Module: AutomateEm::DeviceConnection

Included in:
DatagramBase, AutomateEm::Device::Base
Defined in:
lib/automate-em/device/device_connection.rb

Instance Method Summary collapse

Instance Method Details

#add_to_queue(command) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 556

def add_to_queue(command)
  begin
    if @connected || @make_break
      if @com_paused && !@make_break                 # We are calling from connected function (and we are connected)

        command[:priority] -=  (2 * @config[:priority_bonus])   # Double bonus

      elsif @make_break
        if !@connected && !@connecting
          EM.next_tick do
            do_connect
          end
        elsif @connected && @disconnecting
          EM.next_tick do
            add_to_queue(command)
          end
          return # Don't add to queue yet

        end
      end
      
      add = true
      if command[:name].present?
        name = command[:name]
        if @named_commands[name].nil?
          @named_commands[name] = [[command[:priority]], command]  #TODO:: we need to deal with the old commands emit values!

        elsif @named_commands[name][0][-1] > command[:priority]
          @named_commands[name][0].push(command[:priority])
          @named_commands[name][1] = command           #TODO:: we need to deal with the old commands emit values!

        else
          @named_commands[name][1] = command           #TODO:: we need to deal with the old commands emit values!

          add = false
        end
      end
      
      @send_queue.push(command, command[:priority]) if add
    end
  rescue => e
    EM.defer do
      AutomateEm.print_error(logger, e, {
        :message => "module #{@parent.class} in device_connection.rb, send : something went terribly wrong to get here",
        :level => Logger::ERROR
      })
    end
  end
end

#call_connected(*args) ⇒ Object

Connection state



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# File 'lib/automate-em/device/device_connection.rb', line 606

def call_connected(*args)
  #

  # NOTE:: Same as add parent in device module!!!

  #  TODO:: Should break into a module and include it

  #

  set_comm_inactivity_timeout(@config[:inactivity_timeout]) unless @config[:inactivity_timeout].nil?
  @task_queue.push lambda {
    EM.defer do
      @parent[:connected] = true
      
      begin
        @send_monitor.mon_synchronize { # Any sends in here are high priority (no emits as this function must return)

          @parent.connected(*args) if @parent.respond_to?(:connected)
        }
      rescue => e
        #

        # save from bad user code (don't want to deplete thread pool)

        #

        AutomateEm.print_error(logger, e, {
          :message => "module #{@parent.class} error whilst calling: connect",
          :level => Logger::ERROR
        })
      ensure
        EM.schedule do
          #

          # First connect if no commands pushed then we disconnect asap

          #

          if @make_break && @first_connect && @send_queue.size == 0
            close_connection_after_writing
            @disconnecting = true
            @com_paused = true
            @first_connect = false
          elsif @com_paused
            @com_paused = false
            @wait_queue.push(nil)
          else
            EM.defer do
              logger.info "Reconnected, communications not paused."
            end
          end
        end
      end
    end
  }
end

#config=(options) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 660

def config= (options)
  EM.schedule do
    @config.merge!(options)
  end
end

#default_send_options=(options) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 654

def default_send_options= (options)
  @status_lock.synchronize {
    @default_send_options.merge!(options)
  }
end

#do_process_response(response, command) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 320

def do_process_response(response, command)
  return if @shutting_down.value
  
  @received_lock.synchronize {   # This lock protects the send queue lock when we are emiting status

    @send_monitor.mon_synchronize {
      result = :abort
      begin
        if @parent.respond_to?(:received)
          if command.present?
            @parent.mark_emit_start(command[:emit]) if command[:emit].present?
            if command[:callback].present?
              result = command[:callback].call(response, command)
              
              #

              # The data may still be usefull

              #

              if [nil, :ignore].include?(result)
                @parent.received(response, nil)
              end
            else
              result = @parent.received(response, command)
            end
          else
            # logger.debug "Out of order response received for: #{@parent.class}"

            result = @parent.received(response, nil)
          end
        else
          if command.present? 
            @parent.mark_emit_start(command[:emit]) if command[:emit].present?
            if command[:callback].present?
              result = command[:callback].call(response, command)
            else
              result = true
            end
          else
            result = true
          end
        end
      rescue => e
        #

