class method self.new

# File activerecord/lib/active_record/connection_adapters/abstract/connection_pool.rb, line 71
      def initialize(spec)
        @spec = spec

        # The cache of reserved connections mapped to threads
        @reserved_connections = {}

        # The mutex used to synchronize pool access
        @connection_mutex = Monitor.new
        @queue = @connection_mutex.new_cond
        @timeout = spec.config[:wait_timeout] || 5

        # default max pool size to 5
        @size = (spec.config[:pool] && spec.config[:pool].to_i) || 5

        @connections         = []
        @checked_out         = []
        @automatic_reconnect = true
        @tables              = {}
        @visitor             = nil

        @columns     = Hash.new do |h, table_name|
          h[table_name] = with_connection do |conn|

            # Fetch a list of columns
            conn.columns(table_name, "#{table_name} Columns").tap do |columns|

              # set primary key information
              columns.each do |column|
                column.primary = column.name == primary_keys[table_name]
              end
            end
          end
        end

        @columns_hash = Hash.new do |h, table_name|
          h[table_name] = Hash[columns[table_name].map { |col|
            [col.name, col]
          }]
        end

        @column_defaults = Hash.new do |h, table_name|
          h[table_name] = Hash[columns[table_name].map { |col|
            [col.name, col.default]
          }]
        end

        @primary_keys = Hash.new do |h, table_name|
          h[table_name] = with_connection do |conn|
            table_exists?(table_name) ? conn.primary_key(table_name) : 'id'
          end
        end
      end