问阻塞时停止任务

EN

with Ada.Text_IO;

procedure Test
is

   task type Serving_Task is
      entry Start;
   end Serving_Task;

   task body Serving_Task is begin
      accept Start;
      Ada.Text_IO.Put_Line ("Started");
      loop
         null; --  Blocking operation, eg. accepting on a socket.
         null; --  Processing on blocking operation's result.
      end loop;
      Ada.Text_IO.Put_Line ("Stopped");
   end Serving_Task;

   type Server is tagged limited record
      Serving : Serving_Task;
   end record;

   procedure Start
     (S : in out Server)
   is begin
      Ada.Text_IO.Put_Line ("Starting");
      S.Serving.Start;
   end Start;

   procedure Stop
     (S : in out Server)
   is begin
      Ada.Text_IO.Put_Line ("Stopping");
      -- TODO To implement.
   end Stop;

   Main_Server : Server;

begin
   Ada.Text_IO.Put_Line ("Calling Start");
   Start (Main_Server);
   delay 5.0;
   Ada.Text_IO.Put_Line ("Calling Stop");
   Stop (Main_Server);
end Test;

select
   accept Stop;
or
   delay 0.1;
   exit;
end select;