About shared ptr

Question

I'm not sure whether it's strict to say, but I'd like to treat shared ptr as a garbage collection strategy.

I've two questions here:

1. When is shared ptr appropriate for garbage collection; and when other strategies such as mark-sweep?
2. Is there any lib implemented shared ptr in C?

Thanks.

Answer 1

If you want garbage collection in C, have a look at the Hans Boehm garbage collection library.

Shared ptr removes much of the necessity of handling object deletion, but has a number of complications: only one shared pointer can hold the pointer at a time. You might want to look also at Boost's smart_ptr pointer handling and related classes.

But shared_ptr, and Boost, is C++. You will struggle to achieve this in C: shared_ptr relies on operator overloading to achieve its magic. Without operator overloading, you have no way of knowing if someone, somewhere, is holding a copy of your pointer. (This is a problem also in C++, but the operator overloading reduces the risk if you use shared_ptr throughout your code.)

I would definitely recommend Hans Boehm instead.