How to use destroy and free.

[Ali Çehreli]

On 5/3/22 07:57, Alain De Vos wrote:

 > But at the same time be able to be sure memory is given free when a
 > variable is going out of scope.

Let's expand on that please. What exactly is the worry there? Are you 
concerned that the program will have memory leaks, and eventually got 
killed by the OS?

Do you want memory to be freed all the way to the OS? Would it be 
possible that a call to some_library_free() puts that memory in a free 
list to be used for later allocations? Or do you insist that memory 
really goes back to the OS?

Why are you worried about how memory is managed?

The way I think is this: When I use some feature and that feature 
allocates memory, it is not up to me to free memory at all. I don't want 
to get involved in how that memory is managed.

On the other hand, if I were the party that did allocate memory, fine, 
then I might be involved in freeing.

Note that 'new' is not raw memory allocation. So it should not involve 
raw memory freeing.

Sorry for all the questions but I am really curious why. At the same 
time, I have a suspicion: You come from a language like C++ that thinks 
deterministic memory freeing is the only way to go. It took me many 
years to learn that C++'s insintence on that topic is wrong.

Memory can be freed altogether at some later time. Further, not every 
object needs to be destroyed. These are based on one of John Lakos's 
C++Now presentations where he shows comparisons of different destruction 
and freeing schemes where (paraphrasing) "no destruction whatsoever; 
poof the array disappears." Not surprisingly, that happens to be the 
fastest destruction plus free.

Ali