class ActiveRecord::ConnectionAdapters::ConnectionPool

:nodoc:
See AbstractAdapter#discard!

pool (except #spec and #schema_cache) is undefined.
leased!), along with the pool itself. Any further interaction with the
Discards all connections in the pool (even if they're currently

def discard! # :nodoc:
  synchronize do
    return if self.discarded?
    @connections.each do |conn|
      conn.discard!
    end
    @connections = @available = @thread_cached_conns = nil
  end
end