Merge pull request #35 from MikaylaFischler/32-mek-api-parallel-exec

32 mek api parallel exec

reactor-plc/startup.lua

@@ -6,12 +6,13 @@ os.loadAPI("scada-common/log.lua")
 os.loadAPI("scada-common/util.lua")
 os.loadAPI("scada-common/ppm.lua")
 os.loadAPI("scada-common/comms.lua")
+os.loadAPI("scada-common/mqueue.lua")
 
 os.loadAPI("config.lua")
 os.loadAPI("plc.lua")
 os.loadAPI("threads.lua")
 
-local R_PLC_VERSION = "alpha-v0.3.3"
+local R_PLC_VERSION = "alpha-v0.4.2"
 
 local print = util.print
 local println = util.println
@@ -28,30 +29,41 @@ ppm.mount_all()
 
 -- shared memory across threads
 local __shared_memory = {
+    -- networked setting
     networked = config.NETWORKED,
 
+    -- PLC system state flags
     plc_state = {
         init_ok = true,
+        shutdown = false,
         scram = true,
         degraded = false,
         no_reactor = false,
         no_modem = false
     },
     
-    plc_devices = {
+    -- core PLC devices
+    plc_dev = {
         reactor = ppm.get_fission_reactor(),
         modem = ppm.get_wireless_modem()
     },
 
-    system = {
+    -- system objects
+    plc_sys = {
         iss = nil,
         plc_comms = nil,
         conn_watchdog = nil
+    },
+
+    -- message queues
+    q = {
+        mq_iss = mqueue.new(),
+        mq_comms = mqueue.new()
     }
 }
 
-local smem_dev = __shared_memory.plc_devices
+local smem_dev = __shared_memory.plc_dev
-local smem_sys = __shared_memory.system
+local smem_sys = __shared_memory.plc_sys
 
 local plc_state = __shared_memory.plc_state
 
@@ -112,12 +124,16 @@ end
 init()
 
 -- init threads
-local main_thread = threads.thread__main(__shared_memory, init)
+local main_thread  = threads.thread__main(__shared_memory, init)
-local iss_thread = threads.thread__iss(__shared_memory)
+local iss_thread   = threads.thread__iss(__shared_memory)
--- local comms_thread = plc.thread__comms(__shared_memory)
+local comms_thread = threads.thread__comms(__shared_memory)
 
 -- run threads
-parallel.waitForAll(main_thread.exec, iss_thread.exec)
+if __shared_memory.networked then
+    parallel.waitForAll(main_thread.exec, iss_thread.exec, comms_thread.exec)
+else
+    parallel.waitForAll(main_thread.exec, iss_thread.exec)
+end
 
 -- send an alarm: plc_comms.send_alarm(ALARMS.PLC_SHUTDOWN) ?
 println_ts("exited")

reactor-plc/threads.lua

@@ -1,6 +1,6 @@
 -- #REQUIRES comms.lua
+-- #REQUIRES log.lua
 -- #REQUIRES ppm.lua
--- #REQUIRES plc.lua
 -- #REQUIRES util.lua
 
 local print = util.print
@@ -8,36 +8,41 @@ local println = util.println
 local print_ts = util.print_ts
 local println_ts = util.println_ts
 
-local async_wait = util.async_wait
+local psleep = util.psleep
 
-local MAIN_CLOCK = 0.5  -- (2Hz, 10 ticks)
+local MAIN_CLOCK  = 1    -- (1Hz, 20 ticks)
-local ISS_CLOCK  = 0.25 -- (4Hz, 5 ticks) however this is AFTER all the ISS checks, so it is a pause between calls, not start-to-start
+local ISS_CLOCK   = 0.5  -- (2Hz, 10 ticks)
+local COMMS_CLOCK = 0.25 -- (4Hz, 5 ticks)
 
-local ISS_EVENT = {
+local MQ__ISS_CMD = {
     SCRAM = 1,
     DEGRADED_SCRAM = 2,
     TRIP_TIMEOUT = 3
 }
 
+local MQ__COMM_CMD = {
+    SEND_STATUS = 1
+}
+
 -- main thread
-function thread__main(shared_memory, init)
+function thread__main(smem, init)
     -- execute thread
     local exec = function ()
+        log._debug("main thread init, clock inactive")
+
         -- send status updates at 2Hz (every 10 server ticks) (every loop tick)
         -- send link requests at 0.5Hz (every 40 server ticks) (every 4 loop ticks)
         local LINK_TICKS = 4
-        
-        local loop_clock = nil
         local ticks_to_update = 0
+        local loop_clock = nil
 
