First draft of some kind of Action Queue (just like the globalstep queue in to_update), but more flexible and also including delay functionality (mesecon_delayer).

The queue is also saved to a file, so that when restarting mesecons, delayers resume to the state they had when the game shut down. Needs testing.

mesecons/actionqueue.lua

@@ -0,0 +1,90 @@
+mesecon.queue.actions={} -- contains all ActionQueue actions
+
+function mesecon.queue:add_function(name, func)
+	mesecon.queue.funcs[name] = func
+end
+
+-- If add_action with twice the same overwritecheck and same position are called, the first one is overwritten
+-- use overwritecheck nil to never overwrite, but just add the event to the queue
+function mesecon.queue:add_action(pos, func, params, time, overwritecheck)
+	-- Create Action Table:
+	time = time or 0 -- time <= 0 --> execute, time > 0 --> wait time until execution
+	action = {	pos=pos,
+			func=func,
+			params=mesecon:tablecopy(params),
+			time=time,
+			owcheck=overwritecheck}
+
+	--print(dump(action))
+	-- if not using the queue, (MESECONS_GLOBALSTEP off), just execute the function an we're done
+	if not MESECONS_GLOBALSTEP then
+		mesecon.queue:execute(action)
+		return
+	end
+
+	-- Otherwise, add the action to the queue
+	if overwritecheck then -- check if old action has to be overwritten / removed:
+		for i, ac in ipairs(mesecon.queue.actions) do
+			if(mesecon:cmpPos(pos, action.pos)
+			and mesecon:cmpAny(overwritecheck, ac.owcheck)) then
+				table.remove(mesecon.queue.actions, i)
+				break
+			end
+		end
+	end
+
+	table.insert(mesecon.queue.actions, action)
+end
+
+-- execute the stored functions on a globalstep
+-- if however, the pos of a function is not loaded (get_node_or_nil == nil), do NOT execute the function
+-- this makes sure that resuming mesecons circuits when restarting minetest works fine
+-- However, even that does not work in some cases, that's why we delay the time the globalsteps
+-- start to be execute by 5 seconds
+local m_time = 0
+minetest.register_globalstep(function (dtime)
+	m_time = m_time + dtime
+	if (m_time < 5) then return end -- don't even try if server has not been running for 2 seconds
+	local actions = mesecon:tablecopy(mesecon.queue.actions)
+	mesecon.queue.actions = {}
+
+	for i, action in ipairs(actions) do
+		if action.time > 0 then
+			action.time = action.time - dtime
+			table.insert(mesecon.queue.actions, action) -- will be handled another time
+		else -- execute and remove
+			mesecon.queue:execute(action)
+		end
+	end
+end)
+
+function mesecon.queue:execute(action)
+	mesecon.queue.funcs[action.func](action.pos, unpack(action.params))
+end
+
+
+-- Store and read the ActionQueue to / from a file
+-- so that upcoming actions are remembered when the game
+-- is restarted
+
+local wpath = minetest.get_worldpath()
+local function file2table(filename)
+	local f = io.open(filename, "r")
+	if f==nil then return {} end
+	local t = f:read("*all")
+	f:close()
+	if t=="" or t==nil then return {} end
+	return minetest.deserialize(t)
+end
+
+local function table2file(filename, table)
+	local f = io.open(filename, "w")
+	f:write(minetest.serialize(table))
+	f:close()
+end
+
+mesecon.queue.actions = file2table(wpath.."/mesecon_actionqueue")
+
+minetest.register_on_shutdown(function()
+	mesecon.queue.actions = table2file(wpath.."/mesecon_actionqueue", mesecon.queue.actions)
+end)

