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+--  Area based memory manager
+--  Copyright (C) 2014 Tristan Gingold
+--
+--  GHDL is free software; you can redistribute it and/or modify it under
+--  the terms of the GNU General Public License as published by the Free
+--  Software Foundation; either version 2, or (at your option) any later
+--  version.
+--
+--  GHDL is distributed in the hope that it will be useful, but WITHOUT 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
+--  along with GHDL; see the file COPYING.  If not, write to the Free
+--  Software Foundation, 59 Temple Place - Suite 330, Boston, MA
+--  02111-1307, USA.
+
+with System; use System;
+with System.Storage_Elements; use System.Storage_Elements;
+
+package Areapools is
+   type Areapool is limited private;
+   type Mark_Type is private;
+
+   type Areapool_Acc is access all Areapool;
+
+   --  Modular type for the size.  We don't use Storage_Offset in order to
+   --  make alignment computation efficient (knowing that alignment is a
+   --  power of two).
+   type Size_Type is mod System.Memory_Size;
+
+   --  Allocate SIZE bytes (aligned on ALIGN bytes) in memory pool POOL and
+   --  return the address in RES.
+   procedure Allocate (Pool : in out Areapool;
+                       Res : out Address;
+                       Size : Size_Type;
+                       Align : Size_Type);
+
+   --  Return TRUE iff no memory is allocated in POOL.
+   function Is_Empty (Pool : Areapool) return Boolean;
+
+   --  Higher level abstraction for Allocate.
+   generic
+      type T is private;
+   function Alloc_On_Pool_Addr (Pool : Areapool_Acc; Val : T)
+                               return System.Address;
+
+   --  Get a mark of POOL.
+   procedure Mark (M : out Mark_Type;
+                   Pool : Areapool);
+
+   --  Release memory allocated in POOL after mark M.
+   procedure Release (M : Mark_Type;
+                      Pool : in out Areapool);
+
+   Empty_Marker : constant Mark_Type;
+private
+   --  Minimal size of allocation.
+   Default_Chunk_Size : constant Size_Type := 16 * 1024;
+
+   type Chunk_Type;
+   type Chunk_Acc is access all Chunk_Type;
+
+   type Data_Array is array (Size_Type range <>) of Storage_Element;
+   for Data_Array'Alignment use Standard'Maximum_Alignment;
+
+   type Chunk_Type (Last : Size_Type) is record
+      Prev : Chunk_Acc;
+      Data : Data_Array (0 .. Last);
+   end record;
+   for Chunk_Type'Alignment use Standard'Maximum_Alignment;
+
+   type Areapool is limited record
+      First, Last : Chunk_Acc := null;
+      Next_Use : Size_Type;
+   end record;
+
+   type Mark_Type is record
+      Last : Chunk_Acc := null;
+      Next_Use : Size_Type;
+   end record;
+
+   Empty_Marker : constant Mark_Type := (Last => null, Next_Use => 0);
+
+   Erase_When_Released : constant Boolean := True;
+end Areapools;