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| 1 | // shared_ptr and weak_ptr implementation details -*- C++ -*- | |
| 2 | ||
| 3 | // Copyright (C) 2007-2015 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 3, 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 | // Under Section 7 of GPL version 3, you are granted additional | |
| 17 | // permissions described in the GCC Runtime Library Exception, version | |
| 18 | // 3.1, as published by the Free Software Foundation. | |
| 19 | ||
| 20 | // You should have received a copy of the GNU General Public License and | |
| 21 | // a copy of the GCC Runtime Library Exception along with this program; | |
| 22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
| 23 | // <http://www.gnu.org/licenses/>. | |
| 24 | ||
| 25 | // GCC Note: Based on files from version 1.32.0 of the Boost library. | |
| 26 | ||
| 27 | // shared_count.hpp | |
| 28 | // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. | |
| 29 | ||
| 30 | // shared_ptr.hpp | |
| 31 | // Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes. | |
| 32 | // Copyright (C) 2001, 2002, 2003 Peter Dimov | |
| 33 | ||
| 34 | // weak_ptr.hpp | |
| 35 | // Copyright (C) 2001, 2002, 2003 Peter Dimov | |
| 36 | ||
| 37 | // enable_shared_from_this.hpp | |
| 38 | // Copyright (C) 2002 Peter Dimov | |
| 39 | ||
| 40 | // Distributed under the Boost Software License, Version 1.0. (See | |
| 41 | // accompanying file LICENSE_1_0.txt or copy at | |
| 42 | // http://www.boost.org/LICENSE_1_0.txt) | |
| 43 | ||
| 44 | /** @file bits/shared_ptr_base.h | |
| 45 | * This is an internal header file, included by other library headers. | |
| 46 | * Do not attempt to use it directly. @headername{memory} | |
| 47 | */ | |
| 48 | ||
| 49 | #ifndef _SHARED_PTR_BASE_H | |
| 50 | #define _SHARED_PTR_BASE_H 1 | |
| 51 | ||
| 52 | #include <bits/allocated_ptr.h> | |
| 53 | #include <ext/aligned_buffer.h> | |
| 54 | ||
| 55 | namespace std _GLIBCXX_VISIBILITY(default) | |
| 56 | { | |
| 57 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
| 58 | ||
| 59 | #if _GLIBCXX_USE_DEPRECATED | |
| 60 | template<typename> class auto_ptr; | |
| 61 | #endif | |
| 62 | ||
| 63 | /** | |
| 64 | * @brief Exception possibly thrown by @c shared_ptr. | |
| 65 | * @ingroup exceptions | |
| 66 | */ | |
| 67 | class bad_weak_ptr : public std::exception | |
| 68 | { | |
| 69 | public: | |
| 70 | virtual char const* | |
| 71 | what() const noexcept; | |
| 72 | ||
| 73 | virtual ~bad_weak_ptr() noexcept; | |
| 74 | }; | |
| 75 | ||
| 76 | // Substitute for bad_weak_ptr object in the case of -fno-exceptions. | |
| 77 | inline void | |
| 78 | __throw_bad_weak_ptr() | |
| 79 | { _GLIBCXX_THROW_OR_ABORT(bad_weak_ptr()); } | |
| 80 | ||
| 81 | using __gnu_cxx::_Lock_policy; | |
| 82 | using __gnu_cxx::__default_lock_policy; | |
| 83 | using __gnu_cxx::_S_single; | |
| 84 | using __gnu_cxx::_S_mutex; | |
| 85 | using __gnu_cxx::_S_atomic; | |
| 86 | ||
| 87 | // Empty helper class except when the template argument is _S_mutex. | |
| 88 | template<_Lock_policy _Lp> | |
| 89 | class _Mutex_base | |
| 90 | { | |
| 91 | protected: | |
| 92 | // The atomic policy uses fully-fenced builtins, single doesn't care. | |
| 93 | enum { _S_need_barriers = 0 }; | |
| 94 | }; | |
| 95 | ||
| 96 | template<> | |
| 97 | class _Mutex_base<_S_mutex> | |
| 98 | : public __gnu_cxx::__mutex | |
| 99 | { | |
| 100 | protected: | |
| 101 | // This policy is used when atomic builtins are not available. | |
| 102 | // The replacement atomic operations might not have the necessary | |
| 103 | // memory barriers. | |
| 104 | enum { _S_need_barriers = 1 }; | |
| 105 | }; | |
| 106 | ||
| 107 | template<_Lock_policy _Lp = __default_lock_policy> | |
| 108 | class _Sp_counted_base | |
| 109 | : public _Mutex_base<_Lp> | |
| 110 | { | |
| 111 | public: | |
| 112 | _Sp_counted_base() noexcept | |
| 113 | : _M_use_count(1), _M_weak_count(1) { } | |
| 114 | ||
| 115 | virtual | |
| 116 | ~_Sp_counted_base() noexcept | |
| 117 | { } | |
| 118 | ||
| 119 | // Called when _M_use_count drops to zero, to release the resources | |
| 120 | // managed by *this. | |
| 121 | virtual void | |
| 122 | _M_dispose() noexcept = 0; | |
| 123 | ||
| 124 | // Called when _M_weak_count drops to zero. | |
| 125 | virtual void | |
| 126 | _M_destroy() noexcept | |
| 127 | { delete this; } | |
| 128 | ||
| 129 | virtual void* | |
| 130 | _M_get_deleter(const std::type_info&) noexcept = 0; | |
| 131 | ||
| 132 | void | |
| 133 | _M_add_ref_copy() | |
| 134 | { __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); } | |
| 135 | ||
| 136 | void | |
| 137 | _M_add_ref_lock(); | |
| 138 | ||
| 139 | bool | |
| 140 | _M_add_ref_lock_nothrow(); | |
| 141 | ||
| 142 | void | |
| 143 | _M_release() noexcept | |
| 144 | { | |
| 145 | // Be race-detector-friendly. For more info see bits/c++config. | |
| 146 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count); | |
| 147 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1) | |
| 148 | { | |
| 149 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count); | |
| 150 | _M_dispose(); | |
| 151 | // There must be a memory barrier between dispose() and destroy() | |
| 152 | // to ensure that the effects of dispose() are observed in the | |
| 153 | // thread that runs destroy(). | |
| 154 | // See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html | |
| 155 | if (_Mutex_base<_Lp>::_S_need_barriers) | |
| 156 | { | |
| 157 | _GLIBCXX_READ_MEM_BARRIER; | |
| 158 | _GLIBCXX_WRITE_MEM_BARRIER; | |
| 159 | } | |
| 160 | ||
| 161 | // Be race-detector-friendly. For more info see bits/c++config. | |
| 162 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count); | |
| 163 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, | |
| 164 | -1) == 1) | |
| 165 | { | |
| 166 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count); | |
| 167 | _M_destroy(); | |
| 168 | } | |
| 169 | } | |
| 170 | } | |
| 171 | ||
| 172 | void | |
| 173 | _M_weak_add_ref() noexcept | |
| 174 | { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); } | |
| 175 | ||
| 176 | void | |
| 177 | _M_weak_release() noexcept | |
| 178 | { | |
| 179 | // Be race-detector-friendly. For more info see bits/c++config. | |
| 180 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count); | |
| 181 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1) | |
| 182 | { | |
| 183 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count); | |
| 184 | if (_Mutex_base<_Lp>::_S_need_barriers) | |
| 185 | { | |
| 186 | // See _M_release(), | |
| 187 | // destroy() must observe results of dispose() | |
| 188 | _GLIBCXX_READ_MEM_BARRIER; | |
| 189 | _GLIBCXX_WRITE_MEM_BARRIER; | |
| 190 | } | |
| 191 | _M_destroy(); | |
| 192 | } | |
| 193 | } | |
| 194 | ||
| 195 | long | |
| 196 | _M_get_use_count() const noexcept | |
| 197 | { | |
| 198 | // No memory barrier is used here so there is no synchronization | |
| 199 | // with other threads. | |
| 200 | return __atomic_load_n(&_M_use_count, __ATOMIC_RELAXED); | |
| 201 | } | |
| 202 | ||
| 203 | private: | |
| 204 | _Sp_counted_base(_Sp_counted_base const&) = delete; | |
| 205 | _Sp_counted_base& operator=(_Sp_counted_base const&) = delete; | |
| 206 | ||
| 207 | _Atomic_word _M_use_count; // #shared | |
