class ActiveRecord::ConnectionAdapters::ConnectionHandler

def initialize
  # These caches are keyed by klass.name, NOT klass. Keying them by klass
  # alone would lead to memory leaks in development mode as all previous
  # instances of the class would stay in memory.
  @owner_to_pool = ThreadSafe::Cache.new(:initial_capacity => 2) do |h,k|
    h[k] = ThreadSafe::Cache.new(:initial_capacity => 2)
  end
  @class_to_pool = ThreadSafe::Cache.new(:initial_capacity => 2) do |h,k|
    h[k] = ThreadSafe::Cache.new
  end
end