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------------------------------------------------------------------------------
-- --
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- SYSTEM.TASK_PRIMITIVES.OPERATIONS.SPECIFIC --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2024, 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 3, 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. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
------------------------------------------------------------------------------
-- This is a VxWorks version of this package using Thread_Local_Storage
-- support (VxWorks 6.6 and higher). The implementation is based on __threads
-- support.
separate (System.Task_Primitives.Operations)
package body Specific is
ATCB : aliased Task_Id := null;
-- Ada Task_Id associated with a thread
pragma Thread_Local_Storage (ATCB);
----------------
-- Initialize --
----------------
procedure Initialize is
begin
null;
end Initialize;
-------------------
-- Is_Valid_Task --
-------------------
function Is_Valid_Task return Boolean is
begin
return ATCB /= Null_Task;
end Is_Valid_Task;
---------
-- Set --
---------
procedure Set (Self_Id : Task_Id) is
begin
ATCB := Self_Id;
end Set;
----------
-- Self --
----------
-- To make Ada tasks and C threads interoperate better, we have added some
-- functionality to Self. Suppose a C main program (with threads) calls an
-- Ada procedure and the Ada procedure calls the tasking runtime system.
-- Eventually, a call will be made to self. Since the call is not coming
-- from an Ada task, there will be no corresponding ATCB.
-- What we do in Self is to catch references that do not come from
-- recognized Ada tasks, and create an ATCB for the calling thread.
-- The new ATCB will be "detached" from the normal Ada task master
-- hierarchy, much like the existing implicitly created signal-server
-- tasks.
function Self return Task_Id is
Result : constant Task_Id := ATCB;
begin
if Result /= null then
return Result;
else
-- If the value is Null then it is a non-Ada task
return Register_Foreign_Thread;
end if;
end Self;
end Specific;
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