Native Collection error

Hello there, I am working on a code that loads/unloads world around player(the code is bellow). When I start it, I get this error:

A Native Collection has not been disposed, resulting in a memory leak. Allocated from:
Unity.Collections.NativeHashSet`1:.ctor(Int32, Allocator) (at Library\PackageCache\com.unity.collections@0.14.0-preview.16\Unity.Collections\NativeHashSet.cs:34)
WorldMaster:OnCreate() (at Assets\WorldMaster.cs:35)
Unity.Entities.ComponentSystemBase:CreateInstance(World) (at Library\PackageCache\com.unity.entities@0.16.0-preview.21\Unity.Entities\ComponentSystemBase.cs:123)
Unity.Entities.World:AddSystem_OnCreate_Internal(ComponentSystemBase) (at Library\PackageCache\com.unity.entities@0.16.0-preview.21\Unity.Entities\World.cs:643)
Unity.Entities.World:GetOrCreateSystemsAndLogException(IEnumerable`1, Int32) (at Library\PackageCache\com.unity.entities@0.16.0-preview.21\Unity.Entities\World.cs:858)
Unity.Entities.DefaultWorldInitialization:AddSystemToRootLevelSystemGroupsInternal(World, IEnumerable`1, Int32) (at Library\PackageCache\com.unity.entities@0.16.0-preview.21\Unity.Entities\DefaultWorldInitialization.cs:190)
Unity.Entities.DefaultWorldInitialization:Initialize(String, Boolean) (at Library\PackageCache\com.unity.entities@0.16.0-preview.21\Unity.Entities\DefaultWorldInitialization.cs:131)
Unity.Entities.AutomaticWorldBootstrap:Initialize() (at Library\PackageCache\com.unity.entities@0.16.0-preview.21\Unity.Entities.Hybrid\Injection\AutomaticWorldBootstrap.cs:15)

And when I create entity with certain component needed for the code(LoaderComponent), it fires another error message:

InvalidOperationException: The UNKNOWN_OBJECT_TYPE has been deallocated, it is not allowed to access it
Unity.Collections.LowLevel.Unsafe.AtomicSafetyHandle.CheckWriteAndBumpSecondaryVersion (Unity.Collections.LowLevel.Unsafe.AtomicSafetyHandle handle) (at <e2bce5d33e704a76a5c9576f4d43769b>:0)
Unity.Collections.NativeHashMap`2[TKey,TValue].CheckWrite () (at Library/PackageCache/com.unity.collections@0.14.0-preview.16/Unity.Collections/NativeHashMap.cs:541)
Unity.Collections.NativeHashMap`2[TKey,TValue].Clear () (at Library/PackageCache/com.unity.collections@0.14.0-preview.16/Unity.Collections/NativeHashMap.cs:191)
Unity.Collections.NativeHashSet`1[T].Clear () (at Library/PackageCache/com.unity.collections@0.14.0-preview.16/Unity.Collections/NativeHashSet.cs:88)
WorldMaster.OnUpdate () (at Assets/WorldMaster.cs:42)
Unity.Entities.SystemBase.Update () (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/SystemBase.cs:413)
Unity.Entities.ComponentSystemGroup.UpdateAllSystems () (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystemGroup.cs:435)
UnityEngine.Debug:LogException(Exception)
Unity.Debug:LogException(Exception) (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/Stubs/Unity/Debug.cs:19)
Unity.Entities.ComponentSystemGroup:UpdateAllSystems() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystemGroup.cs:440)
Unity.Entities.ComponentSystemGroup:OnUpdate() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystemGroup.cs:387)
Unity.Entities.ComponentSystem:Update() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ComponentSystem.cs:113)
Unity.Entities.DummyDelegateWrapper:TriggerUpdate() (at Library/PackageCache/com.unity.entities@0.16.0-preview.21/Unity.Entities/ScriptBehaviourUpdateOrder.cs:333)

I have no idea what the error(s?) is and I tried to debug it for some time. It is in the Generation part of the script definitely, just dont know what. Anyway heres the entire code:

Note: Even tough I use "chunks" as a way to segment the world, I am not using DOTS chunks in the script so dont worry.

