#247 renamed tcallbackdsp to tcd and added handler to RTU

scada-common/tcd.lua

@@ -0,0 +1,85 @@
+--
+-- Timer Callback Dispatcher
+--
+
+local log  = require("scada-common.log")
+local util = require("scada-common.util")
+
+local tcd = {}
+
+local registry = {}
+
+-- request a function to be called after the specified time
+---@param time number seconds
+---@param f function callback function
+function tcd.dispatch(time, f)
+    local timer = util.start_timer(time)
+    registry[timer] = {
+        callback = f,
+        duration = time,
+        expiry = time + util.time_s()
+    }
+end
+
+-- request a function to be called after the specified time, aborting any registered instances of that function reference
+---@param time number seconds
+---@param f function callback function
+function tcd.dispatch_unique(time, f)
+    -- cancel if already registered
+    for timer, entry in pairs(registry) do
+        if entry.callback == f then
+            -- found an instance of this function reference, abort it
+            log.debug(util.c("TCD: aborting duplicate timer callback [timer: ", timer, ", ", f, "]"))
+
+            -- cancel event and remove from registry (even if it fires it won't call)
+            util.cancel_timer(timer)
+            registry[timer] = nil
+        end
+    end
+
+    local timer = util.start_timer(time)
+    registry[timer] = {
+        callback = f,
+        duration = time,
+        expiry = time + util.time_s()
+    }
+end
+
+-- abort a requested callback
+---@param f function callback function
+function tcd.abort(f)
+    for timer, entry in pairs(registry) do
+        if entry.callback == f then
+            -- cancel event and remove from registry (even if it fires it won't call)
+            util.cancel_timer(timer)
+            registry[timer] = nil
+        end
+    end
+end
+
+-- lookup a timer event and execute the callback if found
+---@param event integer timer event timer ID
+function tcd.handle(event)
+    if registry[event] ~= nil then
+        local callback = registry[event].callback
+        -- clear first so that dispatch_unique call from inside callback won't throw a debug message
+        registry[event] = nil
+        callback()
+    end
+end
+
+-- identify any overdo callbacks<br>
+-- prints to log debug output
+function tcd.diagnostics()
+    for timer, entry in pairs(registry) do
+        if entry.expiry < util.time_s() then
+            local overtime = util.time_s() - entry.expiry
+            log.debug(util.c("TCD: unserviced timer ", timer, " for callback ", entry.callback, " is at least ", overtime, "s late"))
+        else
+            local time = entry.expiry - util.time_s()
+            log.debug(util.c("TCD: pending timer ", timer, " for callback ", entry.callback, " (call after ", entry.duration, "s, expires ", time, ")"))
+        end
+    end
+end
+
+return tcd