| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . S E C O N D A R Y _ S T A C K -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.1 $ |
| -- -- |
| -- Copyright (C) 1992-1999 Free Software Foundation, Inc. -- |
| -- -- |
| -- GNAT is free software; you can redistribute it and/or modify it under -- |
| -- terms of the GNU General Public License as published by the Free Soft- -- |
| -- ware Foundation; either version 2, or (at your option) any later ver- -- |
| -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
| -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- |
| -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- |
| -- for more details. You should have received a copy of the GNU General -- |
| -- Public License distributed with GNAT; see file COPYING. If not, write -- |
| -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, USA. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System.Storage_Elements; |
| |
| package System.Secondary_Stack is |
| |
| package SSE renames System.Storage_Elements; |
| |
| Default_Secondary_Stack_Size : constant := 10 * 1024; |
| -- Default size of a secondary stack |
| |
| procedure SS_Init |
| (Stk : in out System.Address; |
| Size : Natural := Default_Secondary_Stack_Size); |
| -- Initialize the secondary stack with a main stack of the given Size. |
| -- |
| -- If System.Parameters.Sec_Stack_Ratio equals Dynamic, Stk is really an |
| -- "out" parameter that will be allocated on the heap. Then all further |
| -- allocations which do not overflow the main stack will not generate |
| -- dynamic (de)allocation calls. If the main Stack overflows, a new |
| -- chuck of at least the same size will be allocated and linked to the |
| -- previous chunk. |
| -- |
| -- Otherwise (Sec_Stack_Ratio between 0 and 100), Stk is an "in" parameter |
| -- that is already pointing to a Stack_Id. The secondary stack in this case |
| -- is fixed, and any attempt to allocated more than the initial size will |
| -- result in a Storage_Error being raised. |
| -- |
| -- Note: the reason that Stk is passed is that SS_Init is called before |
| -- the proper interface is established to obtain the address of the |
| -- stack using System.Soft_Links.Get_Sec_Stack_Addr. |
| |
| procedure SS_Allocate |
| (Address : out System.Address; |
| Storage_Size : SSE.Storage_Count); |
| -- Allocate enough space for a 'Storage_Size' bytes object with Maximum |
| -- alignment. The address of the allocated space is returned in 'Address' |
| |
| procedure SS_Free (Stk : in out System.Address); |
| -- Release the memory allocated for the Secondary Stack. That is to say, |
| -- all the allocated chuncks. |
| -- Upon return, Stk will be set to System.Null_Address |
| |
| type Mark_Id is private; |
| -- Type used to mark the stack. |
| |
| function SS_Mark return Mark_Id; |
| -- Return the Mark corresponding to the current state of the stack |
| |
| procedure SS_Release (M : Mark_Id); |
| -- Restore the state of the stack corresponding to the mark M. If an |
| -- additional chunk have been allocated, it will never be freed during a |
| |
| generic |
| with procedure Put_Line (S : String); |
| procedure SS_Info; |
| -- Debugging procedure used to print out secondary Stack allocation |
| -- information. This procedure is generic in order to avoid a direct |
| -- dependence on a particular IO package. |
| |
| private |
| |
| SS_Pool : Integer; |
| -- Unused entity that is just present to ease the sharing of the pool |
| -- mechanism for specific allocation/deallocation in the compiler |
| |
| type Mark_Id is new SSE.Integer_Address; |
| |
| end System.Secondary_Stack; |
