+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
--- --
--- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S . --
--- S P E C I F I C --
--- --
--- B o d y --
--- --
--- $Revision: 1.2 $
--- --
--- Copyright (C) 1991-2003, Florida State University --
--- Copyright (C) 2008-2012, Free Software Foundation, Inc. --
--- --
--- GNARL 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. It is --
--- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
--- State University (http://www.gnat.com). --
--- --
-------------------------------------------------------------------------------
-
--- This is a RTEMS version of this package which uses a special
--- variable for Ada self which is context switched implicitly by RTEMS.
---
--- This is the same as the POSIX version except that an RTEMS variable
--- is used instead of a POSIX key.
-
-separate (System.Task_Primitives.Operations)
-package body Specific is
-
- -- The following gives the Ada run-time direct access to a variable
- -- context switched by RTEMS at the lowest level.
-
- ATCB_Key : System.Address;
- pragma Import (C, ATCB_Key, "rtems_ada_self");
-
- ----------------
- -- Initialize --
- ----------------
-
- procedure Initialize (Environment_Task : Task_Id) is
- pragma Warnings (Off, Environment_Task);
-
- begin
- ATCB_Key := To_Address (Environment_Task);
- end Initialize;
-
- -------------------
- -- Is_Valid_Task --
- -------------------
-
- function Is_Valid_Task return Boolean is
- begin
- return ATCB_Key /= System.Null_Address;
- end Is_Valid_Task;
-
- ---------
- -- Set --
- ---------
-
- procedure Set (Self_Id : Task_Id) is
- begin
- ATCB_Key := To_Address (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 : System.Address;
-
- begin
- Result := ATCB_Key;
-
- -- If the key value is Null, then it is a non-Ada task.
-
- if Result /= System.Null_Address then
- return To_Task_Id (Result);
- else
- return Register_Foreign_Thread;
- end if;
- end Self;
-
-end Specific;