         -- load in from shared memory
-        local networked   = shared_memory.networked
+        local networked     = smem.networked
-        local plc_state   = shared_memory.plc_state
+        local plc_state     = smem.plc_state
-        local plc_devices = shared_memory.plc_devices
+        local plc_dev       = smem.plc_dev
-
+        local iss           = smem.plc_sys.iss
-        local iss           = shared_memory.system.iss
+        local plc_comms     = smem.plc_sys.plc_comms
-        local plc_comms     = shared_memory.system.plc_comms
+        local conn_watchdog = smem.plc_sys.conn_watchdog
-        local conn_watchdog = shared_memory.system.conn_watchdog
 
         -- debug
         local last_update = util.time()
@@ -56,10 +61,7 @@ function thread__main(shared_memory, init)
                     -- send updated data
                     if not plc_state.no_modem then
                         if plc_comms.is_linked() then
-                            async_wait(function () 
+                            smem.q.mq_comms.push_command(MQ__COMM_CMD.SEND_STATUS)
-                                plc_comms.send_status(iss_tripped, plc_state.degraded)
-                                plc_comms.send_iss_status()
-                            end)
                         else
                             if ticks_to_update == 0 then
                                 plc_comms.send_link_req()
@@ -80,15 +82,15 @@ function thread__main(shared_memory, init)
                 -- feed the watchdog first so it doesn't uhh...eat our packets
                 conn_watchdog.feed()
 
-                -- handle the packet (plc_state passed to allow clearing SCRAM flag)
+                -- handle the packet
-                async_wait(function () 
+                local packet = plc_comms.parse_packet(param1, param2, param3, param4, param5)
-                    local packet = plc_comms.parse_packet(param1, param2, param3, param4, param5)
+                if packet ~= nil then
-                    plc_comms.handle_packet(packet, plc_state) 
+                    smem.q.mq_comms.push_packet(packet)
-                end)
+                end
             elseif event == "timer" and networked and param1 == conn_watchdog.get_timer() then
                 -- haven't heard from server recently? shutdown reactor
                 plc_comms.unlink()
-                os.queueEvent("iss_command", ISS_EVENT.TRIP_TIMEOUT)
+                smem.q.mq_iss.push_command(MQ__ISS_CMD.TRIP_TIMEOUT)
             elseif event == "peripheral_detach" then
                 -- peripheral disconnect
                 local device = ppm.handle_unmount(param1)
@@ -108,7 +110,7 @@ function thread__main(shared_memory, init)
 
                         if plc_state.init_ok then
                             -- try to scram reactor if it is still connected
-                            os.queueEvent("iss_command", ISS_EVENT.DEGRADED_SCRAM)
+                            smem.q.mq_iss.push_command(MQ__ISS_CMD.DEGRADED_SCRAM)
                         end
 
                         plc_state.degraded = true
@@ -122,18 +124,18 @@ function thread__main(shared_memory, init)
 
                 if type == "fissionReactor" then
                     -- reconnected reactor
-                    plc_devices.reactor = device
+                    plc_dev.reactor = device
 
-                    os.queueEvent("iss_command", ISS_EVENT.SCRAM)
+                    smem.q.mq_iss.push_command(MQ__ISS_CMD.SCRAM)
 
                     println_ts("reactor reconnected.")
                     log._info("reactor reconnected.")
                     plc_state.no_reactor = false
 
                     if plc_state.init_ok then
-                        iss.reconnect_reactor(plc_devices.reactor)
+                        iss.reconnect_reactor(plc_dev.reactor)
                         if networked then
-                            plc_comms.reconnect_reactor(plc_devices.reactor)
+                            plc_comms.reconnect_reactor(plc_dev.reactor)
                         end
                     end
 
@@ -144,10 +146,10 @@ function thread__main(shared_memory, init)
                 elseif networked and type == "modem" then
                     if device.isWireless() then
                         -- reconnected modem
-                        plc_devices.modem = device
+                        plc_dev.modem = device
 
                         if plc_state.init_ok then
-                            plc_comms.reconnect_modem(plc_devices.modem)
+                            plc_comms.reconnect_modem(plc_dev.modem)
                         end
 
