1 ------------------------------------------------------------------------------
3 -- GNAT LIBRARY COMPONENTS --
5 -- ADA.CONTAINERS.BOUNDED_PRIORITY_QUEUES --
9 -- Copyright (C) 2011-2013, Free Software Foundation, Inc. --
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. --
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. --
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. --
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/>. --
31 -- This unit was originally developed by Matthew J Heaney. --
32 ------------------------------------------------------------------------------
36 with Ada.Containers.Synchronized_Queue_Interfaces;
37 with Ada.Containers.Bounded_Doubly_Linked_Lists;
40 with package Queue_Interfaces is
41 new Ada.Containers.Synchronized_Queue_Interfaces (<>);
43 type Queue_Priority is private;
45 with function Get_Priority
46 (Element : Queue_Interfaces.Element_Type) return Queue_Priority is <>;
49 (Left, Right : Queue_Priority) return Boolean is <>;
51 Default_Capacity : Count_Type;
52 Default_Ceiling : System.Any_Priority := System.Priority'Last;
54 package Ada.Containers.Bounded_Priority_Queues is
57 package Implementation is
59 -- All identifiers in this unit are implementation defined
61 pragma Implementation_Defined;
63 type List_Type (Capacity : Count_Type) is tagged limited private;
66 (List : in out List_Type;
67 New_Item : Queue_Interfaces.Element_Type);
70 (List : in out List_Type;
71 Element : out Queue_Interfaces.Element_Type);
74 (List : in out List_Type;
75 At_Least : Queue_Priority;
76 Element : in out Queue_Interfaces.Element_Type;
77 Success : out Boolean);
79 function First_Element
80 (List : List_Type) return Queue_Interfaces.Element_Type;
82 function Length (List : List_Type) return Count_Type;
84 function Max_Length (List : List_Type) return Count_Type;
88 -- We need a better data structure here, such as a proper heap. ???
90 package List_Types is new Bounded_Doubly_Linked_Lists
91 (Element_Type => Queue_Interfaces.Element_Type,
92 "=" => Queue_Interfaces."=");
94 type List_Type (Capacity : Count_Type) is tagged limited record
95 Container : List_Types.List (Capacity);
96 Max_Length : Count_Type := 0;
102 (Capacity : Count_Type := Default_Capacity;
103 Ceiling : System.Any_Priority := Default_Ceiling)
106 is new Queue_Interfaces.Queue with
108 overriding entry Enqueue (New_Item : Queue_Interfaces.Element_Type);
110 overriding entry Dequeue (Element : out Queue_Interfaces.Element_Type);
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
119 procedure Dequeue_Only_High_Priority
120 (At_Least : Queue_Priority;
121 Element : in out Queue_Interfaces.Element_Type;
122 Success : out Boolean);
124 overriding function Current_Use return Count_Type;
126 overriding function Peak_Use return Count_Type;
129 List : Implementation.List_Type (Capacity);
132 end Ada.Containers.Bounded_Priority_Queues;