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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME COMPONENTS --
-- --
-- A D A . T A S K _ T E R M I N A T I O N --
-- --
-- B o d y --
-- --
-- Copyright (C) 2005-2006, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 2, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with System.Tasking;
-- used for Task_Id
with System.Task_Primitives.Operations;
-- used for Self
-- Write_Lock
-- Unlock
-- Lock_RTS
-- Unlock_RTS
with System.Parameters;
-- used for Single_Lock
with System.Soft_Links;
-- use for Abort_Defer
-- Abort_Undefer
with Unchecked_Conversion;
package body Ada.Task_Termination is
use type Ada.Task_Identification.Task_Id;
package STPO renames System.Task_Primitives.Operations;
package SSL renames System.Soft_Links;
use System.Parameters;
-----------------------
-- Local subprograms --
-----------------------
function To_TT is new Unchecked_Conversion
(System.Tasking.Termination_Handler, Termination_Handler);
function To_ST is new Unchecked_Conversion
(Termination_Handler, System.Tasking.Termination_Handler);
function To_Task_Id is new Unchecked_Conversion
(Ada.Task_Identification.Task_Id, System.Tasking.Task_Id);
-----------------------------------
-- Current_Task_Fallback_Handler --
-----------------------------------
function Current_Task_Fallback_Handler return Termination_Handler is
begin
-- There is no need for explicit protection against race conditions
-- for this function because this function can only be executed by
-- Self, and the Fall_Back_Handler can only be modified by Self.
return To_TT (STPO.Self.Common.Fall_Back_Handler);
end Current_Task_Fallback_Handler;
-------------------------------------
-- Set_Dependents_Fallback_Handler --
-------------------------------------
procedure Set_Dependents_Fallback_Handler
(Handler : Termination_Handler)
is
Self : constant System.Tasking.Task_Id := STPO.Self;
begin
SSL.Abort_Defer.all;
if Single_Lock then
STPO.Lock_RTS;
end if;
STPO.Write_Lock (Self);
Self.Common.Fall_Back_Handler := To_ST (Handler);
STPO.Unlock (Self);
if Single_Lock then
STPO.Unlock_RTS;
end if;
SSL.Abort_Undefer.all;
end Set_Dependents_Fallback_Handler;
--------------------------
-- Set_Specific_Handler --
--------------------------
procedure Set_Specific_Handler
(T : Ada.Task_Identification.Task_Id;
Handler : Termination_Handler)
is
begin
-- Tasking_Error is raised if the task identified by T has already
-- terminated. Program_Error is raised if the value of T is
-- Null_Task_Id.
if T = Ada.Task_Identification.Null_Task_Id then
raise Program_Error;
elsif Ada.Task_Identification.Is_Terminated (T) then
raise Tasking_Error;
else
declare
Target : constant System.Tasking.Task_Id := To_Task_Id (T);
begin
SSL.Abort_Defer.all;
if Single_Lock then
STPO.Lock_RTS;
end if;
STPO.Write_Lock (Target);
Target.Common.Specific_Handler := To_ST (Handler);
STPO.Unlock (Target);
if Single_Lock then
STPO.Unlock_RTS;
end if;
SSL.Abort_Undefer.all;
end;
end if;
end Set_Specific_Handler;
----------------------
-- Specific_Handler --
----------------------
function Specific_Handler
(T : Ada.Task_Identification.Task_Id) return Termination_Handler
is
begin
-- Tasking_Error is raised if the task identified by T has already
-- terminated. Program_Error is raised if the value of T is
-- Null_Task_Id.
if T = Ada.Task_Identification.Null_Task_Id then
raise Program_Error;
elsif Ada.Task_Identification.Is_Terminated (T) then
raise Tasking_Error;
else
declare
Target : constant System.Tasking.Task_Id := To_Task_Id (T);
TH : Termination_Handler;
begin
SSL.Abort_Defer.all;
if Single_Lock then
STPO.Lock_RTS;
end if;
STPO.Write_Lock (Target);
TH := To_TT (Target.Common.Specific_Handler);
STPO.Unlock (Target);
if Single_Lock then
STPO.Unlock_RTS;
end if;
SSL.Abort_Undefer.all;
return TH;
end;
end if;
end Specific_Handler;
end Ada.Task_Termination;
|
