| 1 | // <tr1/shared_ptr.h> -*- C++ -*-
|
|---|
| 2 |
|
|---|
| 3 | // Copyright (C) 2007-2021 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 | // shared_count.hpp
|
|---|
| 26 | // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
|
|---|
| 27 |
|
|---|
| 28 | // shared_ptr.hpp
|
|---|
| 29 | // Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes.
|
|---|
| 30 | // Copyright (C) 2001, 2002, 2003 Peter Dimov
|
|---|
| 31 |
|
|---|
| 32 | // weak_ptr.hpp
|
|---|
| 33 | // Copyright (C) 2001, 2002, 2003 Peter Dimov
|
|---|
| 34 |
|
|---|
| 35 | // enable_shared_from_this.hpp
|
|---|
| 36 | // Copyright (C) 2002 Peter Dimov
|
|---|
| 37 |
|
|---|
| 38 | // Distributed under the Boost Software License, Version 1.0. (See
|
|---|
| 39 | // accompanying file LICENSE_1_0.txt or copy at
|
|---|
| 40 | // http://www.boost.org/LICENSE_1_0.txt)
|
|---|
| 41 |
|
|---|
| 42 | // GCC Note: based on version 1.32.0 of the Boost library.
|
|---|
| 43 |
|
|---|
| 44 | /** @file tr1/shared_ptr.h
|
|---|
| 45 | * This is an internal header file, included by other library headers.
|
|---|
| 46 | * Do not attempt to use it directly. @headername{tr1/memory}
|
|---|
| 47 | */
|
|---|
| 48 |
|
|---|
| 49 | #ifndef _TR1_SHARED_PTR_H
|
|---|
| 50 | #define _TR1_SHARED_PTR_H 1
|
|---|
| 51 |
|
|---|
| 52 | namespace std _GLIBCXX_VISIBILITY(default)
|
|---|
| 53 | {
|
|---|
| 54 | _GLIBCXX_BEGIN_NAMESPACE_VERSION
|
|---|
| 55 |
|
|---|
| 56 | namespace tr1
|
|---|
| 57 | {
|
|---|
| 58 | /**
|
|---|
| 59 | * @brief Exception possibly thrown by @c shared_ptr.
|
|---|
| 60 | * @ingroup exceptions
|
|---|
| 61 | */
|
|---|
| 62 | class bad_weak_ptr : public std::exception
|
|---|
| 63 | {
|
|---|
| 64 | public:
|
|---|
| 65 | virtual char const*
|
|---|
| 66 | what() const throw()
|
|---|
| 67 | { return "tr1::bad_weak_ptr"; }
|
|---|
| 68 | };
|
|---|
| 69 |
|
|---|
| 70 | // Substitute for bad_weak_ptr object in the case of -fno-exceptions.
|
|---|
| 71 | inline void
|
|---|
| 72 | __throw_bad_weak_ptr()
|
|---|
| 73 | { _GLIBCXX_THROW_OR_ABORT(bad_weak_ptr()); }
|
|---|
| 74 |
|
|---|
| 75 | using __gnu_cxx::_Lock_policy;
|
|---|
| 76 | using __gnu_cxx::__default_lock_policy;
|
|---|
| 77 | using __gnu_cxx::_S_single;
|
|---|
| 78 | using __gnu_cxx::_S_mutex;
|
|---|
| 79 | using __gnu_cxx::_S_atomic;
|
|---|
| 80 |
|
|---|
| 81 | // Empty helper class except when the template argument is _S_mutex.
|
|---|
| 82 | template<_Lock_policy _Lp>
|
|---|
| 83 | class _Mutex_base
|
|---|
| 84 | {
|
|---|
| 85 | protected:
|
|---|
| 86 | // The atomic policy uses fully-fenced builtins, single doesn't care.
|
|---|
| 87 | enum { _S_need_barriers = 0 };
|
|---|
| 88 | };
|
|---|
| 89 |
|
|---|
| 90 | template<>
|
|---|
| 91 | class _Mutex_base<_S_mutex>
|
|---|
| 92 | : public __gnu_cxx::__mutex
|
|---|
| 93 | {
|
|---|
| 94 | protected:
|
|---|
| 95 | // This policy is used when atomic builtins are not available.
|
|---|
| 96 | // The replacement atomic operations might not have the necessary
|
|---|
| 97 | // memory barriers.
|
|---|
| 98 | enum { _S_need_barriers = 1 };
|
|---|
| 99 | };
|
|---|
| 100 |
|
|---|
| 101 | template<_Lock_policy _Lp = __default_lock_policy>
|
|---|
| 102 | class _Sp_counted_base
|
|---|
| 103 | : public _Mutex_base<_Lp>
|
|---|
| 104 | {
|
|---|
| 105 | public:
|
|---|
| 106 | _Sp_counted_base()
|
|---|
| 107 | : _M_use_count(1), _M_weak_count(1) { }
|
|---|
| 108 |
|
|---|
| 109 | virtual
|
|---|
| 110 | ~_Sp_counted_base() // nothrow
|
|---|
| 111 | { }
|
|---|
| 112 |
|
|---|
| 113 | // Called when _M_use_count drops to zero, to release the resources
|
|---|
| 114 | // managed by *this.
|
|---|
| 115 | virtual void
|
|---|
| 116 | _M_dispose() = 0; // nothrow
|
|---|
| 117 |
|
|---|
| 118 | // Called when _M_weak_count drops to zero.
|
|---|
| 119 | virtual void
|
|---|
| 120 | _M_destroy() // nothrow
|
|---|
| 121 | { delete this; }
|
|---|
| 122 |
|
|---|
| 123 | virtual void*
|
|---|
| 124 | _M_get_deleter(const std::type_info&) = 0;
|
|---|
| 125 |
|
|---|
| 126 | void
|
|---|
| 127 | _M_add_ref_copy()
|
|---|
| 128 | { __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); }
|
|---|
| 129 |
|
|---|
| 130 | void
|
|---|
| 131 | _M_add_ref_lock();
|
|---|
| 132 |
|
|---|
| 133 | void
|
|---|
| 134 | _M_release() // nothrow
|
|---|
| 135 | {
|
|---|
| 136 | // Be race-detector-friendly. For more info see bits/c++config.
|
|---|
| 137 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count);
|
|---|
| 138 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1)
|
|---|
| 139 | {
|
|---|
| 140 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count);
|
|---|
| 141 | _M_dispose();
|
|---|
| 142 | // There must be a memory barrier between dispose() and destroy()
|
|---|
| 143 | // to ensure that the effects of dispose() are observed in the
|
|---|
| 144 | // thread that runs destroy().
|
|---|
| 145 | // See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html
|
|---|
| 146 | if (_Mutex_base<_Lp>::_S_need_barriers)
|
|---|
| 147 | {
|
|---|
| 148 | __atomic_thread_fence (__ATOMIC_ACQ_REL);
|
|---|
| 149 | }
|
|---|
| 150 |
|
|---|
| 151 | // Be race-detector-friendly. For more info see bits/c++config.
|
|---|
| 152 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
|
|---|
| 153 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count,
|
|---|
| 154 | -1) == 1)
|
|---|
| 155 | {
|
|---|
| 156 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
|
|---|
| 157 | _M_destroy();
|
|---|
| 158 | }
|
|---|
| 159 | }
|
|---|
| 160 | }
|
|---|
| 161 |
|
|---|
| 162 | void
|
|---|
| 163 | _M_weak_add_ref() // nothrow
|
|---|
| 164 | { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); }
|
|---|
| 165 |
|
|---|
| 166 | void
|
|---|
| 167 | _M_weak_release() // nothrow
|
|---|
| 168 | {
|
|---|
| 169 | // Be race-detector-friendly. For more info see bits/c++config.