                         println_ts("wireless modem reconnected.")
@@ -170,12 +172,13 @@ function thread__main(shared_memory, init)
             elseif event == "clock_start" then
                 -- start loop clock
                 loop_clock = os.startTimer(MAIN_CLOCK)
-                log._debug("main thread started")
+                log._debug("main thread clock started")
             end
 
             -- check for termination request
             if event == "terminate" or ppm.should_terminate() then
                 -- iss handles reactor shutdown
+                plc_state.shutdown = true
                 log._warning("terminate requested, main thread exiting")
                 break
             end
@@ -186,80 +189,68 @@ function thread__main(shared_memory, init)
 end
 
 -- ISS monitor thread
-function thread__iss(shared_memory)
+function thread__iss(smem)
     -- execute thread
     local exec = function ()
-        local loop_clock = nil
+        log._debug("iss thread start")
 
         -- load in from shared memory
-        local networked   = shared_memory.networked
+        local networked   = smem.networked
-        local plc_state   = shared_memory.plc_state
+        local plc_state   = smem.plc_state
-        local plc_devices = shared_memory.plc_devices
+        local plc_dev     = smem.plc_dev
+        local iss         = smem.plc_sys.iss
+        local plc_comms   = smem.plc_sys.plc_comms
 
-        local iss         = shared_memory.system.iss
+        local iss_queue   = smem.q.mq_iss
-        local plc_comms   = shared_memory.system.plc_comms
 
-        -- debug
+        local last_update = util.time()
-        -- local last_update = util.time()
 
-        -- event loop
+        -- thread loop
         while true do
-            local event, param1, param2, param3, param4, param5 = os.pullEventRaw()
+            local reactor = smem.plc_dev.reactor
             
-            local reactor = shared_memory.plc_devices.reactor
+            -- ISS checks
-    
+            if plc_state.init_ok then
-            if event == "timer" and param1 == loop_clock then
+                -- if we tried to SCRAM but failed, keep trying
-                -- ISS checks
+                -- in that case, SCRAM won't be called until it reconnects (this is the expected use of this check)
-                if plc_state.init_ok then
+                if not plc_state.no_reactor and plc_state.scram and reactor.getStatus() then
-                    -- if we tried to SCRAM but failed, keep trying
+                    reactor.scram()
-                    -- in that case, SCRAM won't be called until it reconnects (this is the expected use of this check)
-                    async_wait(function ()
-                        if not plc_state.no_reactor and plc_state.scram and reactor.getStatus() then
-                            reactor.scram()
-                        end
-                    end)
-
-                    -- if we are in standalone mode, continuously reset ISS
-                    -- ISS will trip again if there are faults, but if it isn't cleared, the user can't re-enable
-                    if not networked then
-                        plc_state.scram = false
-                        iss.reset()
-                    end
-
-                    -- check safety (SCRAM occurs if tripped)
-                    async_wait(function () 
-                        if not plc_state.degraded then
-                            local iss_tripped, iss_status_string, iss_first = iss.check()
-                            plc_state.scram = plc_state.scram or iss_tripped
-    
-                            if iss_first then
-                                println_ts("[ISS] SCRAM! safety trip: " .. iss_status_string)
-                                if networked then
-                                    plc_comms.send_iss_alarm(iss_status_string)
-                                end
-                            end
-                        end
-                    end)
                 end
 
-                -- start next clock timer after all the long operations
+                -- if we are in standalone mode, continuously reset ISS
-                -- otherwise we will never get around to other events
+                -- ISS will trip again if there are faults, but if it isn't cleared, the user can't re-enable
-                loop_clock = os.startTimer(ISS_CLOCK)
+                if not networked then
+                    plc_state.scram = false
+                    iss.reset()
+                end
 
