gcroot cleanup/destruction question (.net 2003)

[rabidus]

> class UnmanagedClass
> {
> public:
> gcroot<ManagedClass *>pMc;
>
> UnmanagedClass(ManagedClass * in)
> {
> pMc = in;
> }
>
> ~ UnmanagedClass()
> {
> delete pMc;
> }

I took this from another post, but I have a question on a very similar topic. When I try to run the following code, and call the destructor on UnmanagedClass, it tells me that there is no destructor defined for ManagedClass. (I'm substituting System::XML::XmlDocument for ManagedClass)

I am having a memory leak because I am unable to destroy the managed object created in the unmanaged class. Any help would be GREATLY appreciated. Thanks!!!!

[rabidus]

I should say, I think the problem comes from the fact that I'm not destroying the gcroot pointer, which has a reference to the managed object, and so the managed object is persisting in memory, even when the unmanaged class goes out of scope. Thanks again !!

> class UnmanagedClass
> {
> public:
> gcroot<ManagedClass *>pMc;
>
> UnmanagedClass(ManagedClass * in)
> {
> pMc = in;
> }
>
> ~ UnmanagedClass()
> {
> delete pMc;
> }

I took this from another post, but I have a question on a very similar topic. When I try to run the following code, and call the destructor on UnmanagedClass, it tells me that there is no destructor defined for ManagedClass. (I'm substituting System::XML::XmlDocument for ManagedClass)

I am having a memory leak because I am unable to destroy the managed object created in the unmanaged class. Any help would be GREATLY appreciated. Thanks!!!!

[Ganon11]

It doesn't look like pMc is actually a pointer, but some class holding a pointer - you may consider writing a deconstructor for gcroot.

[rabidus]

Thank you very much for your quick reply!!

Yes, you are correct in that the gcroot object holds a pointer, and isn't a pointer itself. However, in gcroot.h (visual c++ code from microsoft), there is already a destructor defined for gcroot objects. However, when I I try to compile with the call:

delete pMc;

The compiler gives an error saying "there is no destructor for managed class ManagedClass"

Does anyone have any ideas as to why I'm getting that message, and any possible solutions to fix the leak that I am encountering? Thanks!

[Ganon11]

Is ManagedClass a class that you are writing and modifying? If so, is there a deconstructor for it?

Your gcroot pointer's deconstructor may be trying to delete the ManagedClass pointer it has, but is unable to because managedClass has no deconstructor.

[rabidus]

ManagedClass is a visual studio .net 2003 class (System::Xml::XmlDocument to be exact), and there is no deconstructor for that type.

Normally the resources are freed up by the garbage collector for that type. However, I am using gcroot, in unmanaged code (on the native heap, outside the scope of the garbage collector), to get a pointer to a location on the managed heap, so I can instantiate a managed object.

The problem is that when the unmanaged class that contains the gcroot pointer is destroyed, there is some memory that is being leaked, presumably that which the gcroot pointer was pointing to, and I'm not sure how to remedy the problem. I'm almost certain it has something to do with the inability to delete the gcroot pointer.