18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
|
-
+
-
+
|
package body Natools.References is
---------------------------------
-- Low-level memory management --
---------------------------------
overriding procedure Adjust (Object : in out Reference) is
overriding procedure Adjust (Object : in out Immutable_Reference) is
begin
if Object.Count /= null then
Object.Count.all := Object.Count.all + 1;
end if;
end Adjust;
overriding procedure Finalize (Object : in out Reference) is
overriding procedure Finalize (Object : in out Immutable_Reference) is
procedure Free is
new Ada.Unchecked_Deallocation (Held_Data, Data_Access);
procedure Free is
new Ada.Unchecked_Deallocation (Counter, Counter_Access);
begin
if Object.Count /= null then
Object.Count.all := Object.Count.all - 1;
|
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
-
+
-
+
-
+
-
+
-
+
-
+
-
+
|
-----------------------------------------
-- Object construction and destruction --
-----------------------------------------
function Create
(Constructor : not null access function return Held_Data)
return Reference is
return Immutable_Reference is
begin
return (Ada.Finalization.Controlled with
Data => new Held_Data'(Constructor.all),
Count => new Counter'(1));
end Create;
procedure Replace
(Ref : in out Reference;
(Ref : in out Immutable_Reference;
Constructor : not null access function return Held_Data) is
begin
Finalize (Ref);
Ref.Data := new Held_Data'(Constructor.all);
Ref.Count := new Counter'(1);
end Replace;
procedure Reset (Ref : in out Reference) is
procedure Reset (Ref : in out Immutable_Reference) is
begin
Finalize (Ref);
end Reset;
function Is_Empty (Ref : Reference) return Boolean is
function Is_Empty (Ref : Immutable_Reference) return Boolean is
begin
return Ref.Count = null;
end Is_Empty;
function "=" (Left, Right : Reference) return Boolean is
function "=" (Left, Right : Immutable_Reference) return Boolean is
begin
return Left.Data = Right.Data;
end "=";
----------------------
-- Dereferenciation --
----------------------
function Query (Ref : in Reference) return Accessor is
function Query (Ref : in Immutable_Reference) return Accessor is
begin
return Accessor'(Data => Ref.Data, Parent => Ref);
end Query;
function Update (Ref : in Reference) return Mutator is
begin
return Mutator'(Data => Ref.Data, Parent => Ref);
end Update;
procedure Query
(Ref : in Reference;
(Ref : in Immutable_Reference;
Process : not null access procedure (Object : in Held_Data)) is
begin
Process.all (Ref.Data.all);
end Query;
procedure Update
|