|
|---|
| 170 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
|
|---|
| 171 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1)
|
|---|
| 172 | {
|
|---|
| 173 | _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
|
|---|
| 174 | if (_Mutex_base<_Lp>::_S_need_barriers)
|
|---|
| 175 | {
|
|---|
| 176 | // See _M_release(),
|
|---|
| 177 | // destroy() must observe results of dispose()
|
|---|
| 178 | __atomic_thread_fence (__ATOMIC_ACQ_REL);
|
|---|
| 179 | }
|
|---|
| 180 | _M_destroy();
|
|---|
| 181 | }
|
|---|
| 182 | }
|
|---|
| 183 |
|
|---|
| 184 | long
|
|---|
| 185 | _M_get_use_count() const // nothrow
|
|---|
| 186 | {
|
|---|
| 187 | // No memory barrier is used here so there is no synchronization
|
|---|
| 188 | // with other threads.
|
|---|
| 189 | return const_cast<const volatile _Atomic_word&>(_M_use_count);
|
|---|
| 190 | }
|
|---|
| 191 |
|
|---|
| 192 | private:
|
|---|
| 193 | _Sp_counted_base(_Sp_counted_base const&);
|
|---|
| 194 | _Sp_counted_base& operator=(_Sp_counted_base const&);
|
|---|
| 195 |
|
|---|
| 196 | _Atomic_word _M_use_count; // #shared
|
|---|
| 197 | _Atomic_word _M_weak_count; // #weak + (#shared != 0)
|
|---|
| 198 | };
|
|---|
| 199 |
|
|---|
| 200 | template<>
|
|---|
| 201 | inline void
|
|---|
| 202 | _Sp_counted_base<_S_single>::
|
|---|
| 203 | _M_add_ref_lock()
|
|---|
| 204 | {
|
|---|
| 205 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
|
|---|
| 206 | {
|
|---|
| 207 | _M_use_count = 0;
|
|---|
| 208 | __throw_bad_weak_ptr();
|
|---|
| 209 | }
|
|---|
| 210 | }
|
|---|
| 211 |
|
|---|
| 212 | template<>
|
|---|
| 213 | inline void
|
|---|
| 214 | _Sp_counted_base<_S_mutex>::
|
|---|
| 215 | _M_add_ref_lock()
|
|---|
| 216 | {
|
|---|
| 217 | __gnu_cxx::__scoped_lock sentry(*this);
|
|---|
| 218 | if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
|
|---|
| 219 | {
|
|---|
| 220 | _M_use_count = 0;
|
|---|
| 221 | __throw_bad_weak_ptr();
|
|---|
| 222 | }
|
|---|
| 223 | }
|
|---|
| 224 |
|
|---|
| 225 | template<>
|
|---|
| 226 | inline void
|
|---|
| 227 | _Sp_counted_base<_S_atomic>::
|
|---|
| 228 | _M_add_ref_lock()
|
|---|
| 229 | {
|
|---|
| 230 | // Perform lock-free add-if-not-zero operation.
|
|---|
| 231 | _Atomic_word __count = _M_use_count;
|
|---|
| 232 | do
|
|---|
| 233 | {
|
|---|
| 234 | if (__count == 0)
|
|---|
| 235 | __throw_bad_weak_ptr();
|
|---|
| 236 | // Replace the current counter value with the old value + 1, as
|
|---|
| 237 | // long as it's not changed meanwhile.
|
|---|
| 238 | }
|
|---|
| 239 | while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1,
|
|---|
| 240 | true, __ATOMIC_ACQ_REL,
|
|---|
| 241 | __ATOMIC_RELAXED));
|
|---|
| 242 | }
|
|---|
| 243 |
|
|---|
| 244 | template<typename _Ptr, typename _Deleter, _Lock_policy _Lp>
|
|---|
| 245 | class _Sp_counted_base_impl
|
|---|
| 246 | : public _Sp_counted_base<_Lp>
|
|---|
| 247 | {
|
|---|
| 248 | public:
|
|---|
| 249 | // Precondition: __d(__p) must not throw.
|
|---|
| 250 | _Sp_counted_base_impl(_Ptr __p, _Deleter __d)
|
|---|
| 251 | : _M_ptr(__p), _M_del(__d) { }
|
|---|
| 252 |
|
|---|
| 253 | virtual void
|
|---|
| 254 | _M_dispose() // nothrow
|
|---|
| 255 | { _M_del(_M_ptr); }
|
|---|
| 256 |
|
|---|
| 257 | virtual void*
|
|---|
| 258 | _M_get_deleter(const std::type_info& __ti)
|
|---|
| 259 | {
|
|---|
| 260 | #if __cpp_rtti
|
|---|
| 261 | return __ti == typeid(_Deleter) ? &_M_del : 0;
|
|---|
| 262 | #else
|
|---|
| 263 | return 0;
|
|---|
| 264 | #endif
|
|---|
| 265 | }
|
|---|
| 266 |
|
|---|
| 267 | private:
|
|---|
| 268 | _Sp_counted_base_impl(const _Sp_counted_base_impl&);
|
|---|
| 269 | _Sp_counted_base_impl& operator=(const _Sp_counted_base_impl&);
|
|---|
| 270 |
|
|---|
| 271 | _Ptr _M_ptr; // copy constructor must not throw
|
|---|
| 272 | _Deleter _M_del; // copy constructor must not throw
|
|---|
| 273 | };
|
|---|
| 274 |
|
|---|
| 275 | template<_Lock_policy _Lp = __default_lock_policy>
|
|---|
| 276 | class __weak_count;
|
|---|
| 277 |
|
|---|
| 278 | template<typename _Tp>
|
|---|
| 279 | struct _Sp_deleter
|
|---|
| 280 | {
|
|---|
| 281 | typedef void result_type;
|
|---|
| 282 | typedef _Tp* argument_type;
|
|---|
| 283 | void operator()(_Tp* __p) const { delete __p; }
|
|---|
| 284 | };
|
|---|
| 285 |
|
|---|
| 286 | template<_Lock_policy _Lp = __default_lock_policy>
|
|---|
| 287 | class __shared_count
|
|---|
| 288 | {
|
|---|
| 289 | public:
|
|---|
| 290 | __shared_count()
|
|---|
| 291 | : _M_pi(0) // nothrow
|
|---|
| 292 | { }
|
|---|
| 293 |
|
|---|
| 294 | template<typename _Ptr>
|
|---|
| 295 | __shared_count(_Ptr __p) : _M_pi(0)
|
|---|
| 296 | {
|
|---|
| 297 | __try
|
|---|
| 298 | {
|
|---|
| 299 | typedef typename std::tr1::remove_pointer<_Ptr>::type _Tp;
|
|---|
| 300 | _M_pi = new _Sp_counted_base_impl<_Ptr, _Sp_deleter<_Tp>, _Lp>(
|
|---|
| 301 | __p, _Sp_deleter<_Tp>());
|
|---|
| 302 | }
|
|---|
| 303 | __catch(...)
|
|---|
| 304 | {
|
|---|
| 305 | delete __p;
|
|---|
| 306 | __throw_exception_again;
|
|---|
| 307 | }
|
|---|
| 308 | }
|
|---|
| 309 |
|
|---|
| 310 | template<typename _Ptr, typename _Deleter>
|
|---|
| 311 | __shared_count(_Ptr __p, _Deleter __d) : _M_pi(0)
|
|---|
| 312 | {
|
|---|
| 313 | __try
|
|---|
| 314 | {
|
|---|
| 315 | _M_pi = new _Sp_counted_base_impl<_Ptr, _Deleter, _Lp>(__p, __d);
|
|---|
| 316 | }
|
|---|
| 317 | __catch(...)
|
|---|
| 318 | {
|
|---|
| 319 | __d(__p); // Call _Deleter on __p.
|
|---|
| 320 | __throw_exception_again;
|
|---|
| 321 | }
|
|---|
| 322 | }
|
|---|
| 323 |
|
|---|
| 324 | #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
|
|---|
| 325 | #pragma GCC diagnostic push
|
|---|
| 326 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|---|
| 327 | // Special case for auto_ptr<_Tp> to provide the strong guarantee.
