1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT COMPILER COMPONENTS                         --
4--                                                                          --
5--                   S Y S T E M . P O O L _ G L O B A L                    --
6--                                                                          --
7--                                 B o d y                                  --
8--                                                                          --
9--          Copyright (C) 1992-2011, Free Software Foundation, Inc.         --
10--                                                                          --
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 3,  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.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 3.1, as published by the Free Software Foundation.               --
21--                                                                          --
22-- You should have received a copy of the GNU General Public License and    --
23-- a copy of the GCC Runtime Library Exception along with this program;     --
24-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
25-- <http://www.gnu.org/licenses/>.                                          --
26--                                                                          --
27-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32with System.Storage_Pools; use System.Storage_Pools;
33with System.Memory;
34
35package body System.Pool_Global is
36
37   package SSE renames System.Storage_Elements;
38
39   --------------
40   -- Allocate --
41   --------------
42
43   overriding procedure Allocate
44     (Pool         : in out Unbounded_No_Reclaim_Pool;
45      Address      : out System.Address;
46      Storage_Size : SSE.Storage_Count;
47      Alignment    : SSE.Storage_Count)
48   is
49      use SSE;
50      pragma Warnings (Off, Pool);
51
52      Aligned_Size    : Storage_Count := Storage_Size;
53      Aligned_Address : System.Address;
54      Allocated       : System.Address;
55
56   begin
57      if Alignment > Standard'System_Allocator_Alignment then
58         Aligned_Size := Aligned_Size + Alignment;
59      end if;
60
61      Allocated := Memory.Alloc (Memory.size_t (Aligned_Size));
62
63      --  The call to Alloc returns an address whose alignment is compatible
64      --  with the worst case alignment requirement for the machine; thus the
65      --  Alignment argument can be safely ignored.
66
67      if Allocated = Null_Address then
68         raise Storage_Error;
69      end if;
70
71      --  Case where alignment requested is greater than the alignment that is
72      --  guaranteed to be provided by the system allocator.
73
74      if Alignment > Standard'System_Allocator_Alignment then
75
76         --  Realign the returned address
77
78         Aligned_Address := To_Address
79           (To_Integer (Allocated) + Integer_Address (Alignment)
80              - (To_Integer (Allocated) mod Integer_Address (Alignment)));
81
82         --  Save the block address
83
84         declare
85            Saved_Address : System.Address;
86            pragma Import (Ada, Saved_Address);
87            for Saved_Address'Address use
88               Aligned_Address
89               - Storage_Offset (System.Address'Size / Storage_Unit);
90         begin
91            Saved_Address := Allocated;
92         end;
93
94         Address := Aligned_Address;
95
96      else
97         Address := Allocated;
98      end if;
99   end Allocate;
100
101   ----------------
102   -- Deallocate --
103   ----------------
104
105   overriding procedure Deallocate
106     (Pool         : in out Unbounded_No_Reclaim_Pool;
107      Address      : System.Address;
108      Storage_Size : SSE.Storage_Count;
109      Alignment    : SSE.Storage_Count)
110   is
111      use System.Storage_Elements;
112      pragma Warnings (Off, Pool);
113      pragma Warnings (Off, Storage_Size);
114
115   begin
116      --  Case where the alignment of the block exceeds the guaranteed
117      --  alignment required by the system storage allocator, meaning that
118      --  this was specially wrapped at allocation time.
119
120      if Alignment > Standard'System_Allocator_Alignment then
121
122         --  Retrieve the block address
123
124         declare
125            Saved_Address : System.Address;
126            pragma Import (Ada, Saved_Address);
127            for Saved_Address'Address use
128              Address - Storage_Offset (System.Address'Size / Storage_Unit);
129         begin
130            Memory.Free (Saved_Address);
131         end;
132
133      else
134         Memory.Free (Address);
135      end if;
136   end Deallocate;
137
138   ------------------
139   -- Storage_Size --
140   ------------------
141
142   overriding function Storage_Size
143     (Pool  : Unbounded_No_Reclaim_Pool)
144      return  SSE.Storage_Count
145   is
146      pragma Warnings (Off, Pool);
147
148   begin
149      --  Intuitively, should return System.Memory_Size. But on Sun/Alsys,
150      --  System.Memory_Size > System.Max_Int, which means all you can do with
151      --  it is raise CONSTRAINT_ERROR...
152
153      return SSE.Storage_Count'Last;
154   end Storage_Size;
155
156end System.Pool_Global;
157