| 208 | _Atomic_word _M_weak_count; // #weak + (#shared != 0) | |
| 209 | }; | |
| 210 | ||
| 211 | template<> | |
| 212 | inline void | |
| 213 | _Sp_counted_base<_S_single>:: | |
| 214 | _M_add_ref_lock() | |
| 215 | { | |
| 216 | if (_M_use_count == 0) | |
| 217 | __throw_bad_weak_ptr(); | |
| 218 | ++_M_use_count; | |
| 219 | } | |
| 220 | ||
| 221 | template<> | |
| 222 | inline void | |
| 223 | _Sp_counted_base<_S_mutex>:: | |
| 224 | _M_add_ref_lock() | |
| 225 | { | |
| 226 | __gnu_cxx::__scoped_lock sentry(*this); | |
| 227 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0) | |
| 228 | { | |
| 229 | _M_use_count = 0; | |
| 230 | __throw_bad_weak_ptr(); | |
| 231 | } | |
| 232 | } | |
| 233 | ||
| 234 | template<> | |
| 235 | inline void | |
| 236 | _Sp_counted_base<_S_atomic>:: | |
| 237 | _M_add_ref_lock() | |
| 238 | { | |
| 239 | // Perform lock-free add-if-not-zero operation. | |
| 240 | _Atomic_word __count = _M_get_use_count(); | |
| 241 | do | |
| 242 | { | |
| 243 | if (__count == 0) | |
| 244 | __throw_bad_weak_ptr(); | |
| 245 | // Replace the current counter value with the old value + 1, as | |
| 246 | // long as it's not changed meanwhile. | |
| 247 | } | |
| 248 | while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1, | |
| 249 | true, __ATOMIC_ACQ_REL, | |
| 250 | __ATOMIC_RELAXED)); | |
| 251 | } | |
| 252 | ||
| 253 | template<> | |
| 254 | inline bool | |
| 255 | _Sp_counted_base<_S_single>:: | |
| 256 | _M_add_ref_lock_nothrow() | |
| 257 | { | |
| 258 | if (_M_use_count == 0) | |
| 259 | return false; | |
| 260 | ++_M_use_count; | |
| 261 | return true; | |
| 262 | } | |
| 263 | ||
| 264 | template<> | |
| 265 | inline bool | |
| 266 | _Sp_counted_base<_S_mutex>:: | |
| 267 | _M_add_ref_lock_nothrow() | |
| 268 | { | |
| 269 | __gnu_cxx::__scoped_lock sentry(*this); | |
| 270 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0) | |
| 271 | { | |
| 272 | _M_use_count = 0; | |
| 273 | return false; | |
| 274 | } | |
| 275 | return true; | |
| 276 | } | |
| 277 | ||
| 278 | template<> | |
| 279 | inline bool | |
| 280 | _Sp_counted_base<_S_atomic>:: | |
| 281 | _M_add_ref_lock_nothrow() | |
| 282 | { | |
| 283 | // Perform lock-free add-if-not-zero operation. | |
| 284 | _Atomic_word __count = _M_get_use_count(); | |
| 285 | do | |
| 286 | { | |
| 287 | if (__count == 0) | |
| 288 | return false; | |
| 289 | // Replace the current counter value with the old value + 1, as | |
| 290 | // long as it's not changed meanwhile. | |
| 291 | } | |
| 292 | while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1, | |
| 293 | true, __ATOMIC_ACQ_REL, | |
| 294 | __ATOMIC_RELAXED)); | |
| 295 | return true; | |
| 296 | } | |
| 297 | ||
| 298 | template<> | |
| 299 | inline void | |
| 300 | _Sp_counted_base<_S_single>::_M_add_ref_copy() | |
| 301 | { ++_M_use_count; } | |
| 302 | ||
| 303 | template<> | |
| 304 | inline void | |
| 305 | _Sp_counted_base<_S_single>::_M_release() noexcept | |
| 306 | { | |
| 307 | if (--_M_use_count == 0) | |
| 308 | { | |
| 309 | _M_dispose(); | |
| 310 | if (--_M_weak_count == 0) | |
| 311 | _M_destroy(); | |
| 312 | } | |
| 313 | } | |
| 314 | ||
| 315 | template<> | |
| 316 | inline void | |
| 317 | _Sp_counted_base<_S_single>::_M_weak_add_ref() noexcept | |
| 318 | { ++_M_weak_count; } | |
| 319 | ||
| 320 | template<> | |
| 321 | inline void | |
| 322 | _Sp_counted_base<_S_single>::_M_weak_release() noexcept | |
| 323 | { | |
| 324 | if (--_M_weak_count == 0) | |
| 325 | _M_destroy(); | |
| 326 | } | |
| 327 | ||
| 328 | template<> | |
| 329 | inline long | |
| 330 | _Sp_counted_base<_S_single>::_M_get_use_count() const noexcept | |
| 331 | { return _M_use_count; } | |
| 332 | ||
| 333 | ||
| 334 | // Forward declarations. | |
| 335 | template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> | |
| 336 | class __shared_ptr; | |
| 337 | ||
| 338 | template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> | |
| 339 | class __weak_ptr; | |
| 340 | ||
| 341 | template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> | |
| 342 | class __enable_shared_from_this; | |
| 343 | ||
| 344 | template<typename _Tp> | |
| 345 | class shared_ptr; | |
| 346 | ||
| 347 | template<typename _Tp> | |
| 348 | class weak_ptr; | |
| 349 | ||
| 350 | template<typename _Tp> | |
| 351 | struct owner_less; | |
| 352 | ||
| 353 | template<typename _Tp> | |
| 354 | class enable_shared_from_this; | |
| 355 | ||
| 356 | template<_Lock_policy _Lp = __default_lock_policy> | |
| 357 | class __weak_count; | |
| 358 | ||
| 359 | template<_Lock_policy _Lp = __default_lock_policy> | |
| 360 | class __shared_count; | |
| 361 | ||
| 362 | ||
| 363 | // Counted ptr with no deleter or allocator support | |
| 364 | template<typename _Ptr, _Lock_policy _Lp> | |
| 365 | class _Sp_counted_ptr final : public _Sp_counted_base<_Lp> | |
| 366 | { | |
| 367 | public: | |
| 368 | explicit | |
| 369 | _Sp_counted_ptr(_Ptr __p) noexcept | |
| 370 | : _M_ptr(__p) { } | |
| 371 | ||
| 372 | virtual void | |
| 373 | _M_dispose() noexcept | |
| 374 | { delete _M_ptr; } | |
| 375 | ||
| 376 | virtual void | |
| 377 | _M_destroy() noexcept | |
| 378 | { delete this; } | |
| 379 | ||
| 380 | virtual void* | |
| 381 | _M_get_deleter(const std::type_info&) noexcept | |
| 382 | { return nullptr; } | |
| 383 | ||
| 384 | _Sp_counted_ptr(const _Sp_counted_ptr&) = delete; | |
| 385 | _Sp_counted_ptr& operator=(const _Sp_counted_ptr&) = delete; | |
| 386 | ||
| 387 | private: | |
| 388 | _Ptr _M_ptr; | |
| 389 | }; | |
| 390 | ||
| 391 | template<> | |
| 392 | inline void | |
| 393 | _Sp_counted_ptr<nullptr_t, _S_single>::_M_dispose() noexcept { } | |
| 394 | ||
| 395 | template<> | |
| 396 | inline void | |
| 397 | _Sp_counted_ptr<nullptr_t, _S_mutex>::_M_dispose() noexcept { } | |
| 398 | ||
| 399 | template<> | |
| 400 | inline void | |
| 401 | _Sp_counted_ptr<nullptr_t, _S_atomic>::_M_dispose() noexcept { } | |
| 402 | ||
| 403 | template<int _Nm, typename _Tp, | |
| 404 | bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)> | |
| 405 | struct _Sp_ebo_helper; | |
| 406 | ||
| 407 | /// Specialization using EBO. | |
| 408 | template<int _Nm, typename _Tp> | |
| 409 | struct _Sp_ebo_helper<_Nm, _Tp, true> : private _Tp | |
| 410 | { | |
| 411 | explicit _Sp_ebo_helper(const _Tp& __tp) : _Tp(__tp) { } | |
| 412 | ||
| 413 | static _Tp& | |
| 414 | _S_get(_Sp_ebo_helper& __eboh) { return static_cast<_Tp&>(__eboh); } | |
| 415 | }; | |
| 416 | ||
| 417 | /// Specialization not using EBO. | |
| 418 | template<int _Nm, typename _Tp> | |
| 419 | struct _Sp_ebo_helper<_Nm, _Tp, false> | |
| 420 | { | |
| 421 | explicit _Sp_ebo_helper(const _Tp& __tp) : _M_tp(__tp) { } | |
| 422 | ||
| 423 | static _Tp& | |
| 424 | _S_get(_Sp_ebo_helper& __eboh) | |
| 425 | { return __eboh._M_tp; } | |
| 426 | ||
| 427 | private: | |
| 428 | _Tp _M_tp; | |
| 429 | }; | |
| 430 | ||
| 431 | // Support for custom deleter and/or allocator | |
| 432 | template<typename _Ptr, typename _Deleter, typename _Alloc, _Lock_policy _Lp> | |
| 433 | class _Sp_counted_deleter final : public _Sp_counted_base<_Lp> | |
| 434 | { | |
| 435 | class _Impl : _Sp_ebo_helper<0, _Deleter>, _Sp_ebo_helper<1, _Alloc> | |
| 436 | { | |
| 437 | typedef _Sp_ebo_helper<0, _Deleter> _Del_base; | |
