Method: Workling::Invokers::ThreadedPoller#clazz_listen

Defined in:
lib/workling/invokers/threaded_poller.rb

#clazz_listen(clazz) ⇒ Object

Listen for one worker class



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# File 'lib/workling/invokers/threaded_poller.rb', line 63

def clazz_listen(clazz)
  logger.debug("Listener thread #{clazz.name} started")

  # Read thread configuration if available
  if Workling.config.has_key?(:listeners)
    if Workling.config[:listeners].has_key?(clazz.to_s)
      config = Workling.config[:listeners][clazz.to_s].symbolize_keys
      thread_sleep_time = config[:sleep_time] if config.has_key?(:sleep_time)
      Thread.current.priority = config[:priority] if config.has_key?(:priority)
    end
  end

  thread_sleep_time ||= self.class.sleep_time

  # Setup connection to client (one per thread)
  connection = @client_class.new
  connection.connect
  logger.info("** Starting client #{ connection.class } for #{clazz.name} queue")

  # Start dispatching those messages
  while (!Thread.current[:shutdown]) do
    begin

      # Thanks for this Brent! 
      #
      #     ...Just a heads up, due to how rails’ MySQL adapter handles this  
      #     call ‘ActiveRecord::Base.connection.active?’, you’ll need 
      #     to wrap the code that checks for a connection in in a mutex.
      #
      #     ....I noticed this while working with a multi-core machine that 
      #     was spawning multiple workling threads. Some of my workling 
      #     threads would hit serious issues at this block of code without 
      #     the mutex.            
      #
      if defined?(ActiveRecord::Base)
        @mutex.synchronize do 
          unless ActiveRecord::Base.connection.active?  # Keep MySQL connection alive
            unless ActiveRecord::Base.connection.reconnect!
              logger.fatal("Failed - Database not available!")
              break
            end
          end
        end
      end

      # Dispatch and process the messages
      n = dispatch!(connection, clazz)
      logger.debug("Listener thread #{clazz.name} processed #{n.to_s} queue items") if n > 0
      sleep(thread_sleep_time) unless n > 0

    # If there is a memcache error, hang for a bit to give it a chance to fire up again
    # and reset the connection.
    rescue Workling::WorklingConnectionError
      logger.warn("Listener thread #{clazz.name} failed to connect. Resetting connection.")
      sleep(self.class.reset_time)
      connection.reset
    end
  end

  logger.debug("Listener thread #{clazz.name} ended")
end