| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- A D A . C O N T A I N E R S . I N D E F I N I T E _ H O L D E R S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 2013-2022, Free Software Foundation, Inc. -- |
| -- -- |
| -- This specification is derived from the Ada Reference Manual for use with -- |
| -- GNAT. The copyright notice above, and the license provisions that follow -- |
| -- apply solely to the contents of the part following the private keyword. -- |
| -- -- |
| -- 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 3, 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. -- |
| -- -- |
| -- As a special exception under Section 7 of GPL version 3, you are granted -- |
| -- additional permissions described in the GCC Runtime Library Exception, -- |
| -- version 3.1, as published by the Free Software Foundation. -- |
| -- -- |
| -- You should have received a copy of the GNU General Public License and -- |
| -- a copy of the GCC Runtime Library Exception along with this program; -- |
| -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- |
| -- <http://www.gnu.org/licenses/>. -- |
| ------------------------------------------------------------------------------ |
| |
| -- This is an optimized version of Indefinite_Holders using copy-on-write. |
| -- It is used on platforms that support atomic built-ins. |
| |
| private with Ada.Finalization; |
| private with Ada.Streams; |
| |
| private with System.Atomic_Counters; |
| private with Ada.Strings.Text_Buffers; |
| |
| generic |
| type Element_Type (<>) is private; |
| with function "=" (Left, Right : Element_Type) return Boolean is <>; |
| |
| package Ada.Containers.Indefinite_Holders is |
| pragma Annotate (CodePeer, Skip_Analysis); |
| pragma Preelaborate (Indefinite_Holders); |
| pragma Remote_Types (Indefinite_Holders); |
| |
| type Holder is tagged private; |
| pragma Preelaborable_Initialization (Holder); |
| |
| Empty_Holder : constant Holder; |
| |
| function "=" (Left, Right : Holder) return Boolean; |
| |
| function To_Holder (New_Item : Element_Type) return Holder; |
| |
| function Is_Empty (Container : Holder) return Boolean; |
| |
| procedure Clear (Container : in out Holder); |
| |
| function Element (Container : Holder) return Element_Type; |
| |
| procedure Replace_Element |
| (Container : in out Holder; |
| New_Item : Element_Type); |
| |
| procedure Query_Element |
| (Container : Holder; |
| Process : not null access procedure (Element : Element_Type)); |
| |
| procedure Update_Element |
| (Container : in out Holder; |
| Process : not null access procedure (Element : in out Element_Type)); |
| |
| type Constant_Reference_Type |
| (Element : not null access constant Element_Type) is private |
| with |
| Implicit_Dereference => Element; |
| |
| type Reference_Type |
| (Element : not null access Element_Type) is private |
| with |
| Implicit_Dereference => Element; |
| |
| function Constant_Reference |
| (Container : aliased Holder) return Constant_Reference_Type; |
| pragma Inline (Constant_Reference); |
| |
| function Reference |
| (Container : aliased in out Holder) return Reference_Type; |
| pragma Inline (Reference); |
| |
| procedure Assign (Target : in out Holder; Source : Holder); |
| |
| function Copy (Source : Holder) return Holder; |
| |
| procedure Move (Target : in out Holder; Source : in out Holder); |
| |
| procedure Swap (Left, Right : in out Holder); |
| |
| private |
| |
| use Ada.Finalization; |
| use Ada.Streams; |
| |
| type Element_Access is access all Element_Type; |
| |
| type Holder_Access is access all Holder; |
| |
| type Shared_Holder is record |
| Counter : System.Atomic_Counters.Atomic_Counter; |
| Element : Element_Access; |
| end record; |
| |
| type Shared_Holder_Access is access all Shared_Holder; |
| |
| procedure Reference (Item : not null Shared_Holder_Access); |
| -- Increment reference counter |
| |
| procedure Unreference (Item : not null Shared_Holder_Access); |
| -- Decrement reference counter, deallocate Item when counter goes to zero |
| |
| procedure Read |
| (Stream : not null access Ada.Streams.Root_Stream_Type'Class; |
| Container : out Holder); |
| |
| procedure Write |
| (Stream : not null access Ada.Streams.Root_Stream_Type'Class; |
| Container : Holder); |
| |
| type Holder is new Ada.Finalization.Controlled with record |
| Reference : Shared_Holder_Access; |
| Busy : Natural := 0; |
| end record with Put_Image => Put_Image; |
| |
| procedure Put_Image |
| (S : in out Ada.Strings.Text_Buffers.Root_Buffer_Type'Class; V : Holder); |
| |
| for Holder'Read use Read; |
| for Holder'Write use Write; |
| |
| overriding procedure Adjust (Container : in out Holder); |
| overriding procedure Finalize (Container : in out Holder); |
| |
| type Reference_Control_Type is new Controlled with record |
| Container : Holder_Access; |
| end record; |
| |
| overriding procedure Adjust (Control : in out Reference_Control_Type); |
| pragma Inline (Adjust); |
| |
| overriding procedure Finalize (Control : in out Reference_Control_Type); |
| pragma Inline (Finalize); |
| |
| type Constant_Reference_Type |
| (Element : not null access constant Element_Type) is |
| record |
| Control : Reference_Control_Type := |
| raise Program_Error with "uninitialized reference"; |
| -- The RM says, "The default initialization of an object of |
| -- type Constant_Reference_Type or Reference_Type propagates |
| -- Program_Error." |
| end record; |
| |
| procedure Write |
| (Stream : not null access Root_Stream_Type'Class; |
| Item : Constant_Reference_Type); |
| |
| for Constant_Reference_Type'Write use Write; |
| |
| procedure Read |
| (Stream : not null access Root_Stream_Type'Class; |
| Item : out Constant_Reference_Type); |
| |
| for Constant_Reference_Type'Read use Read; |
| |
| type Reference_Type (Element : not null access Element_Type) is record |
| Control : Reference_Control_Type := |
| raise Program_Error with "uninitialized reference"; |
| -- The RM says, "The default initialization of an object of |
| -- type Constant_Reference_Type or Reference_Type propagates |
| -- Program_Error." |
| end record; |
| |
| procedure Write |
| (Stream : not null access Root_Stream_Type'Class; |
| Item : Reference_Type); |
| |
| for Reference_Type'Write use Write; |
| |
| procedure Read |
| (Stream : not null access Root_Stream_Type'Class; |
| Item : out Reference_Type); |
| |
| for Reference_Type'Read use Read; |
| |
| Empty_Holder : constant Holder := (Controlled with null, 0); |
| |
| end Ada.Containers.Indefinite_Holders; |