Re: Tasking issues

[anon@anon.org (anon)]

--
-- This works and is almost the same code that you used.
-- Exceptions to make the program function with the ability
-- to stop task.
--
-- For help it is better that you write your code 
-- test with 
--               gnatmake main.adb
-- then for help compile with:
--               gnat1 main.adb  -gnatl >main.lst
--
-- Then copy and paste the main.lst file to your post
-- so that we can the compiler errors. Without too 
-- much editing of the code.
--
with Ada.Text_io ;
use  Ada.Text_io ;
procedure main is

  task get_name;
  task print_something;

  continue : boolean := True ; -- task to continue running

  task body get_name is
      Name : String ( 1 .. 25 ) ;
      Last : Integer ;
    begin
      loop
        Get_Line ( Name, Last ) ;

          -- Set stop flag

        if Name ( 1 .. 4 ) = "stop" then
            continue := false ;
        end if ;
        delay 0.0 ;
      end loop ;
    end get_name ;

  task body print_something is
    begin
      loop
        Put_Line ( "blah..." ) ;
        delay 0.0 ;
      end loop ;
    end print_something ;

begin --- main

    -- do nothing!

  while continue loop
    delay 0.0 ;
  end loop ;

    -- abort tasks.  But because get_name may be in the process of 
    -- obtaining data from standard_input. it may require a CR/LF 
    -- to be entered to fully abort the 'get_name' task.

  abort get_name ;
  Put_Line ( "EOT -- get_name" ) ;
  abort print_something ;
  Put_Line ( "EOT -- print_something" ) ;
  Put_Line ( "EOJ" ) ;
end main;



In <1186851804.567302.223160@q4g2000prc.googlegroups.com>,  shaunpatterson@gmail.com writes:
>I'm having trouble with tasking in Ada.  I'm used to working with
>pthreads
>in C/C++... and I'm finding tasks to be somewhat different/annoying.
>
>My basic problem is I want to have 2 threads in my program.
>
>One thread sits in the background and reads in messages,
>dispatches them, etc and the other thread reads off a queue
>and sends out messages when they are available.
>
>As an analogy, let's assume my background task just got
>input from the user (simulating the socket read) and the other
>task just printed out stuff.
>
>Something like
>
>procedure main is
>begin
>  task get_name;
>  task print_something;
>
>  task body get_name is
>      Name : String (1..25);
>      Last : Integer;
>  begin
>      loop
>          Get_Line (Name, Last);
>      end loop;
>  end get_name;
>
>  task body print_something is
>  begin
>      loop
>      Put_Line ("blah...");
>      end loop;
>   end print_something;
>
>begin --- main
>
>     loop;
>          null;
>     end loop;
>end main;
>
>
>Of course, this doesn't work as I'd expect.  Is there a way to
>"timeout" the
>first get_name thread... so the OS only waits on that thread for a
>short period
>of time to allow the other threads to do their business? and then go
>back to
>the thread?
>
>Thanks
>-- Shaun
>