gcc/ada/libgnarl/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) 1998-2018, 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.Tasking.Utilities;
  37 with System.OS_Interface;     use System.OS_Interface;
  38 with System.Soft_Links;       use System.Soft_Links;
  39 with Ada.Unchecked_Conversion;
  40
  41 package 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
 196 end GNAT.Threads;