gcc/ada/s-thread.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                       S Y S T E M . T H R E A D S                        --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2003 Free Software Foundation, Inc.          --
  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 2,  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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package provides facilities to register a thread to the runtime,
  35 --  and allocate its task specific datas.
  36
  37 --  pragma Thread_Body is currently supported for:
  38 --  VxWorks AE653 with the restricted / cert runtime
  39
  40 with Ada.Exceptions;
  41 --  used for Exception_Occurrence
  42
  43 with System.Soft_Links;
  44 --  used for TSD
  45
  46 package System.Threads is
  47
  48    subtype EO is Ada.Exceptions.Exception_Occurrence;
  49
  50    subtype EOA is Ada.Exceptions.Exception_Occurrence_Access;
  51
  52    type ATSD is limited private;
  53    --  Type of the Ada thread specific data. It contains datas needed
  54    --  by the GNAT runtime.
  55
  56    type ATSD_Access is access ATSD;
  57
  58    --  Get/Set for the attributes of the current thread
  59
  60    function  Get_Jmpbuf_Address return  Address;
  61    pragma Inline (Get_Jmpbuf_Address);
  62
  63    procedure Set_Jmpbuf_Address (Addr : Address);
  64    pragma Inline (Get_Jmpbuf_Address);
  65
  66    function  Get_Sec_Stack_Addr return  Address;
  67    pragma Inline (Get_Sec_Stack_Addr);
  68
  69    procedure Set_Sec_Stack_Addr (Addr : Address);
  70    pragma Inline (Set_Sec_Stack_Addr);
  71
  72    function Get_Current_Excep return EOA;
  73    pragma Inline (Get_Current_Excep);
  74
  75    --------------------------
  76    -- Thread Body Handling --
  77    --------------------------
  78
  79    --  The subprograms in this section are called by the expansion of a
  80    --  subprogram body to which a Thread_Body pragma has been applied:
  81
  82    --  Given a subprogram body
  83
  84    --     procedure xyz (params ....) is    -- can also be a function
  85    --       <user declarations>
  86    --     begin
  87    --       <user statements>
  88    --     <user exception handlers>
  89    --     end xyz;
  90
  91    --  The expansion resulting from use of the Thread_Body pragma is:
  92
  93    --     procedure xyz (params ...) is
  94
  95    --       _Secondary_Stack : aliased
  96    --          Storage_Elements.Storage_Array
  97    --            (1 .. Storage_Offset (Sec_Stack_Size));
  98    --       for _Secondary_Stack'Alignment use Standard'Maximum_Alignment;
  99
 100    --       _Process_ATSD : aliased System.Threads.ATSD;
 101
 102    --     begin
 103    --        System.Threads.Thread_Body_Enter;
 104    --          (_Secondary_Stack'Address,
 105    --           _Secondary_Stack'Length,
 106    --           _Process_ATSD'Address);
 107
 108    --        declare
 109    --           <user declarations>
 110    --        begin
 111    --           <user statements>
 112    --        <user exception handlers>
 113    --        end;
 114
 115    --       System.Threads.Thread_Body_Leave;
 116
 117    --     exception
 118    --        when E : others =>
 119    --          System.Threads.Thread_Body_Exceptional_Exit (E);
 120    --     end;
 121
 122    --  Note the exception handler is omitted if pragma Restriction
 123    --  No_Exception_Handlers is currently active.
 124
 125    --  Note: the secondary stack size (Sec_Stack_Size) comes either from
 126    --  the pragma, if specified, or is the default value taken from
 127    --  the declaration in System.Secondary_Stack.
 128
 129    procedure Thread_Body_Enter
 130      (Sec_Stack_Address    : System.Address;
 131       Sec_Stack_Size       : Natural;
 132       Process_ATSD_Address : System.Address);
 133    --  Enter thread body, see above for details
 134
 135    procedure Thread_Body_Leave;
 136    --  Leave thread body (normally), see above for details
 137
 138    procedure Thread_Body_Exceptional_Exit
 139      (EO : Ada.Exceptions.Exception_Occurrence);
 140    --  Leave thread body (abnormally on exception), see above for details
 141
 142 private
 143
 144    type ATSD is new System.Soft_Links.TSD;
 145
 146 end System.Threads;