There are several classes that define @var instance variables at class level. For example:
https://github.com/apache/whimsy/blob/master/lib/whimsy/asf/svn.rb#L12 This defines @semaphore = Mutex.new in the body of the class. I would expect to see a class variable at this point, i.e. @@semaphore = Mutex.new This is done later for a different variable: https://github.com/apache/whimsy/blob/master/lib/whimsy/asf/svn.rb#L17 What is the reason for using instance variables here? AFAICT in this case the class is only expected to be used as a singleton. It could/should be a Module instead?
