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
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
* 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.
*
* Copyright (c) 2002
* Hewlett-Packard Company
*
* 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. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*/
/*
* This implements standard-conforming allocators that interact with
* the garbage collector. Gc_alloctor<T> allocates garbage-collectable
* objects of type T. Traceable_allocator<T> allocates objects that
* are not temselves garbage collected, but are scanned by the
* collector for pointers to collectable objects. Traceable_alloc
* should be used for explicitly managed STL containers that may
* point to collectable objects.
*
* This code was derived from an earlier version of the GNU C++ standard
* library, which itself was derived from the SGI STL implementation.
*/
#ifndef GC_ALLOCATOR_H
#define GC_ALLOCATOR_H
#include "gc.h"
#if defined(__GNUC__)
# define GC_ATTR_UNUSED __attribute__((unused))
#else
# define GC_ATTR_UNUSED
#endif
/* First some helpers to allow us to dispatch on whether or not a type
* is known to be pointerfree.
* These are private, except that the client may invoke the
* GC_DECLARE_PTRFREE macro.
*/
struct GC_true_type {};
struct GC_false_type {};
template <class GC_tp>
struct GC_type_traits {
GC_false_type GC_is_ptr_free;
};
# define GC_DECLARE_PTRFREE(T) \
template<> struct GC_type_traits<T> { GC_true_type GC_is_ptr_free; }
GC_DECLARE_PTRFREE(signed char);
GC_DECLARE_PTRFREE(unsigned char);
GC_DECLARE_PTRFREE(signed short);
GC_DECLARE_PTRFREE(unsigned short);
GC_DECLARE_PTRFREE(signed int);
GC_DECLARE_PTRFREE(unsigned int);
GC_DECLARE_PTRFREE(signed long);
GC_DECLARE_PTRFREE(unsigned long);
GC_DECLARE_PTRFREE(float);
GC_DECLARE_PTRFREE(double);
/* The client may want to add others. */
// In the following GC_Tp is GC_true_type iff we are allocating a
// pointerfree object.
template <class GC_Tp>
inline void * GC_selective_alloc(size_t n, GC_Tp) {
return GC_MALLOC(n);
}
template <>
inline void * GC_selective_alloc<GC_true_type>(size_t n, GC_true_type) {
return GC_MALLOC_ATOMIC(n);
}
/* Now the public gc_allocator<T> class:
*/
template <class GC_Tp>
class gc_allocator {
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef GC_Tp* pointer;
typedef const GC_Tp* const_pointer;
typedef GC_Tp& reference;
typedef const GC_Tp& const_reference;
typedef GC_Tp value_type;
template <class GC_Tp1> struct rebind {
typedef gc_allocator<GC_Tp1> other;
};
gc_allocator() {}
# ifndef _MSC_VER
// I'm not sure why this is needed here in addition to the following.
// The standard specifies it for the standard allocator, but VC++ rejects
// it. -HB
gc_allocator(const gc_allocator&) throw() {}
# endif
template <class GC_Tp1> gc_allocator(const gc_allocator<GC_Tp1>&) throw() {}
~gc_allocator() throw() {}
pointer address(reference GC_x) const { return &GC_x; }
const_pointer address(const_reference GC_x) const { return &GC_x; }
// GC_n is permitted to be 0. The C++ standard says nothing about what
// the return value is when GC_n == 0.
GC_Tp* allocate(size_type GC_n, const void* = 0) {
GC_type_traits<GC_Tp> traits;
return static_cast<GC_Tp *>
(GC_selective_alloc(GC_n * sizeof(GC_Tp),
traits.GC_is_ptr_free));
}
// __p is not permitted to be a null pointer.
void deallocate(pointer __p, size_type GC_ATTR_UNUSED GC_n)
{ GC_FREE(__p); }
size_type max_size() const throw()
{ return size_t(-1) / sizeof(GC_Tp); }
void construct(pointer __p, const GC_Tp& __val) { new(__p) GC_Tp(__val); }
void destroy(pointer __p) { __p->~GC_Tp(); }
};
template<>
class gc_allocator<void> {
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef void* pointer;
typedef const void* const_pointer;
typedef void value_type;
template <class GC_Tp1> struct rebind {
typedef gc_allocator<GC_Tp1> other;
};
};
template <class GC_T1, class GC_T2>
inline bool operator==(const gc_allocator<GC_T1>&, const gc_allocator<GC_T2>&)
{
return true;
}
template <class GC_T1, class GC_T2>
inline bool operator!=(const gc_allocator<GC_T1>&, const gc_allocator<GC_T2>&)
{
return false;
}
/*
* And the public traceable_allocator class.
*/
// Note that we currently don't specialize the pointer-free case, since a
// pointer-free traceable container doesn't make that much sense,
// though it could become an issue due to abstraction boundaries.
template <class GC_Tp>
class traceable_allocator {
public:
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef GC_Tp* pointer;
typedef const GC_Tp* const_pointer;
typedef GC_Tp& reference;
typedef const GC_Tp& const_reference;
typedef GC_Tp value_type;
template <class GC_Tp1> struct rebind {
typedef traceable_allocator<GC_Tp1> other;
};
traceable_allocator() throw() {}
# ifndef _MSC_VER
traceable_allocator(const traceable_allocator&) throw() {}
# endif
template <class GC_Tp1> traceable_allocator
(const traceable_allocator<GC_Tp1>&) throw() {}
~traceable_allocator() throw() {}
pointer address(reference GC_x) const { return &GC_x; }
const_pointer address(const_reference GC_x) const { return &GC_x; }
// GC_n is permitted to be 0. The C++ standard says nothing about what
// the return value is when GC_n == 0.
GC_Tp* allocate(size_type GC_n, const void* = 0) {
return static_cast<GC_Tp*>(GC_MALLOC_UNCOLLECTABLE(GC_n * sizeof(GC_Tp)));
}
// __p is not permitted to be a null pointer.
void deallocate(pointer __p, size_type GC_ATTR_UNUSED GC_n)
{ GC_FREE(__p); }
size_type max_size() const throw()
{ return size_t(-1) / sizeof(GC_Tp); }
void construct(pointer __p, const GC_Tp& __val) { new(__p) GC_Tp(__val); }
void destroy(pointer __p) { __p->~GC_Tp(); }
};
template<>
class traceable_allocator<void> {
typedef size_t size_type;
typedef ptrdiff_t difference_type;
typedef void* pointer;
typedef const void* const_pointer;
typedef void value_type;
template <class GC_Tp1> struct rebind {
typedef traceable_allocator<GC_Tp1> other;
};
};
template <class GC_T1, class GC_T2>
inline bool operator==(const traceable_allocator<GC_T1>&, const traceable_allocator<GC_T2>&)
{
return true;
}
template <class GC_T1, class GC_T2>
inline bool operator!=(const traceable_allocator<GC_T1>&, const traceable_allocator<GC_T2>&)
{
return false;
}
#endif /* GC_ALLOCATOR_H */
|
