gcc/ada/1ssecsta.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --               S Y S T E M . S E C O N D A R Y _ S T A C K                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                                                                          --
  10 --          Copyright (C) 1992-2001 Free Software Foundation, Inc.          --
  11 --                                                                          --
  12 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  13 -- terms of the  GNU General Public License as published  by the Free Soft- --
  14 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  15 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  16 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  17 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  18 -- for  more details.  You should have  received  a copy of the GNU General --
  19 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  20 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  21 -- MA 02111-1307, USA.                                                      --
  22 --                                                                          --
  23 -- As a special exception,  if other files  instantiate  generics from this --
  24 -- unit, or you link  this unit with other files  to produce an executable, --
  25 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  26 -- covered  by the  GNU  General  Public  License.  This exception does not --
  27 -- however invalidate  any other reasons why  the executable file  might be --
  28 -- covered by the  GNU Public License.                                      --
  29 --                                                                          --
  30 -- GNAT was originally developed  by the GNAT team at  New York University. --
  31 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  32 --                                                                          --
  33 ------------------------------------------------------------------------------
  34
  35 with System.Storage_Elements;
  36
  37 package System.Secondary_Stack is
  38
  39    package SSE renames System.Storage_Elements;
  40
  41    Default_Secondary_Stack_Size : constant := 10 * 1024;
  42    --  Default size of a secondary stack
  43
  44    procedure SS_Init
  45      (Stk  : System.Address;
  46       Size : Natural := Default_Secondary_Stack_Size);
  47    --  Initialize the secondary stack with a main stack of the given Size.
  48    --
  49    --  Stk is an "in" parameter that is already pointing to a memory area of
  50    --  size Size.
  51    --
  52    --  The secondary stack is fixed, and any attempt to allocate more than the
  53    --  initial size will result in a Storage_Error being raised.
  54
  55    procedure SS_Allocate
  56      (Address      : out System.Address;
  57       Storage_Size : SSE.Storage_Count);
  58    --  Allocate enough space for a 'Storage_Size' bytes object with Maximum
  59    --  alignment. The address of the allocated space is returned in 'Address'
  60
  61    procedure SS_Free (Stk : in out System.Address);
  62    --  Release the memory allocated for the Secondary Stack. That is to say,
  63    --  all the allocated chuncks.
  64    --  Upon return, Stk will be set to System.Null_Address
  65
  66    type Mark_Id is private;
  67    --  Type used to mark the stack.
  68
  69    function SS_Mark return Mark_Id;
  70    --  Return the Mark corresponding to the current state of the stack
  71
  72    procedure SS_Release (M : Mark_Id);
  73    --  Restore the state of the stack corresponding to the mark M. If an
  74    --  additional chunk have been allocated, it will never be freed during a
  75
  76 private
  77
  78    SS_Pool : Integer;
  79    --  Unused entity that is just present to ease the sharing of the pool
  80    --  mechanism for specific allocation/deallocation in the compiler
  81
  82    type Mark_Id is new SSE.Integer_Address;
  83
  84 end System.Secondary_Stack;