1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT RUN-TIME COMPONENTS                         --
4--                                                                          --
5--                         G N A T . T H R E A D S                          --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--                    Copyright (C) 1998-2010, AdaCore                      --
10--                                                                          --
11-- GNAT 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-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32with Ada.Task_Identification; use Ada.Task_Identification;
33with System.Task_Primitives.Operations;
34with System.Tasking;
35with System.Tasking.Stages;   use System.Tasking.Stages;
36with System.OS_Interface;     use System.OS_Interface;
37with System.Soft_Links;       use System.Soft_Links;
38with Ada.Unchecked_Conversion;
39
40package body GNAT.Threads is
41
42   use System;
43
44   package STPO renames System.Task_Primitives.Operations;
45
46   type Thread_Id_Ptr is access all Thread_Id;
47
48   pragma Warnings (Off);
49   --  The following unchecked conversions are aliasing safe, since they
50   --  are never used to create pointers to improperly aliased data.
51
52   function To_Addr is new Ada.Unchecked_Conversion (Task_Id, Address);
53   function To_Id   is new Ada.Unchecked_Conversion (Address, Task_Id);
54   function To_Id   is new Ada.Unchecked_Conversion (Address, Tasking.Task_Id);
55   function To_Tid  is new Ada.Unchecked_Conversion
56     (Address, Ada.Task_Identification.Task_Id);
57   function To_Thread is new Ada.Unchecked_Conversion (Address, Thread_Id_Ptr);
58
59   pragma Warnings (On);
60
61   type Code_Proc is access procedure (Id : Address; Parm : Void_Ptr);
62
63   task type Thread
64     (Stsz : Natural;
65      Prio : Any_Priority;
66      Parm : Void_Ptr;
67      Code : Code_Proc)
68   is
69      pragma Priority (Prio);
70      pragma Storage_Size (Stsz);
71   end Thread;
72
73   task body Thread is
74   begin
75      Code.all (To_Addr (Current_Task), Parm);
76   end Thread;
77
78   type Tptr is access Thread;
79
80   -------------------
81   -- Create_Thread --
82   -------------------
83
84   function Create_Thread
85     (Code : Address;
86      Parm : Void_Ptr;
87      Size : Natural;
88      Prio : Integer) return System.Address
89   is
90      TP : Tptr;
91
92      function To_CP is new Ada.Unchecked_Conversion (Address, Code_Proc);
93
94   begin
95      TP := new Thread (Size, Prio, Parm, To_CP (Code));
96      return To_Addr (TP'Identity);
97   end Create_Thread;
98
99   ---------------------
100   -- Register_Thread --
101   ---------------------
102
103   function Register_Thread return System.Address is
104   begin
105      return Task_Primitives.Operations.Register_Foreign_Thread.all'Address;
106   end Register_Thread;
107
108   -----------------------
109   -- Unregister_Thread --
110   -----------------------
111
112   procedure Unregister_Thread is
113      Self_Id : constant Tasking.Task_Id := Task_Primitives.Operations.Self;
114   begin
115      Self_Id.Common.State := Tasking.Terminated;
116      Destroy_TSD (Self_Id.Common.Compiler_Data);
117      Free_Task (Self_Id);
118   end Unregister_Thread;
119
120   --------------------------
121   -- Unregister_Thread_Id --
122   --------------------------
123
124   procedure Unregister_Thread_Id (Thread : System.Address) is
125      Thr : constant Thread_Id := To_Thread (Thread).all;
126      T   : Tasking.Task_Id;
127
128      use type Tasking.Task_Id;
129      --  This use clause should be removed once a visibility problem
130      --  with the MaRTE run time has been fixed. ???
131
132      pragma Warnings (Off);
133      use type System.OS_Interface.Thread_Id;
134      pragma Warnings (On);
135
136   begin
137      STPO.Lock_RTS;
138
139      T := Tasking.All_Tasks_List;
140      loop
141         exit when T = null or else STPO.Get_Thread_Id (T) = Thr;
142
143         T := T.Common.All_Tasks_Link;
144      end loop;
145
146      STPO.Unlock_RTS;
147
148      if T /= null then
149         T.Common.State := Tasking.Terminated;
150         Destroy_TSD (T.Common.Compiler_Data);
151         Free_Task (T);
152      end if;
153   end Unregister_Thread_Id;
154
155   --------------------
156   -- Destroy_Thread --
157   --------------------
158
159   procedure Destroy_Thread (Id : Address) is
160      Tid : constant Task_Id := To_Id (Id);
161   begin
162      Abort_Task (Tid);
163   end Destroy_Thread;
164
165   ----------------
166   -- Get_Thread --
167   ----------------
168
169   procedure Get_Thread (Id : Address; Thread : Address) is
170      Thr : constant Thread_Id_Ptr := To_Thread (Thread);
171   begin
172      Thr.all := Task_Primitives.Operations.Get_Thread_Id (To_Id (Id));
173   end Get_Thread;
174
175   ----------------
176   -- To_Task_Id --
177   ----------------
178
179   function To_Task_Id
180     (Id : System.Address) return Ada.Task_Identification.Task_Id
181   is
182   begin
183      return To_Tid (Id);
184   end To_Task_Id;
185
186end GNAT.Threads;
187