allow_concurrency=

# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 41
      def allow_concurrency=(threaded) #:nodoc:
        logger.debug "allow_concurrency=#{threaded}" if logger
        return if @@allow_concurrency == threaded
        clear_all_cached_connections!
        @@allow_concurrency = threaded
        method_prefix = threaded ? "thread_safe" : "single_threaded"
        sing = (class << self; self; end)
        [:active_connections, :scoped_methods].each do |method|
          sing.send(:alias_method, method, "#{method_prefix}_#{method}")
        end
        log_connections if logger
      end