Re: Is the Ada run-time required to detect out-of-memory conditions?

[Simon Wright <simon@pushface.org>]

Ludovic Brenta <ludovic.brenta@insalien.org> writes:

> I forgot to point you at one of Ada's neat features called
> "User-Defined Storage Pools".  Look at the Ada Reference Manual[1]
> section 13.11.  You can define your own allocation and deallocation
> mechanism for any access type; your storage pool may for example
> preallocate X megabytes from the operating system, allocate from that
> buffer, and raise Storage_Error when it is exhausted.  As long as X <=
> Physical_Ram, you then have a guarantee that your porgram receives
> Storage_Error and not SIGKILL.

The easiest way to do this is to specify the storage size for the
access type:

   type S is access ...;
   for S'Storage_Size use ...;   --  in storage elements

ALRM 3.11(18):

   If Storage_Size is specified for an access type, then the
   Storage_Size of this pool is at least that requested, and the
   storage for the pool is reclaimed when the master containing the
   declaration of the access type is left. If the implementation
   cannot satisfy the request, Storage_Error is raised at the point of
   the attribute_definition_clause. If neither Storage_Pool nor
   Storage_Size are specified, then the meaning of Storage_Size is
   implementation defined.

-- 
Simon Wright                               100% Ada, no bugs.