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Diffstat (limited to 'gcc/ada/a-coinho-shared.adb')
| -rw-r--r-- | gcc/ada/a-coinho-shared.adb | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/gcc/ada/a-coinho-shared.adb b/gcc/ada/a-coinho-shared.adb new file mode 100644 index 00000000000..9300c0b1dc6 --- /dev/null +++ b/gcc/ada/a-coinho-shared.adb @@ -0,0 +1,358 @@ +------------------------------------------------------------------------------ +-- -- +-- 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 -- +-- -- +-- B o d y -- +-- -- +-- Copyright (C) 2013, 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 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/>. -- +------------------------------------------------------------------------------ + +with Ada.Unchecked_Deallocation; + +package body Ada.Containers.Indefinite_Holders is + + procedure Free is + new Ada.Unchecked_Deallocation (Element_Type, Element_Access); + + --------- + -- "=" -- + --------- + + function "=" (Left, Right : Holder) return Boolean is + begin + if Left.Reference = null and Right.Reference = null then + return True; + + elsif Left.Reference /= null and Right.Reference /= null then + return Left.Reference.Element.all = Right.Reference.Element.all; + + else + return False; + end if; + end "="; + + ------------ + -- Adjust -- + ------------ + + overriding procedure Adjust (Container : in out Holder) is + begin + if Container.Reference /= null then + Reference (Container.Reference); + end if; + + Container.Busy := 0; + end Adjust; + + ------------ + -- Assign -- + ------------ + + procedure Assign (Target : in out Holder; Source : Holder) is + begin + if Target.Busy /= 0 then + raise Program_Error with "attempt to tamper with elements"; + end if; + + if Target.Reference /= Source.Reference then + if Target.Reference /= null then + Unreference (Target.Reference); + end if; + + Target.Reference := Source.Reference; + + if Source.Reference /= null then + Reference (Target.Reference); + end if; + end if; + end Assign; + + ----------- + -- Clear -- + ----------- + + procedure Clear (Container : in out Holder) is + begin + if Container.Busy /= 0 then + raise Program_Error with "attempt to tamper with elements"; + end if; + + Unreference (Container.Reference); + Container.Reference := null; + end Clear; + + ---------- + -- Copy -- + ---------- + + function Copy (Source : Holder) return Holder is + begin + if Source.Reference = null then + return (AF.Controlled with null, 0); + else + Reference (Source.Reference); + + return (AF.Controlled with Source.Reference, 0); + end if; + end Copy; + + ------------- + -- Element -- + ------------- + + function Element (Container : Holder) return Element_Type is + begin + if Container.Reference = null then + raise Constraint_Error with "container is empty"; + else + return Container.Reference.Element.all; + end if; + end Element; + + -------------- + -- Finalize -- + -------------- + + overriding procedure Finalize (Container : in out Holder) is + begin + if Container.Busy /= 0 then + raise Program_Error with "attempt to tamper with elements"; + end if; + + if Container.Reference /= null then + Unreference (Container.Reference); + Container.Reference := null; + end if; + end Finalize; + + -------------- + -- Is_Empty -- + -------------- + + function Is_Empty (Container : Holder) return Boolean is + begin + return Container.Reference = null; + end Is_Empty; + + ---------- + -- Move -- + ---------- + + procedure Move (Target : in out Holder; Source : in out Holder) is + begin + if Target.Busy /= 0 then + raise Program_Error with "attempt to tamper with elements"; + end if; + + if Source.Busy /= 0 then + raise Program_Error with "attempt to tamper with elements"; + end if; + + if Target.Reference /= Source.Reference then + if Target.Reference /= null then + Unreference (Target.Reference); + end if; + + Target.Reference := Source.Reference; + Source.Reference := null; + end if; + end Move; + + ------------------- + -- Query_Element -- + ------------------- + + procedure Query_Element + (Container : Holder; + Process : not null access procedure (Element : Element_Type)) + is + B : Natural renames Container'Unrestricted_Access.Busy; + + begin + if Container.Reference = null then + raise Constraint_Error with "container is empty"; + end if; + + B := B + 1; + + begin + Process (Container.Reference.Element.all); + exception + when others => + B := B - 1; + raise; + end; + + B := B - 1; + end Query_Element; + + ---------- + -- Read -- + ---------- + + procedure Read + (Stream : not null access Ada.Streams.Root_Stream_Type'Class; + Container : out Holder) + is + begin + Clear (Container); + + if not Boolean'Input (Stream) then + Container.Reference := + new Shared_Holder' + (Counter => <>, + Element => new Element_Type'(Element_Type'Input (Stream))); + end if; + end Read; + + --------------- + -- Reference -- + --------------- + + procedure Reference (Item : not null Shared_Holder_Access) is + begin + System.Atomic_Counters.Increment (Item.Counter); + end Reference; + + --------------------- + -- Replace_Element -- + --------------------- + + procedure Replace_Element + (Container : in out Holder; + New_Item : Element_Type) + is + -- Element allocator may need an accessibility check in case actual type + -- is class-wide or has access discriminants (RM 4.8(10.1) and + -- AI12-0035). + + pragma Unsuppress (Accessibility_Check); + + begin + if Container.Busy /= 0 then + raise Program_Error with "attempt to tamper with elements"; + end if; + + if Container.Reference = null then + -- Holder is empty, allocate new Shared_Holder. + + Container.Reference := + new Shared_Holder' + (Counter => <>, + Element => new Element_Type'(New_Item)); + + elsif System.Atomic_Counters.Is_One (Container.Reference.Counter) then + -- Shared_Holder can be reused. + + Free (Container.Reference.Element); + Container.Reference.Element := new Element_Type'(New_Item); + + else + Unreference (Container.Reference); + Container.Reference := + new Shared_Holder' + (Counter => <>, + Element => new Element_Type'(New_Item)); + end if; + end Replace_Element; + + --------------- + -- To_Holder -- + --------------- + + function To_Holder (New_Item : Element_Type) return Holder is + -- The element allocator may need an accessibility check in the case the + -- actual type is class-wide or has access discriminants (RM 4.8(10.1) + -- and AI12-0035). + + pragma Unsuppress (Accessibility_Check); + + begin + return + (AF.Controlled with + new Shared_Holder' + (Counter => <>, + Element => new Element_Type'(New_Item)), 0); + end To_Holder; + + ----------------- + -- Unreference -- + ----------------- + + procedure Unreference (Item : not null Shared_Holder_Access) is + + procedure Free is + new Ada.Unchecked_Deallocation (Shared_Holder, Shared_Holder_Access); + + Aux : Shared_Holder_Access := Item; + + begin + if System.Atomic_Counters.Decrement (Aux.Counter) then + Free (Aux.Element); + Free (Aux); + end if; + end Unreference; + + -------------------- + -- Update_Element -- + -------------------- + + procedure Update_Element + (Container : Holder; + Process : not null access procedure (Element : in out Element_Type)) + is + B : Natural renames Container'Unrestricted_Access.Busy; + + begin + if Container.Reference = null then + raise Constraint_Error with "container is empty"; + end if; + + B := B + 1; + + begin + Process (Container.Reference.Element.all); + exception + when others => + B := B - 1; + raise; + end; + + B := B - 1; + end Update_Element; + + ----------- + -- Write -- + ----------- + + procedure Write + (Stream : not null access Ada.Streams.Root_Stream_Type'Class; + Container : Holder) + is + begin + Boolean'Output (Stream, Container.Reference = null); + + if Container.Reference /= null then + Element_Type'Output (Stream, Container.Reference.Element.all); + end if; + end Write; + +end Ada.Containers.Indefinite_Holders; |