| 438 | typedef _Sp_ebo_helper<1, _Alloc> _Alloc_base; | |
| 439 | ||
| 440 | public: | |
| 441 | _Impl(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept | |
| 442 | : _M_ptr(__p), _Del_base(__d), _Alloc_base(__a) | |
| 443 | { } | |
| 444 | ||
| 445 | _Deleter& _M_del() noexcept { return _Del_base::_S_get(*this); } | |
| 446 | _Alloc& _M_alloc() noexcept { return _Alloc_base::_S_get(*this); } | |
| 447 | ||
| 448 | _Ptr _M_ptr; | |
| 449 | }; | |
| 450 | ||
| 451 | public: | |
| 452 | using __allocator_type = __alloc_rebind<_Alloc, _Sp_counted_deleter>; | |
| 453 | ||
| 454 | // __d(__p) must not throw. | |
| 455 | _Sp_counted_deleter(_Ptr __p, _Deleter __d) noexcept | |
| 456 | : _M_impl(__p, __d, _Alloc()) { } | |
| 457 | ||
| 458 | // __d(__p) must not throw. | |
| 459 | _Sp_counted_deleter(_Ptr __p, _Deleter __d, const _Alloc& __a) noexcept | |
| 460 | : _M_impl(__p, __d, __a) { } | |
| 461 | ||
| 462 | ~_Sp_counted_deleter() noexcept { } | |
| 463 | ||
| 464 | virtual void | |
| 465 | _M_dispose() noexcept | |
| 466 | { _M_impl._M_del()(_M_impl._M_ptr); } | |
| 467 | ||
| 468 | virtual void | |
| 469 | _M_destroy() noexcept | |
| 470 | { | |
| 471 | __allocator_type __a(_M_impl._M_alloc()); | |
| 472 | __allocated_ptr<__allocator_type> __guard_ptr{ __a, this }; | |
| 473 | this->~_Sp_counted_deleter(); | |
| 474 | } | |
| 475 | ||
| 476 | virtual void* | |
| 477 | _M_get_deleter(const std::type_info& __ti) noexcept | |
| 478 | { | |
| 479 | #if __cpp_rtti | |
| 480 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
| 481 | // 2400. shared_ptr's get_deleter() should use addressof() | |
| 482 | return __ti == typeid(_Deleter) | |
| 483 | ? std::__addressof(_M_impl._M_del()) | |
| 484 | : nullptr; | |
| 485 | #else | |
| 486 | return nullptr; | |
| 487 | #endif | |
| 488 | } | |
| 489 | ||
| 490 | private: | |
| 491 | _Impl _M_impl; | |
| 492 | }; | |
| 493 | ||
| 494 | // helpers for make_shared / allocate_shared | |
| 495 | ||
| 496 | struct _Sp_make_shared_tag { }; | |
| 497 | ||
| 498 | template<typename _Tp, typename _Alloc, _Lock_policy _Lp> | |
| 499 | class _Sp_counted_ptr_inplace final : public _Sp_counted_base<_Lp> | |
| 500 | { | |
| 501 | class _Impl : _Sp_ebo_helper<0, _Alloc> | |
| 502 | { | |
| 503 | typedef _Sp_ebo_helper<0, _Alloc> _A_base; | |
| 504 | ||
| 505 | public: | |
| 506 | explicit _Impl(_Alloc __a) noexcept : _A_base(__a) { } | |
| 507 | ||
| 508 | _Alloc& _M_alloc() noexcept { return _A_base::_S_get(*this); } | |
| 509 | ||
| 510 | __gnu_cxx::__aligned_buffer<_Tp> _M_storage; | |
| 511 | }; | |
| 512 | ||
| 513 | public: | |
| 514 | using __allocator_type = __alloc_rebind<_Alloc, _Sp_counted_ptr_inplace>; | |
| 515 | ||
| 516 | template<typename... _Args> | |
| 517 | _Sp_counted_ptr_inplace(_Alloc __a, _Args&&... __args) | |
| 518 | : _M_impl(__a) | |
| 519 | { | |
| 520 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
| 521 | // 2070. allocate_shared should use allocator_traits<A>::construct | |
| 522 | allocator_traits<_Alloc>::construct(__a, _M_ptr(), | |
| 523 | std::forward<_Args>(__args)...); // might throw | |
| 524 | } | |
| 525 | ||
| 526 | ~_Sp_counted_ptr_inplace() noexcept { } | |
| 527 | ||
| 528 | virtual void | |
| 529 | _M_dispose() noexcept | |
| 530 | { | |
| 531 | allocator_traits<_Alloc>::destroy(_M_impl._M_alloc(), _M_ptr()); | |
| 532 | } | |
| 533 | ||
| 534 | // Override because the allocator needs to know the dynamic type | |
| 535 | virtual void | |
| 536 | _M_destroy() noexcept | |
| 537 | { | |
| 538 | __allocator_type __a(_M_impl._M_alloc()); | |
| 539 | __allocated_ptr<__allocator_type> __guard_ptr{ __a, this }; | |
| 540 | this->~_Sp_counted_ptr_inplace(); | |
| 541 | } | |
| 542 | ||
| 543 | // Sneaky trick so __shared_ptr can get the managed pointer | |
| 544 | virtual void* | |
| 545 | _M_get_deleter(const std::type_info& __ti) noexcept | |
| 546 | { | |
| 547 | #if __cpp_rtti | |
| 548 | if (__ti == typeid(_Sp_make_shared_tag)) | |
| 549 | return const_cast<typename remove_cv<_Tp>::type*>(_M_ptr()); | |
| 550 | #endif | |
| 551 | return nullptr; | |
| 552 | } | |
| 553 | ||
| 554 | private: | |
| 555 | _Tp* _M_ptr() noexcept { return _M_impl._M_storage._M_ptr(); } | |
| 556 | ||
| 557 | _Impl _M_impl; | |
| 558 | }; | |
| 559 | ||
| 560 | ||
| 561 | template<_Lock_policy _Lp> | |
| 562 | class __shared_count | |
| 563 | { | |
| 564 | public: | |
| 565 | constexpr __shared_count() noexcept : _M_pi(0) | |
| 566 | { } | |
| 567 | ||
| 568 | template<typename _Ptr> | |
| 569 | explicit | |
| 570 | __shared_count(_Ptr __p) : _M_pi(0) | |
| 571 | { | |
| 572 | __try | |
| 573 | { | |
| 574 | _M_pi = new _Sp_counted_ptr<_Ptr, _Lp>(__p); | |
| 575 | } | |
| 576 | __catch(...) | |
| 577 | { | |
| 578 | delete __p; | |
| 579 | __throw_exception_again; | |
| 580 | } | |
| 581 | } | |
| 582 | ||
| 583 | template<typename _Ptr, typename _Deleter> | |
| 584 | __shared_count(_Ptr __p, _Deleter __d) | |
| 585 | : __shared_count(__p, std::move(__d), allocator<void>()) | |
| 586 | { } | |
| 587 | ||
| 588 | template<typename _Ptr, typename _Deleter, typename _Alloc> | |
| 589 | __shared_count(_Ptr __p, _Deleter __d, _Alloc __a) : _M_pi(0) | |
| 590 | { | |
| 591 | typedef _Sp_counted_deleter<_Ptr, _Deleter, _Alloc, _Lp> _Sp_cd_type; | |
| 592 | __try | |
| 593 | { | |
| 594 | typename _Sp_cd_type::__allocator_type __a2(__a); | |
| 595 | auto __guard = std::__allocate_guarded(__a2); | |
| 596 | _Sp_cd_type* __mem = __guard.get(); | |
| 597 | ::new (__mem) _Sp_cd_type(__p, std::move(__d), std::move(__a)); | |
| 598 | _M_pi = __mem; | |
| 599 | __guard = nullptr; | |
| 600 | } | |
| 601 | __catch(...) | |
| 602 | { | |
| 603 | __d(__p); // Call _Deleter on __p. | |
| 604 | __throw_exception_again; | |
| 605 | } | |
| 606 | } | |
| 607 | ||
| 608 | template<typename _Tp, typename _Alloc, typename... _Args> | |
| 609 | __shared_count(_Sp_make_shared_tag, _Tp*, const _Alloc& __a, | |
| 610 | _Args&&... __args) | |
| 611 | : _M_pi(0) | |
| 612 | { | |
| 613 | typedef _Sp_counted_ptr_inplace<_Tp, _Alloc, _Lp> _Sp_cp_type; | |
| 614 | typename _Sp_cp_type::__allocator_type __a2(__a); | |
| 615 | auto __guard = std::__allocate_guarded(__a2); | |
| 616 | _Sp_cp_type* __mem = __guard.get(); | |
| 617 | ::new (__mem) _Sp_cp_type(std::move(__a), | |
| 618 | std::forward<_Args>(__args)...); | |
| 619 | _M_pi = __mem; | |
| 620 | __guard = nullptr; | |
| 621 | } | |
| 622 | ||
| 623 | #if _GLIBCXX_USE_DEPRECATED | |
| 624 | // Special case for auto_ptr<_Tp> to provide the strong guarantee. | |
| 625 | template<typename _Tp> | |
| 626 | explicit | |
| 627 | __shared_count(std::auto_ptr<_Tp>&& __r); | |
| 628 | #endif | |
| 629 | ||
| 630 | // Special case for unique_ptr<_Tp,_Del> to provide the strong guarantee. | |
| 631 | template<typename _Tp, typename _Del> | |
| 632 | explicit | |
| 633 | __shared_count(std::unique_ptr<_Tp, _Del>&& __r) : _M_pi(0) | |
| 634 | { | |
| 635 | using _Ptr = typename unique_ptr<_Tp, _Del>::pointer; | |
| 636 | using _Del2 = typename conditional<is_reference<_Del>::value, | |
| 637 | reference_wrapper<typename remove_reference<_Del>::type>, | |
| 638 | _Del>::type; | |
| 639 | using _Sp_cd_type | |
| 640 | = _Sp_counted_deleter<_Ptr, _Del2, allocator<void>, _Lp>; | |
