1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME COMPONENTS --
5 -- S Y S T E M . M E M O R Y --
9 -- Copyright (C) 2001-2009, 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 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. --
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. --
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/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 -- This is the default implementation of this package
34 -- This implementation assumes that the underlying malloc/free/realloc
35 -- implementation is thread safe, and thus, no additional lock is required.
36 -- Note that we still need to defer abort because on most systems, an
37 -- asynchronous signal (as used for implementing asynchronous abort of
38 -- task) cannot safely be handled while malloc is executing.
40 -- If you are not using Ada constructs containing the "abort" keyword, then
41 -- 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");