------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . F I N A L I Z A T I O N _ I M P L E M E N T A T I O N -- -- -- -- S p e c -- -- -- -- -- -- Copyright (C) 1992-1998 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. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with System.Finalization_Root; package System.Finalization_Implementation is pragma Elaborate_Body (Finalization_Implementation); package SFR renames System.Finalization_Root; ------------------------------------------------ -- Finalization Management Abstract Interface -- ------------------------------------------------ Global_Final_List : SFR.Finalizable_Ptr; -- This list stores the controlled objects defined in library-level -- packages. They will be finalized after the main program completion. procedure Finalize_Global_List; -- The procedure to be called in order to finalize the global list; procedure Attach_To_Final_List (L : in out SFR.Finalizable_Ptr; Obj : in out SFR.Finalizable; Nb_Link : Short_Short_Integer); -- Attach finalizable object Obj to the linked list L. Nb_Link controls -- the number of link of the linked_list, and can be either 0 for no -- attachement, 1 for simple linked lists or 2 for doubly linked lists -- or even 3 for a simple attachement of a whole array of elements. -- Attachement to a simply linked list is not protected against -- concurrent access and should only be used in context where it -- doesn't matter, such as for objects allocated on the stack. In the -- case of an attachment on a doubly linked list, L must not be null -- and Obj will be inserted AFTER the first element and the attachment -- is protected against concurrent call. Typically used to attach to -- a dynamically allocated object to a List_Controller (whose first -- element is always a dummy element) procedure Finalize_List (L : SFR.Finalizable_Ptr); -- Call Finalize on each element of the list L; procedure Finalize_One (Obj : in out SFR.Finalizable); -- Call Finalize on Obj and remove its final list. --------------------- -- Deep Procedures -- --------------------- procedure Deep_Tag_Initialize (L : in out SFR.Finalizable_Ptr; A : System.Address; B : Short_Short_Integer); -- Generic initialize for tagged objects with controlled components. A -- is the address of the object, L the finalization list when it needs -- to be attached and B the attachement level (see Attach_To_Final_List) procedure Deep_Tag_Adjust (L : in out SFR.Finalizable_Ptr; A : System.Address; B : Short_Short_Integer); -- Generic adjust for tagged objects with controlled components. A -- is the address of the object, L the finalization list when it needs -- to be attached and B the attachement level (see Attach_To_Final_List) procedure Deep_Tag_Finalize (L : in out SFR.Finalizable_Ptr; A : System.Address; B : Boolean); -- Generic finalize for tagged objects with controlled components. A -- is the address of the object, L the finalization list when it needs -- to be attached and B the attachement level (see Attach_To_Final_List) procedure Deep_Tag_Attach (L : in out SFR.Finalizable_Ptr; A : System.Address; B : Short_Short_Integer); -- Generic attachement for tagged objects with controlled components. A -- is the address of the object, L the finalization list when it needs -- to be attached and B the attachement level (see Attach_To_Final_List) ----------------------------- -- Record Controller Types -- ----------------------------- -- Definition of the types of the controller component that is included -- in records containing controlled components. This controller is -- attached to the finalization chain of the upper-level and carries -- the pointer of the finalization chain for the lower level type Limited_Record_Controller is new SFR.Root_Controlled with record F : SFR.Finalizable_Ptr; end record; procedure Initialize (Object : in out Limited_Record_Controller); -- Does nothing procedure Finalize (Object : in out Limited_Record_Controller); -- Finalize the controlled components of the enclosing record by -- following the list starting at Object.F type Record_Controller is new Limited_Record_Controller with record My_Address : System.Address; end record; procedure Initialize (Object : in out Record_Controller); -- Initialize the field My_Address to the Object'Address procedure Adjust (Object : in out Record_Controller); -- Adjust the components and their finalization pointers by subtracting -- by the offset of the target and the source addresses of the assignment -- Inherit Finalize from Limited_Record_Controller procedure Detach_From_Final_List (Obj : in out SFR.Finalizable); -- Remove the specified object from its Final list which must be a -- doubly linked list. end System.Finalization_Implementation;