-                -- debug
+                -- check safety (SCRAM occurs if tripped)
-                -- print(util.time() - last_update)
+                if not plc_state.degraded then
-                -- println("ms")
+                    local iss_tripped, iss_status_string, iss_first = iss.check()
-                -- last_update = util.time()
+                    plc_state.scram = plc_state.scram or iss_tripped
-            elseif event == "iss_command" then
+
-                -- handle ISS commands
+                    if iss_first then
-                if param1 == ISS_EVENT.SCRAM then
+                        println_ts("[ISS] SCRAM! safety trip: " .. iss_status_string)
-                    -- basic SCRAM
+                        if networked then
-                    plc_state.scram = true
+                            plc_comms.send_iss_alarm(iss_status_string)
-                    async_wait(reactor.scram)
+                        end
-                elseif param1 == ISS_EVENT.DEGRADED_SCRAM then
+                    end
-                    -- SCRAM with print
+                end
-                    plc_state.scram = true
+            end
-                    async_wait(function () 
+        
+            -- check for messages in the message queue
+            while iss_queue.ready() do
+                local msg = iss_queue.pop()
+
+                if msg.qtype == mqueue.TYPE.COMMAND then
+                    -- received a command
+                    if msg.message == MQ__ISS_CMD.SCRAM then
+                        -- basic SCRAM
+                        plc_state.scram = true
+                        reactor.scram()
+                    elseif msg.message == MQ__ISS_CMD.DEGRADED_SCRAM then
+                        -- SCRAM with print
+                        plc_state.scram = true
                         if reactor.scram() then
                             println_ts("successful reactor SCRAM")
                             log._error("successful reactor SCRAM")
@@ -267,36 +258,115 @@ function thread__iss(shared_memory)
                             println_ts("failed reactor SCRAM")
                             log._error("failed reactor SCRAM")
                         end
-                    end)
+                    elseif msg.message == MQ__ISS_CMD.TRIP_TIMEOUT then
-                elseif param1 == ISS_EVENT.TRIP_TIMEOUT then
+                        -- watchdog tripped
-                    -- watchdog tripped
+                        plc_state.scram = true
-                    plc_state.scram = true
+                        iss.trip_timeout()
-                    iss.trip_timeout()
+                        println_ts("server timeout")
-                    println_ts("server timeout")
+                        log._warning("server timeout")
-                    log._warning("server timeout")
+                    end
+                elseif msg.qtype == mqueue.TYPE.DATA then
+                    -- received data
+                elseif msg.qtype == mqueue.TYPE.PACKET then
+                    -- received a packet
                 end
-            elseif event == "clock_start" then
+
-                -- start loop clock
+                -- quick yield if we are looping right back
-                loop_clock = os.startTimer(ISS_CLOCK)
+                if iss_queue.ready() then util.nop() end
-                log._debug("iss thread started")
             end
 
             -- check for termination request
-            if event == "terminate" or ppm.should_terminate() then
+            if plc_state.shutdown then
                 -- safe exit
-                log._warning("terminate requested, iss thread shutdown")
+                log._warning("iss thread shutdown initiated")
                 if plc_state.init_ok then
                     plc_state.scram = true
-                    async_wait(reactor.scram)
+                    reactor.scram()
                     if reactor.__p_is_ok() then
                         println_ts("reactor disabled")
+                        log._info("iss thread reactor SCRAM OK")
                     else
                         -- send an alarm: plc_comms.send_alarm(ALARMS.PLC_LOST_CONTROL) ?
                         println_ts("exiting, reactor failed to disable")
+                        log._error("iss thread failed to SCRAM reactor on exit")
                     end
                 end
+                log._warning("iss thread exiting")
                 break
             end
+
+            -- debug
+            -- print(util.time() - last_update)
+            -- println("ms")
+            -- last_update = util.time()
+
+            -- delay before next check
+            local sleep_for = ISS_CLOCK - (util.time() - last_update)
+            last_update = util.time()
+            if sleep_for > 0 then
+                psleep(sleep_for)
+            else
+                psleep(0.05)
+            end
+        end
+    end
+
+    return { exec = exec }
+end
+
+-- communications handler thread
+function thread__comms(smem)
+    -- execute thread
+    local exec = function ()
+        log._debug("comms thread start")
+
+        -- load in from shared memory
+        local plc_state   = smem.plc_state
+        local plc_comms   = smem.plc_sys.plc_comms
+
+        local comms_queue = smem.q.mq_comms
+
+        local last_update = util.time()
+
+        -- thread loop
+        while true do
+            -- check for messages in the message queue
+            while comms_queue.ready() do
+                local msg = comms_queue.pop()
+
+                if msg.qtype == mqueue.TYPE.COMMAND then
+                    -- received a command
+                    if msg.message == MQ__COMM_CMD.SEND_STATUS then
+                        -- send PLC/ISS status
+                        plc_comms.send_status(plc_state.degraded)
+                        plc_comms.send_iss_status()
+                    end
+                elseif msg.qtype == mqueue.TYPE.DATA then
+                    -- received data
+                elseif msg.qtype == mqueue.TYPE.PACKET then
+                    -- received a packet
+                    -- handle the packet (plc_state passed to allow clearing SCRAM flag)
+                    plc_comms.handle_packet(msg.message, plc_state) 
+                end
+
+                -- quick yield if we are looping right back
+                if comms_queue.ready() then util.nop() end
+            end
+
+            -- check for termination request
+            if plc_state.shutdown then
+                log._warning("comms thread exiting")
+                break
+            end
+
+            -- delay before next check
+            local sleep_for = COMMS_CLOCK - (util.time() - last_update)
+            last_update = util.time()
+            if sleep_for > 0 then
+                psleep(sleep_for)
+            else
+                psleep(0.05)
+            end
         end
     end
 

