Fixed 2 issues

Fixed an issue causing gap.update crashes the game(engine issue)
Fixed an potential issue that on MacOS we cannot get core count and cause MaxDegreeOfParallelism will be set to 0. Now if we cant get that number we simply use a fixed 16 instead

Barotrauma/BarotraumaShared/SharedSource/Map/MapEntity.cs

@@ -646,13 +646,17 @@ namespace Barotrauma
             var sw = new System.Diagnostics.Stopwatch();
             sw.Start();
 #endif
-
             // Buffer lists to avoid repeated allocations
             var hullList = Hull.HullList.ToList();
             var structureList = Structure.WallList.ToList();
             var gapList = Gap.GapList.ToList();
             var itemList = Item.ItemList.ToList();
 
+            Parallel.ForEach(gapList, parallelOptions, gap =>
+            {
+                gap.ResetWaterFlowThisFrame();
+            });
+
             // First phase: parallel updates that have no order dependencies
             Parallel.Invoke(parallelOptions,
                 () =>
@@ -674,10 +678,13 @@ namespace Barotrauma
                 // Gap reset (must be done before update)
                 () =>
                 {
-                    Parallel.ForEach(gapList, parallelOptions, gap =>
+                    // Gap update (has order dependencies, keep random order but execute sequentially)
+                    var shuffledGaps = gapList.OrderBy(g => Rand.Int(int.MaxValue)).ToList();
+                    foreach (var gap in shuffledGaps)
                     {
-                        gap.ResetWaterFlowThisFrame();
+                        gap.Update(deltaTime, cam);
-                    });
+                    }
+
                 },
                 // Powered components update
                 () =>
@@ -689,16 +696,6 @@ namespace Barotrauma
 #if CLIENT
             // Hull Cheats need to be executed after Hull update
             Hull.UpdateCheats(deltaTime, cam);
-#endif
-
-            // Gap update (has order dependencies, keep random order but execute sequentially)
-            var shuffledGaps = gapList.OrderBy(g => Rand.Int(int.MaxValue)).ToList();
-            Parallel.ForEach(gapList, parallelOptions, gap =>
-            {
-                gap.Update(deltaTime, cam);
-            });
-
-#if CLIENT
             sw.Stop();
             GameMain.PerformanceCounter.AddElapsedTicks("Update:MapEntity:Misc", sw.ElapsedTicks);
             sw.Restart();

Barotrauma/BarotraumaShared/SharedSource/Screens/GameScreen.cs

@@ -25,7 +25,7 @@ namespace Barotrauma
 
         private static readonly ParallelOptions parallelOptions = new ParallelOptions
         {
-            MaxDegreeOfParallelism = Environment.ProcessorCount * 2,
+            MaxDegreeOfParallelism = Environment.ProcessorCount > 0 ? Environment.ProcessorCount  * 2 : 16,
         };
 
 #if CLIENT