ATC, an example please.

["e.coli" <maurizio.ferracini@gmail.com>]

how ATC work?
can you fix this example,please?

------------------------------------------------------------------
with Ada.Text_Io;

procedure Atc_Test is

   task A_Task is
      entry Foo;
   end A_Task;

   task body A_Task is
   begin
      loop
         accept Foo;
         Ada.Text_Io.Put_Line("one.start");
         for Iteration in 1..100000 loop
            Ada.Text_Io.Put(".");
         end loop;
         Ada.Text_Io.Put_Line("one.end");
      end loop;
   end A_Task;

begin
   select
      delay 2.0;
      Ada.Text_Io.Put_Line ("Long calculation abandoned");
   then
      abort
      A_Task.Foo;
   end select;
   Ada.Text_Io.Put_Line ("end main");

end Atc_Test;
-----------------------------------------------------------------

best regards
Maurizio