rtu/rtu.lua

@@ -183,7 +183,7 @@ function rtu_comms(modem, local_port, server_port)
     end
 
     -- handle a MODBUS/SCADA packet
-    local handle_packet = function(packet, units, ref)
+    local handle_packet = function(packet, units, rtu_state)
         if packet ~= nil then
             local protocol = packet.scada_frame.protocol()
 
@@ -209,7 +209,7 @@ function rtu_comms(modem, local_port, server_port)
                 -- SCADA management packet
                 if packet.type == SCADA_MGMT_TYPES.REMOTE_LINKED then
                     -- acknowledgement
-                    ref.linked = true
+                    rtu_state.linked = true
                 elseif packet.type == SCADA_MGMT_TYPES.RTU_ADVERT then
                     -- request for capabilities again
                     send_advertisement(units)

rtu/startup.lua

@@ -6,26 +6,26 @@ os.loadAPI("scada-common/log.lua")
 os.loadAPI("scada-common/util.lua")
 os.loadAPI("scada-common/ppm.lua")
 os.loadAPI("scada-common/comms.lua")
+os.loadAPI("scada-common/mqueue.lua")
 os.loadAPI("scada-common/modbus.lua")
 os.loadAPI("scada-common/rsio.lua")
 
 os.loadAPI("config.lua")
 os.loadAPI("rtu.lua")
+os.loadAPI("threads.lua")
 
 os.loadAPI("dev/redstone_rtu.lua")
 os.loadAPI("dev/boiler_rtu.lua")
 os.loadAPI("dev/imatrix_rtu.lua")
 os.loadAPI("dev/turbine_rtu.lua")
 
-local RTU_VERSION = "alpha-v0.3.2"
+local RTU_VERSION = "alpha-v0.4.2"
 
 local print = util.print
 local println = util.println
 local print_ts = util.print_ts
 local println_ts = util.println_ts
 
-local async_wait = util.async_wait
-
 log._info("========================================")
 log._info("BOOTING rtu.startup " .. RTU_VERSION)
 log._info("========================================")
@@ -35,26 +35,51 @@ println(">> RTU " .. RTU_VERSION .. " <<")
 -- startup
 ----------------------------------------
 
-local units = {}
-local linked = false
-
 -- mount connected devices
 ppm.mount_all()
 
+local __shared_memory = {
+    -- RTU system state flags
+    rtu_state = {
+        linked = false,
+        shutdown = false
+    },
+
+    -- core RTU devices
+    rtu_dev = {
+        modem = ppm.get_wireless_modem()
+    },
+
+    -- system objects
+    rtu_sys = {
+        rtu_comms = nil,
+        units = {}
+    },
+
+    -- message queues
+    q = {
+        mq_comms = mqueue.new()
+    }
+}
+
+local smem_dev = __shared_memory.rtu_dev
+local smem_sys = __shared_memory.rtu_sys
+
 -- get modem
-local modem = ppm.get_wireless_modem()
+if smem_dev.modem == nil then
-if modem == nil then
     println("boot> wireless modem not found")
     log._warning("no wireless modem on startup")
     return
 end
 
-local rtu_comms = rtu.rtu_comms(modem, config.LISTEN_PORT, config.SERVER_PORT)
+smem_sys.rtu_comms = rtu.rtu_comms(smem_dev.modem, config.LISTEN_PORT, config.SERVER_PORT)
 
 ----------------------------------------
--- determine configuration
+-- interpret config and init units
 ----------------------------------------
 
+local units = __shared_memory.rtu_sys.units
+
 local rtu_redstone = config.RTU_REDSTONE
 local rtu_devices = config.RTU_DEVICES
 
@@ -69,12 +94,12 @@ for reactor_idx = 1, #rtu_redstone do
 
     for i = 1, #io_table do
         local valid = false
-        local config = io_table[i]
+        local conf = io_table[i]
 
