Resolved MemoryProfiler: Jagged array may not be collected in memory captures

Hi there, I found jagged array (T[][]) may not be collected in memory captures.

Test codes are something like:

Code (CSharp):

1. public class TestComponent : MonoBehaviour
2. {
3.     ...
4.     private TestClass[] array1 =
5.     {
6.         new TestClass(),
7.     };
8.     private TestClass[][] array2 =
9.     {
10.         new [] {new TestClass(), null},
11.         null,
12.     };
13.     ...
14. }

Then managed object

array2

and managed type

TestClass[][]

not found in captured snapshot (using Unity 2019.4.5f1 + com.unity.memoryprofiler@0.2.9-preview.1).

 

And, managed object of type

TestClass[]

inside

array2

also not found.

 

FYI, same issue in Heap Explorer:
https://github.com/pschraut/UnityHeapExplorer/issues/9

 

Alright, I found it has been fixed in 2019.4.10:

https://unity3d.com/unity/whats-new/2019.4.10

 

Thank you for the reply!

But I found another question: it seems that interned strings, including literals and strings passed to

string.Intern()

, neither be collected. Is this expected? Or a known issue?
For me, it is unexpected. Because these strings should be on the heap, and contribute to the total size of managed heap, right?

 

Oh, that is to say, the interned string instances will not be created until I try to access them by literals or

string.Intern()

?

 

Thank you for the explanation! And I agree with you mostly.
But I am confused with where is the pool that contains the interned strings. Is it on the heap?
If it is, I am wondering why they not be collected by snapshot. Otherwise, it doesn't matter anymore

 

Thank you very much for the explanation in detail!

So glad to hear that! Afaik, interned strings often take considerable memories and there is no good way to profile them now. So this is important information for us.