Fun with Tasking

Below is sample code I made representing something I wanted to do with
a program, of course it doesn't work quite the way I would like.
Hopefully this sample doesn't cause eye (or brain) injury, it is more
symbolic than useful - the procedure "Exec" is, of course, really a
package (rather, several similar packages).

The problem is, how to "transport" a task? As seen in the sample
below, I would like to use just a single address in the Control_Block
type, but it's never that simple, is it? In actuality, how I get this
program in its full incarnation to work is to define the "test_task"s
in the acc_add_test part of the program. I really don't like doing
this, as I mentioned, "exec" is representative of a family of several
different packages. I would like the task definition to be local to
the "exec" pacakage(s), not all kludged together in acc_add_test,
which then requires all sorts of (ideally private) types being moved
out of the local "exec" packages into acc_add_test and then the
Control_Block record now has nearly a dozen different task pointers
stuffed into it, only one of which is going to be used at any given
time.

One last caveat, the Acc_Add_Test program should have *no* visibility
into the "exec" procedure/package. The "exec" package(s), in fact,
"push" their procedures into the main program. So is there something
simple I'm having a brain fart over in missing here, or is a complete
re-architecture required here?

with Text_Io;
with System;
with System.Address_To_Access_Conversions;

procedure Acc_Add_test is

Exec_Count : constant Natural := 10;

type Control_Block is
record
Task_Addr : System.Address;
end record;

type Mode_Type is (preprocess, process);

procedure Exec (Mode : in Mode_Type;
Cntl : in out Control_Block) is

task type Test_Task is
entry Start (Addr : System.Address);
entry Complete;
end Test_Task;

package Convert is new System.Address_To_Access_Conversions
(Test_Task);
use Convert;

task body Test_Task is
Task_Ptr : Convert.Object_Pointer := null;
Count : Natural := 0;
begin
loop
begin
select
accept Start (Addr : System.Address) do
Task_Ptr := Convert.To_Pointer (Addr);
end Start;

or
accept Complete do
Count := Count + 1;
end Complete;
if Count = Exec_Count then
Text_Io.Put_Line ("Completed All Tasks");
abort Task_Ptr.all;
end if;
end select;
end;
end loop;
end Test_Task;

begin
case Mode is
when Preprocess =>
declare
Task_Ptr : Convert.Object_Pointer;
Address : System.Address;
begin
Task_Ptr := new Test_Task;
Address := Convert.To_Address (Task_Ptr);
Task_Ptr.Start (Address);
Cntl.Task_Addr := Address;
end;

when Process =>
declare
Task_Ptr : Convert.Object_Pointer;
begin
Task_Ptr := Convert.To_Pointer (Cntl.Task_Addr);
Task_Ptr.Complete;
end;
end case;
end Exec;

Controls : Control_Block;

begin
Exec (Preprocess, Controls);
for I in 1 .. Exec_Count loop
Exec (Process, Controls);
end loop;
end Acc_Add_Test;

Thanks for any input!

.

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