1------------------------------------------------------------------------------ 2-- -- 3-- GNAT LIBRARY COMPONENTS -- 4-- -- 5-- ADA.CONTAINERS.BOUNDED_PRIORITY_QUEUES -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2011, 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-- This unit was originally developed by Matthew J Heaney. -- 32------------------------------------------------------------------------------ 33 34with System; 35 36with Ada.Containers.Synchronized_Queue_Interfaces; 37with Ada.Containers.Bounded_Doubly_Linked_Lists; 38 39generic 40 with package Queue_Interfaces is 41 new Ada.Containers.Synchronized_Queue_Interfaces (<>); 42 43 type Queue_Priority is private; 44 45 with function Get_Priority 46 (Element : Queue_Interfaces.Element_Type) return Queue_Priority is <>; 47 48 with function Before 49 (Left, Right : Queue_Priority) return Boolean is <>; 50 51 Default_Capacity : Count_Type; 52 Default_Ceiling : System.Any_Priority := System.Priority'Last; 53 54package Ada.Containers.Bounded_Priority_Queues is 55 pragma Preelaborate; 56 57 package Implementation is 58 59 -- All identifiers in this unit are implementation defined 60 61 pragma Implementation_Defined; 62 63 type List_Type (Capacity : Count_Type) is tagged limited private; 64 65 procedure Enqueue 66 (List : in out List_Type; 67 New_Item : Queue_Interfaces.Element_Type); 68 69 procedure Dequeue 70 (List : in out List_Type; 71 Element : out Queue_Interfaces.Element_Type); 72 73 procedure Dequeue 74 (List : in out List_Type; 75 At_Least : Queue_Priority; 76 Element : in out Queue_Interfaces.Element_Type; 77 Success : out Boolean); 78 79 function First_Element 80 (List : List_Type) return Queue_Interfaces.Element_Type; 81 82 function Length (List : List_Type) return Count_Type; 83 84 function Max_Length (List : List_Type) return Count_Type; 85 86 private 87 88 -- We need a better data structure here, such as a proper heap. ??? 89 90 package List_Types is new Bounded_Doubly_Linked_Lists 91 (Element_Type => Queue_Interfaces.Element_Type, 92 "=" => Queue_Interfaces."="); 93 94 type List_Type (Capacity : Count_Type) is tagged limited record 95 Container : List_Types.List (Capacity); 96 Max_Length : Count_Type := 0; 97 end record; 98 99 end Implementation; 100 101 protected type Queue 102 (Capacity : Count_Type := Default_Capacity; 103 Ceiling : System.Any_Priority := Default_Ceiling) 104 with Priority => Ceiling is new Queue_Interfaces.Queue with 105 106 overriding 107 entry Enqueue (New_Item : Queue_Interfaces.Element_Type); 108 109 overriding 110 entry Dequeue (Element : out Queue_Interfaces.Element_Type); 111 112 -- The priority queue operation Dequeue_Only_High_Priority had been a 113 -- protected entry in early drafts of AI05-0159, but it was discovered 114 -- that that operation as specified was not in fact implementable. The 115 -- operation was changed from an entry to a protected procedure per the 116 -- ARG meeting in Edinburgh (June 2011), with a different signature and 117 -- semantics. 118 119 not overriding 120 procedure Dequeue_Only_High_Priority 121 (At_Least : Queue_Priority; 122 Element : in out Queue_Interfaces.Element_Type; 123 Success : out Boolean); 124 125 overriding 126 function Current_Use return Count_Type; 127 128 overriding 129 function Peak_Use return Count_Type; 130 131 private 132 133 List : Implementation.List_Type (Capacity); 134 135 end Queue; 136 137end Ada.Containers.Bounded_Priority_Queues; 138