1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
// Allocators -*- C++ -*-
// Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
* Copyright (c) 1996-1997
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/** @file allocator.h
* This is an internal header file, included by other library headers.
* You should not attempt to use it directly.
*/
/**
* @defgroup Allocators Memory Allocators
* @if maint
* allocator.h implements some node allocators. These are NOT the same as
* allocators in the C++ standard, nor in the original H-P STL. They do not
* encapsulate different pointer types; we assume that there is only one
* pointer type. The C++ standard allocators are intended to allocate
* individual objects, not pools or arenas.
*
* In this file allocators are of two different styles: "standard" and
* "SGI" (quotes included). "Standard" allocators conform to 20.4. "SGI"
* allocators differ in AT LEAST the following ways (add to this list as you
* discover them):
*
* - "Standard" allocate() takes two parameters (n_count,hint=0) but "SGI"
* allocate() takes one paramter (n_size).
* - Likewise, "standard" deallocate()'s argument is a count, but in "SGI"
* is a byte size.
* - max_size(), construct(), and destroy() are missing in "SGI" allocators.
* - reallocate(p,oldsz,newsz) is added in "SGI", and behaves as
* if p=realloc(p,newsz).
*
* "SGI" allocators may be wrapped in __allocator to convert the interface
* into a "standard" one.
* @endif
*
* The canonical description of these classes is in docs/html/ext/howto.html
* or online at http://gcc.gnu.org/onlinedocs/libstdc++/ext/howto.html#3
*/
#ifndef _ALLOCATOR_H
#define _ALLOCATOR_H 1
#include <bits/functexcept.h> // For __throw_bad_alloc
#include <bits/allocator_traits.h>
// Pick a default underlying allocator.
#include <ext/pool_allocator.h>
namespace std
{
typedef __gnu_cxx::__pool_alloc<true, 0> __alloc;
/// The version for the default allocator.
template<typename _Tp, typename _Tp1>
struct _Alloc_traits<_Tp, allocator<_Tp1> >
{
static const bool _S_instanceless = true;
typedef __simple_alloc<_Tp, __alloc> _Alloc_type;
typedef allocator<_Tp> allocator_type;
};
//@}
}
namespace std
{
/**
* @brief The "standard" allocator, as per [20.4].
*
* The private _Alloc is "SGI" style. (See comments at the top
* of allocator.h.)
*
* The underlying allocator behaves as follows.
* - __pool_alloc is used via two typedefs
* - "__alloc" typedef is threadsafe via the locks
* - __new_alloc is used for memory requests
*
* (See @link Allocators allocators info @endlink for more.)
*/
template<typename _Tp>
class allocator
{
// The underlying allocator.
typedef __alloc _Alloc;
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef _Tp* pointer;
typedef const _Tp* const_pointer;
typedef _Tp& reference;
typedef const _Tp& const_reference;
typedef _Tp value_type;
template<typename _Tp1>
struct rebind
{ typedef allocator<_Tp1> other; };
allocator() throw() { }
allocator(const allocator&) throw() { }
template<typename _Tp1>
allocator(const allocator<_Tp1>&) throw() { }
~allocator() throw() { }
pointer
address(reference __x) const { return &__x; }
const_pointer
address(const_reference __x) const { return &__x; }
// NB: __n is permitted to be 0. The C++ standard says nothing
// about what the return value is when __n == 0.
_Tp*
allocate(size_type __n, const void* = 0)
{
_Tp* __ret = 0;
if (__n)
{
if (__n <= this->max_size())
__ret = static_cast<_Tp*>(_Alloc::allocate(__n * sizeof(_Tp)));
else
__throw_bad_alloc();
}
return __ret;
}
// __p is not permitted to be a null pointer.
void
deallocate(pointer __p, size_type __n)
{ _Alloc::deallocate(__p, __n * sizeof(_Tp)); }
size_type
max_size() const throw() { return size_t(-1) / sizeof(_Tp); }
void construct(pointer __p, const _Tp& __val) { new(__p) _Tp(__val); }
void destroy(pointer __p) { __p->~_Tp(); }
};
template<>
class allocator<void>
{
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef void* pointer;
typedef const void* const_pointer;
typedef void value_type;
template<typename _Tp1>
struct rebind
{ typedef allocator<_Tp1> other; };
};
template<typename _T1, typename _T2>
inline bool
operator==(const allocator<_T1>&, const allocator<_T2>&)
{ return true; }
template<typename _T1, typename _T2>
inline bool
operator!=(const allocator<_T1>&, const allocator<_T2>&)
{ return false; }
// Inhibit implicit instantiations for required instantiations,
// which are defined via explicit instantiations elsewhere.
// NB: This syntax is a GNU extension.
#if _GLIBCXX_EXTERN_TEMPLATE
extern template class allocator<char>;
extern template class allocator<wchar_t>;
#endif
} // namespace std
#endif
|
