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) 1998-2019, 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.Tasking.Utilities;
37with System.OS_Interface;     use System.OS_Interface;
38with System.Soft_Links;       use System.Soft_Links;
39with Ada.Unchecked_Conversion;
40
41package body GNAT.Threads is
42
43   use System;
44
45   package STPO renames System.Task_Primitives.Operations;
46
47   type Thread_Id_Ptr is access all Thread_Id;
48
49   pragma Warnings (Off);
50   --  The following unchecked conversions are aliasing safe, since they
51   --  are never used to create pointers to improperly aliased data.
52
53   function To_Addr is new Ada.Unchecked_Conversion (Task_Id, Address);
54   function To_Id   is new Ada.Unchecked_Conversion (Address, Task_Id);
55   function To_Id   is new Ada.Unchecked_Conversion (Address, Tasking.Task_Id);
56   function To_Tid  is new Ada.Unchecked_Conversion
57     (Address, Ada.Task_Identification.Task_Id);
58   function To_Thread is new Ada.Unchecked_Conversion (Address, Thread_Id_Ptr);
59
60   pragma Warnings (On);
61
62   type Code_Proc is access procedure (Id : Address; Parm : Void_Ptr);
63
64   task type Thread
65     (Stsz : Natural;
66      Prio : Any_Priority;
67      Parm : Void_Ptr;
68      Code : Code_Proc)
69   is
70      pragma Priority (Prio);
71      pragma Storage_Size (Stsz);
72   end Thread;
73
74   task body Thread is
75   begin
76      Code.all (To_Addr (Current_Task), Parm);
77   end Thread;
78
79   type Tptr is access Thread;
80
81   -------------------
82   -- Create_Thread --
83   -------------------
84
85   function Create_Thread
86     (Code : Address;
87      Parm : Void_Ptr;
88      Size : Natural;
89      Prio : Integer) return System.Address
90   is
91      TP : Tptr;
92
93      function To_CP is new Ada.Unchecked_Conversion (Address, Code_Proc);
94
95   begin
96      TP := new Thread (Size, Prio, Parm, To_CP (Code));
97      return To_Addr (TP'Identity);
98   end Create_Thread;
99
100   ---------------------
101   -- Register_Thread --
102   ---------------------
103
104   function Register_Thread return System.Address is
105   begin
106      return Task_Primitives.Operations.Register_Foreign_Thread.all'Address;
107   end Register_Thread;
108
109   -----------------------
110   -- Unregister_Thread --
111   -----------------------
112
113   procedure Unregister_Thread is
114      Self_Id : constant Tasking.Task_Id := Task_Primitives.Operations.Self;
115   begin
116      Self_Id.Common.State := Tasking.Terminated;
117      Destroy_TSD (Self_Id.Common.Compiler_Data);
118      Free_Task (Self_Id);
119   end Unregister_Thread;
120
121   --------------------------
122   -- Unregister_Thread_Id --
123   --------------------------
124
125   procedure Unregister_Thread_Id (Thread : System.Address) is
126      Thr : constant Thread_Id := To_Thread (Thread).all;
127      T   : Tasking.Task_Id;
128
129      use type Tasking.Task_Id;
130      --  This use clause should be removed once a visibility problem
131      --  with the MaRTE run time has been fixed. ???
132
133      pragma Warnings (Off);
134      use type System.OS_Interface.Thread_Id;
135      pragma Warnings (On);
136
137   begin
138      STPO.Lock_RTS;
139
140      T := Tasking.All_Tasks_List;
141      loop
142         exit when T = null or else STPO.Get_Thread_Id (T) = Thr;
143
144         T := T.Common.All_Tasks_Link;
145      end loop;
146
147      STPO.Unlock_RTS;
148
149      if T /= null then
150         T.Common.State := Tasking.Terminated;
151         Destroy_TSD (T.Common.Compiler_Data);
152         Free_Task (T);
153      end if;
154   end Unregister_Thread_Id;
155
156   --------------------
157   -- Destroy_Thread --
158   --------------------
159
160   procedure Destroy_Thread (Id : Address) is
161      Tid : constant Task_Id := To_Id (Id);
162   begin
163      Abort_Task (Tid);
164   end Destroy_Thread;
165
166   ----------------
167   -- Get_Thread --
168   ----------------
169
170   procedure Get_Thread (Id : Address; Thread : Address) is
171      Thr : constant Thread_Id_Ptr := To_Thread (Thread);
172   begin
173      Thr.all := Task_Primitives.Operations.Get_Thread_Id (To_Id (Id));
174   end Get_Thread;
175
176   ----------------------
177   -- Make_Independent --
178   ----------------------
179
180   function Make_Independent return Boolean is
181   begin
182      return System.Tasking.Utilities.Make_Independent;
183   end Make_Independent;
184
185   ----------------
186   -- To_Task_Id --
187   ----------------
188
189   function To_Task_Id
190     (Id : System.Address) return Ada.Task_Identification.Task_Id
191   is
192   begin
193      return To_Tid (Id);
194   end To_Task_Id;
195
196end GNAT.Threads;
197