(Case 1104590) PackedMemorySnapshot: "subSystemList" detected with wrong type

Using the UnityEditor.MemoryProfiler API to capture a PackedMemorySnapshot, causes some fields to be detected with the wrong type.

The following "PlayerLoopSystem" struct contains the "PlayerLoopSystem[] subSystemList" field in code.
When capturing a memory snapshot, this field is detected as ValueType, rather than an array.

This issue seems to occur with ScriptingBackend .NET 4 only. If ScriptingBackend is set to .NET 3.x, it causes a different issue, which I reported as Case 1104581.

Code (CSharp):

1. public struct PlayerLoopSystem // Located in namespace UnityEngine.Experimental.LowLevel
2. {
3.     public Type type;
4.     public PlayerLoopSystem[] subSystemList;  // this field is NOT detected as array in the memory snapshot
5.     public UpdateFunction updateDelegate;
6.     public IntPtr updateFunction;
7.     public IntPtr loopConditionFunction;
8. }

Reproduce

• Open user attached project
• Click Mainmenu > BugReport > Open TestCode Window
• Click "Capture Memory" button

Observe the text shows "PlayerLoopSystem subSystemList; // (isArray=False, isValueType=True)".


Actual
The "subSystemList" field is detected as ValueType.


Expected
The "subSystemList" field is detected as Array, which is a ReferenceType.


Sidenode
Why is this an issue you might think. The current information in the snapshot makes the "PlayerLoopSystem" struct look like it contains a field of a "PlayerLoopSystem" struct, thus infinite nesting. This infinite nesting causes the managed heap crawler in Heap Explorer to fail.

 

QA was able to reproduce the issue. Thank you!
https://issuetracker.unity3d.com/issues/packedmemorysnapshot-subsystemlist-detected-with-wrong-type