Merge branch 'master' of ssh://crater.dragonflybsd.org/repository/git/dragonfly
[dragonfly.git] / contrib / gcc-3.4 / libstdc++-v3 / include / ext / debug_allocator.h
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1// Allocators -*- C++ -*-
2
3// Copyright (C) 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
4//
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 2, or (at your option)
9// any later version.
10
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
15
16// You should have received a copy of the GNU General Public License along
17// with this library; see the file COPYING. If not, write to the Free
18// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
19// USA.
20
21// As a special exception, you may use this file as part of a free software
22// library without restriction. Specifically, if other files instantiate
23// templates or use macros or inline functions from this file, or you compile
24// this file and link it with other files to produce an executable, this
25// file does not by itself cause the resulting executable to be covered by
26// the GNU General Public License. This exception does not however
27// invalidate any other reasons why the executable file might be covered by
28// the GNU General Public License.
29
30/*
31 * Copyright (c) 1996-1997
32 * Silicon Graphics Computer Systems, Inc.
33 *
34 * Permission to use, copy, modify, distribute and sell this software
35 * and its documentation for any purpose is hereby granted without fee,
36 * provided that the above copyright notice appear in all copies and
37 * that both that copyright notice and this permission notice appear
38 * in supporting documentation. Silicon Graphics makes no
39 * representations about the suitability of this software for any
40 * purpose. It is provided "as is" without express or implied warranty.
41 */
42
43/** @file ext/debug_allocator.h
44 * This file is a GNU extension to the Standard C++ Library.
45 * You should only include this header if you are using GCC 3 or later.
46 */
47
48#ifndef _DEBUG_ALLOCATOR_H
49#define _DEBUG_ALLOCATOR_H 1
50
51#include <cstdlib>
52
53namespace __gnu_cxx
54{
55 /**
56 * @brief A meta-allocator with debugging bits, as per [20.4].
57 *
58 * This is precisely the allocator defined in the C++ Standard.
59 * - all allocation calls operator new
60 * - all deallocation calls operator delete
61 *
62 * (See @link Allocators allocators info @endlink for more.)
63 */
64 template<typename _Alloc>
65 class debug_allocator
66 {
67 public:
68 typedef typename _Alloc::size_type size_type;
69 typedef typename _Alloc::difference_type difference_type;
70 typedef typename _Alloc::pointer pointer;
71 typedef typename _Alloc::const_pointer const_pointer;
72 typedef typename _Alloc::reference reference;
73 typedef typename _Alloc::const_reference const_reference;
74 typedef typename _Alloc::value_type value_type;
75
76 private:
77 // _M_extra is the number of objects that correspond to the
78 // extra space where debug information is stored.
79 size_type _M_extra;
80
81 _Alloc _M_allocator;
82
83 public:
84 debug_allocator()
85 {
86 const size_t __obj_size = sizeof(value_type);
87 _M_extra = (sizeof(size_type) + __obj_size - 1) / __obj_size;
88 }
89
90 pointer
91 allocate(size_type __n)
92 {
93 pointer __res = _M_allocator.allocate(__n + _M_extra);
94 size_type* __ps = reinterpret_cast<size_type*>(__res);
95 *__ps = __n;
96 return __res + _M_extra;
97 }
98
99 pointer
100 allocate(size_type __n, const void* __hint)
101 {
102 pointer __res = _M_allocator.allocate(__n + _M_extra, __hint);
103 size_type* __ps = reinterpret_cast<size_type*>(__res);
104 *__ps = __n;
105 return __res + _M_extra;
106 }
107
108 void
109 deallocate(pointer __p, size_type __n)
110 {
111 if (!__p)
112 abort();
113 pointer __real_p = __p - _M_extra;
114 if (*reinterpret_cast<size_type*>(__real_p) != __n)
115 abort();
116 _M_allocator.deallocate(__real_p, __n + _M_extra);
117 }
118 };
119} // namespace __gnu_cxx
120
121#endif