         -- verify configuration
-        if rsio.is_valid_channel(config.channel) and rsio.is_valid_side(config.side) then
+        if rsio.is_valid_channel(conf.channel) and rsio.is_valid_side(conf.side) then
-            if config.bundled_color then
+            if conf.bundled_color then
-                valid = rsio.is_color(config.bundled_color)
+                valid = rsio.is_color(conf.bundled_color)
             else
                 valid = true
             end
@@ -87,24 +112,24 @@ for reactor_idx = 1, #rtu_redstone do
             log._warning(message)
         else
             -- link redstone in RTU
-            local mode = rsio.get_io_mode(config.channel)
+            local mode = rsio.get_io_mode(conf.channel)
             if mode == rsio.IO_MODE.DIGITAL_IN then
-                rs_rtu.link_di(config.channel, config.side, config.bundled_color)
+                rs_rtu.link_di(conf.channel, conf.side, conf.bundled_color)
             elseif mode == rsio.IO_MODE.DIGITAL_OUT then
-                rs_rtu.link_do(config.channel, config.side, config.bundled_color)
+                rs_rtu.link_do(conf.channel, conf.side, conf.bundled_color)
             elseif mode == rsio.IO_MODE.ANALOG_IN then
-                rs_rtu.link_ai(config.channel, config.side)
+                rs_rtu.link_ai(conf.channel, conf.side)
             elseif mode == rsio.IO_MODE.ANALOG_OUT then
-                rs_rtu.link_ao(config.channel, config.side)
+                rs_rtu.link_ao(conf.channel, conf.side)
             else
                 -- should be unreachable code, we already validated channels
                 log._error("init> fell through if chain attempting to identify IO mode", true)
                 break
             end
 
-            table.insert(capabilities, config.channel)
+            table.insert(capabilities, conf.channel)
 
-            log._debug("init> linked redstone " .. #capabilities .. ": " .. rsio.to_string(config.channel) .. " (" .. config.side ..
+            log._debug("init> linked redstone " .. #capabilities .. ": " .. rsio.to_string(conf.channel) .. " (" .. conf.side ..
                 ") for reactor " .. rtu_redstone[reactor_idx].for_reactor)
         end
     end
@@ -171,82 +196,15 @@ for i = 1, #rtu_devices do
 end
 
 ----------------------------------------
--- main loop
+-- start system
 ----------------------------------------
 
--- advertisement/heartbeat clock (every 2 seconds)
+-- init threads
-local loop_clock = os.startTimer(2)
+local main_thread  = threads.thread__main(__shared_memory)
+local comms_thread = threads.thread__comms(__shared_memory)
 
--- event loop
+-- run threads
-while true do
+parallel.waitForAll(main_thread.exec, comms_thread.exec)
-    local event, param1, param2, param3, param4, param5 = os.pullEventRaw()
-
-    if event == "peripheral_detach" then
-        -- handle loss of a device
-        local device = ppm.handle_unmount(param1)
-
-        for i = 1, #units do
-            -- find disconnected device
-            if units[i].device == device.dev then
-                -- we are going to let the PPM prevent crashes
-                -- return fault flags/codes to MODBUS queries
-                local unit = units[i]
-                println_ts("lost the " .. unit.type .. " on interface " .. unit.name)
-            end
-        end
-    elseif event == "peripheral" then
-        -- relink lost peripheral to correct unit entry
-        local type, device = ppm.mount(param1)
-
-        for i = 1, #units do
-            local unit = units[i]
-
-            -- find disconnected device to reconnect
-            if unit.name == param1 then
-                -- found, re-link
-                unit.device = device
-
-                if unit.type == "boiler" then
-                    unit.rtu = boiler_rtu.new(device)
-                elseif unit.type == "turbine" then
-                    unit.rtu = turbine_rtu.new(device)
-                elseif unit.type == "imatrix" then
-                    unit.rtu = imatrix_rtu.new(device)
-                end
-
-                unit.modbus_io = modbus.new(unit.rtu)
-
-                println_ts("reconnected the " .. unit.type .. " on interface " .. unit.name)
-            end
-        end
-    elseif event == "timer" and param1 == loop_clock then
-        -- start next clock timer
-        loop_clock = os.startTimer(2)
-
-        -- period tick, if we are linked send heartbeat, if not send advertisement
-        if linked then
-            rtu_comms.send_heartbeat()
-        else
-            -- advertise units
-            rtu_comms.send_advertisement(units)
-        end
-    elseif event == "modem_message" then
-        -- got a packet
-        local link_ref = { linked = linked }
-        local packet = rtu_comms.parse_packet(param1, param2, param3, param4, param5)
-
-        async_wait(function () rtu_comms.handle_packet(packet, units, link_ref) end)
-
-        -- if linked, stop sending advertisements
-        linked = link_ref.linked
-    end
-
-    -- check for termination request
-    if event == "terminate" or ppm.should_terminate() then
-        log._warning("terminate requested, exiting...")
-        break
-    end
-end
 