        # save from bad user code (don't want to deplete thread pool)

        # This error should be logged in some consistent manner

        #

        AutomateEm.print_error(logger, e, {
          :message => "module #{@parent.class} error whilst calling: received",
          :level => Logger::ERROR
        })
      ensure
        if command.present?
          @parent.mark_emit_end if command[:emit].present?
        end
        ActiveRecord::Base.clear_active_connections!
      end
      
      if command.present? && command[:wait]
        EM.schedule do
          process_result(result)
        end
      end
    }
  }
end

#do_receive_data(data) ⇒ Object

Data received Allow modules to set message delimiters for auto-buffering Default max buffer length == 1mb (setting can be overwritten) NOTE: The buffer cannot be defered otherwise there are concurrency issues



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# File 'lib/automate-em/device/device_connection.rb', line 254

def do_receive_data(data)
  @last_receive_at = Time.now.to_f
  
  begin
    if @config[:response_delimiter].present?
      if @buf.nil?
        del = @config[:response_delimiter]
        if del.class == Array
          del = array_to_str(del)
        elsif del.class == Fixnum
          del = "" << del #array_to_str([del & 0xFF])

        end
        @buf = BufferedTokenizer.new(del, @config[:max_buffer])    # Call back for character

      end
      data = @buf.extract(data)
    elsif @config[:response_length].present?
      (@buf ||= "") << data
      data = @buf.scan(/.{1,#{@config[:response_length]}}/)
      if data[-1].length == @config[:response_length]
        @buf = nil
      else
        @buf = data[-1]
        data = data[0..-2]
      end
    else
      data = [data]
    end
  rescue => e
    @buf = nil  # clear the buffer

    EM.defer do # Error in a thread

      AutomateEm.print_error(logger, e, {
        :message => "module #{@parent.class} error whilst setting delimiter",
        :level => Logger::ERROR
      })
    end
    data = [data]
  end
  
  if @waiting && data.length > 0
    if @processing
      @receive_queue.push(*data)
    else
      @processing = true
      @timeout.cancel
      process_response(data.shift, @command)
      if data.length > 0
        @receive_queue.push(*data)
      end
    end
  else
    data.each do |result|
      process_response(result, nil)
    end
  end
end

#do_send_command(data, options = {}, *args, &block) ⇒ Object

Processes sends in strict order



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# File 'lib/automate-em/device/device_connection.rb', line 488

def do_send_command(data, options = {}, *args, &block)
  
  begin
    @status_lock.synchronize {
      options = @default_send_options.merge(options)
    }
    
    #

    # Make sure we are sending appropriately formatted data

    #

    if data.is_a?(Array)
      data = array_to_str(data)
    elsif options[:hex_string] == true
      data = hex_to_byte(data)
    end
    
    options[:data] = data
    options[:retries] = 0 if options[:wait] == false
    
    if options[:callback].nil? && (args.length > 0 || block.present?)
      options[:callback] = args[0] unless args.empty? || args[0].class != Proc
      options[:callback] = block unless block.nil?
    end
    
    if options[:name].present?
      options[:name] = options[:name].to_sym
    end
  rescue => e
    AutomateEm.print_error(logger, e, {
      :message => "module #{@parent.class} in device_connection.rb, send : possible bad data or options hash",
      :level => Logger::ERROR
    })
    
    return true
  end
    
    
  #

  # Use a monitor here to allow for re-entrant locking

  #  This allows for a priority queue and we guarentee order of operations

  #

  bonus = false
  begin
    @send_monitor.mon_exit
    @send_monitor.mon_enter
    bonus = true
  rescue
  end
  
  EM.schedule do
    if bonus
      options[:priority] -= @config[:priority_bonus]
    end
    add_to_queue(options)
  end
    
  return false
rescue => e
  #

  # Save from a fatal error

  #

  AutomateEm.print_error(logger, e, {
    :message => "module #{@parent.class} in device_connection.rb, send : something went terribly wrong to get here",
    :level => Logger::ERROR
  })
  return true
end

#initialize(parent, udp) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 9

def initialize( parent, udp )
  #super


  @default_send_options = {
    :wait => true,      # Wait for response

    :delay => 0,      # Delay next send by x.y seconds

    :delay_on_receive => 0, # Delay next send after a receive by x.y seconds (only works when we are waiting for responses)

    #:emit

    :max_waits => 3,
    :callback => nil,   # Alternative to the received function

    :retries => 2,
    :hex_string => false,
    :timeout => 5,      # Timeout in seconds

    :priority => 50,
    :retry_on_disconnect => true,
    :force_disconnect => false  # part of make and break options

