Get pointers to native container buffers using reflection

Hi,

I am trying to get the pointer to the internal memory buffer of a native array or a native slice for debugging purposes at runtime. I'm using this code but it doesn't give me the correct memory address somehow (it prints the log below). Am I doing something wrong or is there a bug with reflection for pointers? If there's a bug, would there be an alternative way of getting this pointer using reflection? I was also thinking maybe of reading the value using pointers but I'm not sure how I could get the memory address of a value type if it's boxed as an object.

Code (CSharp):

1. public class Test : MonoBehaviour
2. {
3.     unsafe void Start()
4.     {
5.         NativeArray<int> nativeArray = new NativeArray<int>(10, Allocator.Temp);
6.         NativeSlice<int> nativeSlice = nativeArray;
7.         Type nativeSliceType = nativeSlice.GetType();
8.         FieldInfo bufferField = nativeSliceType.GetField("m_Buffer", BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
9.         object bufferPointerBoxed = bufferField.GetValue(nativeSlice);
10.         byte* pointer = (byte*)Pointer.Unbox(bufferPointerBoxed);
11.         if (pointer != NativeSliceUnsafeUtility.GetUnsafePtr(nativeSlice))
12.         {
13.             Debug.Log("Something went wrong.");
14.         }
15.         nativeArray.Dispose();
16.     }
17. }

 

I didn't manage to make it work with reflection but I found a workaround/hack with pointers:

Code (CSharp):

1. public unsafe IntPtr GetNativeArrayBufferPointer(object nativeArray)
2.     {
3.         ulong gcHandle;
4.         IntPtr* nativeArrayBoxedPointer = (IntPtr*)UnsafeUtility.PinGCObjectAndGetAddress(nativeArray, out gcHandle);
5.         IntPtr bufferPointer = *(nativeArrayBoxedPointer + 2);
6.         UnsafeUtility.ReleaseGCObject(gcHandle);
7.         return bufferPointer;
8.     }
9.  
10.     public unsafe IntPtr GetNativeSliceBufferPointer(object nativeSlice)
11.     {
12.         ulong gcHandle;
13.         IntPtr* nativeSliceBoxedPointer = (IntPtr*)UnsafeUtility.PinGCObjectAndGetAddress(nativeSlice, out gcHandle);
14.         IntPtr bufferPointer = *(nativeSliceBoxedPointer + 2);
15.         UnsafeUtility.ReleaseGCObject(gcHandle);
16.         return bufferPointer;
17.     }
18.  
19.     private unsafe IntPtr GetNativeListBufferPointer(object nativeList)
20.     {
21.         ulong gcHandle;
22.         IntPtr* nativeListBoxedPointer = (IntPtr*)UnsafeUtility.PinGCObjectAndGetAddress(nativeList, out gcHandle);
23.         // According to https://www.red-gate.com/simple-talk/dotnet/.net-framework/object-overhead-the-hidden-.net-memory--allocation-cost/
24.         byte* nativeListDataPointerPointer = (byte*)(nativeListBoxedPointer + 2);
25. #if ENABLE_UNITY_COLLECTIONS_CHECKS
26.         nativeListDataPointerPointer += UnsafeUtility.SizeOf<AtomicSafetyHandle>();
27.         // Dispose sentinel size
28.         nativeListDataPointerPointer += IntPtr.Size;
29. #endif
30.         IntPtr nativeListDataPointer = *((IntPtr*)nativeListDataPointerPointer);
31.         IntPtr nativeListBufferPointer = *((IntPtr*)nativeListDataPointer);
32.         UnsafeUtility.ReleaseGCObject(gcHandle);
33.         return nativeListBufferPointer;
34.     }