 println_ts("exited")
 log._info("exited")

rtu/threads.lua

@@ -0,0 +1,159 @@
+-- #REQUIRES comms.lua
+-- #REQUIRES log.lua
+-- #REQUIRES ppm.lua
+-- #REQUIRES util.lua
+
+local print = util.print
+local println = util.println
+local print_ts = util.print_ts
+local println_ts = util.println_ts
+
+local psleep = util.psleep
+
+local MAIN_CLOCK = 2 -- (2Hz, 40 ticks)
+local COMMS_CLOCK = 0.25 -- (4Hz, 5 ticks)
+
+-- main thread
+function thread__main(smem)
+    -- execute thread
+    local exec = function ()
+        log._debug("main thread start")
+
+        -- advertisement/heartbeat clock
+        local loop_clock = os.startTimer(MAIN_CLOCK)
+
+        -- load in from shared memory
+        local rtu_state = smem.rtu_state
+        local rtu_dev   = smem.rtu_dev
+        local rtu_comms = smem.rtu_sys.rtu_comms
+        local units     = smem.rtu_sys.units
+
+        -- event loop
+        while true do
+            local event, param1, param2, param3, param4, param5 = os.pullEventRaw()
+
+            if event == "peripheral_detach" then
+                -- handle loss of a device
+                local device = ppm.handle_unmount(param1)
+
+                for i = 1, #units do
+                    -- find disconnected device
+                    if units[i].device == device.dev then
+                        -- we are going to let the PPM prevent crashes
+                        -- return fault flags/codes to MODBUS queries
+                        local unit = units[i]
+                        println_ts("lost the " .. unit.type .. " on interface " .. unit.name)
+                    end
+                end
+            elseif event == "peripheral" then
+                -- relink lost peripheral to correct unit entry
+                local type, device = ppm.mount(param1)
+
+                for i = 1, #units do
+                    local unit = units[i]
+
+                    -- find disconnected device to reconnect
+                    if unit.name == param1 then
+                        -- found, re-link
+                        unit.device = device
+
+                        if unit.type == "boiler" then
+                            unit.rtu = boiler_rtu.new(device)
+                        elseif unit.type == "turbine" then
+                            unit.rtu = turbine_rtu.new(device)
+                        elseif unit.type == "imatrix" then
+                            unit.rtu = imatrix_rtu.new(device)
+                        end
+
+                        unit.modbus_io = modbus.new(unit.rtu)
+
+                        println_ts("reconnected the " .. unit.type .. " on interface " .. unit.name)
+                    end
+                end
+            elseif event == "timer" and param1 == loop_clock then
+                -- start next clock timer
+                loop_clock = os.startTimer(MAIN_CLOCK)
+
+                -- period tick, if we are linked send heartbeat, if not send advertisement
+                if rtu_state.linked then
+                    rtu_comms.send_heartbeat()
+                else
+                    -- advertise units
+                    rtu_comms.send_advertisement(units)
+                end
+            elseif event == "modem_message" then
+                -- got a packet
+                local packet = rtu_comms.parse_packet(param1, param2, param3, param4, param5)
+                if packet ~= nil then
+                    smem.q.mq_comms.push_packet(packet)
+                end
+
+                rtu_comms.handle_packet(packet, units, link_ref)
+            end
+
+            -- check for termination request
+            if event == "terminate" or ppm.should_terminate() then
+                rtu_state.shutdown = true
+                log._warning("terminate requested, main thread exiting")
+                break
+            end
+        end
+    end
+
+    return { exec = exec }
+end
+
+-- communications handler thread
+function thread__comms(smem)
+    -- execute thread
+    local exec = function ()
+        log._debug("comms thread start")
+
+        -- load in from shared memory
+        local rtu_state   = smem.rtu_state
+        local rtu_comms   = smem.rtu_sys.rtu_comms
+        local units       = smem.rtu_sys.units
+
+        local comms_queue = smem.q.mq_comms
+
+        local last_update = util.time()
+
+        -- thread loop
+        while true do
+            -- check for messages in the message queue
+            while comms_queue.ready() do
+                local msg = comms_queue.pop()
+
+                if msg.qtype == mqueue.TYPE.COMMAND then
+                    -- received a command
+                elseif msg.qtype == mqueue.TYPE.DATA then
+                    -- received data
+                elseif msg.qtype == mqueue.TYPE.PACKET then
+                    -- received a packet
+                    -- handle the packet (rtu_state passed to allow setting link flag)
+                    rtu_comms.handle_packet(msg.message, units, rtu_state) 
+                end
+
+                -- quick yield if we are looping right back
+                if comms_queue.ready() then util.nop() end
+            end
+
+            -- check for termination request
+            if rtu_state.shutdown then
+                log._warning("comms thread exiting")
+                break
+            end
+
+            -- delay before next check
+            local sleep_for = COMMS_CLOCK - (util.time() - last_update)
+            last_update = util.time()
+            if sleep_for > 0 then
+                psleep(sleep_for)
+            else
+                psleep(0.05)
+            end
+        end
+    end
+
+    return { exec = exec }
+end