|
|---|
| 328 | template<typename _Tp>
|
|---|
| 329 | explicit
|
|---|
| 330 | __shared_count(std::auto_ptr<_Tp>& __r)
|
|---|
| 331 | : _M_pi(new _Sp_counted_base_impl<_Tp*,
|
|---|
| 332 | _Sp_deleter<_Tp>, _Lp >(__r.get(), _Sp_deleter<_Tp>()))
|
|---|
| 333 | { __r.release(); }
|
|---|
| 334 | #pragma GCC diagnostic pop
|
|---|
| 335 | #endif
|
|---|
| 336 |
|
|---|
| 337 | // Throw bad_weak_ptr when __r._M_get_use_count() == 0.
|
|---|
| 338 | explicit
|
|---|
| 339 | __shared_count(const __weak_count<_Lp>& __r);
|
|---|
| 340 |
|
|---|
| 341 | ~__shared_count() // nothrow
|
|---|
| 342 | {
|
|---|
| 343 | if (_M_pi != 0)
|
|---|
| 344 | _M_pi->_M_release();
|
|---|
| 345 | }
|
|---|
| 346 |
|
|---|
| 347 | __shared_count(const __shared_count& __r)
|
|---|
| 348 | : _M_pi(__r._M_pi) // nothrow
|
|---|
| 349 | {
|
|---|
| 350 | if (_M_pi != 0)
|
|---|
| 351 | _M_pi->_M_add_ref_copy();
|
|---|
| 352 | }
|
|---|
| 353 |
|
|---|
| 354 | __shared_count&
|
|---|
| 355 | operator=(const __shared_count& __r) // nothrow
|
|---|
| 356 | {
|
|---|
| 357 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
|
|---|
| 358 | if (__tmp != _M_pi)
|
|---|
| 359 | {
|
|---|
| 360 | if (__tmp != 0)
|
|---|
| 361 | __tmp->_M_add_ref_copy();
|
|---|
| 362 | if (_M_pi != 0)
|
|---|
| 363 | _M_pi->_M_release();
|
|---|
| 364 | _M_pi = __tmp;
|
|---|
| 365 | }
|
|---|
| 366 | return *this;
|
|---|
| 367 | }
|
|---|
| 368 |
|
|---|
| 369 | void
|
|---|
| 370 | _M_swap(__shared_count& __r) // nothrow
|
|---|
| 371 | {
|
|---|
| 372 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
|
|---|
| 373 | __r._M_pi = _M_pi;
|
|---|
| 374 | _M_pi = __tmp;
|
|---|
| 375 | }
|
|---|
| 376 |
|
|---|
| 377 | long
|
|---|
| 378 | _M_get_use_count() const // nothrow
|
|---|
| 379 | { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }
|
|---|
| 380 |
|
|---|
| 381 | bool
|
|---|
| 382 | _M_unique() const // nothrow
|
|---|
| 383 | { return this->_M_get_use_count() == 1; }
|
|---|
| 384 |
|
|---|
| 385 | friend inline bool
|
|---|
| 386 | operator==(const __shared_count& __a, const __shared_count& __b)
|
|---|
| 387 | { return __a._M_pi == __b._M_pi; }
|
|---|
| 388 |
|
|---|
| 389 | friend inline bool
|
|---|
| 390 | operator<(const __shared_count& __a, const __shared_count& __b)
|
|---|
| 391 | { return std::less<_Sp_counted_base<_Lp>*>()(__a._M_pi, __b._M_pi); }
|
|---|
| 392 |
|
|---|
| 393 | void*
|
|---|
| 394 | _M_get_deleter(const std::type_info& __ti) const
|
|---|
| 395 | { return _M_pi ? _M_pi->_M_get_deleter(__ti) : 0; }
|
|---|
| 396 |
|
|---|
| 397 | private:
|
|---|
| 398 | friend class __weak_count<_Lp>;
|
|---|
| 399 |
|
|---|
| 400 | _Sp_counted_base<_Lp>* _M_pi;
|
|---|
| 401 | };
|
|---|
| 402 |
|
|---|
| 403 |
|
|---|
| 404 | template<_Lock_policy _Lp>
|
|---|
| 405 | class __weak_count
|
|---|
| 406 | {
|
|---|
| 407 | public:
|
|---|
| 408 | __weak_count()
|
|---|
| 409 | : _M_pi(0) // nothrow
|
|---|
| 410 | { }
|
|---|
| 411 |
|
|---|
| 412 | __weak_count(const __shared_count<_Lp>& __r)
|
|---|
| 413 | : _M_pi(__r._M_pi) // nothrow
|
|---|
| 414 | {
|
|---|
| 415 | if (_M_pi != 0)
|
|---|
| 416 | _M_pi->_M_weak_add_ref();
|
|---|
| 417 | }
|
|---|
| 418 |
|
|---|
| 419 | __weak_count(const __weak_count<_Lp>& __r)
|
|---|
| 420 | : _M_pi(__r._M_pi) // nothrow
|
|---|
| 421 | {
|
|---|
| 422 | if (_M_pi != 0)
|
|---|
| 423 | _M_pi->_M_weak_add_ref();
|
|---|
| 424 | }
|
|---|
| 425 |
|
|---|
| 426 | ~__weak_count() // nothrow
|
|---|
| 427 | {
|
|---|
| 428 | if (_M_pi != 0)
|
|---|
| 429 | _M_pi->_M_weak_release();
|
|---|
| 430 | }
|
|---|
| 431 |
|
|---|
| 432 | __weak_count<_Lp>&
|
|---|
| 433 | operator=(const __shared_count<_Lp>& __r) // nothrow
|
|---|
| 434 | {
|
|---|
| 435 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
|
|---|
| 436 | if (__tmp != 0)
|
|---|
| 437 | __tmp->_M_weak_add_ref();
|
|---|
| 438 | if (_M_pi != 0)
|
|---|
| 439 | _M_pi->_M_weak_release();
|
|---|
| 440 | _M_pi = __tmp;
|
|---|
| 441 | return *this;
|
|---|
| 442 | }
|
|---|
| 443 |
|
|---|
| 444 | __weak_count<_Lp>&
|
|---|
| 445 | operator=(const __weak_count<_Lp>& __r) // nothrow
|
|---|
| 446 | {
|
|---|
| 447 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
|
|---|
| 448 | if (__tmp != 0)
|
|---|
| 449 | __tmp->_M_weak_add_ref();
|
|---|
| 450 | if (_M_pi != 0)
|
|---|
| 451 | _M_pi->_M_weak_release();
|
|---|
| 452 | _M_pi = __tmp;
|
|---|
| 453 | return *this;
|
|---|
| 454 | }
|
|---|
| 455 |
|
|---|
| 456 | void
|
|---|
| 457 | _M_swap(__weak_count<_Lp>& __r) // nothrow
|
|---|
| 458 | {
|
|---|
| 459 | _Sp_counted_base<_Lp>* __tmp = __r._M_pi;
|
|---|
| 460 | __r._M_pi = _M_pi;
|
|---|
| 461 | _M_pi = __tmp;
|
|---|
| 462 | }
|
|---|
| 463 |
|
|---|
| 464 | long
|
|---|
| 465 | _M_get_use_count() const // nothrow
|
|---|
| 466 | { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }
|
|---|
| 467 |
|
|---|
| 468 | friend inline bool
|
|---|
| 469 | operator==(const __weak_count<_Lp>& __a, const __weak_count<_Lp>& __b)
|
|---|
| 470 | { return __a._M_pi == __b._M_pi; }
|
|---|
| 471 |
|
|---|
| 472 | friend inline bool
|
|---|
| 473 | operator<(const __weak_count<_Lp>& __a, const __weak_count<_Lp>& __b)
|
|---|
| 474 | { return std::less<_Sp_counted_base<_Lp>*>()(__a._M_pi, __b._M_pi); }
|
|---|
| 475 |
|
|---|
| 476 | private:
|
|---|
| 477 | friend class __shared_count<_Lp>;
|
|---|
| 478 |
|
|---|
| 479 | _Sp_counted_base<_Lp>* _M_pi;
|
|---|
| 480 | };
|
|---|
| 481 |
|
|---|
| 482 | // now that __weak_count is defined we can define this constructor:
|
|---|
| 483 | template<_Lock_policy _Lp>
|
|---|
| 484 | inline
|
|---|
| 485 | __shared_count<_Lp>::
|
|---|
| 486 | __shared_count(const __weak_count<_Lp>& __r)
|
|---|
| 487 | : _M_pi(__r._M_pi)
|
|---|
| 488 | {
|
|---|
| 489 | if (_M_pi != 0)
|
|---|
| 490 | _M_pi->_M_add_ref_lock();
|
|---|
| 491 | else
|
|---|
| 492 | __throw_bad_weak_ptr();
|
|---|
| 493 | }
|
|---|
| 494 |
|
|---|
| 495 | // Forward declarations.
