Re: A simple question about the "new" allocator

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Tue, 12 Aug 2014 16:41:10 -0700 (PDT), Adam Beneschan wrote:

> Not necessarily.  Nothing says Pool has to have the memory used for
> allocation as part of the object.  The Initialize routine could allocate a
> byte array on the normal heap.  If this byte array isn't deallocated by
> My_Storage_Pool's Finalize routine, then the storage won't be reclaimed.
> 
> This isn't really relevant to the real world, since hopefully nobody would
> write My_Storage_Pool like that.

Why? "Proxy pools" are quite useful.

Consider an implementation of doubly-linked list. The pointer to an element
goes to the proxy pool. Upon allocation the pool gets memory from the heap.
It allocates more memory than needed to keep the element adding space for
the list's forward and backward links. The advantage of this approach is
that the element can be of any type used as-is, links are totally
invisible, no extra redirection needed, pointer to the element is plain
direct access type.

Simple components has such an implementation:

http://www.dmitry-kazakov.de/ada/components.htm#Generic_Doubly_Linked_Web

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de