ScriptableObject Out Of Scope / Memory Help

Hi,

I have several classes that inherit from ScriptableObject. Some of these classes have properties that are also derived from ScriptableObject.

When the OnDestroy function is called I can Destroy the properties however what if one of my properties is being referenced by multiple objects? How can I know if its safe to destroy the object?
The doumentation says the OnDisable function is called when a ScriptableObject goes out of scope however i have not seen this happen so far.
How would i know if a property was being referenced elsewhere? I could implement a reference counting system but would prefer not to.

Here is an example:

Code (csharp):

1.  
2. public class ClassA : ScriptableObject
3. {
4.     ~ClassA()
5.     {
6.         Debug.Log( "Deleted Class A" );
7.     }
8.  
9.  
10.     void OnDisable()
11.     {
12.         Debug.Log( "OnDisable Class A" );
13.     }
14.    
15.     void OnDestroy()
16.     {
17.         Debug.Log( "OnDestroy Class A" );
18.     }
19. }
20.  

Code (csharp):

1.  
2. public class ClassB : ScriptableObject
3. {
4.     public ClassA classA;
5.    
6.     ~ClassB()
7.     {        
8.         Debug.Log( "Deleted Class B" );
9.     }
10.  
11.  
12.     void OnDisable()
13.     {
14.         Debug.Log( "OnDisable Class B" );
15.     }
16.    
17.     void OnDestroy()
18.     {        
19.         Debug.Log( "OnDestroy Class B" );
20.     }
21. }
22.  

My Test class

Code (csharp):

1.  
2.  
3.  
4. public class MemoryTest : MonoBehaviour
5. {
6.     public ClassB bRef1;
7.     public ClassB bRef2;
8.  
9.  
10.     IEnumerator Start()
11.     {
12.         bRef1 = ScriptableObject.CreateInstance<ClassB>();
13.         bRef2 = ScriptableObject.CreateInstance<ClassB>();
14.  
15.  
16.         bRef1.classA = ScriptableObject.CreateInstance<ClassA>();
17.         bRef2.classA = bRef1.classA; // Share class A;
18.        
19.         yield return new WaitForSeconds( 5 );
20.  
21.  
22.         DestroyImmediate( bRef1 );
23.         DestroyImmediate( bRef2 ); // Now classA should be destroyed but it is not. How can i know its safe to destroy??
24.     }
25. }
26.  
27.  
28.  

Thanks

Karl

 

So I was thinking of using a reference counting system, has anyone else tried this? Any implementation methods you could recommend?

Karl

 

I'm encountering a similar problem trying to hook into ScriptableObject's OnDisable message. I cannot discern when OnDisable gets called, even though the documentation says "when [it] goes out of scope." I understand that to mean when nothing's referencing the ScriptableObject.

As a test I created 2 scenes. The first scene contains a MonoBehaviour with a serialized reference to a ScriptableObject asset in my project tree. The second scene is empty. When I play the first scene in the Editor and trigger a scene load into the 2nd scene, I do not get an OnDisable call to the ScriptableObject.

So I am going to try manually implementing a reference counting system to do this instead.