Re: Problems freeing memory with Free

[Kilgallen@eisner.decus.org.nospam (Larry Kilgallen)]

In article <slrn9eq5ht.13j.randhol+abuse@kiuk0156.chembio.ntnu.no>, randhol+abuse@pvv.org (Preben Randhol) writes:
> On 30 Apr 2001 00:16:09 +0200, Florian Weimer wrote:
>> randhol+abuse@pvv.org (Preben Randhol) writes:
>> 
>> There's no error.  A typical implementation of a storage pool
>> retrieves memory in large chunks from the operating systems and
>> allocates several objects in each chunk.  When the objects are freed,
>> a chunk can only be returned to the operating system if all objects
>> which had been allocated in it before have been freed (unless you've
>> got a compacting garbage collector, but that's another story).
> 
> 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?

But that is just _typical_ of the way implementations are most often
built.  There is no guarantee regarding when or if memory will be
returned to an operating system by all Ada implementations.