  }
  
  @config = {
    :max_buffer => 524288,    # 512kb

    :clear_queue_on_disconnect => false,
    :flush_buffer_on_disconnect => false,
    :priority_bonus => 20
    # :inactivity_timeout => 0  # part of make and break options

    # :response_length      # an alternative to response_delimiter (lower priority)

    # :response_delimiter   # here instead of a function call

  }
  
  
  #

  # Queues

  #

  @task_queue = EM::Queue.new    # basically we add tasks here that we want to run in a strict order (connect, disconnect)

  @receive_queue = EM::Queue.new # So we can process responses in different ways

  @wait_queue = EM::Queue.new
  @send_queue = EM::PriorityQueue.new(:fifo => true) {|x,y| x < y} # regular priority

  
  #

  # Named commands

  #  Allowing for state control

  #

  @named_commands = {}
  
  #

  # Locks

  #

  @received_lock = Mutex.new
  @task_lock = Mutex.new
  @status_lock = Mutex.new
  @send_monitor = Object.new.extend(MonitorMixin)
  
  
  #

  # State

  #

  @connected = udp
  @connecting = false
  @disconnecting = false
  @com_paused = true
  
  @command = nil
  @waiting = false
  @processing = false
  @last_sent_at = 0.0
  @last_receive_at = 0.0
  @timeout = nil
  
  
  #

  # Configure links between objects (This is a very loose tie)

  #  Relies on serial loading of modules

  #

  @parent = parent
  @parent.setbase(self)
  
  @tls_enabled = @parent.secure_connection
  if @parent.makebreak_connection
    @make_break = true
    @first_connect = true
  else
    @make_break = false
  end
  @make_occured = false
  
  @shutting_down = Atomic.new(false)
  
  
  #

  # Task event loop

  #

  @task_queue_proc = Proc.new do |task|
    if !@shutting_down.value
      EM.defer do
        begin
          @task_lock.synchronize {
            task.call
          }
        rescue => e
          AutomateEm.print_error(logger, e, {
            :message => "module #{@parent.class} in device_connection.rb, base : error in task loop",
            :level => Logger::ERROR
          })
        ensure
          ActiveRecord::Base.clear_active_connections!
          @task_queue.pop &@task_queue_proc
        end
      end
    end
  end
  @task_queue.pop &@task_queue_proc  # First task is ready

  
  
  #

  # send loop

  #

  @wait_queue_proc = Proc.new do |ignore|
    if ignore != :shutdown
    
      @send_queue.pop {|command|
        if command != :shutdown
          begin
            
            process = true
            if command[:name].present?
              begin
                name = command[:name]
                @named_commands[name][0].pop        # Extract the command data

                command = @named_commands[name][1]
                
                if @named_commands[name][0].empty?      # See if any more of these commands are queued

                  @named_commands.delete(name) # Delete if there are not

                else
                  @named_commands[name][1] = nil     # Reset if there are

                end
                
                if command.nil?               # decide if to continue or not

                  command = {}
                  process = false
                end
              rescue
                #

                # Retry (pop empty, lets let it have it)

                #

              end
            end
            
            if process
              if command[:delay] > 0.0
                delay = @last_sent_at + command[:delay] - Time.now.to_f
                if delay > 0.0
                  EM.add_timer delay do
                    process_send(command)
                  end
                else
                  process_send(command)
                end
              else
                process_send(command)
              end
            else
              process_next_send(command)
            end
          rescue => e
            EM.defer do
              AutomateEm.print_error(logger, e, {
                :message => "module #{@parent.class} in device_connection.rb, base : error in send loop",
                :level => Logger::ERROR
              })
            end
          ensure
            ActiveRecord::Base.clear_active_connections!
            @wait_queue.pop &@wait_queue_proc
          end
        end
      }
    end
  end
  
  #@wait_queue.push(nil)   Start paused

  @wait_queue.pop &@wait_queue_proc
end

#logger ⇒ Object

Everything below here is called from a deferred thread



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# File 'lib/automate-em/device/device_connection.rb', line 476

def logger
  @parent.logger
end

#process_next_send(command) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 236

def process_next_send(command)
  if command[:force_disconnect]    # Allow connection control

    close_connection_after_writing
    @disconnecting = true
    @com_paused = true
  else
    EM.next_tick do
      @wait_queue.push(nil)  # Allows next response to process

    end
  end
end

#process_response(response, command) ⇒ Object

Called from receive



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# File 'lib/automate-em/device/device_connection.rb', line 314

def process_response(response, command)
  EM.defer do
    do_process_response(response, command)
  end
end

