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