[omniORB] My program crashes when I try to dereference an object from a sequence

[Martin Trappel]

Lane, Frank L wrote:
> Hi,
> 
> My program is crashing and I don't understand why, will someone please
> tell me what I'm doing wrong?
> Visual Studio 2008, XP, OmniORB 4.1.3
> 
>(...) 
>    Customer_impl * TheCustomer
>       = new Customer_impl (CustomerName, CustomerAccount);
> 
>    cout << "New customer created, " << TheCustomer->Name()
>       << ", " << TheCustomer->Account() << endl;
> 
>    CORBA::Long size = _Customers.length();
>    _Customers.length(size+1);
>    _Customers[size] = (Customer_ptr)TheCustomer;
> 
Never, ever use c-style casts.
What you probably wanted to do was:
_Customers[size] = TheCustomer->_this();


>    if (CORBA::is_nil(_Customers[0]))
>       cout << "The newly created seq member is nil?" << endl;
>    else {
>       cout << "_Customers[0]: " << _Customers[0] << endl;
>       cout << "TheCustomer: " << TheCustomer << endl;
>    cout << "TheCustomer data, " << TheCustomer->Name()
>       << ", " << TheCustomer->Account() << endl;
> 
You are aware that the calls on TheCustomer are direct calls on the 
implementation object, and won't involve any CORBA?

> !!!!! ----- Here is where it is crashing -----!!!!!!
> !!!!! ----- The instant I try to get data back out of the sequence it
> crashes ----- !!!!!!!
>    Customer_var temp = (Customer_ptr)_Customers[0];
Never, ever use c-style casts.
You should use a _ptr type for the temp or duplicate() the sequence element!

>    cout << "The sequence data, " << temp->Name()
>       << ", " << (*temp).Account() << endl;
>       //cout << "New customer created, " << _Customers[0]->Name() <<
> endl;
>    }
> 
> 
>    return Customer::_duplicate((Customer_ptr)TheCustomer);
> 
Never, ever use c-style casts.


1) Look at the omniORB examples. example #1 will show you how to 
correctly instantiate and the use an object.

2) After looking at the examples, get "Adavced CORBA programming with 
C++" by Henning,Vinoski


br,
Martin