1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- SYSTEM.TASK_PRIMITIVES.OPERATIONS.SPECIFIC -- 6-- -- 7-- B o d y -- 8-- -- 9-- Copyright (C) 1992-2011, Free Software Foundation, Inc. -- 10-- -- 11-- GNARL is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNARL was developed by the GNARL team at Florida State University. -- 28-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This is a version of this package using TLS and where foreign threads are 33-- recognized. 34 35separate (System.Task_Primitives.Operations) 36package body Specific is 37 38 ATCB : aliased Task_Id := null; 39 pragma Thread_Local_Storage (ATCB); 40 41 ---------------- 42 -- Initialize -- 43 ---------------- 44 45 procedure Initialize (Environment_Task : Task_Id) is 46 begin 47 ATCB := Environment_Task; 48 end Initialize; 49 50 ------------------- 51 -- Is_Valid_Task -- 52 ------------------- 53 54 function Is_Valid_Task return Boolean is 55 begin 56 return ATCB /= null; 57 end Is_Valid_Task; 58 59 --------- 60 -- Set -- 61 --------- 62 63 procedure Set (Self_Id : Task_Id) is 64 begin 65 ATCB := Self_Id; 66 end Set; 67 68 ---------- 69 -- Self -- 70 ---------- 71 72 -- To make Ada tasks and C threads interoperate better, we have added some 73 -- functionality to Self. Suppose a C main program (with threads) calls an 74 -- Ada procedure and the Ada procedure calls the tasking runtime system. 75 -- Eventually, a call will be made to self. Since the call is not coming 76 -- from an Ada task, there will be no corresponding ATCB. 77 78 -- What we do in Self is to catch references that do not come from 79 -- recognized Ada tasks, and create an ATCB for the calling thread. 80 81 -- The new ATCB will be "detached" from the normal Ada task master 82 -- hierarchy, much like the existing implicitly created signal-server 83 -- tasks. 84 85 function Self return Task_Id is 86 Result : constant Task_Id := ATCB; 87 begin 88 if Result /= null then 89 return Result; 90 else 91 -- If the value is Null then it is a non-Ada task 92 93 return Register_Foreign_Thread; 94 end if; 95 end Self; 96 97end Specific; 98