| 641 | using _Alloc = allocator<_Sp_cd_type>; | |
| 642 | using _Alloc_traits = allocator_traits<_Alloc>; | |
| 643 | _Alloc __a; | |
| 644 | _Sp_cd_type* __mem = _Alloc_traits::allocate(__a, 1); | |
| 645 | _Alloc_traits::construct(__a, __mem, __r.release(), | |
| 646 | __r.get_deleter()); // non-throwing | |
| 647 | _M_pi = __mem; | |
| 648 | } | |
| 649 | ||
| 650 | // Throw bad_weak_ptr when __r._M_get_use_count() == 0. | |
| 651 | explicit __shared_count(const __weak_count<_Lp>& __r); | |
| 652 | ||
| 653 | // Does not throw if __r._M_get_use_count() == 0, caller must check. | |
| 654 | explicit __shared_count(const __weak_count<_Lp>& __r, std::nothrow_t); | |
| 655 | ||
| 656 | ~__shared_count() noexcept | |
| 657 | { | |
| 658 | if (_M_pi != nullptr) | |
| 659 | _M_pi->_M_release(); | |
| 660 | } | |
| 661 | ||
| 662 | __shared_count(const __shared_count& __r) noexcept | |
| 663 | : _M_pi(__r._M_pi) | |
| 664 | { | |
| 665 | if (_M_pi != 0) | |
| 666 | _M_pi->_M_add_ref_copy(); | |
| 667 | } | |
| 668 | ||
| 669 | __shared_count& | |
| 670 | operator=(const __shared_count& __r) noexcept | |
| 671 | { | |
| 672 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi; | |
| 673 | if (__tmp != _M_pi) | |
| 674 | { | |
| 675 | if (__tmp != 0) | |
| 676 | __tmp->_M_add_ref_copy(); | |
| 677 | if (_M_pi != 0) | |
| 678 | _M_pi->_M_release(); | |
| 679 | _M_pi = __tmp; | |
| 680 | } | |
| 681 | return *this; | |
| 682 | } | |
| 683 | ||
| 684 | void | |
| 685 | _M_swap(__shared_count& __r) noexcept | |
| 686 | { | |
| 687 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi; | |
| 688 | __r._M_pi = _M_pi; | |
| 689 | _M_pi = __tmp; | |
| 690 | } | |
| 691 | ||
| 692 | long | |
| 693 | _M_get_use_count() const noexcept | |
| 694 | { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; } | |
| 695 | ||
| 696 | bool | |
| 697 | _M_unique() const noexcept | |
| 698 | { return this->_M_get_use_count() == 1; } | |
| 699 | ||
| 700 | void* | |
| 701 | _M_get_deleter(const std::type_info& __ti) const noexcept | |
| 702 | { return _M_pi ? _M_pi->_M_get_deleter(__ti) : nullptr; } | |
| 703 | ||
| 704 | bool | |
| 705 | _M_less(const __shared_count& __rhs) const noexcept | |
| 706 | { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } | |
| 707 | ||
| 708 | bool | |
| 709 | _M_less(const __weak_count<_Lp>& __rhs) const noexcept | |
| 710 | { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } | |
| 711 | ||
| 712 | // Friend function injected into enclosing namespace and found by ADL | |
| 713 | friend inline bool | |
| 714 | operator==(const __shared_count& __a, const __shared_count& __b) noexcept | |
| 715 | { return __a._M_pi == __b._M_pi; } | |
| 716 | ||
| 717 | private: | |
| 718 | friend class __weak_count<_Lp>; | |
| 719 | ||
| 720 | _Sp_counted_base<_Lp>* _M_pi; | |
| 721 | }; | |
| 722 | ||
| 723 | ||
| 724 | template<_Lock_policy _Lp> | |
| 725 | class __weak_count | |
| 726 | { | |
| 727 | public: | |
| 728 | constexpr __weak_count() noexcept : _M_pi(nullptr) | |
| 729 | { } | |
| 730 | ||
| 731 | __weak_count(const __shared_count<_Lp>& __r) noexcept | |
| 732 | : _M_pi(__r._M_pi) | |
| 733 | { | |
| 734 | if (_M_pi != nullptr) | |
| 735 | _M_pi->_M_weak_add_ref(); | |
| 736 | } | |
| 737 | ||
| 738 | __weak_count(const __weak_count& __r) noexcept | |
| 739 | : _M_pi(__r._M_pi) | |
| 740 | { | |
| 741 | if (_M_pi != nullptr) | |
| 742 | _M_pi->_M_weak_add_ref(); | |
| 743 | } | |
| 744 | ||
| 745 | __weak_count(__weak_count&& __r) noexcept | |
| 746 | : _M_pi(__r._M_pi) | |
| 747 | { __r._M_pi = nullptr; } | |
| 748 | ||
| 749 | ~__weak_count() noexcept | |
| 750 | { | |
| 751 | if (_M_pi != nullptr) | |
| 752 | _M_pi->_M_weak_release(); | |
| 753 | } | |
| 754 | ||
| 755 | __weak_count& | |
| 756 | operator=(const __shared_count<_Lp>& __r) noexcept | |
| 757 | { | |
| 758 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi; | |
| 759 | if (__tmp != nullptr) | |
| 760 | __tmp->_M_weak_add_ref(); | |
| 761 | if (_M_pi != nullptr) | |
| 762 | _M_pi->_M_weak_release(); | |
| 763 | _M_pi = __tmp; | |
| 764 | return *this; | |
| 765 | } | |
| 766 | ||
| 767 | __weak_count& | |
| 768 | operator=(const __weak_count& __r) noexcept | |
| 769 | { | |
| 770 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi; | |
| 771 | if (__tmp != nullptr) | |
| 772 | __tmp->_M_weak_add_ref(); | |
| 773 | if (_M_pi != nullptr) | |
| 774 | _M_pi->_M_weak_release(); | |
| 775 | _M_pi = __tmp; | |
| 776 | return *this; | |
| 777 | } | |
| 778 | ||
| 779 | __weak_count& | |
| 780 | operator=(__weak_count&& __r) noexcept | |
| 781 | { | |
| 782 | if (_M_pi != nullptr) | |
| 783 | _M_pi->_M_weak_release(); | |
| 784 | _M_pi = __r._M_pi; | |
| 785 | __r._M_pi = nullptr; | |
| 786 | return *this; | |
| 787 | } | |
| 788 | ||
| 789 | void | |
| 790 | _M_swap(__weak_count& __r) noexcept | |
| 791 | { | |
| 792 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi; | |
| 793 | __r._M_pi = _M_pi; | |
| 794 | _M_pi = __tmp; | |
| 795 | } | |
| 796 | ||
| 797 | long | |
| 798 | _M_get_use_count() const noexcept | |
| 799 | { return _M_pi != nullptr ? _M_pi->_M_get_use_count() : 0; } | |
| 800 | ||
| 801 | bool | |
| 802 | _M_less(const __weak_count& __rhs) const noexcept | |
| 803 | { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } | |
| 804 | ||
| 805 | bool | |
| 806 | _M_less(const __shared_count<_Lp>& __rhs) const noexcept | |
| 807 | { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } | |
| 808 | ||
| 809 | // Friend function injected into enclosing namespace and found by ADL | |
| 810 | friend inline bool | |
| 811 | operator==(const __weak_count& __a, const __weak_count& __b) noexcept | |
| 812 | { return __a._M_pi == __b._M_pi; } | |
| 813 | ||
| 814 | private: | |
| 815 | friend class __shared_count<_Lp>; | |
| 816 | ||
| 817 | _Sp_counted_base<_Lp>* _M_pi; | |
| 818 | }; | |
| 819 | ||
| 820 | // Now that __weak_count is defined we can define this constructor: | |
| 821 | template<_Lock_policy _Lp> | |
| 822 | inline | |
| 823 | __shared_count<_Lp>::__shared_count(const __weak_count<_Lp>& __r) | |
| 824 | : _M_pi(__r._M_pi) | |
| 825 | { | |
| 826 | if (_M_pi != nullptr) | |
| 827 | _M_pi->_M_add_ref_lock(); | |
| 828 | else | |
| 829 | __throw_bad_weak_ptr(); | |
| 830 | } | |
| 831 | ||
| 832 | // Now that __weak_count is defined we can define this constructor: | |
| 833 | template<_Lock_policy _Lp> | |
| 834 | inline | |
| 835 | __shared_count<_Lp>:: | |
| 836 | __shared_count(const __weak_count<_Lp>& __r, std::nothrow_t) | |
| 837 | : _M_pi(__r._M_pi) | |
| 838 | { | |
| 839 | if (_M_pi != nullptr) | |
| 840 | if (!_M_pi->_M_add_ref_lock_nothrow()) | |
| 841 | _M_pi = nullptr; | |
| 842 | } | |
| 843 | ||
| 844 | // Support for enable_shared_from_this. | |
| 845 | ||
| 846 | // Friend of __enable_shared_from_this. | |
| 847 | template<_Lock_policy _Lp, typename _Tp1, typename _Tp2> | |
| 848 | void | |
| 849 | __enable_shared_from_this_helper(const __shared_count<_Lp>&, | |
| 850 | const __enable_shared_from_this<_Tp1, | |
| 851 | _Lp>*, const _Tp2*) noexcept; | |
| 852 | ||
| 853 | // Friend of enable_shared_from_this. | |
| 854 | template<typename _Tp1, typename _Tp2> | |
| 855 | void | |
| 856 | __enable_shared_from_this_helper(const __shared_count<>&, | |
