Re: Creation of storage pools

[Matthew Heaney <matthew_heaney@acm.org>]

Graeme Perkes <graeme.perkes@sydney.gecm.com> writes:

> The problem is how to use the storage pools I've created.
> I'm having trouble with  "for XYZ'storage_pool use ..." syntax
> when used with a USER_POOL access variable:
> 
>    STORAGE_POOLS_LIST : POOL_CFG_PTR := null;
> 
>    -- STORAGE_POOLS_LIST is populated by an initialisation procedure
> 
>    MY_POOL : POOL_LIST.POOL_PTR := STORAGE_POOLS_LIST(I);
> 
>    type INT_ACC is access INTEGER;
>    for INT_ACC'storage_pool use MY_POOL.all;
> 
> GNAT 3.11b2 responds with the following error for the use clause:
> 
> 	"incorrect reference to a Storage Pool"
> 
> What am I doing wrong?

Aren't attribute rep clauses static?  You have to bind to a statically
declared storage pool object, not a dynamically declared one.

> What obscure syntax do I need?

  type My_Storage_Pool is new Root_Storage_Pool with ...;

  Storage_Pool : My_Storage_Pool;

  type Integer_Access is access Integer;

  for Integer_Access'Storage_Pool use Storage_Pool;


> Am I trying to violate basic principles of storage pools?

It would appear so.  

See the package System.Pool_Global, in the gnat sources, for an example.