potential thread hanging fix

src/main/java/electrosphere/engine/threads/ThreadManager.java

@@ -12,7 +12,9 @@ import electrosphere.engine.loadingthreads.LoadingThread;
 import electrosphere.engine.threads.LabeledThread.ThreadLabel;
 import electrosphere.entity.types.terrain.BlockChunkEntity;
 import electrosphere.entity.types.terrain.TerrainChunk;
+import electrosphere.server.ai.services.PathfindingService;
 import electrosphere.server.datacell.Realm;
+import electrosphere.server.datacell.gridded.GriddedDataCellLoaderService;
 import electrosphere.util.CodeUtils;
 
 /**
@@ -134,9 +136,8 @@ public class ThreadManager {
         TerrainChunk.haltThreads();
         FoliageModel.haltThreads();
         BlockChunkEntity.haltThreads();
-        if(Globals.aiManager != null && Globals.aiManager.getPathfindingService() != null){
-            Globals.aiManager.getPathfindingService().shutdown();
-        }
+        GriddedDataCellLoaderService.haltThreads();
+        PathfindingService.haltThreads();
 
         //
         //interrupt all threads

src/main/java/electrosphere/server/ai/services/PathfindingService.java

@@ -19,7 +19,7 @@ public class PathfindingService implements AIService {
     /**
      * The executor service
      */
-    ExecutorService executorService;
+    static final ExecutorService executorService = Executors.newFixedThreadPool(ThreadCounts.PATHFINDING_THREADS);
 
     /**
      * Queues a pathfinding job
@@ -31,9 +31,6 @@ public class PathfindingService implements AIService {
      */
     public PathingProgressiveData queuePathfinding(Vector3d start, Vector3d end, VoxelPathfinder pathfinder, VoxelCellManager voxelCellManager){
         PathingProgressiveData rVal = new PathingProgressiveData(end);
-        if(executorService == null){
-            executorService = Executors.newFixedThreadPool(ThreadCounts.PATHFINDING_THREADS);
-        }
         executorService.submit(() -> {
             List<Vector3d> points = pathfinder.findPath(voxelCellManager, start, end, VoxelPathfinder.DEFAULT_MAX_COST);
             points.add(end);
@@ -50,10 +47,13 @@ public class PathfindingService implements AIService {
 
     @Override
     public void shutdown() {
-        if(executorService != null){
-            executorService.shutdownNow();
-        }
-        executorService = null;
+    }
+
+    /**
+     * Halts all threads in the pathfinding service
+     */
+    public static void haltThreads(){
+        executorService.shutdownNow();
     }
 
 }

src/main/java/electrosphere/server/datacell/gridded/GriddedDataCellLoaderService.java

@@ -93,4 +93,11 @@ public class GriddedDataCellLoaderService {
         lock.unlock();
     }
 
+    /**
+     * Halts the threads for the data cell loader service
+     */
+    public static void haltThreads(){
+        ioThreadService.shutdownNow();
+    }
+    
 }