| 857 | const enable_shared_from_this<_Tp1>*, | |
| 858 | const _Tp2*) noexcept; | |
| 859 | ||
| 860 | template<_Lock_policy _Lp> | |
| 861 | inline void | |
| 862 | __enable_shared_from_this_helper(const __shared_count<_Lp>&, ...) noexcept | |
| 863 | { } | |
| 864 | ||
| 865 | ||
| 866 | template<typename _Tp, _Lock_policy _Lp> | |
| 867 | class __shared_ptr | |
| 868 | { | |
| 869 | template<typename _Ptr> | |
| 870 | using _Convertible | |
| 871 | = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type; | |
| 872 | ||
| 873 | public: | |
| 874 | typedef _Tp element_type; | |
| 875 | ||
| 876 | constexpr __shared_ptr() noexcept | |
| 877 | : _M_ptr(0), _M_refcount() | |
| 878 | { } | |
| 879 | ||
| 880 | template<typename _Tp1> | |
| 881 | explicit __shared_ptr(_Tp1* __p) | |
| 882 | : _M_ptr(__p), _M_refcount(__p) | |
| 883 | { | |
| 884 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) | |
| 885 | static_assert( !is_void<_Tp1>::value, "incomplete type" ); | |
| 886 | static_assert( sizeof(_Tp1) > 0, "incomplete type" ); | |
| 887 | __enable_shared_from_this_helper(_M_refcount, __p, __p); | |
| 888 | } | |
| 889 | ||
| 890 | template<typename _Tp1, typename _Deleter> | |
| 891 | __shared_ptr(_Tp1* __p, _Deleter __d) | |
| 892 | : _M_ptr(__p), _M_refcount(__p, __d) | |
| 893 | { | |
| 894 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) | |
| 895 | // TODO requires _Deleter CopyConstructible and __d(__p) well-formed | |
| 896 | __enable_shared_from_this_helper(_M_refcount, __p, __p); | |
| 897 | } | |
| 898 | ||
| 899 | template<typename _Tp1, typename _Deleter, typename _Alloc> | |
| 900 | __shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a) | |
| 901 | : _M_ptr(__p), _M_refcount(__p, __d, std::move(__a)) | |
| 902 | { | |
| 903 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) | |
| 904 | // TODO requires _Deleter CopyConstructible and __d(__p) well-formed | |
| 905 | __enable_shared_from_this_helper(_M_refcount, __p, __p); | |
| 906 | } | |
| 907 | ||
| 908 | template<typename _Deleter> | |
| 909 | __shared_ptr(nullptr_t __p, _Deleter __d) | |
| 910 | : _M_ptr(0), _M_refcount(__p, __d) | |
| 911 | { } | |
| 912 | ||
| 913 | template<typename _Deleter, typename _Alloc> | |
| 914 | __shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a) | |
| 915 | : _M_ptr(0), _M_refcount(__p, __d, std::move(__a)) | |
| 916 | { } | |
| 917 | ||
| 918 | template<typename _Tp1> | |
| 919 | __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, _Tp* __p) noexcept | |
| 920 | : _M_ptr(__p), _M_refcount(__r._M_refcount) // never throws | |
| 921 | { } | |
| 922 | ||
| 923 | __shared_ptr(const __shared_ptr&) noexcept = default; | |
| 924 | __shared_ptr& operator=(const __shared_ptr&) noexcept = default; | |
| 925 | ~__shared_ptr() = default; | |
| 926 | ||
| 927 | template<typename _Tp1, typename = _Convertible<_Tp1*>> | |
| 928 | __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 929 | : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) | |
| 930 | { } | |
| 931 | ||
| 932 | __shared_ptr(__shared_ptr&& __r) noexcept | |
| 933 | : _M_ptr(__r._M_ptr), _M_refcount() | |
| 934 | { | |
| 935 | _M_refcount._M_swap(__r._M_refcount); | |
| 936 | __r._M_ptr = 0; | |
| 937 | } | |
| 938 | ||
| 939 | template<typename _Tp1, typename = _Convertible<_Tp1*>> | |
| 940 | __shared_ptr(__shared_ptr<_Tp1, _Lp>&& __r) noexcept | |
| 941 | : _M_ptr(__r._M_ptr), _M_refcount() | |
| 942 | { | |
| 943 | _M_refcount._M_swap(__r._M_refcount); | |
| 944 | __r._M_ptr = 0; | |
| 945 | } | |
| 946 | ||
| 947 | template<typename _Tp1> | |
| 948 | explicit __shared_ptr(const __weak_ptr<_Tp1, _Lp>& __r) | |
| 949 | : _M_refcount(__r._M_refcount) // may throw | |
| 950 | { | |
| 951 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) | |
| 952 | ||
| 953 | // It is now safe to copy __r._M_ptr, as | |
| 954 | // _M_refcount(__r._M_refcount) did not throw. | |
| 955 | _M_ptr = __r._M_ptr; | |
| 956 | } | |
| 957 | ||
| 958 | // If an exception is thrown this constructor has no effect. | |
| 959 | template<typename _Tp1, typename _Del, typename | |
| 960 | = _Convertible<typename unique_ptr<_Tp1, _Del>::pointer>> | |
| 961 | __shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r) | |
| 962 | : _M_ptr(__r.get()), _M_refcount() | |
| 963 | { | |
| 964 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) | |
| 965 | auto __raw = _S_raw_ptr(__r.get()); | |
| 966 | _M_refcount = __shared_count<_Lp>(std::move(__r)); | |
| 967 | __enable_shared_from_this_helper(_M_refcount, __raw, __raw); | |
| 968 | } | |
| 969 | ||
| 970 | #if _GLIBCXX_USE_DEPRECATED | |
| 971 | // Postcondition: use_count() == 1 and __r.get() == 0 | |
| 972 | template<typename _Tp1> | |
| 973 | __shared_ptr(std::auto_ptr<_Tp1>&& __r); | |
| 974 | #endif | |
| 975 | ||
| 976 | constexpr __shared_ptr(nullptr_t) noexcept : __shared_ptr() { } | |
| 977 | ||
| 978 | template<typename _Tp1> | |
| 979 | __shared_ptr& | |
| 980 | operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 981 | { | |
| 982 | _M_ptr = __r._M_ptr; | |
| 983 | _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw | |
| 984 | return *this; | |
| 985 | } | |
| 986 | ||
| 987 | #if _GLIBCXX_USE_DEPRECATED | |
| 988 | template<typename _Tp1> | |
| 989 | __shared_ptr& | |
| 990 | operator=(std::auto_ptr<_Tp1>&& __r) | |
| 991 | { | |
| 992 | __shared_ptr(std::move(__r)).swap(*this); | |
| 993 | return *this; | |
| 994 | } | |
| 995 | #endif | |
| 996 | ||
| 997 | __shared_ptr& | |
| 998 | operator=(__shared_ptr&& __r) noexcept | |
| 999 | { | |
| 1000 | __shared_ptr(std::move(__r)).swap(*this); | |
| 1001 | return *this; | |
| 1002 | } | |
| 1003 | ||
| 1004 | template<class _Tp1> | |
| 1005 | __shared_ptr& | |
| 1006 | operator=(__shared_ptr<_Tp1, _Lp>&& __r) noexcept | |
| 1007 | { | |
| 1008 | __shared_ptr(std::move(__r)).swap(*this); | |
| 1009 | return *this; | |
| 1010 | } | |
| 1011 | ||
| 1012 | template<typename _Tp1, typename _Del> | |
| 1013 | __shared_ptr& | |
| 1014 | operator=(std::unique_ptr<_Tp1, _Del>&& __r) | |
| 1015 | { | |
| 1016 | __shared_ptr(std::move(__r)).swap(*this); | |
| 1017 | return *this; | |
| 1018 | } | |
| 1019 | ||
| 1020 | void | |
| 1021 | reset() noexcept | |
| 1022 | { __shared_ptr().swap(*this); } | |
| 1023 | ||
| 1024 | template<typename _Tp1> | |
| 1025 | void | |
| 1026 | reset(_Tp1* __p) // _Tp1 must be complete. | |
| 1027 | { | |
| 1028 | // Catch self-reset errors. | |
| 1029 | _GLIBCXX_DEBUG_ASSERT(__p == 0 || __p != _M_ptr); | |
| 1030 | __shared_ptr(__p).swap(*this); | |
| 1031 | } | |
| 1032 | ||
| 1033 | template<typename _Tp1, typename _Deleter> | |
| 1034 | void | |
| 1035 | reset(_Tp1* __p, _Deleter __d) | |
| 1036 | { __shared_ptr(__p, __d).swap(*this); } | |
| 1037 | ||
| 1038 | template<typename _Tp1, typename _Deleter, typename _Alloc> | |
| 1039 | void | |
| 1040 | reset(_Tp1* __p, _Deleter __d, _Alloc __a) | |
| 1041 | { __shared_ptr(__p, __d, std::move(__a)).swap(*this); } | |
| 1042 | ||
| 1043 | // Allow class instantiation when _Tp is [cv-qual] void. | |
| 1044 | typename std::add_lvalue_reference<_Tp>::type | |
| 1045 | operator*() const noexcept | |
| 1046 | { | |
| 1047 | _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0); | |
