1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
10 -- Copyright (C) 2001-2002 Free Software Foundation, Inc. --
12 -- This specification is derived from the Ada Reference Manual for use with --
13 -- GNAT. The copyright notice above, and the license provisions that follow --
14 -- apply solely to the contents of the part following the private keyword. --
16 -- GNAT is free software; you can redistribute it and/or modify it under --
17 -- terms of the GNU General Public License as published by the Free Soft- --
18 -- ware Foundation; either version 2, or (at your option) any later ver- --
19 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
20 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
21 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
22 -- for more details. You should have received a copy of the GNU General --
23 -- Public License distributed with GNAT; see file COPYING. If not, write --
24 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
25 -- MA 02111-1307, USA. --
27 -- As a special exception, if other files instantiate generics from this --
28 -- unit, or you link this unit with other files to produce an executable, --
29 -- this unit does not by itself cause the resulting executable to be --
30 -- covered by the GNU General Public License. This exception does not --
31 -- however invalidate any other reasons why the executable file might be --
32 -- covered by the GNU Public License. --
34 -- GNAT was originally developed by the GNAT team at New York University. --
35 -- Extensive contributions were provided by Ada Core Technologies Inc. --
37 ------------------------------------------------------------------------------
39 -- This is the default implementation of this package.
41 -- This implementation assumes that the underlying malloc/free/realloc
42 -- implementation is thread safe, and thus, no additional lock is required.
43 -- Note that we still need to defer abortion because on most systems,
44 -- an asynchronous signal (as used for implementing asynchronous abortion
45 -- of task) cannot safely be handled while malloc is executing.
47 -- If you are not using Ada constructs containing the "abort" keyword,
48 -- then you can remove the calls to Abort_Defer.all and Abort_Undefer.all
52 with System
.Soft_Links
;
53 with System
.Parameters
;
55 package body System
.Memory
is
58 use System
.Soft_Links
;
60 function c_malloc
(Size
: size_t
) return System
.Address
;
61 pragma Import
(C
, c_malloc
, "malloc");
63 procedure c_free
(Ptr
: System
.Address
);
64 pragma Import
(C
, c_free
, "free");
67 (Ptr
: System
.Address
; Size
: size_t
) return System
.Address
;
68 pragma Import
(C
, c_realloc
, "realloc");
74 function Alloc
(Size
: size_t
) return System
.Address
is
75 Result
: System
.Address
;
76 Actual_Size
: size_t
:= Size
;
79 if Size
= size_t
'Last then
80 Raise_Exception
(Storage_Error
'Identity, "object too large");
83 -- Change size from zero to non-zero. We still want a proper pointer
84 -- for the zero case because pointers to zero length objects have to
85 -- be distinct, but we can't just go ahead and allocate zero bytes,
86 -- since some malloc's return zero for a zero argument.
92 if Parameters
.No_Abort
then
93 Result
:= c_malloc
(Actual_Size
);
96 Result
:= c_malloc
(Actual_Size
);
100 if Result
= System
.Null_Address
then
101 Raise_Exception
(Storage_Error
'Identity, "heap exhausted");
111 procedure Free
(Ptr
: System
.Address
) is
113 if Parameters
.No_Abort
then
127 (Ptr
: System
.Address
;
129 return System
.Address
131 Result
: System
.Address
;
132 Actual_Size
: size_t
:= Size
;
135 if Size
= size_t
'Last then
136 Raise_Exception
(Storage_Error
'Identity, "object too large");
139 if Parameters
.No_Abort
then
140 Result
:= c_realloc
(Ptr
, Actual_Size
);
143 Result
:= c_realloc
(Ptr
, Actual_Size
);
147 if Result
= System
.Null_Address
then
148 Raise_Exception
(Storage_Error
'Identity, "heap exhausted");