1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . P O O L _ L O C A L --
9 -- Copyright (C) 1992-2002, Free Software Foundation, Inc. --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
35 with System
.Storage_Elements
;
37 with Unchecked_Conversion
;
39 package body System
.Pool_Local
is
41 package SSE
renames System
.Storage_Elements
;
42 use type SSE
.Storage_Offset
;
44 Pointer_Size
: constant SSE
.Storage_Offset
:= Address
'Size / Storage_Unit
;
45 Pointers_Size
: constant SSE
.Storage_Offset
:= 2 * Pointer_Size
;
47 type Acc_Address
is access all Address
;
48 function To_Acc_Address
is new Unchecked_Conversion
(Address
, Acc_Address
);
50 -----------------------
51 -- Local Subprograms --
52 -----------------------
54 function Next
(A
: Address
) return Acc_Address
;
56 -- Given an address of a block, return an access to the next block
58 function Prev
(A
: Address
) return Acc_Address
;
60 -- Given an address of a block, return an access to the previous block
67 (Pool
: in out Unbounded_Reclaim_Pool
;
68 Address
: out System
.Address
;
69 Storage_Size
: SSE
.Storage_Count
;
70 Alignment
: SSE
.Storage_Count
)
72 pragma Warnings
(Off
, Alignment
);
74 Allocated
: constant System
.Address
:=
76 (Memory
.size_t
(Storage_Size
+ Pointers_Size
));
79 -- The call to Alloc returns an address whose alignment is compatible
80 -- with the worst case alignment requirement for the machine; thus the
81 -- Alignment argument can be safely ignored.
83 if Allocated
= Null_Address
then
86 Address
:= Allocated
+ Pointers_Size
;
87 Next
(Allocated
).all := Pool
.First
;
88 Prev
(Allocated
).all := Null_Address
;
90 if Pool
.First
/= Null_Address
then
91 Prev
(Pool
.First
).all := Allocated
;
94 Pool
.First
:= Allocated
;
103 (Pool
: in out Unbounded_Reclaim_Pool
;
104 Address
: System
.Address
;
105 Storage_Size
: SSE
.Storage_Count
;
106 Alignment
: SSE
.Storage_Count
)
108 pragma Warnings
(Off
, Storage_Size
);
109 pragma Warnings
(Off
, Alignment
);
111 Allocated
: constant System
.Address
:= Address
- Pointers_Size
;
114 if Prev
(Allocated
).all = Null_Address
then
115 Pool
.First
:= Next
(Allocated
).all;
116 Prev
(Pool
.First
).all := Null_Address
;
118 Next
(Prev
(Allocated
).all).all := Next
(Allocated
).all;
121 if Next
(Allocated
).all /= Null_Address
then
122 Prev
(Next
(Allocated
).all).all := Prev
(Allocated
).all;
125 Memory
.Free
(Allocated
);
132 procedure Finalize
(Pool
: in out Unbounded_Reclaim_Pool
) is
133 N
: System
.Address
:= Pool
.First
;
134 Allocated
: System
.Address
;
137 while N
/= Null_Address
loop
140 Memory
.Free
(Allocated
);
148 function Next
(A
: Address
) return Acc_Address
is
150 return To_Acc_Address
(A
);
157 function Prev
(A
: Address
) return Acc_Address
is
159 return To_Acc_Address
(A
+ Pointer_Size
);
162 end System
.Pool_Local
;