| 1048 | return *_M_ptr; | |
| 1049 | } | |
| 1050 | ||
| 1051 | _Tp* | |
| 1052 | operator->() const noexcept | |
| 1053 | { | |
| 1054 | _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0); | |
| 1055 | return _M_ptr; | |
| 1056 | } | |
| 1057 | ||
| 1058 | _Tp* | |
| 1059 | get() const noexcept | |
| 1060 | { return _M_ptr; } | |
| 1061 | ||
| 1062 | explicit operator bool() const // never throws | |
| 1063 | { return _M_ptr == 0 ? false : true; } | |
| 1064 | ||
| 1065 | bool | |
| 1066 | unique() const noexcept | |
| 1067 | { return _M_refcount._M_unique(); } | |
| 1068 | ||
| 1069 | long | |
| 1070 | use_count() const noexcept | |
| 1071 | { return _M_refcount._M_get_use_count(); } | |
| 1072 | ||
| 1073 | void | |
| 1074 | swap(__shared_ptr<_Tp, _Lp>& __other) noexcept | |
| 1075 | { | |
| 1076 | std::swap(_M_ptr, __other._M_ptr); | |
| 1077 | _M_refcount._M_swap(__other._M_refcount); | |
| 1078 | } | |
| 1079 | ||
| 1080 | template<typename _Tp1> | |
| 1081 | bool | |
| 1082 | owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const | |
| 1083 | { return _M_refcount._M_less(__rhs._M_refcount); } | |
| 1084 | ||
| 1085 | template<typename _Tp1> | |
| 1086 | bool | |
| 1087 | owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const | |
| 1088 | { return _M_refcount._M_less(__rhs._M_refcount); } | |
| 1089 | ||
| 1090 | #if __cpp_rtti | |
| 1091 | protected: | |
| 1092 | // This constructor is non-standard, it is used by allocate_shared. | |
| 1093 | template<typename _Alloc, typename... _Args> | |
| 1094 | __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a, | |
| 1095 | _Args&&... __args) | |
| 1096 | : _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a, | |
| 1097 | std::forward<_Args>(__args)...) | |
| 1098 | { | |
| 1099 | // _M_ptr needs to point to the newly constructed object. | |
| 1100 | // This relies on _Sp_counted_ptr_inplace::_M_get_deleter. | |
| 1101 | void* __p = _M_refcount._M_get_deleter(typeid(__tag)); | |
| 1102 | _M_ptr = static_cast<_Tp*>(__p); | |
| 1103 | __enable_shared_from_this_helper(_M_refcount, _M_ptr, _M_ptr); | |
| 1104 | } | |
| 1105 | #else | |
| 1106 | template<typename _Alloc> | |
| 1107 | struct _Deleter | |
| 1108 | { | |
| 1109 | void operator()(typename _Alloc::value_type* __ptr) | |
| 1110 | { | |
| 1111 | __allocated_ptr<_Alloc> __guard{ _M_alloc, __ptr }; | |
| 1112 | allocator_traits<_Alloc>::destroy(_M_alloc, __guard.get()); | |
| 1113 | } | |
| 1114 | _Alloc _M_alloc; | |
| 1115 | }; | |
| 1116 | ||
| 1117 | template<typename _Alloc, typename... _Args> | |
| 1118 | __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a, | |
| 1119 | _Args&&... __args) | |
| 1120 | : _M_ptr(), _M_refcount() | |
| 1121 | { | |
| 1122 | typedef typename allocator_traits<_Alloc>::template | |
| 1123 | rebind_traits<typename std::remove_cv<_Tp>::type> __traits; | |
| 1124 | _Deleter<typename __traits::allocator_type> __del = { __a }; | |
| 1125 | auto __guard = std::__allocate_guarded(__del._M_alloc); | |
| 1126 | auto __ptr = __guard.get(); | |
| 1127 | // _GLIBCXX_RESOLVE_LIB_DEFECTS | |
| 1128 | // 2070. allocate_shared should use allocator_traits<A>::construct | |
| 1129 | __traits::construct(__del._M_alloc, __ptr, | |
| 1130 | std::forward<_Args>(__args)...); | |
| 1131 | __guard = nullptr; | |
| 1132 | __shared_count<_Lp> __count(__ptr, __del, __del._M_alloc); | |
| 1133 | _M_refcount._M_swap(__count); | |
| 1134 | _M_ptr = __ptr; | |
| 1135 | __enable_shared_from_this_helper(_M_refcount, _M_ptr, _M_ptr); | |
| 1136 | } | |
| 1137 | #endif | |
| 1138 | ||
| 1139 | template<typename _Tp1, _Lock_policy _Lp1, typename _Alloc, | |
| 1140 | typename... _Args> | |
| 1141 | friend __shared_ptr<_Tp1, _Lp1> | |
| 1142 | __allocate_shared(const _Alloc& __a, _Args&&... __args); | |
| 1143 | ||
| 1144 | // This constructor is used by __weak_ptr::lock() and | |
| 1145 | // shared_ptr::shared_ptr(const weak_ptr&, std::nothrow_t). | |
| 1146 | __shared_ptr(const __weak_ptr<_Tp, _Lp>& __r, std::nothrow_t) | |
| 1147 | : _M_refcount(__r._M_refcount, std::nothrow) | |
| 1148 | { | |
| 1149 | _M_ptr = _M_refcount._M_get_use_count() ? __r._M_ptr : nullptr; | |
| 1150 | } | |
| 1151 | ||
| 1152 | friend class __weak_ptr<_Tp, _Lp>; | |
| 1153 | ||
| 1154 | private: | |
| 1155 | void* | |
| 1156 | _M_get_deleter(const std::type_info& __ti) const noexcept | |
| 1157 | { return _M_refcount._M_get_deleter(__ti); } | |
| 1158 | ||
| 1159 | template<typename _Tp1> | |
| 1160 | static _Tp1* | |
| 1161 | _S_raw_ptr(_Tp1* __ptr) | |
| 1162 | { return __ptr; } | |
| 1163 | ||
| 1164 | template<typename _Tp1> | |
| 1165 | static auto | |
| 1166 | _S_raw_ptr(_Tp1 __ptr) -> decltype(std::__addressof(*__ptr)) | |
| 1167 | { return std::__addressof(*__ptr); } | |
| 1168 | ||
| 1169 | template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr; | |
| 1170 | template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr; | |
| 1171 | ||
| 1172 | template<typename _Del, typename _Tp1, _Lock_policy _Lp1> | |
| 1173 | friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept; | |
| 1174 | ||
| 1175 | _Tp* _M_ptr; // Contained pointer. | |
| 1176 | __shared_count<_Lp> _M_refcount; // Reference counter. | |
| 1177 | }; | |
| 1178 | ||
| 1179 | ||
| 1180 | // 20.7.2.2.7 shared_ptr comparisons | |
| 1181 | template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> | |
| 1182 | inline bool | |
| 1183 | operator==(const __shared_ptr<_Tp1, _Lp>& __a, | |
| 1184 | const __shared_ptr<_Tp2, _Lp>& __b) noexcept | |
| 1185 | { return __a.get() == __b.get(); } | |
| 1186 | ||
| 1187 | template<typename _Tp, _Lock_policy _Lp> | |
| 1188 | inline bool | |
| 1189 | operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | |
| 1190 | { return !__a; } | |
| 1191 | ||
| 1192 | template<typename _Tp, _Lock_policy _Lp> | |
| 1193 | inline bool | |
| 1194 | operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | |
| 1195 | { return !__a; } | |
| 1196 | ||
| 1197 | template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> | |
| 1198 | inline bool | |
| 1199 | operator!=(const __shared_ptr<_Tp1, _Lp>& __a, | |
| 1200 | const __shared_ptr<_Tp2, _Lp>& __b) noexcept | |
| 1201 | { return __a.get() != __b.get(); } | |
| 1202 | ||
| 1203 | template<typename _Tp, _Lock_policy _Lp> | |
| 1204 | inline bool | |
| 1205 | operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | |
| 1206 | { return (bool)__a; } | |
| 1207 | ||
| 1208 | template<typename _Tp, _Lock_policy _Lp> | |
| 1209 | inline bool | |
| 1210 | operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | |
| 1211 | { return (bool)__a; } | |
| 1212 | ||
| 1213 | template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> | |
| 1214 | inline bool | |
| 1215 | operator<(const __shared_ptr<_Tp1, _Lp>& __a, | |
| 1216 | const __shared_ptr<_Tp2, _Lp>& __b) noexcept | |
| 1217 | { | |
| 1218 | typedef typename std::common_type<_Tp1*, _Tp2*>::type _CT; | |
| 1219 | return std::less<_CT>()(__a.get(), __b.get()); | |
| 1220 | } | |
| 1221 | ||
| 1222 | template<typename _Tp, _Lock_policy _Lp> | |
| 1223 | inline bool | |
| 1224 | operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | |
| 1225 | { return std::less<_Tp*>()(__a.get(), nullptr); } | |
| 1226 | ||
