added util adaptive_delay to replace repeated code

reactor-plc/threads.lua

@@ -287,12 +287,8 @@ function thread__iss(smem)
                 break
             end
 
-            -- delay before next check, only if >50ms since we did already yield
+            -- delay before next check
-            local sleep_for = ISS_SLEEP - (util.time() - last_update)
+            last_update = util.adaptive_delay(ISS_SLEEP, last_update)
-            last_update = util.time()
-            if sleep_for >= 50 then
-                psleep(sleep_for / 1000.0)
-            end
         end
     end
 
@@ -344,12 +340,8 @@ function thread__comms(smem)
                 break
             end
 
-            -- delay before next check, only if >50ms since we did already yield
+            -- delay before next check
-            local sleep_for = COMMS_SLEEP - (util.time() - last_update)
+            last_update = util.adaptive_delay(COMMS_SLEEP, last_update)
-            last_update = util.time()
-            if sleep_for >= 50 then
-                psleep(sleep_for / 1000.0)
-            end
         end
     end
 

rtu/threads.lua

@@ -144,12 +144,8 @@ function thread__comms(smem)
                 break
             end
 
-            -- delay before next check, only if >50ms since we did already yield
+            -- delay before next check
-            local sleep_for = COMMS_SLEEP - (util.time() - last_update)
+            last_update = util.adaptive_delay(COMMS_SLEEP, last_update)
-            last_update = util.time()
-            if sleep_for >= 50 then
-                psleep(sleep_for / 1000.0)
-            end
         end
     end
 

scada-common/util.lua

@@ -50,6 +50,16 @@ function nop()
     psleep(0.05)
 end
 
+-- attempt to maintain a minimum loop timing (duration of execution)
+function adaptive_delay(target_timing, last_update)
+    local sleep_for = target_timing - (time() - last_update)
+    -- only if >50ms since worker loops already yield 0.05s
+    if sleep_for >= 50 then
+        psleep(sleep_for / 1000.0)
+    end
+    return time()
+end
+
 -- WATCHDOG --
 
 -- ComputerCraft OS Timer based Watchdog