mesecons/init.lua

@@ -42,37 +42,8 @@
 
 -- PUBLIC VARIABLES
 mesecon={} -- contains all functions and all global variables
-mesecon.actions_on={} -- Saves registered function callbacks for mesecon on | DEPRECATED
-mesecon.actions_off={} -- Saves registered function callbacks for mesecon off | DEPRECATED
-mesecon.actions_change={} -- Saves registered function callbacks for mesecon change | DEPRECATED
-mesecon.receptors={} --  saves all information about receptors  | DEPRECATED
-mesecon.effectors={} --  saves all information about effectors  | DEPRECATED
-mesecon.conductors={} -- saves all information about conductors | DEPRECATED
-
-
-local wpath = minetest.get_worldpath()
-local function read_file(fn)
-	local f = io.open(fn, "r")
-	if f==nil then return {} end
-	local t = f:read("*all")
-	f:close()
-	if t=="" or t==nil then return {} end
-	return minetest.deserialize(t)
-end
-
-local function write_file(fn, tbl)
-	local f = io.open(fn, "w")
-	f:write(minetest.serialize(tbl))
-	f:close()
-end
-
-mesecon.to_update = read_file(wpath.."/mesecon_to_update")
-mesecon.r_to_update = read_file(wpath.."/mesecon_r_to_update")
-
-minetest.register_on_shutdown(function()
-	write_file(wpath.."/mesecon_to_update",mesecon.to_update)
-	write_file(wpath.."/mesecon_r_to_update",mesecon.r_to_update)
-end)
+mesecon.queue={} -- contains the ActionQueue
+mesecon.queue.funcs={} -- contains all ActionQueue functions
 
 -- Settings
 dofile(minetest.get_modpath("mesecons").."/settings.lua")
@@ -86,6 +57,10 @@ dofile(minetest.get_modpath("mesecons").."/presets.lua");
 -- mostly things that make the source look cleaner
 dofile(minetest.get_modpath("mesecons").."/util.lua");
 
+-- The ActionQueue
+-- Saves all the actions that have to be execute in the future
+dofile(minetest.get_modpath("mesecons").."/actionqueue.lua");
+
 -- Internal stuff
 -- This is the most important file
 -- it handles signal transmission and basically everything else
@@ -101,31 +76,33 @@ dofile(minetest.get_modpath("mesecons").."/legacy.lua");
 -- API
 -- these are the only functions you need to remember
 
-function mesecon:receptor_on_i(pos, rules)
+mesecon.queue:add_function("receptor_on", function (pos, rules)
 	rules = rules or mesecon.rules.default
 
 	for _, rule in ipairs(mesecon:flattenrules(rules)) do
 		local np = mesecon:addPosRule(pos, rule)
+		-- if area is not loaded, keep trying
+		if minetest.env:get_node_or_nil(np) == nil then
+			mesecon.queue:add_action(pos, "receptor_on", {rules})
+		end
 		local rulenames = mesecon:rules_link_rule_all(pos, rule)
 		for _, rulename in ipairs(rulenames) do
 			mesecon:turnon(np, rulename)
 		end
 	end
-end
+end)
 
 function mesecon:receptor_on(pos, rules)
-	if MESECONS_GLOBALSTEP then
-		rules = rules or mesecon.rules.default
-		mesecon.r_to_update[#mesecon.r_to_update+1]={pos=pos, rules=rules, action="on"}
-	else
-		mesecon:receptor_on_i(pos, rules)
-	end
+	mesecon.queue:add_action(pos, "receptor_on", {rules})
 end
 
-function mesecon:receptor_off_i(pos, rules)
+mesecon.queue:add_function("receptor_off", function (pos, rules)
 	rules = rules or mesecon.rules.default
 	for _, rule in ipairs(mesecon:flattenrules(rules)) do
 		local np = mesecon:addPosRule(pos, rule)
+		if minetest.env:get_node_or_nil(np) == nil then
+			mesecon.queue:add_action(pos, "receptor_off", {rules})
+		end
 		local rulenames = mesecon:rules_link_rule_all(pos, rule)
 		for _, rulename in ipairs(rulenames) do
 			if not mesecon:connected_to_receptor(np, mesecon:invertRule(rule)) then
@@ -135,15 +112,10 @@ function mesecon:receptor_off_i(pos, rules)
 			end
 		end
 	end
-end
+end)
 
 function mesecon:receptor_off(pos, rules)
-	if MESECONS_GLOBALSTEP then
-		rules = rules or mesecon.rules.default
-		mesecon.r_to_update[#mesecon.r_to_update+1]={pos=pos, rules=rules, action="off"}
-	else
-		mesecon:receptor_off_i(pos, rules)
-	end
+	mesecon.queue:add_action(pos, "receptor_off", {rules})
 end
 
