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Diffstat (limited to 'gcc-4.9/gcc/ada/s-tpopsp-rtems.adb')
| -rw-r--r-- | gcc-4.9/gcc/ada/s-tpopsp-rtems.adb | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/ada/s-tpopsp-rtems.adb b/gcc-4.9/gcc/ada/s-tpopsp-rtems.adb new file mode 100644 index 000000000..805d6d98b --- /dev/null +++ b/gcc-4.9/gcc/ada/s-tpopsp-rtems.adb @@ -0,0 +1,113 @@ +------------------------------------------------------------------------------ +-- -- +-- 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; |