|
|---|
| 496 | template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
|
|---|
| 497 | class __shared_ptr;
|
|---|
| 498 |
|
|---|
| 499 | template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
|
|---|
| 500 | class __weak_ptr;
|
|---|
| 501 |
|
|---|
| 502 | template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
|
|---|
| 503 | class __enable_shared_from_this;
|
|---|
| 504 |
|
|---|
| 505 | template<typename _Tp>
|
|---|
| 506 | class shared_ptr;
|
|---|
| 507 |
|
|---|
| 508 | template<typename _Tp>
|
|---|
| 509 | class weak_ptr;
|
|---|
| 510 |
|
|---|
| 511 | template<typename _Tp>
|
|---|
| 512 | class enable_shared_from_this;
|
|---|
| 513 |
|
|---|
| 514 | // Support for enable_shared_from_this.
|
|---|
| 515 |
|
|---|
| 516 | // Friend of __enable_shared_from_this.
|
|---|
| 517 | template<_Lock_policy _Lp, typename _Tp1, typename _Tp2>
|
|---|
| 518 | void
|
|---|
| 519 | __enable_shared_from_this_helper(const __shared_count<_Lp>&,
|
|---|
| 520 | const __enable_shared_from_this<_Tp1,
|
|---|
| 521 | _Lp>*, const _Tp2*);
|
|---|
| 522 |
|
|---|
| 523 | // Friend of enable_shared_from_this.
|
|---|
| 524 | template<typename _Tp1, typename _Tp2>
|
|---|
| 525 | void
|
|---|
| 526 | __enable_shared_from_this_helper(const __shared_count<>&,
|
|---|
| 527 | const enable_shared_from_this<_Tp1>*,
|
|---|
| 528 | const _Tp2*);
|
|---|
| 529 |
|
|---|
| 530 | template<_Lock_policy _Lp>
|
|---|
| 531 | inline void
|
|---|
| 532 | __enable_shared_from_this_helper(const __shared_count<_Lp>&, ...)
|
|---|
| 533 | { }
|
|---|
| 534 |
|
|---|
| 535 |
|
|---|
| 536 | struct __static_cast_tag { };
|
|---|
| 537 | struct __const_cast_tag { };
|
|---|
| 538 | struct __dynamic_cast_tag { };
|
|---|
| 539 |
|
|---|
| 540 | // A smart pointer with reference-counted copy semantics. The
|
|---|
| 541 | // object pointed to is deleted when the last shared_ptr pointing to
|
|---|
| 542 | // it is destroyed or reset.
|
|---|
| 543 | template<typename _Tp, _Lock_policy _Lp>
|
|---|
| 544 | class __shared_ptr
|
|---|
| 545 | {
|
|---|
| 546 | public:
|
|---|
| 547 | typedef _Tp element_type;
|
|---|
| 548 |
|
|---|
| 549 | __shared_ptr()
|
|---|
| 550 | : _M_ptr(0), _M_refcount() // never throws
|
|---|
| 551 | { }
|
|---|
| 552 |
|
|---|
| 553 | template<typename _Tp1>
|
|---|
| 554 | explicit
|
|---|
| 555 | __shared_ptr(_Tp1* __p)
|
|---|
| 556 | : _M_ptr(__p), _M_refcount(__p)
|
|---|
| 557 | {
|
|---|
| 558 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
|
|---|
| 559 | typedef int _IsComplete[sizeof(_Tp1)];
|
|---|
| 560 | __enable_shared_from_this_helper(_M_refcount, __p, __p);
|
|---|
| 561 | }
|
|---|
| 562 |
|
|---|
| 563 | template<typename _Tp1, typename _Deleter>
|
|---|
| 564 | __shared_ptr(_Tp1* __p, _Deleter __d)
|
|---|
| 565 | : _M_ptr(__p), _M_refcount(__p, __d)
|
|---|
| 566 | {
|
|---|
| 567 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
|
|---|
| 568 | // TODO requires _Deleter CopyConstructible and __d(__p) well-formed
|
|---|
| 569 | __enable_shared_from_this_helper(_M_refcount, __p, __p);
|
|---|
| 570 | }
|
|---|
| 571 |
|
|---|
| 572 | // generated copy constructor, assignment, destructor are fine.
|
|---|
| 573 |
|
|---|
| 574 | template<typename _Tp1>
|
|---|
| 575 | __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r)
|
|---|
| 576 | : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws
|
|---|
| 577 | { __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) }
|
|---|
| 578 |
|
|---|
| 579 | template<typename _Tp1>
|
|---|
| 580 | explicit
|
|---|
| 581 | __shared_ptr(const __weak_ptr<_Tp1, _Lp>& __r)
|
|---|
| 582 | : _M_refcount(__r._M_refcount) // may throw
|
|---|
| 583 | {
|
|---|
| 584 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
|
|---|
| 585 | // It is now safe to copy __r._M_ptr, as _M_refcount(__r._M_refcount)
|
|---|
| 586 | // did not throw.
|
|---|
| 587 | _M_ptr = __r._M_ptr;
|
|---|
| 588 | }
|
|---|
| 589 |
|
|---|
| 590 | #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
|
|---|
| 591 | #pragma GCC diagnostic push
|
|---|
| 592 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|---|
| 593 | // Postcondition: use_count() == 1 and __r.get() == 0
|
|---|
| 594 | template<typename _Tp1>
|
|---|
| 595 | explicit
|
|---|
| 596 | __shared_ptr(std::auto_ptr<_Tp1>& __r)
|
|---|
| 597 | : _M_ptr(__r.get()), _M_refcount()
|
|---|
| 598 | { // TODO requries delete __r.release() well-formed
|
|---|
| 599 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
|
|---|
| 600 | typedef int _IsComplete[sizeof(_Tp1)];
|
|---|
| 601 | _Tp1* __tmp = __r.get();
|
|---|
| 602 | _M_refcount = __shared_count<_Lp>(__r);
|
|---|
| 603 | __enable_shared_from_this_helper(_M_refcount, __tmp, __tmp);
|
|---|
| 604 | }
|
|---|
| 605 | #pragma GCC diagnostic pop
|
|---|
| 606 | #endif
|
|---|
| 607 |
|
|---|
| 608 | template<typename _Tp1>
|
|---|
| 609 | __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, __static_cast_tag)
|
|---|
| 610 | : _M_ptr(static_cast<element_type*>(__r._M_ptr)),
|
|---|
| 611 | _M_refcount(__r._M_refcount)
|
|---|
| 612 | { }
|
|---|
| 613 |
|
|---|
| 614 | template<typename _Tp1>
|
|---|
| 615 | __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, __const_cast_tag)
|
|---|
| 616 | : _M_ptr(const_cast<element_type*>(__r._M_ptr)),
|
|---|
| 617 | _M_refcount(__r._M_refcount)
|
|---|
| 618 | { }
|
|---|
| 619 |
|
|---|
| 620 | template<typename _Tp1>
|
|---|
| 621 | __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, __dynamic_cast_tag)
|
|---|
| 622 | : _M_ptr(dynamic_cast<element_type*>(__r._M_ptr)),
|
|---|
| 623 | _M_refcount(__r._M_refcount)
|
|---|
| 624 | {
|
|---|
| 625 | if (_M_ptr == 0) // need to allocate new counter -- the cast failed
|
|---|
| 626 | _M_refcount = __shared_count<_Lp>();
|
|---|
| 627 | }
|
|---|
| 628 |
|
|---|
| 629 | template<typename _Tp1>
|
|---|
| 630 | __shared_ptr&
|
|---|
| 631 | operator=(const __shared_ptr<_Tp1, _Lp>& __r) // never throws
|
|---|
| 632 | {
|
|---|
| 633 | _M_ptr = __r._M_ptr;
|
|---|
| 634 | _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw
|
|---|
| 635 | return *this;
|
|---|
| 636 | }
|
|---|
| 637 |
|
|---|
| 638 | #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
|
|---|
| 639 | #pragma GCC diagnostic push
|
|---|
| 640 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|---|
| 641 | template<typename _Tp1>
|
|---|
| 642 | __shared_ptr&
|
|---|
| 643 | operator=(std::auto_ptr<_Tp1>& __r)
|
|---|
| 644 | {
|
|---|
| 645 | __shared_ptr(__r).swap(*this);
|
|---|
| 646 | return *this;
|
|---|
| 647 | }
|
|---|
| 648 | #pragma GCC diagnostic pop
|
|---|
| 649 | #endif
|
|---|
| 650 |
|
|---|
| 651 | void
|
|---|
| 652 | reset() // never throws
|
|---|
| 653 | { __shared_ptr().swap(*this); }
|
|---|
| 654 |
|
|---|
| 655 | template<typename _Tp1>
|
|---|
| 656 | void
|
|---|
| 657 | reset(_Tp1* __p) // _Tp1 must be complete.
