Advice : Personal project : garbage collector.. i need a starting point

Question

hello, i've been reading about memory allocation and c++ programming in general.. my boss thinks it is a good idea to try and design a simple garbage collector to enhance my learning ( i always believed.. it is better to code a project, than to do a generalized written code, to test functions, because it helps understand the exact usage of functions)..

so anyway.. i read about garbage collectors and i understand "generally" what they do..and why we need them.. what i need is for some1 to point out to me..where to start programming..:S or maybe a book/tutorial.. that would help me start the work..

Edit: i know it is not the best place to start learning c++ .. but i have the basic knowledge covered (university courses) , and been playing alittle with winapis.. i am sorry for the misunderstanding on the "and c++ programming in general".. what i am trying to do is enhance my coding skills and professinality ..

Answer 1

Richar Jones's Garbage Collection Page references lot of ressource, included a book.

Note that in practice, writing a garbage collector means entering deep in the implementation dependent realm. I'm not sure it is the best way of learning to program in C++ in general.

Answer 2

You could take a look at the shared_ptr in boost. It is considered as an explicit garbage collector.

Answer 3

I'm afraid that your boss is wrong. This is a misguided project for at least two reasons:

• Firstly, there really is no such thing as simple garbage collector, particularly when you need to retrofit it to an existing language implementation.

• Secondly, garbage collection does not play well with C++ because it cannot normally call destructors to free non-memory resources. There have been experiments in this area but none has been notably succesful.

If I were you, I would spend the time you would have spent on this project familiarising yourself with the concept of RAII, smart pointers and possibly memory pools, which fit better into the C++ way of doing things than GC ever can.

Answer 4

I think you first have to define at which level you want to set your "exercise". Writting a true garbage collector might be a tremendeous task. Real ones are written for new languages...

Why ? because to do garbage collection, you have to control the memory management of what you want to garbage (memory allocation/deallocation). When you write a new language, you define memory management.

If the goal is not to write a new language but to practise c++ you first have to decide at which level of memory management you want to work.

You can design a simple memory allocation procedure with reference counting. You can then use a simple garbage collector algorithm that automatically delete dereferenced objects. Writting such a system is quite simple but a real good exercise. You will find that in real world using a smart shared pointer (see boost) is the same thing in principle, but a best one.

Going further is not simple. As I have said you have to deal with memory management. There is no simple/portable/C++ way to do that.

Then my advice is : write a simple object allocation and a simple garbage collector algorithm (reference counting). Then look at boost source code to learn a state of the art shared pointer implementation. And if in the future your need is not to do some c++ practise but you need some C++ automatic memory management, use smart pointers ... unless you want to write a new language !

my 2 cents.