 

mesecons/internal.lua

@@ -177,121 +177,76 @@ function mesecon:effector_get_rules(node)
 	return mesecon.rules.default
 end
 
---Signals
+-- #######################
+-- # Signals (effectors) #
+-- #######################
+
+-- Activation:
+mesecon.queue:add_function("activate", function (pos, rulename)
+	node = minetest.get_node(pos)
+	effector = mesecon:get_effector(node.name)
+
+	if effector and effector.action_on then
+		effector.action_on(pos, node, rulename)
+	end
+end)
 
 function mesecon:activate(pos, node, rulename)
-	if MESECONS_GLOBALSTEP then
 	if rulename == nil then
 		for _,rule in ipairs(mesecon:effector_get_rules(node)) do
 			mesecon:activate(pos, node, rule)
 		end
 		return
 	end
-		add_action(pos, "on", rulename)
-	else
-		local effector = mesecon:get_effector(node.name)
-		if effector and effector.action_on then
-			effector.action_on (pos, node, rulename)
-		end
-	end
+	mesecon.queue:add_action(pos, "activate", {rulename}, nil, rulename)
 end
 
+
+-- Deactivation
+mesecon.queue:add_function("deactivate", function (pos, rulename)
+	node = minetest.get_node(pos)
+	effector = mesecon:get_effector(node.name)
+
+	if effector and effector.action_off then
+		effector.action_off(pos, node, rulename)
+	end
+end)
+
 function mesecon:deactivate(pos, node, rulename)
-	if MESECONS_GLOBALSTEP then
 	if rulename == nil then
 		for _,rule in ipairs(mesecon:effector_get_rules(node)) do
 			mesecon:deactivate(pos, node, rule)
 		end
 		return
 	end
-		add_action(pos, "off", rulename)
-	else
-		local effector = mesecon:get_effector(node.name)
-		if effector and effector.action_off then
-			effector.action_off (pos, node, rulename)
-		end
+	mesecon.queue:add_action(pos, "deactivate", {rulename}, nil, rulename)
 end
+
+
+-- Change
+mesecon.queue:add_function("change", function (pos, rulename, changetype)
+	node = minetest.get_node(pos)
+	effector = mesecon:get_effector(node.name)
+
+	if effector and effector.action_change then
+		effector.action_change(pos, node, rulename, changetype)
 	end
+end)
 
 function mesecon:changesignal(pos, node, rulename, newstate)
-	
-	newstate = newstate or "on"
-	--rulename = rulename or mesecon.rules.default
-	if MESECONS_GLOBALSTEP then
 	if rulename == nil then
 		for _,rule in ipairs(mesecon:effector_get_rules(node)) do
 			mesecon:changesignal(pos, node, rule, newstate)
 		end
 		return
 	end
-		add_action(pos, "c"..newstate, rulename)
-	else
-		local effector = mesecon:get_effector(node.name)
-		if effector and effector.action_change then
-			effector.action_change (pos, node, rulename, newstate)
-		end
-	end
+
+	mesecon.queue:add_action(pos, "change", {rulename, newstate}, nil, rulename)
 end
 