|
|---|
| 658 | {
|
|---|
| 659 | // Catch self-reset errors.
|
|---|
| 660 | _GLIBCXX_DEBUG_ASSERT(__p == 0 || __p != _M_ptr);
|
|---|
| 661 | __shared_ptr(__p).swap(*this);
|
|---|
| 662 | }
|
|---|
| 663 |
|
|---|
| 664 | template<typename _Tp1, typename _Deleter>
|
|---|
| 665 | void
|
|---|
| 666 | reset(_Tp1* __p, _Deleter __d)
|
|---|
| 667 | { __shared_ptr(__p, __d).swap(*this); }
|
|---|
| 668 |
|
|---|
| 669 | // Allow class instantiation when _Tp is [cv-qual] void.
|
|---|
| 670 | typename std::tr1::add_reference<_Tp>::type
|
|---|
| 671 | operator*() const // never throws
|
|---|
| 672 | {
|
|---|
| 673 | _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0);
|
|---|
| 674 | return *_M_ptr;
|
|---|
| 675 | }
|
|---|
| 676 |
|
|---|
| 677 | _Tp*
|
|---|
| 678 | operator->() const // never throws
|
|---|
| 679 | {
|
|---|
| 680 | _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0);
|
|---|
| 681 | return _M_ptr;
|
|---|
| 682 | }
|
|---|
| 683 |
|
|---|
| 684 | _Tp*
|
|---|
| 685 | get() const // never throws
|
|---|
| 686 | { return _M_ptr; }
|
|---|
| 687 |
|
|---|
| 688 | // Implicit conversion to "bool"
|
|---|
| 689 | private:
|
|---|
| 690 | typedef _Tp* __shared_ptr::*__unspecified_bool_type;
|
|---|
| 691 |
|
|---|
| 692 | public:
|
|---|
| 693 | operator __unspecified_bool_type() const // never throws
|
|---|
| 694 | { return _M_ptr == 0 ? 0 : &__shared_ptr::_M_ptr; }
|
|---|
| 695 |
|
|---|
| 696 | bool
|
|---|
| 697 | unique() const // never throws
|
|---|
| 698 | { return _M_refcount._M_unique(); }
|
|---|
| 699 |
|
|---|
| 700 | long
|
|---|
| 701 | use_count() const // never throws
|
|---|
| 702 | { return _M_refcount._M_get_use_count(); }
|
|---|
| 703 |
|
|---|
| 704 | void
|
|---|
| 705 | swap(__shared_ptr<_Tp, _Lp>& __other) // never throws
|
|---|
| 706 | {
|
|---|
| 707 | std::swap(_M_ptr, __other._M_ptr);
|
|---|
| 708 | _M_refcount._M_swap(__other._M_refcount);
|
|---|
| 709 | }
|
|---|
| 710 |
|
|---|
| 711 | private:
|
|---|
| 712 | void*
|
|---|
| 713 | _M_get_deleter(const std::type_info& __ti) const
|
|---|
| 714 | { return _M_refcount._M_get_deleter(__ti); }
|
|---|
| 715 |
|
|---|
| 716 | template<typename _Tp1, _Lock_policy _Lp1>
|
|---|
| 717 | bool
|
|---|
| 718 | _M_less(const __shared_ptr<_Tp1, _Lp1>& __rhs) const
|
|---|
| 719 | { return _M_refcount < __rhs._M_refcount; }
|
|---|
| 720 |
|
|---|
| 721 | template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
|
|---|
| 722 | template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
|
|---|
| 723 |
|
|---|
| 724 | template<typename _Del, typename _Tp1, _Lock_policy _Lp1>
|
|---|
| 725 | friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&);
|
|---|
| 726 |
|
|---|
| 727 | // Friends injected into enclosing namespace and found by ADL:
|
|---|
| 728 | template<typename _Tp1>
|
|---|
| 729 | friend inline bool
|
|---|
| 730 | operator==(const __shared_ptr& __a, const __shared_ptr<_Tp1, _Lp>& __b)
|
|---|
| 731 | { return __a.get() == __b.get(); }
|
|---|
| 732 |
|
|---|
| 733 | template<typename _Tp1>
|
|---|
| 734 | friend inline bool
|
|---|
| 735 | operator!=(const __shared_ptr& __a, const __shared_ptr<_Tp1, _Lp>& __b)
|
|---|
| 736 | { return __a.get() != __b.get(); }
|
|---|
| 737 |
|
|---|
| 738 | template<typename _Tp1>
|
|---|
| 739 | friend inline bool
|
|---|
| 740 | operator<(const __shared_ptr& __a, const __shared_ptr<_Tp1, _Lp>& __b)
|
|---|
| 741 | { return __a._M_less(__b); }
|
|---|
| 742 |
|
|---|
| 743 | _Tp* _M_ptr; // Contained pointer.
|
|---|
| 744 | __shared_count<_Lp> _M_refcount; // Reference counter.
|
|---|
| 745 | };
|
|---|
| 746 |
|
|---|
| 747 | // 2.2.3.8 shared_ptr specialized algorithms.
|
|---|
| 748 | template<typename _Tp, _Lock_policy _Lp>
|
|---|
| 749 | inline void
|
|---|
| 750 | swap(__shared_ptr<_Tp, _Lp>& __a, __shared_ptr<_Tp, _Lp>& __b)
|
|---|
| 751 | { __a.swap(__b); }
|
|---|
| 752 |
|
|---|
| 753 | // 2.2.3.9 shared_ptr casts
|
|---|
| 754 | /* The seemingly equivalent
|
|---|
| 755 | * shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get()))
|
|---|
| 756 | * will eventually result in undefined behaviour,
|
|---|
| 757 | * attempting to delete the same object twice.
|
|---|
| 758 | */
|
|---|
| 759 | template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
|
|---|
| 760 | inline __shared_ptr<_Tp, _Lp>
|
|---|
| 761 | static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r)
|
|---|
| 762 | { return __shared_ptr<_Tp, _Lp>(__r, __static_cast_tag()); }
|
|---|
| 763 |
|
|---|
| 764 | /* The seemingly equivalent
|
|---|
| 765 | * shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get()))
|
|---|
| 766 | * will eventually result in undefined behaviour,
|
|---|
| 767 | * attempting to delete the same object twice.
