Problem with inheritance and object share use?

This is the skeleton of my app.

Code:

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- ClassA       has a    ClassE    * myclassE_inside_A    public var.
    - ClassB    Inherits ClassD 
    - ClassC    Inherits ClassD  
 
- ClassD has some funtions and  *ClassE public var.

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The idea was to deal with classE instance from class A, B and C. And use some common methods of ClassD from ClassB and ClassC.

Pseudocode that describes its operation.

Code:

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Inside ClassA:
    ClassB my_classB;    
    my_classB.create;   (I have the *ClassE filled with data )
    myclassE_inside_A = my_classB.classE;
 
    ClassC my_classC;
    ClassC.set_classE(my_classE_insideA); 
    for(   ) 
    {  do some things with my_classE_inside_A ;
        classC.modify_some_things_on_classE }    
 
    -  classC.modify_some_things_on_classE uses own methods and one function  inheritated from classD.

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When I run the program I have a lot a heap error and a lot of crahes
HEAP: Free Heap block c977e28 modified at c977e5c after it was freed
(Internal error: pc 0x2ff in read in psymtab, but not in symtab.)
(Internal error: pc 0x2ff in read in psymtab, but not in symtab.)
(Internal error: pc 0x2ff in read in psymtab, but not in symtab.)
,,,,

The error was related with classC, after the first modification of classE object. the second time I use it (it is the same if I do it from myclassE_insideA or int classC) i have the crash.
I'm sure that I' forget to do something but I dont view it.

It is as If I can't use the classE object by pointer. ?

Any idea ?

I dont like this idea - who is responsible for deleting the classE object ?

Code:

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ClassB my_classB;    
    my_classB.create;   (I have the *ClassE filled with data )
    myclassE_inside_A = my_classB.classE; // who owns the classE now ? this or my_classB
 
    ClassC my_classC;
    ClassC.set_classE(my_classE_insideA); // and now ? is ownership passed to my_classC ?

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You can get lost here easily, passing around, modifying and storing pointer to an object created by temporary object (my_classB on stack) smells like crash sooner or later.

Quote:

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Free Heap block c977e28 modified at c977e5c after it was freed

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I dont know who owns the created object, and it seems like you dont know either, because you want to access it after deleting it somewhere.
I gues you should rethink the design, because its not clear now, and will be very painful to modify and maintain this kind of code.

One of possible solutions is to do reference counting on "E" and copy it by value (with a shared reference counter of course) between those objects that use it. Or if you use Qt, QSharedPointer is the thing you want to use (if you don't but you use C++ you can use boost/std::shared_ptr). And for clarity E should be created outside B to avoid doubts related to ownership of E (since E can live longer than B if it is shared with another object). As for now you are trying to access an already deleted object.