but trying to use them to pass messages is a Bad Idea. There's too many ways for any changes to get lost - a subsequent request might go to a different worker, the worker with the value might get killed (by hitting memory limits, or just things like Passenger's idle timeout, etc). And they *definitely* go away in development mode, of course. Note that the typical use of class variables in most of the Rails source is as a cache of values that should stay constant throughout execution, which avoids the issue entirely by only setting values once. --Matt Jones -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
