Game loop performance and component approach

Question

I have an idea of organising a game loop. I have some doubts about performance. May be there are better ways of doing things.

Consider you have an array of game components. They all are called to do some stuff at every game loop iteration. For example:

GameData data; // shared
app.registerComponent("AI", ComponentAI(data) );
app.registerComponent("Logic", ComponentGameLogic(data) );
app.registerComponent("2d", Component2d(data) );
app.registerComponent("Menu", ComponentMenu(data) )->setActive(false);
//...
while (ok)
{
//...
app.runAllComponents();
//...
}

Benefits:

1. good component-based application, no dependencies, good modularity
2. we can activate/deactivate, register/unregister components dynamically
3. some components can be transparently removed or replaced and the system still will be working as nothing have happened (change 2d to 3d)(team-work: every programmer creates his/her own components and does not require other components to compile the code)

Doubts:

1. inner loop in the game loop with virtual calls to Component::run()
2. I would like Component::run() to return bool value and check this value. If returned false, component must be deactivated. So inner loop becomes more expensive.

Well, how good is this solution? Have you used it in real projects?

Answer 1

Some C++ programmers have way too many fears about the overhead of virtual functions. The overhead of the virtual call is usually negligible compared to whatever the function does. A boolean check is not very expensive either.

Do whatever results in the easiest-to-maintain code. Optimize later only if you need to do so. If you do find you need to optimize, eliminating virtual calls will probably not be the optimization you need.