1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
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
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . P O O L _ L O C A L --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2011, 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/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with System.Memory;
with Ada.Unchecked_Conversion;
package body System.Pool_Local is
package SSE renames System.Storage_Elements;
use type SSE.Storage_Offset;
Pointer_Size : constant SSE.Storage_Offset := Address'Size / Storage_Unit;
Pointers_Size : constant SSE.Storage_Offset := 2 * Pointer_Size;
type Acc_Address is access all Address;
function To_Acc_Address is
new Ada.Unchecked_Conversion (Address, Acc_Address);
-----------------------
-- Local Subprograms --
-----------------------
function Next (A : Address) return Acc_Address;
pragma Inline (Next);
-- Given an address of a block, return an access to the next block
function Prev (A : Address) return Acc_Address;
pragma Inline (Prev);
-- Given an address of a block, return an access to the previous block
--------------
-- Allocate --
--------------
procedure Allocate
(Pool : in out Unbounded_Reclaim_Pool;
Address : out System.Address;
Storage_Size : SSE.Storage_Count;
Alignment : SSE.Storage_Count)
is
pragma Warnings (Off, Alignment);
Allocated : constant System.Address :=
Memory.Alloc
(Memory.size_t (Storage_Size + Pointers_Size));
begin
-- The call to Alloc returns an address whose alignment is compatible
-- with the worst case alignment requirement for the machine; thus the
-- Alignment argument can be safely ignored.
if Allocated = Null_Address then
raise Storage_Error;
else
Address := Allocated + Pointers_Size;
Next (Allocated).all := Pool.First;
Prev (Allocated).all := Null_Address;
if Pool.First /= Null_Address then
Prev (Pool.First).all := Allocated;
end if;
Pool.First := Allocated;
end if;
end Allocate;
----------------
-- Deallocate --
----------------
procedure Deallocate
(Pool : in out Unbounded_Reclaim_Pool;
Address : System.Address;
Storage_Size : SSE.Storage_Count;
Alignment : SSE.Storage_Count)
is
pragma Warnings (Off, Storage_Size);
pragma Warnings (Off, Alignment);
Allocated : constant System.Address := Address - Pointers_Size;
begin
if Prev (Allocated).all = Null_Address then
Pool.First := Next (Allocated).all;
-- Comment needed
if Pool.First /= Null_Address then
Prev (Pool.First).all := Null_Address;
end if;
else
Next (Prev (Allocated).all).all := Next (Allocated).all;
end if;
if Next (Allocated).all /= Null_Address then
Prev (Next (Allocated).all).all := Prev (Allocated).all;
end if;
Memory.Free (Allocated);
end Deallocate;
--------------
-- Finalize --
--------------
procedure Finalize (Pool : in out Unbounded_Reclaim_Pool) is
N : System.Address := Pool.First;
Allocated : System.Address;
begin
while N /= Null_Address loop
Allocated := N;
N := Next (N).all;
Memory.Free (Allocated);
end loop;
end Finalize;
----------
-- Next --
----------
function Next (A : Address) return Acc_Address is
begin
return To_Acc_Address (A);
end Next;
----------
-- Prev --
----------
function Prev (A : Address) return Acc_Address is
begin
return To_Acc_Address (A + Pointer_Size);
end Prev;
end System.Pool_Local;
|
