1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001-2002 Free Software Foundation, Inc. --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 2, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
21 -- for more details. You should have received a copy of the GNU General --
22 -- Public License distributed with GNAT; see file COPYING. If not, write --
23 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
24 -- MA 02111-1307, USA. --
26 -- As a special exception, if other files instantiate generics from this --
27 -- unit, or you link this unit with other files to produce an executable, --
28 -- this unit does not by itself cause the resulting executable to be --
29 -- covered by the GNU General Public License. This exception does not --
30 -- however invalidate any other reasons why the executable file might be --
31 -- covered by the GNU Public License. --
33 -- GNAT was originally developed by the GNAT team at New York University. --
34 -- Extensive contributions were provided by Ada Core Technologies Inc. --
36 ------------------------------------------------------------------------------
38 -- This is the default implementation of this package.
40 -- This implementation assumes that the underlying malloc/free/realloc
41 -- implementation is thread safe, and thus, no additional lock is required.
42 -- Note that we still need to defer abortion because on most systems,
43 -- an asynchronous signal (as used for implementing asynchronous abortion
44 -- of task) cannot safely be handled while malloc is executing.
46 -- If you are not using Ada constructs containing the "abort" keyword,
47 -- then you can remove the calls to Abort_Defer.all and Abort_Undefer.all
51 with System.Soft_Links;
52 with System.Parameters;
54 package body System.Memory is
57 use System.Soft_Links;
59 function c_malloc (Size : size_t) return System.Address;
60 pragma Import (C, c_malloc, "malloc");
62 procedure c_free (Ptr : System.Address);
63 pragma Import (C, c_free, "free");
66 (Ptr : System.Address; Size : size_t) return System.Address;
67 pragma Import (C, c_realloc, "realloc");
73 function Alloc (Size : size_t) return System.Address is
74 Result : System.Address;
75 Actual_Size : size_t := Size;
78 if Size = size_t'Last then
79 Raise_Exception (Storage_Error'Identity, "object too large");
82 -- Change size from zero to non-zero. We still want a proper pointer
83 -- for the zero case because pointers to zero length objects have to
84 -- be distinct, but we can't just go ahead and allocate zero bytes,
85 -- since some malloc's return zero for a zero argument.
91 if Parameters.No_Abort then
92 Result := c_malloc (Actual_Size);
95 Result := c_malloc (Actual_Size);
99 if Result = System.Null_Address then
100 Raise_Exception (Storage_Error'Identity, "heap exhausted");
110 procedure Free (Ptr : System.Address) is
112 if Parameters.No_Abort then
126 (Ptr : System.Address;
128 return System.Address
130 Result : System.Address;
131 Actual_Size : size_t := Size;
134 if Size = size_t'Last then
135 Raise_Exception (Storage_Error'Identity, "object too large");
138 if Parameters.No_Abort then
139 Result := c_realloc (Ptr, Actual_Size);
142 Result := c_realloc (Ptr, Actual_Size);
146 if Result = System.Null_Address then
147 Raise_Exception (Storage_Error'Identity, "heap exhausted");