Memory Management in Bada/C++

I’ve been getting a hard time knowing the right moment when you must delete, or in other words, deallocate a pointer. Thats why I could never get used to using C++ even if I probably used it for two times. Now that in Bada Development, I’m back programming on C++. These are what I had extracted from the Internet to be a reminder or a checklist whether or not I’m doing things right:

(I am still unsure of some of them since I still have to test them myself)

- Standard Deallocation -

  // Creation
  int *x = new int;

  // Deallocation
  delete x;

- Array Deallocation -

  // Creation
  char *str = new char[30];

  // Deallocation
  delete [] str;

- 2D Array Deallocation -

  // Creation
  byte **array = new byte*[3];
  for(int i=0; i < 3; i++) {
    array[i] = new byte[i+1];
  }

  // Deallocation
  for(i=0; i < 3; i++) {
    delete [] array[i];
  }
  delete [] array;

C++ Reminders

  • Before reusing a pointer, deallocate the pointer first
  • Before assigning a value to a pointer, deallocate first if pointer is alreader pointing somewhere
  • If you declare a pointer within a function, make sure you delete it before the function ends
  • Destructor of classes must be virtual
  • Never return an address of a local pointer variable from a function, either return a real value or initialize the value into the pointer.

Bada Reminders

  • Use Resource Monitor View (Debug on Simulator) to track memory leaks. — Alternatively use Osp::System::RuntimeInfo
  • Methods that end with ‘N’ like pClass->GetCanvasN() return pointers that must be deleted after use.
  • Deallocate all objects constructed except UI Controls added to a UI Container with AddControl(). On the other hand, delete all UI Controls which do not get added to a UI Container: MessageBox, Popup, ContextMenu, OptionMenu
  • Deallocate Variables in Forms, do it two times, OnTerminating and the destructor. But after deleting in OnTerminating, assign zero(0) the pointer.
  • To deallocate a UI Control, use RemoveControl() or RemoveAllControls()
  • To deallocate other types, check API for methods with ‘Remove’ as prefix
  • Delete pointers as soon as they are not used.
  • Deallocate controls that are not seen, and just add them to the container when you need to see them again