release

# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 292
      def release(conn)
        synchronize do
          thread_id = nil

          if @reserved_connections[current_connection_id] == conn
            thread_id = current_connection_id
          else
            thread_id = @reserved_connections.keys.find { |k|
              @reserved_connections[k] == conn
            }
          end

          @reserved_connections.delete thread_id if thread_id
        end
      end