1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001-2005 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 ------------------------------------------------------------------------------
34 -- This is the default implementation of this package.
36 -- This implementation assumes that the underlying malloc/free/realloc
37 -- implementation is thread safe, and thus, no additional lock is required.
38 -- Note that we still need to defer abort because on most systems, an
39 -- asynchronous signal (as used for implementing asynchronous abort of
40 -- task) cannot safely be handled while malloc is executing.
42 -- If you are not using Ada constructs containing the "abort" keyword, then
43 -- you can remove the calls to Abort_Defer.all and Abort_Undefer.all from
47 with System.Soft_Links;
48 with System.Parameters;
51 package body System.Memory is
54 use System.Soft_Links;
56 function c_malloc (Size : System.CRTL.size_t) return System.Address
57 renames System.CRTL.malloc;
59 procedure c_free (Ptr : System.Address)
60 renames System.CRTL.free;
63 (Ptr : System.Address; Size : System.CRTL.size_t) return System.Address
64 renames System.CRTL.realloc;
70 function Alloc (Size : size_t) return System.Address is
71 Result : System.Address;
72 Actual_Size : size_t := Size;
75 if Size = size_t'Last then
76 Raise_Exception (Storage_Error'Identity, "object too large");
79 -- Change size from zero to non-zero. We still want a proper pointer
80 -- for the zero case because pointers to zero length objects have to
81 -- be distinct, but we can't just go ahead and allocate zero bytes,
82 -- since some malloc's return zero for a zero argument.
88 if Parameters.No_Abort then
89 Result := c_malloc (System.CRTL.size_t (Actual_Size));
92 Result := c_malloc (System.CRTL.size_t (Actual_Size));
96 if Result = System.Null_Address then
97 Raise_Exception (Storage_Error'Identity, "heap exhausted");
107 procedure Free (Ptr : System.Address) is
109 if Parameters.No_Abort then
123 (Ptr : System.Address;
125 return System.Address
127 Result : System.Address;
128 Actual_Size : constant size_t := Size;
131 if Size = size_t'Last then
132 Raise_Exception (Storage_Error'Identity, "object too large");
135 if Parameters.No_Abort then
136 Result := c_realloc (Ptr, System.CRTL.size_t (Actual_Size));
139 Result := c_realloc (Ptr, System.CRTL.size_t (Actual_Size));
143 if Result = System.Null_Address then
144 Raise_Exception (Storage_Error'Identity, "heap exhausted");