|
|---|
| 768 | */
|
|---|
| 769 | template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
|
|---|
| 770 | inline __shared_ptr<_Tp, _Lp>
|
|---|
| 771 | const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r)
|
|---|
| 772 | { return __shared_ptr<_Tp, _Lp>(__r, __const_cast_tag()); }
|
|---|
| 773 |
|
|---|
| 774 | /* The seemingly equivalent
|
|---|
| 775 | * shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get()))
|
|---|
| 776 | * will eventually result in undefined behaviour,
|
|---|
| 777 | * attempting to delete the same object twice.
|
|---|
| 778 | */
|
|---|
| 779 | template<typename _Tp, typename _Tp1, _Lock_policy _Lp>
|
|---|
| 780 | inline __shared_ptr<_Tp, _Lp>
|
|---|
| 781 | dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r)
|
|---|
| 782 | { return __shared_ptr<_Tp, _Lp>(__r, __dynamic_cast_tag()); }
|
|---|
| 783 |
|
|---|
| 784 | // 2.2.3.7 shared_ptr I/O
|
|---|
| 785 | template<typename _Ch, typename _Tr, typename _Tp, _Lock_policy _Lp>
|
|---|
| 786 | std::basic_ostream<_Ch, _Tr>&
|
|---|
| 787 | operator<<(std::basic_ostream<_Ch, _Tr>& __os,
|
|---|
| 788 | const __shared_ptr<_Tp, _Lp>& __p)
|
|---|
| 789 | {
|
|---|
| 790 | __os << __p.get();
|
|---|
| 791 | return __os;
|
|---|
| 792 | }
|
|---|
| 793 |
|
|---|
| 794 | // 2.2.3.10 shared_ptr get_deleter (experimental)
|
|---|
| 795 | template<typename _Del, typename _Tp, _Lock_policy _Lp>
|
|---|
| 796 | inline _Del*
|
|---|
| 797 | get_deleter(const __shared_ptr<_Tp, _Lp>& __p)
|
|---|
| 798 | {
|
|---|
| 799 | #if __cpp_rtti
|
|---|
| 800 | return static_cast<_Del*>(__p._M_get_deleter(typeid(_Del)));
|
|---|
| 801 | #else
|
|---|
| 802 | return 0;
|
|---|
| 803 | #endif
|
|---|
| 804 | }
|
|---|
| 805 |
|
|---|
| 806 |
|
|---|
| 807 | template<typename _Tp, _Lock_policy _Lp>
|
|---|
| 808 | class __weak_ptr
|
|---|
| 809 | {
|
|---|
| 810 | public:
|
|---|
| 811 | typedef _Tp element_type;
|
|---|
| 812 |
|
|---|
| 813 | __weak_ptr()
|
|---|
| 814 | : _M_ptr(0), _M_refcount() // never throws
|
|---|
| 815 | { }
|
|---|
| 816 |
|
|---|
| 817 | // Generated copy constructor, assignment, destructor are fine.
|
|---|
| 818 |
|
|---|
| 819 | // The "obvious" converting constructor implementation:
|
|---|
| 820 | //
|
|---|
| 821 | // template<typename _Tp1>
|
|---|
| 822 | // __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r)
|
|---|
| 823 | // : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws
|
|---|
| 824 | // { }
|
|---|
| 825 | //
|
|---|
| 826 | // has a serious problem.
|
|---|
| 827 | //
|
|---|
| 828 | // __r._M_ptr may already have been invalidated. The _M_ptr(__r._M_ptr)
|
|---|
| 829 | // conversion may require access to *__r._M_ptr (virtual inheritance).
|
|---|
| 830 | //
|
|---|
| 831 | // It is not possible to avoid spurious access violations since
|
|---|
| 832 | // in multithreaded programs __r._M_ptr may be invalidated at any point.
|
|---|
| 833 | template<typename _Tp1>
|
|---|
| 834 | __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r)
|
|---|
| 835 | : _M_refcount(__r._M_refcount) // never throws
|
|---|
| 836 | {
|
|---|
| 837 | __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>)
|
|---|
| 838 | _M_ptr = __r.lock().get();
|
|---|
| 839 | }
|
|---|
| 840 |
|
|---|
| 841 | template<typename _Tp1>
|
|---|
| 842 | __weak_ptr(const __shared_ptr<_Tp1, _Lp>& __r)
|
|---|
| 843 | : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws
|
|---|
| 844 | { __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) }
|
|---|
| 845 |
|
|---|
| 846 | template<typename _Tp1>
|
|---|
| 847 | __weak_ptr&
|
|---|
| 848 | operator=(const __weak_ptr<_Tp1, _Lp>& __r) // never throws
|
|---|
| 849 | {
|
|---|
| 850 | _M_ptr = __r.lock().get();
|
|---|
| 851 | _M_refcount = __r._M_refcount;
|
|---|
| 852 | return *this;
|
|---|
| 853 | }
|
|---|
| 854 |
|
|---|
| 855 | template<typename _Tp1>
|
|---|
| 856 | __weak_ptr&
|
|---|
| 857 | operator=(const __shared_ptr<_Tp1, _Lp>& __r) // never throws
|
|---|
| 858 | {
|
|---|
| 859 | _M_ptr = __r._M_ptr;
|
|---|
| 860 | _M_refcount = __r._M_refcount;
|
|---|
| 861 | return *this;
|
|---|
| 862 | }
|
|---|
| 863 |
|
|---|
| 864 | __shared_ptr<_Tp, _Lp>
|
|---|
| 865 | lock() const // never throws
|
|---|
| 866 | {
|
|---|
| 867 | #ifdef __GTHREADS
|
|---|
| 868 | // Optimization: avoid throw overhead.
|
|---|
| 869 | if (expired())
|
|---|
| 870 | return __shared_ptr<element_type, _Lp>();
|
|---|
| 871 |
|
|---|
| 872 | __try
|
|---|
| 873 | {
|
|---|
| 874 | return __shared_ptr<element_type, _Lp>(*this);
|
|---|
| 875 | }
|
|---|
| 876 | __catch(const bad_weak_ptr&)
|
|---|
| 877 | {
|
|---|
| 878 | // Q: How can we get here?
|
|---|
| 879 | // A: Another thread may have invalidated r after the
|
|---|
| 880 | // use_count test above.
|
|---|
| 881 | return __shared_ptr<element_type, _Lp>();
|
|---|
| 882 | }
|
|---|
| 883 |
|
|---|
| 884 | #else
|
|---|
| 885 | // Optimization: avoid try/catch overhead when single threaded.
|
|---|
| 886 | return expired() ? __shared_ptr<element_type, _Lp>()
|
|---|
| 887 | : __shared_ptr<element_type, _Lp>(*this);
|
|---|
| 888 |
|
|---|
| 889 | #endif
|
|---|
| 890 | } // XXX MT
|
|---|
| 891 |
|
|---|
| 892 | long
|
|---|
| 893 | use_count() const // never throws
|
|---|
| 894 | { return _M_refcount._M_get_use_count(); }
|
|---|
| 895 |
|
|---|
| 896 | bool
|
|---|
| 897 | expired() const // never throws
|
|---|
| 898 | { return _M_refcount._M_get_use_count() == 0; }
|
|---|
| 899 |
|
|---|
| 900 | void
|
|---|
| 901 | reset() // never throws
|
|---|
| 902 | { __weak_ptr().swap(*this); }
|
|---|
| 903 |
|
|---|
| 904 | void
|
|---|
| 905 | swap(__weak_ptr& __s) // never throws
|
|---|
| 906 | {
|
|---|
| 907 | std::swap(_M_ptr, __s._M_ptr);
|
|---|
| 908 | _M_refcount._M_swap(__s._M_refcount);
|
|---|
| 909 | }
|
|---|
| 910 |
|
|---|
| 911 | private:
|
|---|
| 912 | // Used by __enable_shared_from_this.
