42 #ifndef _POOL_ALLOCATOR_H
43 #define _POOL_ALLOCATOR_H 1
52 #if __cplusplus >= 201103L
56 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
58 _GLIBCXX_BEGIN_NAMESPACE_VERSION
77 typedef std::size_t size_t;
80 enum { _S_align = 8 };
81 enum { _S_max_bytes = 128 };
82 enum { _S_free_list_size = (size_t)_S_max_bytes / (
size_t)_S_align };
86 union _Obj* _M_free_list_link;
87 char _M_client_data[1];
90 static _Obj*
volatile _S_free_list[_S_free_list_size];
93 static char* _S_start_free;
94 static char* _S_end_free;
95 static size_t _S_heap_size;
98 _M_round_up(
size_t __bytes)
99 {
return ((__bytes + (
size_t)_S_align - 1) & ~((
size_t)_S_align - 1)); }
101 _GLIBCXX_CONST _Obj*
volatile*
102 _M_get_free_list(
size_t __bytes)
throw ();
105 _M_get_mutex()
throw ();
110 _M_refill(
size_t __n);
115 _M_allocate_chunk(
size_t __n,
int& __nobjs);
123 template<
typename _Tp>
127 static _Atomic_word _S_force_new;
130 typedef std::size_t size_type;
131 typedef std::ptrdiff_t difference_type;
132 typedef _Tp* pointer;
133 typedef const _Tp* const_pointer;
134 typedef _Tp& reference;
135 typedef const _Tp& const_reference;
136 typedef _Tp value_type;
138 template<
typename _Tp1>
142 #if __cplusplus >= 201103L
152 template<
typename _Tp1>
158 address(reference __x)
const _GLIBCXX_NOEXCEPT
162 address(const_reference __x)
const _GLIBCXX_NOEXCEPT
166 max_size()
const _GLIBCXX_USE_NOEXCEPT
167 {
return std::size_t(-1) /
sizeof(_Tp); }
169 #if __cplusplus >= 201103L
170 template<
typename _Up,
typename... _Args>
172 construct(_Up* __p, _Args&&... __args)
173 { ::new((
void *)__p) _Up(std::forward<_Args>(__args)...); }
175 template<
typename _Up>
177 destroy(_Up* __p) { __p->~_Up(); }
182 construct(pointer __p,
const _Tp& __val)
183 { ::new((
void *)__p) _Tp(__val); }
186 destroy(pointer __p) { __p->~_Tp(); }
189 _GLIBCXX_NODISCARD pointer
190 allocate(size_type __n,
const void* = 0);
193 deallocate(pointer __p, size_type __n);
196 template<
typename _Tp>
201 template<
typename _Tp>
203 operator!=(
const __pool_alloc<_Tp>&,
const __pool_alloc<_Tp>&)
206 template<
typename _Tp>
208 __pool_alloc<_Tp>::_S_force_new;
210 template<
typename _Tp>
211 _GLIBCXX_NODISCARD _Tp*
212 __pool_alloc<_Tp>::allocate(size_type __n,
const void*)
216 if (__builtin_expect(__n != 0,
true))
218 if (__n > this->max_size())
219 std::__throw_bad_alloc();
221 const size_t __bytes = __n *
sizeof(_Tp);
223 #if __cpp_aligned_new
224 if (
alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
226 std::align_val_t __al = std::align_val_t(
alignof(_Tp));
227 return static_cast<_Tp*
>(::operator
new(__bytes, __al));
234 if (_S_force_new == 0)
236 if (std::getenv(
"GLIBCXX_FORCE_NEW"))
237 __atomic_add_dispatch(&_S_force_new, 1);
239 __atomic_add_dispatch(&_S_force_new, -1);
242 if (__bytes >
size_t(_S_max_bytes) || _S_force_new > 0)
243 __ret =
static_cast<_Tp*
>(::operator
new(__bytes));
246 _Obj*
volatile* __free_list = _M_get_free_list(__bytes);
248 __scoped_lock sentry(_M_get_mutex());
249 _Obj* __restrict__ __result = *__free_list;
250 if (__builtin_expect(__result == 0, 0))
251 __ret =
static_cast<_Tp*
>(_M_refill(_M_round_up(__bytes)));
254 *__free_list = __result->_M_free_list_link;
255 __ret =
reinterpret_cast<_Tp*
>(__result);
258 std::__throw_bad_alloc();
264 template<
typename _Tp>
266 __pool_alloc<_Tp>::deallocate(pointer __p, size_type __n)
269 if (__builtin_expect(__n != 0 && __p != 0,
true))
271 #if __cpp_aligned_new
272 if (
alignof(_Tp) > __STDCPP_DEFAULT_NEW_ALIGNMENT__)
274 ::operator
delete(__p, std::align_val_t(
alignof(_Tp)));
278 const size_t __bytes = __n *
sizeof(_Tp);
279 if (__bytes >
static_cast<size_t>(_S_max_bytes) || _S_force_new > 0)
280 ::
operator delete(__p);
283 _Obj*
volatile* __free_list = _M_get_free_list(__bytes);
284 _Obj* __q =
reinterpret_cast<_Obj*
>(__p);
286 __scoped_lock sentry(_M_get_mutex());
287 __q ->_M_free_list_link = *__free_list;
293 _GLIBCXX_END_NAMESPACE_VERSION