Re: "White House to Developers: Using C or C++ Invites Cybersecurity Risks"

On 08/03/2024 13:41, Paavo Helde wrote:

07.03.2024 17:36 David Brown kirjutas:

>
CPython does use garbage collection, as far as I know.
>

 AFAIK CPython uses reference counting, i.e. basically the same as C++ std::shared_ptr (except that it does not need to be thread-safe).

Yes, that is my understanding too.  (I could be wrong here, so don't rely on anything I write!)  But the way it is used is still a type of garbage collection.  When an object no longer has any "live" references, it is put in a list, and on the next GC it will get cleared up (and call the asynchronous destructor, __del__, for the object).
A similar method is sometimes used in C++ for objects that are time-consuming to destruct.  You have a "tidy up later" container that holds shared pointers.  Each time you make a new object that will have asynchronous destruction, you use a shared_ptr for the access and put a copy of that pointer in the tidy-up container.  A low priority background thread checks this list on occasion - any pointers with only one reference can be cleared up in the context of this separate thread.

 With reference counting one only knows how many pointers there are to a given heap block, but not where they are, so heap compaction would not be straightforward.
 Python also has zillions of extensions written in C or C++ (all of AI related work for example), so having e.g. heap compaction of Python objects only might not be worth of it.