|
|---|
| 913 | void
|
|---|
| 914 | _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount)
|
|---|
| 915 | {
|
|---|
| 916 | _M_ptr = __ptr;
|
|---|
| 917 | _M_refcount = __refcount;
|
|---|
| 918 | }
|
|---|
| 919 |
|
|---|
| 920 | template<typename _Tp1>
|
|---|
| 921 | bool
|
|---|
| 922 | _M_less(const __weak_ptr<_Tp1, _Lp>& __rhs) const
|
|---|
| 923 | { return _M_refcount < __rhs._M_refcount; }
|
|---|
| 924 |
|
|---|
| 925 | template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr;
|
|---|
| 926 | template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr;
|
|---|
| 927 | friend class __enable_shared_from_this<_Tp, _Lp>;
|
|---|
| 928 | friend class enable_shared_from_this<_Tp>;
|
|---|
| 929 |
|
|---|
| 930 | // Friend injected into namespace and found by ADL.
|
|---|
| 931 | template<typename _Tp1>
|
|---|
| 932 | friend inline bool
|
|---|
| 933 | operator<(const __weak_ptr& __lhs, const __weak_ptr<_Tp1, _Lp>& __rhs)
|
|---|
| 934 | { return __lhs._M_less(__rhs); }
|
|---|
| 935 |
|
|---|
| 936 | _Tp* _M_ptr; // Contained pointer.
|
|---|
| 937 | __weak_count<_Lp> _M_refcount; // Reference counter.
|
|---|
| 938 | };
|
|---|
| 939 |
|
|---|
| 940 | // 2.2.4.7 weak_ptr specialized algorithms.
|
|---|
| 941 | template<typename _Tp, _Lock_policy _Lp>
|
|---|
| 942 | inline void
|
|---|
| 943 | swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b)
|
|---|
| 944 | { __a.swap(__b); }
|
|---|
| 945 |
|
|---|
| 946 |
|
|---|
| 947 | template<typename _Tp, _Lock_policy _Lp>
|
|---|
| 948 | class __enable_shared_from_this
|
|---|
| 949 | {
|
|---|
| 950 | protected:
|
|---|
| 951 | __enable_shared_from_this() { }
|
|---|
| 952 |
|
|---|
| 953 | __enable_shared_from_this(const __enable_shared_from_this&) { }
|
|---|
| 954 |
|
|---|
| 955 | __enable_shared_from_this&
|
|---|
| 956 | operator=(const __enable_shared_from_this&)
|
|---|
| 957 | { return *this; }
|
|---|
| 958 |
|
|---|
| 959 | ~__enable_shared_from_this() { }
|
|---|
| 960 |
|
|---|
| 961 | public:
|
|---|
| 962 | __shared_ptr<_Tp, _Lp>
|
|---|
| 963 | shared_from_this()
|
|---|
| 964 | { return __shared_ptr<_Tp, _Lp>(this->_M_weak_this); }
|
|---|
| 965 |
|
|---|
| 966 | __shared_ptr<const _Tp, _Lp>
|
|---|
| 967 | shared_from_this() const
|
|---|
| 968 | { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); }
|
|---|
| 969 |
|
|---|
| 970 | private:
|
|---|
| 971 | template<typename _Tp1>
|
|---|
| 972 | void
|
|---|
| 973 | _M_weak_assign(_Tp1* __p, const __shared_count<_Lp>& __n) const
|
|---|
| 974 | { _M_weak_this._M_assign(__p, __n); }
|
|---|
| 975 |
|
|---|
| 976 | template<typename _Tp1>
|
|---|
| 977 | friend void
|
|---|
| 978 | __enable_shared_from_this_helper(const __shared_count<_Lp>& __pn,
|
|---|
| 979 | const __enable_shared_from_this* __pe,
|
|---|
| 980 | const _Tp1* __px)
|
|---|
| 981 | {
|
|---|
| 982 | if (__pe != 0)
|
|---|
| 983 | __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn);
|
|---|
| 984 | }
|
|---|
| 985 |
|
|---|
| 986 | mutable __weak_ptr<_Tp, _Lp> _M_weak_this;
|
|---|
| 987 | };
|
|---|
| 988 |
|
|---|
| 989 |
|
|---|
| 990 | // The actual shared_ptr, with forwarding constructors and
|
|---|
| 991 | // assignment operators.
|
|---|
| 992 | template<typename _Tp>
|
|---|
| 993 | class shared_ptr
|
|---|
| 994 | : public __shared_ptr<_Tp>
|
|---|
| 995 | {
|
|---|
| 996 | public:
|
|---|
| 997 | shared_ptr()
|
|---|
| 998 | : __shared_ptr<_Tp>() { }
|
|---|
| 999 |
|
|---|
| 1000 | template<typename _Tp1>
|
|---|
| 1001 | explicit
|
|---|
| 1002 | shared_ptr(_Tp1* __p)
|
|---|
| 1003 | : __shared_ptr<_Tp>(__p) { }
|
|---|
| 1004 |
|
|---|
| 1005 | template<typename _Tp1, typename _Deleter>
|
|---|
| 1006 | shared_ptr(_Tp1* __p, _Deleter __d)
|
|---|
| 1007 | : __shared_ptr<_Tp>(__p, __d) { }
|
|---|
| 1008 |
|
|---|
| 1009 | template<typename _Tp1>
|
|---|
| 1010 | shared_ptr(const shared_ptr<_Tp1>& __r)
|
|---|
| 1011 | : __shared_ptr<_Tp>(__r) { }
|
|---|
| 1012 |
|
|---|
| 1013 | template<typename _Tp1>
|
|---|
| 1014 | explicit
|
|---|
| 1015 | shared_ptr(const weak_ptr<_Tp1>& __r)
|
|---|
| 1016 | : __shared_ptr<_Tp>(__r) { }
|
|---|
| 1017 |
|
|---|
| 1018 | #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
|
|---|
| 1019 | #pragma GCC diagnostic push
|
|---|
| 1020 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|---|
| 1021 | template<typename _Tp1>
|
|---|
| 1022 | explicit
|
|---|
| 1023 | shared_ptr(std::auto_ptr<_Tp1>& __r)
|
|---|
| 1024 | : __shared_ptr<_Tp>(__r) { }
|
|---|
| 1025 | #pragma GCC diagnostic pop
|
|---|
| 1026 | #endif
|
|---|
| 1027 |
|
|---|
| 1028 | template<typename _Tp1>
|
|---|
| 1029 | shared_ptr(const shared_ptr<_Tp1>& __r, __static_cast_tag)
|
|---|
| 1030 | : __shared_ptr<_Tp>(__r, __static_cast_tag()) { }
|
|---|
| 1031 |
|
|---|
| 1032 | template<typename _Tp1>
|
|---|
| 1033 | shared_ptr(const shared_ptr<_Tp1>& __r, __const_cast_tag)
|
|---|
| 1034 | : __shared_ptr<_Tp>(__r, __const_cast_tag()) { }
|
|---|
| 1035 |
|
|---|
| 1036 | template<typename _Tp1>
|
|---|
| 1037 | shared_ptr(const shared_ptr<_Tp1>& __r, __dynamic_cast_tag)
|
|---|
| 1038 | : __shared_ptr<_Tp>(__r, __dynamic_cast_tag()) { }
|
|---|
| 1039 |
|
|---|
| 1040 | template<typename _Tp1>
|
|---|
| 1041 | shared_ptr&
|
|---|
| 1042 | operator=(const shared_ptr<_Tp1>& __r) // never throws
|
|---|
| 1043 | {
|
|---|
| 1044 | this->__shared_ptr<_Tp>::operator=(__r);
|
|---|
| 1045 | return *this;
|
|---|
| 1046 | }
|
|---|
| 1047 |
|
|---|
| 1048 | #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
|
|---|
| 1049 | #pragma GCC diagnostic push
|
|---|
| 1050 | #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
|
|---|
| 1051 | template<typename _Tp1>
|
|---|
| 1052 | shared_ptr&
|
|---|
| 1053 | operator=(std::auto_ptr<_Tp1>& __r)
|
|---|
| 1054 | {
|
|---|
| 1055 | this->__shared_ptr<_Tp>::operator=(__r);
|
|---|
| 1056 | return *this;
|
|---|
| 1057 | }
|
|---|
| 1058 | #pragma GCC diagnostic pop
|
|---|
| 1059 | #endif
|
|---|
| 1060 | };
|
|---|
| 1061 |
|
|---|
| 1062 | // 2.2.3.8 shared_ptr specialized algorithms.