| 1227 | template<typename _Tp, _Lock_policy _Lp> | |
| 1228 | inline bool | |
| 1229 | operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | |
| 1230 | { return std::less<_Tp*>()(nullptr, __a.get()); } | |
| 1231 | ||
| 1232 | template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> | |
| 1233 | inline bool | |
| 1234 | operator<=(const __shared_ptr<_Tp1, _Lp>& __a, | |
| 1235 | const __shared_ptr<_Tp2, _Lp>& __b) noexcept | |
| 1236 | { return !(__b < __a); } | |
| 1237 | ||
| 1238 | template<typename _Tp, _Lock_policy _Lp> | |
| 1239 | inline bool | |
| 1240 | operator<=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | |
| 1241 | { return !(nullptr < __a); } | |
| 1242 | ||
| 1243 | template<typename _Tp, _Lock_policy _Lp> | |
| 1244 | inline bool | |
| 1245 | operator<=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | |
| 1246 | { return !(__a < nullptr); } | |
| 1247 | ||
| 1248 | template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> | |
| 1249 | inline bool | |
| 1250 | operator>(const __shared_ptr<_Tp1, _Lp>& __a, | |
| 1251 | const __shared_ptr<_Tp2, _Lp>& __b) noexcept | |
| 1252 | { return (__b < __a); } | |
| 1253 | ||
| 1254 | template<typename _Tp, _Lock_policy _Lp> | |
| 1255 | inline bool | |
| 1256 | operator>(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | |
| 1257 | { return std::less<_Tp*>()(nullptr, __a.get()); } | |
| 1258 | ||
| 1259 | template<typename _Tp, _Lock_policy _Lp> | |
| 1260 | inline bool | |
| 1261 | operator>(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | |
| 1262 | { return std::less<_Tp*>()(__a.get(), nullptr); } | |
| 1263 | ||
| 1264 | template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> | |
| 1265 | inline bool | |
| 1266 | operator>=(const __shared_ptr<_Tp1, _Lp>& __a, | |
| 1267 | const __shared_ptr<_Tp2, _Lp>& __b) noexcept | |
| 1268 | { return !(__a < __b); } | |
| 1269 | ||
| 1270 | template<typename _Tp, _Lock_policy _Lp> | |
| 1271 | inline bool | |
| 1272 | operator>=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept | |
| 1273 | { return !(__a < nullptr); } | |
| 1274 | ||
| 1275 | template<typename _Tp, _Lock_policy _Lp> | |
| 1276 | inline bool | |
| 1277 | operator>=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept | |
| 1278 | { return !(nullptr < __a); } | |
| 1279 | ||
| 1280 | template<typename _Sp> | |
| 1281 | struct _Sp_less : public binary_function<_Sp, _Sp, bool> | |
| 1282 | { | |
| 1283 | bool | |
| 1284 | operator()(const _Sp& __lhs, const _Sp& __rhs) const noexcept | |
| 1285 | { | |
| 1286 | typedef typename _Sp::element_type element_type; | |
| 1287 | return std::less<element_type*>()(__lhs.get(), __rhs.get()); | |
| 1288 | } | |
| 1289 | }; | |
| 1290 | ||
| 1291 | template<typename _Tp, _Lock_policy _Lp> | |
| 1292 | struct less<__shared_ptr<_Tp, _Lp>> | |
| 1293 | : public _Sp_less<__shared_ptr<_Tp, _Lp>> | |
| 1294 | { }; | |
| 1295 | ||
| 1296 | // 20.7.2.2.8 shared_ptr specialized algorithms. | |
| 1297 | template<typename _Tp, _Lock_policy _Lp> | |
| 1298 | inline void | |
| 1299 | swap(__shared_ptr<_Tp, _Lp>& __a, __shared_ptr<_Tp, _Lp>& __b) noexcept | |
| 1300 | { __a.swap(__b); } | |
| 1301 | ||
| 1302 | // 20.7.2.2.9 shared_ptr casts | |
| 1303 | ||
| 1304 | // The seemingly equivalent code: | |
| 1305 | // shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get())) | |
| 1306 | // will eventually result in undefined behaviour, attempting to | |
| 1307 | // delete the same object twice. | |
| 1308 | /// static_pointer_cast | |
| 1309 | template<typename _Tp, typename _Tp1, _Lock_policy _Lp> | |
| 1310 | inline __shared_ptr<_Tp, _Lp> | |
| 1311 | static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1312 | { return __shared_ptr<_Tp, _Lp>(__r, static_cast<_Tp*>(__r.get())); } | |
| 1313 | ||
| 1314 | // The seemingly equivalent code: | |
| 1315 | // shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get())) | |
| 1316 | // will eventually result in undefined behaviour, attempting to | |
| 1317 | // delete the same object twice. | |
| 1318 | /// const_pointer_cast | |
| 1319 | template<typename _Tp, typename _Tp1, _Lock_policy _Lp> | |
| 1320 | inline __shared_ptr<_Tp, _Lp> | |
| 1321 | const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1322 | { return __shared_ptr<_Tp, _Lp>(__r, const_cast<_Tp*>(__r.get())); } | |
| 1323 | ||
| 1324 | // The seemingly equivalent code: | |
| 1325 | // shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get())) | |
| 1326 | // will eventually result in undefined behaviour, attempting to | |
| 1327 | // delete the same object twice. | |
| 1328 | /// dynamic_pointer_cast | |
| 1329 | template<typename _Tp, typename _Tp1, _Lock_policy _Lp> | |
| 1330 | inline __shared_ptr<_Tp, _Lp> | |
| 1331 | dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1332 | { | |
| 1333 | if (_Tp* __p = dynamic_cast<_Tp*>(__r.get())) | |
| 1334 | return __shared_ptr<_Tp, _Lp>(__r, __p); | |
| 1335 | return __shared_ptr<_Tp, _Lp>(); | |
| 1336 | } | |
| 1337 | ||
| 1338 | ||
| 1339 | template<typename _Tp, _Lock_policy _Lp> | |
| 1340 | class __weak_ptr | |
| 1341 | { | |
| 1342 | template<typename _Ptr> | |
| 1343 | using _Convertible | |
| 1344 | = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type; | |
| 1345 | ||
| 1346 | public: | |
| 1347 | typedef _Tp element_type; | |
| 1348 | ||
| 1349 | constexpr __weak_ptr() noexcept | |
| 1350 | : _M_ptr(nullptr), _M_refcount() | |
| 1351 | { } | |
| 1352 | ||
| 1353 | __weak_ptr(const __weak_ptr&) noexcept = default; | |
| 1354 | ||
| 1355 | ~__weak_ptr() = default; | |
| 1356 | ||
| 1357 | // The "obvious" converting constructor implementation: | |
| 1358 | // | |
| 1359 | // template<typename _Tp1> | |
| 1360 | // __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) | |
| 1361 | // : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws | |
| 1362 | // { } | |
| 1363 | // | |
| 1364 | // has a serious problem. | |
| 1365 | // | |
| 1366 | // __r._M_ptr may already have been invalidated. The _M_ptr(__r._M_ptr) | |
| 1367 | // conversion may require access to *__r._M_ptr (virtual inheritance). | |
| 1368 | // | |
| 1369 | // It is not possible to avoid spurious access violations since | |
| 1370 | // in multithreaded programs __r._M_ptr may be invalidated at any point. | |
| 1371 | template<typename _Tp1, typename = _Convertible<_Tp1*>> | |
| 1372 | __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1373 | : _M_refcount(__r._M_refcount) | |
| 1374 | { _M_ptr = __r.lock().get(); } | |
| 1375 | ||
| 1376 | template<typename _Tp1, typename = _Convertible<_Tp1*>> | |
| 1377 | __weak_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1378 | : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) | |
| 1379 | { } | |
| 1380 | ||
| 1381 | __weak_ptr(__weak_ptr&& __r) noexcept | |
| 1382 | : _M_ptr(__r._M_ptr), _M_refcount(std::move(__r._M_refcount)) | |
| 1383 | { __r._M_ptr = nullptr; } | |
| 1384 | ||
| 1385 | template<typename _Tp1, typename = _Convertible<_Tp1*>> | |
| 1386 | __weak_ptr(__weak_ptr<_Tp1, _Lp>&& __r) noexcept | |
| 1387 | : _M_ptr(__r.lock().get()), _M_refcount(std::move(__r._M_refcount)) | |
| 1388 | { __r._M_ptr = nullptr; } | |
| 1389 | ||
| 1390 | __weak_ptr& | |
| 1391 | operator=(const __weak_ptr& __r) noexcept = default; | |