scada-common/mqueue.lua

@@ -4,7 +4,8 @@
 
 TYPE = {
     COMMAND = 0,
-    PACKET = 1
+    DATA = 1,
+    PACKET = 2
 }
 
 function new()
@@ -18,18 +19,26 @@ function new()
         return #queue == 0
     end
 
+    local ready = function ()
+        return #queue > 0
+    end
+    
     local _push = function (qtype, message)
         table.insert(queue, { qtype = qtype, message = message })
     end
     
-    local push_packet = function (message)
-        _push(TYPE.PACKET, message)
-    end
-    
     local push_command = function (message)
         _push(TYPE.COMMAND, message)
     end
 
+    local push_data = function (message)
+        _push(TYPE.DATA, message)
+    end
+
+    local push_packet = function (message)
+        _push(TYPE.PACKET, message)
+    end
+
     local pop = function ()
         if #queue > 0 then
             return table.remove(queue)
@@ -41,7 +50,9 @@ function new()
     return {
         length = length,
         empty = empty,
+        ready = ready,
         push_packet = push_packet,
+        push_data = push_data,
         push_command = push_command,
         pop = pop
     }

scada-common/util.lua

@@ -39,9 +39,10 @@ end
 
 -- PARALLELIZATION --
 
--- block waiting for parallel call
+-- no-op to provide a brief pause (and a yield)
-function async_wait(f)
+-- EVENT_CONSUMER: this function consumes events
-    parallel.waitForAll(f)
+function nop()
+    sleep(0.05)
 end
 
 -- WATCHDOG --

supervisor/session/plc.lua

@@ -330,7 +330,7 @@ function new_session(id, for_reactor, in_queue, out_queue)
             -- handle queue --
             ------------------
 
-            if not self.in_q.empty() then
+            if self.in_q.ready() then
                 -- get a new message to process
                 local message = self.in_q.pop()
 

supervisor/session/svsessions.lua

@@ -130,7 +130,7 @@ local function _iterate(sessions)
             if ok then
                 -- send packets in out queue
                 -- @todo handle commands if that's being used too
-                while not session.out_queue.empty() do
+                while session.out_queue.ready() do
                     local msg = session.out_queue.pop()
                     if msg.qtype == mqueue.TYPE.PACKET then
                         self.modem.transmit(session.r_port, session.l_port, msg.message.raw_sendable())

supervisor/startup.lua

@@ -7,9 +7,9 @@ os.loadAPI("scada-common/util.lua")
 os.loadAPI("scada-common/ppm.lua")
 os.loadAPI("scada-common/comms.lua")
 os.loadAPI("scada-common/modbus.lua")
+os.loadAPI("scada-common/mqueue.lua")
 
 os.loadAPI("config.lua")
-os.loadAPI("mqueue.lua")
 
 os.loadAPI("session/rtu.lua")
 os.loadAPI("session/plc.lua")
@@ -18,7 +18,7 @@ os.loadAPI("session/svsessions.lua")
 
 os.loadAPI("supervisor.lua")
 
-local SUPERVISOR_VERSION = "alpha-v0.1.5"
+local SUPERVISOR_VERSION = "alpha-v0.1.6"
 
 local print = util.print
 local println = util.println