#process_response_complete ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 452

def process_response_complete
  if (@make_break && [nil, 0].include?(@config[:inactivity_timeout]) && @send_queue.empty?) || @command[:force_disconnect]
    if @connected
      close_connection_after_writing
      @disconnecting = true
    end
    @com_paused = true
  else
    EM.next_tick do
      @wait_queue.push(nil)
    end
  end
  
  @command = nil       # free memory

end

#process_result(result) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 405

def process_result(result)
  if [nil, :ignore].include?(result) && @command[:max_waits] > 0
    @command[:max_waits] -= 1
    
    if @receive_queue.size() > 0
      @receive_queue.pop { |response|
        process_response(response, @command)
      }
    else
      @timeout = EM::Timer.new(@command[:timeout]) {
        sending_timeout
      }
      @processing = false
    end
  else
    if [false, :failed].include?(result) && @command[:retries] > 0  # assume command failed, we need to retry

      @command[:retries] -= 1
      @send_queue.push(@command, @command[:priority] - @config[:priority_bonus])
    end
    
    #else    result == :abort || result == :success || result == true || waits and retries exceeded

    
    @receive_queue.size().times do
      @receive_queue.pop { |response|
        process_response(response, nil)
      }
    end
    
    @processing = false
    @waiting = false
    
    if @command[:delay_on_receive] > 0.0
      delay_for = (@last_receive_at + @command[:delay_on_receive] - Time.now.to_f)
      
      if delay_for > 0.0
        EM.add_timer delay_for do
          process_response_complete
        end
      else
        process_response_complete
      end
    else
      process_response_complete
    end
  end
end

#process_send(command) ⇒ Object

this is on the reactor thread



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# File 'lib/automate-em/device/device_connection.rb', line 192

def process_send(command) # this is on the reactor thread

  begin
    if !error? && @connected
      do_send_data(command[:data])
      
      @last_sent_at = Time.now.to_f
      @waiting = command[:wait]
      
      if @waiting
        @command = command
        @timeout = EM::Timer.new(command[:timeout]) {
          sending_timeout
        }
      else
        process_next_send(command)
      end
    else
      if @connected
        process_next_send(command)
      else
        if command[:retry_on_disconnect] || @make_break
          @send_queue.push(command, command[:priority] - (2 * @config[:priority_bonus])) # Double bonus

        end
        @com_paused = true
      end
    end
  rescue => e
    #

    # Save the thread in case of bad data in that send

    #

    EM.defer do
      AutomateEm.print_error(logger, e, {
        :message => "module #{@parent.class} in device_connection.rb, process_send : possible bad data",
        :level => Logger::ERROR
      })
    end
    if @connected
      process_next_send(command)
    else
      @com_paused = true
    end
  end
end

#received_lock ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 480

def received_lock
  @send_monitor    # for monitor use

end

#sending_timeout ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 384

def sending_timeout
  @timeout = true
  if !@processing && @connected && @command.present? # Probably not needed...

    @processing = true  # Ensure responses go into the queue

    
    command = @command[:data]
    process_result(:failed)
    
    EM.defer do
      logger.info "module #{@parent.class} timeout"
      logger.info "A response was not received for the command: #{command}" unless command.nil?
    end
  elsif !@connected && @command.present? && @command[:wait]
    if @command[:retry_on_disconnect] || @make_break
      @send_queue.push(@command, @command[:priority] - (2 * @config[:priority_bonus])) # Double bonus

    end
    @com_paused = true
  end
end

#shutdown(system) ⇒ Object 



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# File 'lib/automate-em/device/device_connection.rb', line 669

def shutdown(system)
  if @parent.leave_system(system) == 0
    @shutting_down.value = true
    
    close_connection
    
    @wait_queue.push(:shutdown)
    @send_queue.push(:shutdown, -32768)
    @task_queue.push(nil)
    
    EM.defer do
      begin
        @parent[:connected] = false # Communicator off at this point

        if @parent.respond_to?(:disconnected)
          @task_lock.synchronize {
            @parent.disconnected
          }
        end
      rescue => e
        #

        # save from bad user code (don't want to deplete thread pool)

        #

        AutomateEm.print_error(logger, e, {
          :message => "module #{@parent.class} error whilst calling: disconnected on shutdown",
          :level => Logger::ERROR
        })
      ensure
        @parent.clear_active_timers
        ActiveRecord::Base.clear_active_connections!
      end
    end
  end
end