-function execute_actions(dtime)
-	local nactions = mesecon.to_update
-	mesecon.to_update = {}
-	for _,i in ipairs(nactions) do
-		node = minetest.get_node(i.pos)
-		if node.name=="ignore" then
-			add_action(i.pos, i.action, i.rname)
-		else
-			effector = mesecon:get_effector(node.name)
-			if i.action == "on" then
-				if effector and effector.action_on then
-					effector.action_on(i.pos, node, i.rname)
-				end
-			elseif i.action == "off" then
-				if effector and effector.action_off then
-					effector.action_off(i.pos, node, i.rname)
-				end
-			elseif i.action == "con" then
-				if effector and effector.action_change then
-					effector.action_change(i.pos, node, i.rname, "on")
-				end
-			elseif i.action == "coff" then
-				if effector and effector.action_change then
-					effector.action_change(i.pos, node, i.rname, "off")
-				end
-			end
-		end
-	end
-	local nactions = mesecon.r_to_update
-	mesecon.r_to_update = {}
-	for _,i in ipairs(nactions) do
-		if i.action == "on" then
-			mesecon:receptor_on_i(i.pos, i.rules)
-		else
-			mesecon:receptor_off_i(i.pos,i.rules)
-		end
-	end
-end
-
-minetest.register_globalstep(execute_actions)
-
-function add_action(pos, action, rname)
-	for _,i in ipairs(mesecon.to_update) do
-		if i.pos.x == pos.x and i.pos.y == pos.y and i.pos.z == pos.z and i.rname.x == rname.x and i.rname.y == rname.y and i.rname.z == rname.z then
-			if (i.action == "on" and action == "on") or (i.action == "off" and action == "off") then
-				--nothing
-			elseif i.action == "coff" and action == "on" then i.action = "on"
-			elseif i.action == "con" and action == "off" then i.action = "off"
-			else
-				if action == "on" or action == "con" then i.action = "con" end
-				if action == "off" or action == "coff" then i.action = "coff" end
-			end
-			break
-		end
-	end
-	mesecon.to_update[#mesecon.to_update+1] = {pos = pos, action = action, rname = rname}
-end
-
---Rules
+-- #########
+-- # Rules # "Database" for rulenames
+-- #########
 
 function mesecon:add_rules(name, rules)
 	mesecon.rules[name] = rules

mesecons/services.lua

@@ -18,7 +18,7 @@ end
 
 mesecon.on_dignode = function (pos, node)
 	if mesecon:is_conductor_on(node) then
-		mesecon:receptor_off_i(pos, mesecon:conductor_get_rules(node))
+		mesecon:receptor_off(pos, mesecon:conductor_get_rules(node))
 	elseif mesecon:is_receptor_on(node.name) then
 		mesecon:receptor_off(pos, mesecon:receptor_get_rules(node))
 	end

mesecons/util.lua

@@ -181,3 +181,14 @@ function mesecon:tablecopy(table) -- deep table copy
 
 	return newtable
 end
+
+function mesecon:cmpAny(t1, t2)
+	if type(t1) ~= type(t2) then return false end
+	if type(t1) ~= "table" and type(t2) ~= "table" then return t1 == t2 end
+
+	for i, e in pairs(t1) do
+		if not mesecon:cmpAny(e, t2[i]) then return false end
+	end
+
+	return true
+end

mesecons_delayer/init.lua

@@ -17,28 +17,18 @@ end
 
 -- Functions that are called after the delay time
 
-local delayer_turnon = function(params)
-	local rules = delayer_get_output_rules(params.node)
-	mesecon:receptor_on(params.pos, rules)
-end
-
-local delayer_turnoff = function(params)
-	local rules = delayer_get_output_rules(params.node)
-	mesecon:receptor_off(params.pos, rules)
-end
-
 local delayer_activate = function(pos, node)
 	local def = minetest.registered_nodes[node.name]
 	local time = def.delayer_time
 	minetest.swap_node(pos, {name = def.delayer_onstate, param2=node.param2})
-	minetest.after(time, delayer_turnon , {pos = pos, node = node})
+	mesecon.queue:add_action(pos, "receptor_on", {rules=delayer_get_output_rules(node)}, time, nil)
 end
 
 local delayer_deactivate = function(pos, node)
 	local def = minetest.registered_nodes[node.name]
 	local time = def.delayer_time
 	minetest.swap_node(pos, {name = def.delayer_offstate, param2=node.param2})
-	minetest.after(time, delayer_turnoff, {pos = pos, node = node})
+	mesecon.queue:add_action(pos, "receptor_off", {rules=delayer_get_output_rules(node)}, time, nil)
 end
 
 -- Register the 2 (states) x 4 (delay times) delayers