| 1392 | ||
| 1393 | template<typename _Tp1> | |
| 1394 | __weak_ptr& | |
| 1395 | operator=(const __weak_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1396 | { | |
| 1397 | _M_ptr = __r.lock().get(); | |
| 1398 | _M_refcount = __r._M_refcount; | |
| 1399 | return *this; | |
| 1400 | } | |
| 1401 | ||
| 1402 | template<typename _Tp1> | |
| 1403 | __weak_ptr& | |
| 1404 | operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept | |
| 1405 | { | |
| 1406 | _M_ptr = __r._M_ptr; | |
| 1407 | _M_refcount = __r._M_refcount; | |
| 1408 | return *this; | |
| 1409 | } | |
| 1410 | ||
| 1411 | __weak_ptr& | |
| 1412 | operator=(__weak_ptr&& __r) noexcept | |
| 1413 | { | |
| 1414 | _M_ptr = __r._M_ptr; | |
| 1415 | _M_refcount = std::move(__r._M_refcount); | |
| 1416 | __r._M_ptr = nullptr; | |
| 1417 | return *this; | |
| 1418 | } | |
| 1419 | ||
| 1420 | template<typename _Tp1> | |
| 1421 | __weak_ptr& | |
| 1422 | operator=(__weak_ptr<_Tp1, _Lp>&& __r) noexcept | |
| 1423 | { | |
| 1424 | _M_ptr = __r.lock().get(); | |
| 1425 | _M_refcount = std::move(__r._M_refcount); | |
| 1426 | __r._M_ptr = nullptr; | |
| 1427 | return *this; | |
| 1428 | } | |
| 1429 | ||
| 1430 | __shared_ptr<_Tp, _Lp> | |
| 1431 | lock() const noexcept | |
| 1432 | { return __shared_ptr<element_type, _Lp>(*this, std::nothrow); } | |
| 1433 | ||
| 1434 | long | |
| 1435 | use_count() const noexcept | |
| 1436 | { return _M_refcount._M_get_use_count(); } | |
| 1437 | ||
| 1438 | bool | |
| 1439 | expired() const noexcept | |
| 1440 | { return _M_refcount._M_get_use_count() == 0; } | |
| 1441 | ||
| 1442 | template<typename _Tp1> | |
| 1443 | bool | |
| 1444 | owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const | |
| 1445 | { return _M_refcount._M_less(__rhs._M_refcount); } | |
| 1446 | ||
| 1447 | template<typename _Tp1> | |
| 1448 | bool | |
| 1449 | owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const | |
| 1450 | { return _M_refcount._M_less(__rhs._M_refcount); } | |
| 1451 | ||
| 1452 | void | |
| 1453 | reset() noexcept | |
| 1454 | { __weak_ptr().swap(*this); } | |
| 1455 | ||
| 1456 | void | |
| 1457 | swap(__weak_ptr& __s) noexcept | |
| 1458 | { | |
| 1459 | std::swap(_M_ptr, __s._M_ptr); | |
| 1460 | _M_refcount._M_swap(__s._M_refcount); | |
| 1461 | } | |
| 1462 | ||
| 1463 | private: | |
| 1464 | // Used by __enable_shared_from_this. | |
| 1465 | void | |
| 1466 | _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount) noexcept | |
| 1467 | { | |
| 1468 | _M_ptr = __ptr; | |
| 1469 | _M_refcount = __refcount; | |
| 1470 | } | |
| 1471 | ||
| 1472 | template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr; | |
| 1473 | template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr; | |
| 1474 | friend class __enable_shared_from_this<_Tp, _Lp>; | |
| 1475 | friend class enable_shared_from_this<_Tp>; | |
| 1476 | ||
| 1477 | _Tp* _M_ptr; // Contained pointer. | |
| 1478 | __weak_count<_Lp> _M_refcount; // Reference counter. | |
| 1479 | }; | |
| 1480 | ||
| 1481 | // 20.7.2.3.6 weak_ptr specialized algorithms. | |
| 1482 | template<typename _Tp, _Lock_policy _Lp> | |
| 1483 | inline void | |
| 1484 | swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b) noexcept | |
| 1485 | { __a.swap(__b); } | |
| 1486 | ||
| 1487 | template<typename _Tp, typename _Tp1> | |
| 1488 | struct _Sp_owner_less : public binary_function<_Tp, _Tp, bool> | |
| 1489 | { | |
| 1490 | bool | |
| 1491 | operator()(const _Tp& __lhs, const _Tp& __rhs) const | |
| 1492 | { return __lhs.owner_before(__rhs); } | |
| 1493 | ||
| 1494 | bool | |
| 1495 | operator()(const _Tp& __lhs, const _Tp1& __rhs) const | |
| 1496 | { return __lhs.owner_before(__rhs); } | |
| 1497 | ||
| 1498 | bool | |
| 1499 | operator()(const _Tp1& __lhs, const _Tp& __rhs) const | |
| 1500 | { return __lhs.owner_before(__rhs); } | |
| 1501 | }; | |
| 1502 | ||
| 1503 | template<typename _Tp, _Lock_policy _Lp> | |
| 1504 | struct owner_less<__shared_ptr<_Tp, _Lp>> | |
| 1505 | : public _Sp_owner_less<__shared_ptr<_Tp, _Lp>, __weak_ptr<_Tp, _Lp>> | |
| 1506 | { }; | |
| 1507 | ||
| 1508 | template<typename _Tp, _Lock_policy _Lp> | |
| 1509 | struct owner_less<__weak_ptr<_Tp, _Lp>> | |
| 1510 | : public _Sp_owner_less<__weak_ptr<_Tp, _Lp>, __shared_ptr<_Tp, _Lp>> | |
| 1511 | { }; | |
| 1512 | ||
| 1513 | ||
| 1514 | template<typename _Tp, _Lock_policy _Lp> | |
| 1515 | class __enable_shared_from_this | |
| 1516 | { | |
| 1517 | protected: | |
| 1518 | constexpr __enable_shared_from_this() noexcept { } | |
| 1519 | ||
| 1520 | __enable_shared_from_this(const __enable_shared_from_this&) noexcept { } | |
| 1521 | ||
| 1522 | __enable_shared_from_this& | |
| 1523 | operator=(const __enable_shared_from_this&) noexcept | |
| 1524 | { return *this; } | |
| 1525 | ||
| 1526 | ~__enable_shared_from_this() { } | |
| 1527 | ||
| 1528 | public: | |
| 1529 | __shared_ptr<_Tp, _Lp> | |
| 1530 | shared_from_this() | |
| 1531 | { return __shared_ptr<_Tp, _Lp>(this->_M_weak_this); } | |
| 1532 | ||
| 1533 | __shared_ptr<const _Tp, _Lp> | |
| 1534 | shared_from_this() const | |
| 1535 | { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); } | |
| 1536 | ||
| 1537 | private: | |
| 1538 | template<typename _Tp1> | |
| 1539 | void | |
| 1540 | _M_weak_assign(_Tp1* __p, const __shared_count<_Lp>& __n) const noexcept | |
| 1541 | { _M_weak_this._M_assign(__p, __n); } | |
| 1542 | ||
| 1543 | template<typename _Tp1> | |
| 1544 | friend void | |
| 1545 | __enable_shared_from_this_helper(const __shared_count<_Lp>& __pn, | |
| 1546 | const __enable_shared_from_this* __pe, | |
| 1547 | const _Tp1* __px) noexcept | |
| 1548 | { | |
| 1549 | if (__pe != 0) | |
| 1550 | __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn); | |
| 1551 | } | |
| 1552 | ||
| 1553 | mutable __weak_ptr<_Tp, _Lp> _M_weak_this; | |
| 1554 | }; | |
| 1555 | ||
| 1556 | ||
| 1557 | template<typename _Tp, _Lock_policy _Lp, typename _Alloc, typename... _Args> | |
| 1558 | inline __shared_ptr<_Tp, _Lp> | |
| 1559 | __allocate_shared(const _Alloc& __a, _Args&&... __args) | |
| 1560 | { | |
| 1561 | return __shared_ptr<_Tp, _Lp>(_Sp_make_shared_tag(), __a, | |
| 1562 | std::forward<_Args>(__args)...); | |
| 1563 | } | |
| 1564 | ||
| 1565 | template<typename _Tp, _Lock_policy _Lp, typename... _Args> | |
| 1566 | inline __shared_ptr<_Tp, _Lp> | |
| 1567 | __make_shared(_Args&&... __args) | |
| 1568 | { | |
| 1569 | typedef typename std::remove_const<_Tp>::type _Tp_nc; | |
| 1570 | return std::__allocate_shared<_Tp, _Lp>(std::allocator<_Tp_nc>(), | |
| 1571 | std::forward<_Args>(__args)...); | |
| 1572 | } | |
| 1573 | ||
| 1574 | /// std::hash specialization for __shared_ptr. | |
| 1575 | template<typename _Tp, _Lock_policy _Lp> | |
| 1576 | struct hash<__shared_ptr<_Tp, _Lp>> | |
| 1577 | : public __hash_base<size_t, __shared_ptr<_Tp, _Lp>> | |
| 1578 | { | |
| 1579 | size_t | |
| 1580 | operator()(const __shared_ptr<_Tp, _Lp>& __s) const noexcept | |
| 1581 | { return std::hash<_Tp*>()(__s.get()); } | |
| 1582 | }; | |
| 1583 | ||
| 1584 | _GLIBCXX_END_NAMESPACE_VERSION | |
| 1585 | } // namespace | |
| 1586 | ||
| 1587 | #endif // _SHARED_PTR_BASE_H | |
| 1588 |
Copyright (c) 2006-2012 Rogue Wave Software, Inc. All Rights Reserved.
Patents pending.