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) 1992-2009, 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 LynxOS version of this package.
33
34separate (System.Task_Primitives.Operations)
35package body Specific is
36
37   ----------------
38   -- Initialize --
39   ----------------
40
41   procedure Initialize (Environment_Task : Task_Id) is
42      pragma Warnings (Off, Environment_Task);
43      Result : Interfaces.C.int;
44
45   begin
46      Result := st_keycreate (null, ATCB_Key'Access);
47      pragma Assert (Result = 0);
48   end Initialize;
49
50   -------------------
51   -- Is_Valid_Task --
52   -------------------
53
54   function Is_Valid_Task return Boolean is
55      Result : Interfaces.C.int;
56      Value : aliased System.Address;
57   begin
58      Result := st_getspecific (ATCB_Key, Value'Address);
59      pragma Assert (Result = 0);
60      return (Value /= System.Null_Address);
61   end Is_Valid_Task;
62
63   ---------
64   -- Set --
65   ---------
66
67   procedure Set (Self_Id : Task_Id) is
68      Result : Interfaces.C.int;
69
70   begin
71      Result := st_setspecific (ATCB_Key, To_Address (Self_Id));
72      pragma Assert (Result = 0);
73   end Set;
74
75   ----------
76   -- Self --
77   ----------
78
79   --  To make Ada tasks and C threads interoperate better, we have added some
80   --  functionality to Self. Suppose a C main program (with threads) calls an
81   --  Ada procedure and the Ada procedure calls the tasking runtime system.
82   --  Eventually, a call will be made to self. Since the call is not coming
83   --  from an Ada task, there will be no corresponding ATCB.
84
85   --  What we do in Self is to catch references that do not come from
86   --  recognized Ada tasks, and create an ATCB for the calling thread.
87
88   --  The new ATCB will be "detached" from the normal Ada task master
89   --  hierarchy, much like the existing implicitly created signal-server
90   --  tasks.
91
92   function Self return Task_Id is
93      Value : aliased System.Address;
94
95      Result : Interfaces.C.int;
96      pragma Unreferenced (Result);
97
98   begin
99      Result := st_getspecific (ATCB_Key, Value'Address);
100      --  Is it OK not to check this result???
101
102      --  If the key value is Null, then it is a non-Ada task.
103
104      if Value /= System.Null_Address then
105         return To_Task_Id (Value);
106      else
107         return Register_Foreign_Thread;
108      end if;
109   end Self;
110
111end Specific;
112