159 lines
5.9 KiB
Ada
159 lines
5.9 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME COMPONENTS --
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-- --
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-- A D A . T A S K _ T E R M I N A T I O N --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 2005-2020, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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with System.Tasking;
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with System.Task_Primitives.Operations;
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with System.Soft_Links;
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with Ada.Unchecked_Conversion;
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package body Ada.Task_Termination is
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use type Ada.Task_Identification.Task_Id;
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package STPO renames System.Task_Primitives.Operations;
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package SSL renames System.Soft_Links;
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-----------------------
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-- Local subprograms --
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-----------------------
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function To_TT is new Ada.Unchecked_Conversion
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(System.Tasking.Termination_Handler, Termination_Handler);
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function To_ST is new Ada.Unchecked_Conversion
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(Termination_Handler, System.Tasking.Termination_Handler);
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function To_Task_Id is new Ada.Unchecked_Conversion
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(Ada.Task_Identification.Task_Id, System.Tasking.Task_Id);
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-----------------------------------
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-- Current_Task_Fallback_Handler --
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-----------------------------------
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function Current_Task_Fallback_Handler return Termination_Handler is
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begin
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-- There is no need for explicit protection against race conditions
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-- for this function because this function can only be executed by
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-- Self, and the Fall_Back_Handler can only be modified by Self.
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return To_TT (STPO.Self.Common.Fall_Back_Handler);
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end Current_Task_Fallback_Handler;
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-------------------------------------
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-- Set_Dependents_Fallback_Handler --
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-------------------------------------
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procedure Set_Dependents_Fallback_Handler
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(Handler : Termination_Handler)
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is
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Self : constant System.Tasking.Task_Id := STPO.Self;
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begin
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SSL.Abort_Defer.all;
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STPO.Write_Lock (Self);
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Self.Common.Fall_Back_Handler := To_ST (Handler);
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STPO.Unlock (Self);
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SSL.Abort_Undefer.all;
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end Set_Dependents_Fallback_Handler;
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--------------------------
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-- Set_Specific_Handler --
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--------------------------
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procedure Set_Specific_Handler
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(T : Ada.Task_Identification.Task_Id;
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Handler : Termination_Handler)
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is
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begin
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-- Tasking_Error is raised if the task identified by T has already
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-- terminated. Program_Error is raised if the value of T is
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-- Null_Task_Id.
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if T = Ada.Task_Identification.Null_Task_Id then
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raise Program_Error;
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elsif Ada.Task_Identification.Is_Terminated (T) then
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raise Tasking_Error;
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else
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declare
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Target : constant System.Tasking.Task_Id := To_Task_Id (T);
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begin
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SSL.Abort_Defer.all;
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STPO.Write_Lock (Target);
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Target.Common.Specific_Handler := To_ST (Handler);
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STPO.Unlock (Target);
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SSL.Abort_Undefer.all;
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end;
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end if;
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end Set_Specific_Handler;
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----------------------
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-- Specific_Handler --
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----------------------
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function Specific_Handler
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(T : Ada.Task_Identification.Task_Id) return Termination_Handler
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is
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begin
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-- Tasking_Error is raised if the task identified by T has already
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-- terminated. Program_Error is raised if the value of T is
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-- Null_Task_Id.
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if T = Ada.Task_Identification.Null_Task_Id then
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raise Program_Error;
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elsif Ada.Task_Identification.Is_Terminated (T) then
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raise Tasking_Error;
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else
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declare
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Target : constant System.Tasking.Task_Id := To_Task_Id (T);
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TH : Termination_Handler;
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begin
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SSL.Abort_Defer.all;
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STPO.Write_Lock (Target);
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TH := To_TT (Target.Common.Specific_Handler);
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STPO.Unlock (Target);
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SSL.Abort_Undefer.all;
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return TH;
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end;
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end if;
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end Specific_Handler;
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end Ada.Task_Termination;
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