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



544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
# File 'lib/automate-em/device/device_connection.rb', line 544

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



594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
# File 'lib/automate-em/device/device_connection.rb', line 594

def call_connected(*args)		# Called from a deferred thread
	#
	# NOTE:: Same as add parent in device module!!!
	#	TODO:: Should break into a module and include it
	#
	@task_queue.push lambda {
		@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

#config=(options) ⇒ Object



645
646
647
648
649
# File 'lib/automate-em/device/device_connection.rb', line 645

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

#default_send_options=(options) ⇒ Object



639
640
641
642
643
# File 'lib/automate-em/device/device_connection.rb', line 639

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

#do_process_response(response, command) ⇒ Object



308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
# File 'lib/automate-em/device/device_connection.rb', line 308

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



251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
# File 'lib/automate-em/device/device_connection.rb', line 251

def do_receive_data(data)
	@last_recieve_at = Time.now.to_f
	
	if @parent.respond_to?(:response_delimiter)
		begin
			if @buf.nil?
				del = @parent.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)
		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
	else
		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



476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
# File 'lib/automate-em/device/device_connection.rb', line 476

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.class == 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) ⇒ Object



9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
# File 'lib/automate-em/device/device_connection.rb', line 9

def initialize( parent )
	super

	@default_send_options = {
		:wait => true,			# Wait for response
		:delay => 0,			# Delay next send by x.y seconds
		:delay_on_recieve => 0,	# Delay next send after a recieve 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
	}
	
	
	#
	# 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 = false
	@connecting = false
	@disconnecting = false
	@com_paused = true
	
	@command = nil
	@waiting = false
	@processing = false
	@last_sent_at = 0.0
	@last_recieve_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

#loggerObject


Everything below here is called from a deferred thread



464
465
466
# File 'lib/automate-em/device/device_connection.rb', line 464

def logger
	@parent.logger
end

#process_next_send(command) ⇒ Object



233
234
235
236
237
238
239
240
241
242
243
# File 'lib/automate-em/device/device_connection.rb', line 233

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

Caled from recieve



302
303
304
305
306
# File 'lib/automate-em/device/device_connection.rb', line 302

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

#process_response_completeObject



440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
# File 'lib/automate-em/device/device_connection.rb', line 440

def process_response_complete
	if (@make_break && @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



393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
# File 'lib/automate-em/device/device_connection.rb', line 393

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_recieve] > 0.0
			delay_for = (@last_recieve_at + @command[:delay_on_recieve] - 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



189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
# File 'lib/automate-em/device/device_connection.rb', line 189

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_lockObject



468
469
470
# File 'lib/automate-em/device/device_connection.rb', line 468

def received_lock
	@send_monitor		# for monitor use
end

#sending_timeoutObject



372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
# File 'lib/automate-em/device/device_connection.rb', line 372

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



654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
# File 'lib/automate-em/device/device_connection.rb', line 654

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