Improved version of luamqtt with fewer bugs

controller-host/mqtt/loop/copas.lua

@@ -0,0 +1,72 @@
+--- Copas specific client handling module.
+-- Typically this module is not used directly, but through `mqtt.loop` when
+-- auto-detecting the environment.
+-- @module mqtt.loop.copas
+
+local copas = require "copas"
+local log = require "mqtt.log"
+
+local client_registry = {}
+
+local _M = {}
+
+
+--- Add MQTT client to the Copas scheduler.
+-- Each received packet will be handled by a new thread, such that the thread
+-- listening on the socket can return immediately.
+-- The client will automatically be removed after it exits. It will set up a
+-- thread to call `Client:check_keep_alive`.
+-- @param cl mqtt-client to add to the Copas scheduler
+-- @return `true` on success or `false` and error message on failure
+function _M.add(cl)
+	if client_registry[cl] then
+		log:warn("MQTT client '%s' was already added to Copas", cl.opts.id)
+		return false, "MQTT client was already added to Copas"
+	end
+	client_registry[cl] = true
+
+	do -- make mqtt device async for incoming packets
+		local handle_received_packet = cl.handle_received_packet
+		local count = 0
+		-- replace packet handler; create a new thread for each packet received
+		cl.handle_received_packet = function(mqttdevice, packet)
+			count = count + 1
+			copas.addnamedthread(handle_received_packet, cl.opts.id..":receive_"..count, mqttdevice, packet)
+			return true
+		end
+	end
+
+	-- add keep-alive timer
+	local timer = copas.addnamedthread(function()
+		while client_registry[cl] do
+			local next_check = cl:check_keep_alive()
+			if next_check > 0 then
+				copas.pause(next_check)
+			end
+		end
+	end, cl.opts.id .. ":keep_alive")
+
+	-- add client to connect and listen
+	copas.addnamedthread(function()
+		while client_registry[cl] do
+			local timeout = cl:step()
+			if not timeout then
+				client_registry[cl] = nil -- exiting
+				log:debug("MQTT client '%s' exited, removed from Copas", cl.opts.id)
+				copas.wakeup(timer)
+			else
+				if timeout > 0 then
+					copas.pause(timeout)
+				end
+			end
+		end
+	end, cl.opts.id .. ":listener")
+
+	return true
+end
+
+return setmetatable(_M, {
+	__call = function(self, ...)
+		return self.add(...)
+	end,
+})

controller-host/mqtt/loop/detect.lua

@@ -0,0 +1,30 @@
+--- Module returns a single function to detect the io-loop in use.
+-- Either 'copas', 'nginx', or 'ioloop', or nil+error
+local log = require "mqtt.log"
+
+local loop
+return function()
+	if loop then return loop end
+	if type(ngx) == "table" then
+		-- there is a global 'ngx' table, so we're running OpenResty
+		log:info("LuaMQTT auto-detected Nginx as the runtime environment")
+		loop = "nginx"
+		return loop
+
+	elseif package.loaded.copas then
+		-- 'copas' was already loaded
+		log:info("LuaMQTT auto-detected Copas as the io-loop in use")
+		loop = "copas"
+		return loop
+
+	elseif pcall(require, "socket") and tostring(require("socket")._VERSION):find("LuaSocket") then
+		-- LuaSocket is available
+		log:info("LuaMQTT auto-detected LuaSocket as the socket library to use with mqtt-ioloop")
+		loop = "ioloop"
+		return loop
+
+	else
+		-- unknown
+		return nil, "LuaMQTT io-loop/connector auto-detection failed, please specify one explicitly"
+	end
+end

