Handling race conditions when Making History is present.

Source/Scale/PrefabDryCostWriter.cs

@@ -1,51 +1,73 @@
-using TweakScale.Annotations;
-using UnityEngine;
-using System.Linq;
+using System.Linq;
 using System;
+using System.Collections;
+
+using UnityEngine;
+using TweakScale.Annotations;
 
 namespace TweakScale
 {
     [KSPAddon(KSPAddon.Startup.MainMenu, true)]
     internal class PrefabDryCostWriter : SingletonBehavior<PrefabDryCostWriter>
     {
+		private static readonly int WAIT_ROUNDS = 120; // @60fps, would render 2 secs.
+
+		internal static bool isConcluded;
+        private IEnumerator coroutine;
+
         [UsedImplicitly]
         private void Start()
         {
-            WriteDryCost();
+            coroutine = WriteDryCost();
+            StartCoroutine(coroutine);
         }
 
-        private void WriteDryCost()
+        private IEnumerator WriteDryCost()
         {
+            PrefabDryCostWriter.isConcluded = false;
             Debug.Log("TweakScale::WriteDryCost: Started");
+			for (int i = WAIT_ROUNDS; i >= 0 && null == PartLoader.LoadedPartsList && PartLoader.LoadedPartsList.Count < 1; --i)
+			{
+				yield return null;
+				if (0 == i) Debug.LogError("TweakScale::Timeout waiting for PartLoader.LoadedPartsList!!");
+			}
+
             foreach (AvailablePart p in PartLoader.LoadedPartsList)
             {
-				Part prefab = p.partPrefab;
-                if (prefab == null)
+				for (int i = WAIT_ROUNDS; i >= 0 && null == p.partPrefab && null == p.partPrefab.Modules && p.partPrefab.Modules.Count < 1; --i)
                 {
-                    Tools.LogWf("partPrefab is null: " + p.name);
-                    continue;
+					yield return null;
+                    if (0 == i) Debug.LogErrorFormat("TweakScale::Timeout waiting for {0}.prefab.Modules!!", p.name);
+				}
+
+                Part prefab = p.partPrefab;
+
+                // Historically, we had problems here.
+                // However, that co-routine stunt appears to have solved it.
+                // But we will keep this as a ghinea-pig in the case the problem happens again.
+				try 
+				{
+					if (!prefab.Modules.Contains("TweakScale"))
+						continue;
+				}
+                catch (Exception e)
+                {
+                    Debug.LogErrorFormat("[TweakScale] Exception on {0}.prefab.Modules.Contains: {1}", p.name, e);
+					Debug.LogWarningFormat("{0}", prefab.Modules);
+                    continue; // TODO: Cook a way to try again!
                 }
+
                 try
                 {
-                    if (prefab.Modules == null)
-                    {
-                        Tools.LogWf("partPrefab.Modules is null: " + p.name);
-                        continue;
-                    }
-                    if (!prefab.Modules.Contains("TweakScale"))
-                        continue;
-
 					TweakScale m = prefab.Modules["TweakScale"] as TweakScale;
                     m.DryCost = (float)(p.cost - prefab.Resources.Cast<PartResource>().Aggregate(0.0, (a, b) => a + b.maxAmount * b.info.unitCost));
-                    if (prefab.Modules.Contains("FSfuelSwitch"))
-                        m.ignoreResourcesForCost = true;
+					m.ignoreResourcesForCost |= prefab.Modules.Contains("FSfuelSwitch");
 
                     if (m.DryCost < 0)
                     {
                         Debug.LogErrorFormat("TweakScale::PrefabDryCostWriter: negative dryCost: part={0}, DryCost={1}", p.name, m.DryCost);
                         m.DryCost = 0;
                     }
-
 #if DEBUG
 					Debug.LogFormat("Part {0} has drycost {1} with ignoreResourcesForCost {2}", p.name, m.DryCost, m.ignoreResourcesForCost);
 #endif
@@ -56,6 +78,7 @@ private void WriteDryCost()
                 }
             }
             Debug.Log("TweakScale::WriteDryCost: Concluded");
+            PrefabDryCostWriter.isConcluded = true;
         }
     }
 }