Question

I think I’m attempting the wrong approach here so please tell me if what I’m trying to achieve won’t work with this “technique”.

I have an object callled Spawner which spawns KillerObjects every X ms, when I want the KillerObject to be destroyed I call:

void Spawner::RemoveKillerObject(KillerObject* removeThis)
{
    garbageList.push_back(removeThis);
}

Then everytime the Spawner is updated it will loop through the garbageList to remove every object that has been pushed into the garbage list, like this:

 void Spawner::Update(float elapsedTime)
 {
     elapsedSince += elapsedTime;
     if (elapsedSince > spawnRate)
     {
        Spawn();
        elapsedSince = 0;
     }
     for each (KillerObject* removeThis in garbageList)
     {
         spawnedObjects.remove(removeThis);
     }
     garbageList.clear();

     for each (KillerObject* ko in spawnedObjects)
     {
            ko->Update(elapsedTime);
     }
 }

Spawn is simply creating a pointer to a KillerObject and pushes it into the spawnedObject list.

The objects are “deleted” in the game as in I can’t collide with them and they won’t be drawn.
But this causes my memory usage to continuously grow, I know this is the cause because if I remove this code the memory usage is stable.

A point in the right direction or any other help is very much appreciated.

Kind regards

Markus

Answer 1

I must admit, that I have not completely understood your code, but you probably have a memory leak, i.e. produce more objects new KillerObject() than you delete. You could use a similar statement somewhere to remove the objects that are no longer needed:

for (std::list<KillerObject*>::iterator it = garbageList.begin(); it != garbageList.end(); ++it) {
  delete (*it);
}
garbageList.clear();

or just change:

void Spawner::RemoveKillerObject(KillerObject* removeThis)
{
  delete removeThis;
  //garbageList.push_back(removeThis);
  // todo: add code to remove the pointer from the list
  removeThis = NULL;
}