Re: GNAT and SIGTERM (Linux x86_64)

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Tue, 26 Oct 2010 17:52:57 +0200, Bryan <brobinson.eng@gmail.com> a  
écrit:

> I'm trying to capture SIGTERM in a very simple test program but I'm
> running into some issues. When I execute the code (at the end of
> message), I get the following output in my terminal when I send "kill -
> SIGTERM <PID>:
>
>> ./entry_point
> SIGTERM handler is NOT reserved
> !!! SIGTERM handler is NOT attached !!!
> Terminated
>
> [...]
> --------------------------------------
> Test program source code:
> --------------------------------------
> -- Signals.ads
> with Ada.Interrupts; use Ada.Interrupts;
> with Ada.Interrupts.Names; use Ada.Interrupts.Names;
> package Signals is
>   pragma Unreserve_All_Interrupts;
>   protected type Signal_Handler is
>     procedure Handle_SIGTERM;
>     pragma Attach_Handler(Handle_SIGTERM, SIGTERM);
>     pragma Interrupt_State (SIGTERM, System);
>   end Signal_Handler;
> end Signals;
>
> -- Signals.adb
> with Ada.Text_IO; use Ada.Text_IO;
> package body Signals is
>   protected body Signal_Handler is
>     procedure Handle_SIGTERM is
>     begin
>       Put_Line( "SIGTERM caught!" );
>     end Handle_SIGTERM;
>   end Signal_Handler;
> end Signals;
>
> -- Entrypoint.adb
> with Ada.Text_IO; use Ada.Text_IO;
> with Ada.Interrupts; use Ada.Interrupts;
> with Ada.Interrupts.Names; use Ada.Interrupts.Names;
> with Signals; use Signals;
>
> procedure Entry_Point is
>   Shutdown_Flag : Boolean := False;
> begin
>   if Is_Reserved(SIGTERM) then
>     Put_Line("SIGTERM handler is reserved");
>   else
>     Put_Line("SIGTERM handler is NOT reserved");
>   end if;
>
>   if Is_Attached(SIGTERM) then
>     Put_Line("SIGTERM handler is attached");
>   else
>     Put_Line("!!! SIGTERM handler is NOT attached !!!");
>   end if;
>
>   loop
>     -- do nothing
>     exit when Shutdown_Flag = True;
>   end loop;
> end Entry_Point;

Signal_Handler is a type, and a type does not live on its own. To make it  
“real”, you have to instantiate an entity of that type.

In few word : in Entry_Point, you forget to declare a variable of type  
Signal_Handler.

Try this :


  procedure Entry_Point is
     Shutdown_Flag : Boolean := False;
     Handler : Signal_Handler; -- < Add this line
  begin
     [... remaining of you cool stuff]
  end Entry_Point;

It works :)


-- 
Si les chats miaulent et font autant de vocalises bizarres, c’est pas pour  
les chiens.