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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- ADA.CONTAINERS.BOUNDED_SYNCHRONIZED_QUEUES --
-- --
-- B o d y --
-- --
-- Copyright (C) 2011-2021, 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/>. --
-- --
-- This unit was originally developed by Matthew J Heaney. --
------------------------------------------------------------------------------
package body Ada.Containers.Bounded_Synchronized_Queues with
SPARK_Mode => Off
is
package body Implementation is
-------------
-- Dequeue --
-------------
procedure Dequeue
(List : in out List_Type;
Element : out Queue_Interfaces.Element_Type)
is
EE : Element_Array renames List.Elements;
begin
Element := EE (List.First);
List.Length := List.Length - 1;
if List.Length = 0 then
List.First := 0;
List.Last := 0;
elsif List.First <= List.Last then
List.First := List.First + 1;
else
List.First := List.First + 1;
if List.First > List.Capacity then
List.First := 1;
end if;
end if;
end Dequeue;
-------------
-- Enqueue --
-------------
procedure Enqueue
(List : in out List_Type;
New_Item : Queue_Interfaces.Element_Type)
is
begin
if List.Length >= List.Capacity then
raise Capacity_Error with "No capacity for insertion";
end if;
if List.Length = 0 then
List.Elements (1) := New_Item;
List.First := 1;
List.Last := 1;
elsif List.First <= List.Last then
if List.Last < List.Capacity then
List.Elements (List.Last + 1) := New_Item;
List.Last := List.Last + 1;
else
List.Elements (1) := New_Item;
List.Last := 1;
end if;
else
List.Elements (List.Last + 1) := New_Item;
List.Last := List.Last + 1;
end if;
List.Length := List.Length + 1;
if List.Length > List.Max_Length then
List.Max_Length := List.Length;
end if;
end Enqueue;
------------
-- Length --
------------
function Length (List : List_Type) return Count_Type is
begin
return List.Length;
end Length;
----------------
-- Max_Length --
----------------
function Max_Length (List : List_Type) return Count_Type is
begin
return List.Max_Length;
end Max_Length;
end Implementation;
protected body Queue is
-----------------
-- Current_Use --
-----------------
function Current_Use return Count_Type is
begin
return List.Length;
end Current_Use;
-------------
-- Dequeue --
-------------
entry Dequeue (Element : out Queue_Interfaces.Element_Type)
when List.Length > 0
is
begin
List.Dequeue (Element);
end Dequeue;
-------------
-- Enqueue --
-------------
entry Enqueue (New_Item : Queue_Interfaces.Element_Type)
when List.Length < Capacity
is
begin
List.Enqueue (New_Item);
end Enqueue;
--------------
-- Peak_Use --
--------------
function Peak_Use return Count_Type is
begin
return List.Max_Length;
end Peak_Use;
end Queue;
end Ada.Containers.Bounded_Synchronized_Queues;