gcc/ada/g-thread.adb

   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
  32 with Ada.Task_Identification; use Ada.Task_Identification;
  33 with System.Task_Primitives.Operations;
  34 with System.Tasking;
  35 with System.Tasking.Stages;   use System.Tasking.Stages;
  36 with System.OS_Interface;     use System.OS_Interface;
  37 with System.Soft_Links;       use System.Soft_Links;
  38 with Ada.Unchecked_Conversion;
  39
  40 package 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
 186 end GNAT.Threads;