Re: Storage_Size in a Simple Program

[Niklas Holsti <niklas.holsti@tidorum.invalid>]

On 18-10-24 12:07 , Charles H. Sampson wrote:
> Charles H. Sampson <csampson@inetworld.net> wrote:
>
>> I've got a conceptually simple program that uses a lot of memory. It is
>> highly recursive (using a lot of stack) and also puts a lot of stuff on
>> the heap. Is there any way to specify that a lot of memory is needed
>> other than pragma Storage_Size?
>>
>> As it is, I have three totally artificial tasks hidden in packages. The
>> packages' entry routines are simply pass-throughs to their embedded
>> task's entries. There are no concurrency issues because the simple
>> program is single-threaded at heart.
>>
>> Is that it? That's a lot of baggage just to give permission to use more
>> memory, particularly when there's a lot of memory lying around now.
>
> All the responses about limit/ulimit are certainly solutions, but
> they're not quite what I was asking about. I was looking for a solution
> written in Ada. I've been around Ada long enough to remember that a goal
> was to be able to completely express programs in Ada itself without
> having to worry about outside influences. (I write this knowing that the
> semantics of pragma Storage_Size are not at all tight.)

If you need a big stack:

- All Ada compilers I have used have had some way of defining the size 
of the stack for the environment task. But usually not by pragma 
Storage_Size, unfortunately.

- If you don't want to use the compiler-specific method to size the 
environment task stack, put all of the code into one task, with a large 
Storage_Size.

- If that doesn't work, because your shell or O/S doesn't let you have 
such a large stack, use limit/ulimit to tell the shell or O/S what you need.

- If you don't want to use limit/ulimit, and the stack is still too 
small, you are trying to run the program on a "machine" with too little 
memory resources, and no language can help.

That said, I would welcome a standard Ada way to specify the stack size 
for the environment task. Perhaps Storage_Size could be specified for 
the main subprogram, in the same way as the Priority for the environment 
task.

-- 
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
       .      @       .