Re: Problems freeing memory with Free

[Florian Weimer <fw@deneb.enyo.de>]

randhol+abuse@pvv.org (Preben Randhol) writes:

> I see. So that explaines why if I delete X of the last nodes it frees
> the memory, while if I free the X first or X in the middle, it may be
> 50_000 nodes or more the size has no influence apparently, it is not
> freed as the OS thinks I still need the memory because the last node is
> still using the memory at a much higher position?

This is the situation with more conventional allocator
implementations, yes.

> The reason why I thought there was an error was that if I excange the
> Data_Type with a record I have:
> 
> type Wordgroup_type is 
>    record
>       Word        :  Unbounded_String := To_Unbounded_String("");
>       Explanation :  Unbounded_String := To_Unbounded_String("");
>    end record;
> 
> and use this in the same way as the integer in the testing program I put
> up on the web, then the program start apparently to leak memory if I
> delete X nodes and then add X nodes again.

Strange.  However, if you create an Unbounded_String object, at least
GNAT invokes an allocated internally, and heap fragmentation might
explain the results you're observing.