AndresTraks / BulletSharpPInvoke

Bullet/BulletSharp is not thread-safe in general.
You should synchronize threads when accessing BulletObjectTracker or any other Bullet objects.

I ran into AV crash in multi-thread app with BULLET_OBJECT_TRACKING flag enabled.
But I can not reproduce without BULLET_OBJECT_TRACKING flag.
So I look into what BULLET_OBJECT_TRACKING is guarding.

I found this hashset might be access by multi-thread without synchronization:

BulletSharpPInvoke/BulletSharp/BulletObjectTracker.cs

Line 11 in 375acae

    
           public HashSet<BulletObject> UserOwnedObjects { get; set; } = new HashSet<BulletObject>();

If you have multiple bullet instances on different threads, it could be problematic.

BulletSharpPInvoke/BulletSharp/BulletObjectTracker.cs

Lines 17 to 28 in 375acae

    
           #if BULLET_OBJECT_TRACKING 
        
           		public static BulletObjectTracker Current { get; } = new BulletObjectTracker(); 
        
           		internal static void Add(BulletDisposableObject obj) 
        
           		{ 
        
           			Current.AddRef(obj); 
        
           		} 
        
           		internal static void Remove(BulletDisposableObject obj) 
        
           		{ 
        
           			Current.RemoveRef(obj); 
        
           		}

That's a good point. I added synchronization: 83fd5ea

Thanks.

	#if BULLET_OBJECT_TRACKING
	public static BulletObjectTracker Current { get; } = new BulletObjectTracker();

	internal static void Add(BulletDisposableObject obj)
	{
	Current.AddRef(obj);
	}

	internal static void Remove(BulletDisposableObject obj)
	{
	Current.RemoveRef(obj);
	}

BulletObjectTracker is not thread safe