gcc/ada/a-coinho-shared.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --    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     --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2013-2014, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- This specification is derived from the Ada Reference Manual for use with --
  12 -- GNAT. The copyright notice above, and the license provisions that follow --
  13 -- apply solely to the  contents of the part following the private keyword. --
  14 --                                                                          --
  15 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  16 -- terms of the  GNU General Public License as published  by the Free Soft- --
  17 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  18 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  19 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  20 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  21 --                                                                          --
  22 -- As a special exception under Section 7 of GPL version 3, you are granted --
  23 -- additional permissions described in the GCC Runtime Library Exception,   --
  24 -- version 3.1, as published by the Free Software Foundation.               --
  25 --                                                                          --
  26 -- You should have received a copy of the GNU General Public License and    --
  27 -- a copy of the GCC Runtime Library Exception along with this program;     --
  28 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  29 -- <http://www.gnu.org/licenses/>.                                          --
  30 ------------------------------------------------------------------------------
  31
  32 private with Ada.Finalization;
  33 private with Ada.Streams;
  34 private with System.Atomic_Counters;
  35
  36 generic
  37    type Element_Type (<>) is private;
  38    with function "=" (Left, Right : Element_Type) return Boolean is <>;
  39
  40 package Ada.Containers.Indefinite_Holders is
  41    pragma Preelaborate (Indefinite_Holders);
  42    pragma Remote_Types (Indefinite_Holders);
  43
  44    type Holder is tagged private;
  45    pragma Preelaborable_Initialization (Holder);
  46
  47    Empty_Holder : constant Holder;
  48
  49    function "=" (Left, Right : Holder) return Boolean;
  50
  51    function To_Holder (New_Item : Element_Type) return Holder;
  52
  53    function Is_Empty (Container : Holder) return Boolean;
  54
  55    procedure Clear (Container : in out Holder);
  56
  57    function Element (Container : Holder) return Element_Type;
  58
  59    procedure Replace_Element
  60      (Container : in out Holder;
  61       New_Item  : Element_Type);
  62
  63    procedure Query_Element
  64      (Container : Holder;
  65       Process   : not null access procedure (Element : Element_Type));
  66    procedure Update_Element
  67      (Container : Holder;
  68       Process   : not null access procedure (Element : in out Element_Type));
  69
  70    type Constant_Reference_Type
  71       (Element : not null access constant Element_Type) is private
  72    with
  73       Implicit_Dereference => Element;
  74
  75    type Reference_Type
  76      (Element : not null access Element_Type) is private
  77    with
  78       Implicit_Dereference => Element;
  79
  80    function Constant_Reference
  81      (Container : aliased Holder) return Constant_Reference_Type;
  82    pragma Inline (Constant_Reference);
  83
  84    function Reference
  85      (Container : aliased in out Holder) return Reference_Type;
  86    pragma Inline (Reference);
  87
  88    procedure Assign (Target : in out Holder; Source : Holder);
  89
  90    function Copy (Source : Holder) return Holder;
  91
  92    procedure Move (Target : in out Holder; Source : in out Holder);
  93
  94 private
  95
  96    use Ada.Finalization;
  97    use Ada.Streams;
  98
  99    type Element_Access is access all Element_Type;
 100
 101    type Shared_Holder is record
 102       Counter : System.Atomic_Counters.Atomic_Counter;
 103       Element : Element_Access;
 104    end record;
 105
 106    type Shared_Holder_Access is access all Shared_Holder;
 107
 108    procedure Reference (Item : not null Shared_Holder_Access);
 109    --  Increment reference counter
 110
 111    procedure Unreference (Item : not null Shared_Holder_Access);
 112    --  Decrement reference counter, deallocate Item when counter goes to zero
 113
 114    procedure Read
 115      (Stream    : not null access Ada.Streams.Root_Stream_Type'Class;
 116       Container : out Holder);
 117
 118    procedure Write
 119      (Stream    : not null access Ada.Streams.Root_Stream_Type'Class;
 120       Container : Holder);
 121
 122    type Holder is new Ada.Finalization.Controlled with record
 123       Reference : Shared_Holder_Access;
 124       Busy      : Natural := 0;
 125    end record;
 126    for Holder'Read use Read;
 127    for Holder'Write use Write;
 128
 129    overriding procedure Adjust (Container : in out Holder);
 130    overriding procedure Finalize (Container : in out Holder);
 131
 132    type Reference_Control_Type is new Controlled with
 133    record
 134       Container : Shared_Holder_Access;
 135    end record;
 136
 137    overriding procedure Adjust (Control : in out Reference_Control_Type);
 138    pragma Inline (Adjust);
 139
 140    overriding procedure Finalize (Control : in out Reference_Control_Type);
 141    pragma Inline (Finalize);
 142
 143    type Constant_Reference_Type
 144       (Element : not null access constant Element_Type) is
 145    record
 146       Control : Reference_Control_Type;
 147    end record;
 148
 149    procedure Write
 150      (Stream : not null access Root_Stream_Type'Class;
 151       Item   : Constant_Reference_Type);
 152
 153    for Constant_Reference_Type'Write use Write;
 154
 155    procedure Read
 156      (Stream : not null access Root_Stream_Type'Class;
 157       Item   : out Constant_Reference_Type);
 158
 159    for Constant_Reference_Type'Read use Read;
 160
 161    type Reference_Type (Element : not null access Element_Type) is record
 162       Control : Reference_Control_Type;
 163    end record;
 164
 165    procedure Write
 166      (Stream : not null access Root_Stream_Type'Class;
 167       Item   : Reference_Type);
 168
 169    for Reference_Type'Write use Write;
 170
 171    procedure Read
 172      (Stream : not null access Root_Stream_Type'Class;
 173       Item   : out Reference_Type);
 174
 175    for Reference_Type'Read use Read;
 176
 177    Empty_Holder : constant Holder := (Controlled with null, 0);
 178
 179 end Ada.Containers.Indefinite_Holders;