controller-host/mqtt/loop/init.lua

@@ -0,0 +1,37 @@
+--- Auto detect the IO loop to use.
+-- Interacting with the supported IO loops (ioloop, copas, and nginx) requires
+-- specific implementations to get it right.
+-- This module will auto-detect the environment and return the proper
+-- module from;
+--
+-- * `mqtt.loop.ioloop`
+--
+-- * `mqtt.loop.copas`
+--
+-- * `mqtt.loop.nginx`
+--
+-- Since the selection is based on a.o. packages loaded, make sure that in case
+-- of using the `copas` scheduler, you require it before the `mqtt` modules.
+--
+-- @usage
+-- --local copas = require "copas"   -- only if you use Copas
+-- local mqtt = require "mqtt"
+-- local add_client = require("mqtt.loop").add  -- returns a loop-specific function
+--
+-- local client = mqtt.create { ... options ... }
+-- add_client(client)  -- works for ioloop, copas, and nginx
+--
+-- @module mqtt.loop
+
+local loops = setmetatable({
+	copas = "mqtt.loop.copas",
+	nginx = "mqtt.loop.nginx",
+	ioloop = "mqtt.loop.ioloop"
+}, {
+	__index = function()
+		error("failed to auto-detect connector to use, please set one explicitly", 2)
+	end
+})
+local loop = require("mqtt.loop.detect")()
+
+return require(loops[loop])

controller-host/mqtt/loop/ioloop.lua

@@ -0,0 +1,24 @@
+--- IOloop specific client handling module.
+-- Typically this module is not used directly, but through `mqtt.loop` when
+-- auto-detecting the environment.
+-- @module mqtt.loop.ioloop
+
+local _M = {}
+
+local mqtt = require "mqtt"
+
+--- Add MQTT client to the integrated ioloop.
+-- The client will automatically be removed after it exits.  It will set up a
+-- function to call `Client:check_keep_alive` in the ioloop.
+-- @param client mqtt-client to add to the ioloop
+-- @return `true` on success or `false` and error message on failure
+function _M.add(client)
+	local default_loop = mqtt.get_ioloop()
+	return default_loop:add(client)
+end
+
+return setmetatable(_M, {
+	__call = function(self, ...)
+		return self.add(...)
+	end,
+})

controller-host/mqtt/loop/nginx.lua

@@ -0,0 +1,76 @@
+--- Nginx specific client handling module.
+-- Typically this module is not used directly, but through `mqtt.loop` when
+-- auto-detecting the environment.
+-- @module mqtt.loop.nginx
+
+local client_registry = {}
+
+local _M = {}
+
+
+--- Add MQTT client to the Nginx environment.
+-- The client will automatically be removed after it exits. It will set up a
+-- thread to call `Client:check_keep_alive`.
+-- @param client mqtt-client to add to the Nginx environment
+-- @return `true` on success or `false` and error message on failure
+function _M.add(client)
+	if client_registry[client] then
+		ngx.log(ngx.WARN, "MQTT client '%s' was already added to Nginx", client.opts.id)
+		return false, "MQTT client was already added to Nginx"
+	end
+
+	do -- make mqtt device async for incoming packets
+		local handle_received_packet = client.handle_received_packet
+
+		-- replace packet handler; create a new thread for each packet received
+		client.handle_received_packet = function(mqttdevice, packet)
+			ngx.thread.spawn(handle_received_packet, mqttdevice, packet)
+			return true
+		end
+	end
+
+
+	local ok, err = ngx.timer.at(0, function()
+		-- spawn a thread to listen on the socket
+		local coro = ngx.thread.spawn(function()
+			while true do
+				local sleeptime = client:step()
+				if not sleeptime then
+					ngx.log(ngx.INFO, "MQTT client '", client.opts.id, "' exited, stopping client-thread")
+					client_registry[client] = nil
+					return
+				else
+					if sleeptime > 0 then
+						ngx.sleep(sleeptime * 1000)
+					end
+				end
+			end
+		end)
+
+		-- endless keep-alive loop
+		while not ngx.worker.exiting() do
+			ngx.sleep((client:check_keep_alive())) -- double (()) to trim to 1 argument
+		end
+
+		-- exiting
+		client_registry[client] = nil
+		ngx.log(ngx.DEBUG, "MQTT client '", client.opts.id, "' keep-alive loop exited")
+		client:disconnect()
+		ngx.thread.wait(coro)
+		ngx.log(ngx.DEBUG, "MQTT client '", client.opts.id, "' exit complete")
+	end)
+
+	if not ok then
+		ngx.log(ngx.CRIT, "Failed to start timer-context for device '", client.id,"': ", err)
+		return false, "timer failed: " .. err
+	end
+
+	return true
+end
+
+
+return setmetatable(_M, {
+	__call = function(self, ...)
+		return self.add(...)
+	end,
+})