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using Unity.Collections;
5. using Unity.Mathematics;
6. using Unity.Transforms;
7. using Unity.Entities;
8. using Unity.Jobs;
9. using Unity.Burst;
10. using static WorldUtils;
11.  
12. public class WorldMaster : SystemBase
13. {
14.     int ChunkSize = 20;
15.  
16.     EndSimulationEntityCommandBufferSystem ECBS;
17.  
18.     EntityArchetype ChunkArchetype;
19.  
20.     NativeHashSet<int2> ActiveChunks;
21.     NativeHashSet<int2> LoadedChunks;
22.     NativeHashSet<int2> PendingChunks;
23.  
24.     protected override void OnCreate()
25.     {
26.         ECBS = World.GetOrCreateSystem<EndSimulationEntityCommandBufferSystem>();
27.  
28.         ChunkArchetype = EntityManager.CreateArchetype
29.             (
30.             typeof(Translation),
31.             typeof(ChunkData),
32.             typeof(UnloadTag)
33.             );
34.  
35.         NativeHashSet<int2> ActiveChunks = new NativeHashSet<int2>(0, Allocator.Persistent);
36.         NativeHashSet<int2> LoadedChunks = new NativeHashSet<int2>(0, Allocator.Persistent);
37.         NativeHashSet<int2> PendingChunks = new NativeHashSet<int2>(0, Allocator.Persistent);
38.     }
39.  
40.     protected override void OnUpdate()
41.     {
42.         ActiveChunks.Clear();
43.  
44.         var activeChunks = ActiveChunks;
45.         var loadedChunks = LoadedChunks;
46.         var pendingChunks = PendingChunks;
47.         var chunkSize = ChunkSize;
48.         var chunkArchetype = ChunkArchetype;
49.  
50.         var ECB = ECBS.CreateCommandBuffer();
51.         var PECB = ECB.AsParallelWriter();
52.  
53.         Entities.WithName("Activate_Chunks").ForEach((ref Translation translation, ref Loader loader) =>
54.         {
55.             float2 Position = new float2(translation.Value.x, translation.Value.y);
56.             int LoadDistance = loader.LoadDistance;
57.  
58.             for (int x = 0; x < LoadDistance; x++)
59.             {
60.                 for (int y = 0; y < LoadDistance; y++)
61.                 {
62.                     int2 chunk = GetChunkFromWorld(Position, chunkSize, new float2(0, 0)) - LoadDistance / 2 + new int2(x, y);
63.                     if (!activeChunks.Contains(chunk))
64.                     {
65.                         activeChunks.Add(chunk);
66.                     }
67.                 }
68.             }
69.         }).WithBurst().Schedule();
70.  
71.         Job.WithName("Load_Chunks").WithReadOnly(activeChunks).WithCode(() =>
72.         {
73.             var activeChunksArray = activeChunks.ToNativeArray(Allocator.Temp);
74.  
75.             for (int i = 0; i < activeChunksArray.Length; i++)
76.             {
77.                 int2 chunk = activeChunksArray[i];
78.                 if (!loadedChunks.Contains(chunk))
79.                 {
80.                     loadedChunks.Add(chunk);
81.                     pendingChunks.Add(chunk);
82.                 }
83.             }
84.             for (int i = activeChunksArray.Length - 1; i != -1; i--)
85.             {
86.                 int2 chunk = activeChunksArray[i];
87.                 if (!activeChunks.Contains(chunk))
88.                     loadedChunks.Remove(chunk);
89.             }
90.         }).WithBurst().Schedule();
91.  
92.         Job.WithName("Generate_Chunks").WithCode(() =>
93.         {
94.             var pendingChunksArray = pendingChunks.ToNativeArray(Allocator.Temp);
95.  
96.             for (int i = pendingChunksArray.Length - 1; i != -1; i--)
97.             {
98.                 int2 chunk = pendingChunksArray[i];
99.  
100.                 Entity entity = ECB.CreateEntity(chunkArchetype);
101.                 float2 position = GetWorldFromChunk(chunk, chunkSize, new float2(0,0)) + GetTileCenter(chunk, chunkSize);
102.                 ECB.SetComponent(entity, new Translation { Value = new float3(position.x, position.y, 0) });
103.  
104.                 pendingChunks.Remove(chunk);
105.             }
106.         }).WithBurst().Schedule();
107.     }
108.  
109.     protected override void OnDestroy()
110.     {
111.         ActiveChunks.Dispose();
112.         LoadedChunks.Dispose();
113.         PendingChunks.Dispose();
114.     }
115. }
116.  

I also have library of my code, from which I used these methods:

Code (CSharp):

1. public static float2 GetTileCenter(int2 TilePosition, float TileSize)
2.     {
3.         return new float2((TilePosition.x + (TileSize * 0.5f)), (TilePosition.y + (TileSize * 0.5f)));
4.     }
5.  
6.     public static int2 GetChunkFromWorld(float2 WorldPosition, int ChunkSize, float2 OriginPosition)
7.     {
8.         int2 ChunkPosition;
9.         ChunkPosition.x = (int)(math.floor((WorldPosition.x - OriginPosition.x) / ChunkSize));
10.         ChunkPosition.y = (int)(math.floor((WorldPosition.y - OriginPosition.y) / ChunkSize));
11.         return ChunkPosition;
12.     }
13.  
14.     public static float2 GetWorldFromChunk(int2 ChunkPosition, int ChunkSize, float2 OriginPosition)
15.     {
16.         float2 WorldPosition;
17.         WorldPosition.x = (ChunkPosition.x * ChunkSize) + OriginPosition.x;
18.         WorldPosition.y = (ChunkPosition.y * ChunkSize) + OriginPosition.y;
19.         return WorldPosition;
20.     }

And I have testing script to create entity with Loader component to kickstart the whole process:

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using Unity.Entities;
4. using Unity.Mathematics;
5. using Unity.Transforms;
6. using UnityEngine;
7.  
8. public class Test : MonoBehaviour
9. {
10.     public float2 Position;
11.     EntityManager EntityManager;
12.  
13.     private void Start()
14.     {
15.         EntityManager = World.DefaultGameObjectInjectionWorld.EntityManager;
16.     }
17.  
18.     private void Update()
19.     {
20.         if (Input.GetKeyDown(KeyCode.G))
21.         {
22.             Entity entity = EntityManager.CreateEntity(typeof (Translation), typeof (Loader));
23.             EntityManager.SetComponentData(entity, new Translation { Value = new float3(Position.x, Position.y, 0) });
24.             EntityManager.SetComponentData(entity, new Loader { LoadDistance = 40 });
25.         }
26.     }
27. }
28.  

And here is the Loader component (ChunkData and UnloadTag are empty components = tags):

Code (CSharp):

1. using System.Collections;
2. using System.Collections.Generic;
3. using UnityEngine;
4. using Unity.Entities;
5.  
6. public struct Loader : IComponentData
7. {
8.     public int LoadDistance;
9. }
10.  

 

So I fixed it, it was me creating new nativecollections instead of allocating the defined ones.