|
|---|
| 1063 | template<typename _Tp>
|
|---|
| 1064 | inline void
|
|---|
| 1065 | swap(__shared_ptr<_Tp>& __a, __shared_ptr<_Tp>& __b)
|
|---|
| 1066 | { __a.swap(__b); }
|
|---|
| 1067 |
|
|---|
| 1068 | template<typename _Tp, typename _Tp1>
|
|---|
| 1069 | inline shared_ptr<_Tp>
|
|---|
| 1070 | static_pointer_cast(const shared_ptr<_Tp1>& __r)
|
|---|
| 1071 | { return shared_ptr<_Tp>(__r, __static_cast_tag()); }
|
|---|
| 1072 |
|
|---|
| 1073 | template<typename _Tp, typename _Tp1>
|
|---|
| 1074 | inline shared_ptr<_Tp>
|
|---|
| 1075 | const_pointer_cast(const shared_ptr<_Tp1>& __r)
|
|---|
| 1076 | { return shared_ptr<_Tp>(__r, __const_cast_tag()); }
|
|---|
| 1077 |
|
|---|
| 1078 | template<typename _Tp, typename _Tp1>
|
|---|
| 1079 | inline shared_ptr<_Tp>
|
|---|
| 1080 | dynamic_pointer_cast(const shared_ptr<_Tp1>& __r)
|
|---|
| 1081 | { return shared_ptr<_Tp>(__r, __dynamic_cast_tag()); }
|
|---|
| 1082 |
|
|---|
| 1083 |
|
|---|
| 1084 | // The actual weak_ptr, with forwarding constructors and
|
|---|
| 1085 | // assignment operators.
|
|---|
| 1086 | template<typename _Tp>
|
|---|
| 1087 | class weak_ptr
|
|---|
| 1088 | : public __weak_ptr<_Tp>
|
|---|
| 1089 | {
|
|---|
| 1090 | public:
|
|---|
| 1091 | weak_ptr()
|
|---|
| 1092 | : __weak_ptr<_Tp>() { }
|
|---|
| 1093 |
|
|---|
| 1094 | template<typename _Tp1>
|
|---|
| 1095 | weak_ptr(const weak_ptr<_Tp1>& __r)
|
|---|
| 1096 | : __weak_ptr<_Tp>(__r) { }
|
|---|
| 1097 |
|
|---|
| 1098 | template<typename _Tp1>
|
|---|
| 1099 | weak_ptr(const shared_ptr<_Tp1>& __r)
|
|---|
| 1100 | : __weak_ptr<_Tp>(__r) { }
|
|---|
| 1101 |
|
|---|
| 1102 | template<typename _Tp1>
|
|---|
| 1103 | weak_ptr&
|
|---|
| 1104 | operator=(const weak_ptr<_Tp1>& __r) // never throws
|
|---|
| 1105 | {
|
|---|
| 1106 | this->__weak_ptr<_Tp>::operator=(__r);
|
|---|
| 1107 | return *this;
|
|---|
| 1108 | }
|
|---|
| 1109 |
|
|---|
| 1110 | template<typename _Tp1>
|
|---|
| 1111 | weak_ptr&
|
|---|
| 1112 | operator=(const shared_ptr<_Tp1>& __r) // never throws
|
|---|
| 1113 | {
|
|---|
| 1114 | this->__weak_ptr<_Tp>::operator=(__r);
|
|---|
| 1115 | return *this;
|
|---|
| 1116 | }
|
|---|
| 1117 |
|
|---|
| 1118 | shared_ptr<_Tp>
|
|---|
| 1119 | lock() const // never throws
|
|---|
| 1120 | {
|
|---|
| 1121 | #ifdef __GTHREADS
|
|---|
| 1122 | if (this->expired())
|
|---|
| 1123 | return shared_ptr<_Tp>();
|
|---|
| 1124 |
|
|---|
| 1125 | __try
|
|---|
| 1126 | {
|
|---|
| 1127 | return shared_ptr<_Tp>(*this);
|
|---|
| 1128 | }
|
|---|
| 1129 | __catch(const bad_weak_ptr&)
|
|---|
| 1130 | {
|
|---|
| 1131 | return shared_ptr<_Tp>();
|
|---|
| 1132 | }
|
|---|
| 1133 | #else
|
|---|
| 1134 | return this->expired() ? shared_ptr<_Tp>()
|
|---|
| 1135 | : shared_ptr<_Tp>(*this);
|
|---|
| 1136 | #endif
|
|---|
| 1137 | }
|
|---|
| 1138 | };
|
|---|
| 1139 |
|
|---|
| 1140 | template<typename _Tp>
|
|---|
| 1141 | class enable_shared_from_this
|
|---|
| 1142 | {
|
|---|
| 1143 | protected:
|
|---|
| 1144 | enable_shared_from_this() { }
|
|---|
| 1145 |
|
|---|
| 1146 | enable_shared_from_this(const enable_shared_from_this&) { }
|
|---|
| 1147 |
|
|---|
| 1148 | enable_shared_from_this&
|
|---|
| 1149 | operator=(const enable_shared_from_this&)
|
|---|
| 1150 | { return *this; }
|
|---|
| 1151 |
|
|---|
| 1152 | ~enable_shared_from_this() { }
|
|---|
| 1153 |
|
|---|
| 1154 | public:
|
|---|
| 1155 | shared_ptr<_Tp>
|
|---|
| 1156 | shared_from_this()
|
|---|
| 1157 | { return shared_ptr<_Tp>(this->_M_weak_this); }
|
|---|
| 1158 |
|
|---|
| 1159 | shared_ptr<const _Tp>
|
|---|
| 1160 | shared_from_this() const
|
|---|
| 1161 | { return shared_ptr<const _Tp>(this->_M_weak_this); }
|
|---|
| 1162 |
|
|---|
| 1163 | private:
|
|---|
| 1164 | template<typename _Tp1>
|
|---|
| 1165 | void
|
|---|
| 1166 | _M_weak_assign(_Tp1* __p, const __shared_count<>& __n) const
|
|---|
| 1167 | { _M_weak_this._M_assign(__p, __n); }
|
|---|
| 1168 |
|
|---|
| 1169 | template<typename _Tp1>
|
|---|
| 1170 | friend void
|
|---|
| 1171 | __enable_shared_from_this_helper(const __shared_count<>& __pn,
|
|---|
| 1172 | const enable_shared_from_this* __pe,
|
|---|
| 1173 | const _Tp1* __px)
|
|---|
| 1174 | {
|
|---|
| 1175 | if (__pe != 0)
|
|---|
| 1176 | __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn);
|
|---|
| 1177 | }
|
|---|
| 1178 |
|
|---|
| 1179 | mutable weak_ptr<_Tp> _M_weak_this;
|
|---|
| 1180 | };
|
|---|
| 1181 | }
|
|---|
| 1182 |
|
|---|
| 1183 | _GLIBCXX_END_NAMESPACE_VERSION
|
|---|
| 1184 | }
|
|---|
| 1185 |
|
|---|
| 1186 | #endif // _TR1_SHARED_PTR_H
|
|---|
