| // shared_ptr and weak_ptr implementation details -*- C++ -*- |
| |
| // Copyright (C) 2007-2013 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| // GCC Note: Based on files from version 1.32.0 of the Boost library. |
| |
| // shared_count.hpp |
| // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. |
| |
| // shared_ptr.hpp |
| // Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes. |
| // Copyright (C) 2001, 2002, 2003 Peter Dimov |
| |
| // weak_ptr.hpp |
| // Copyright (C) 2001, 2002, 2003 Peter Dimov |
| |
| // enable_shared_from_this.hpp |
| // Copyright (C) 2002 Peter Dimov |
| |
| // Distributed under the Boost Software License, Version 1.0. (See |
| // accompanying file LICENSE_1_0.txt or copy at |
| // http://www.boost.org/LICENSE_1_0.txt) |
| |
| /** @file bits/shared_ptr_base.h |
| * This is an internal header file, included by other library headers. |
| * Do not attempt to use it directly. @headername{memory} |
| */ |
| |
| #ifndef _SHARED_PTR_BASE_H |
| #define _SHARED_PTR_BASE_H 1 |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| #if _GLIBCXX_USE_DEPRECATED |
| template<typename> class auto_ptr; |
| #endif |
| |
| /** |
| * @brief Exception possibly thrown by @c shared_ptr. |
| * @ingroup exceptions |
| */ |
| class bad_weak_ptr : public std::exception |
| { |
| public: |
| virtual char const* |
| what() const noexcept; |
| |
| virtual ~bad_weak_ptr() noexcept; |
| }; |
| |
| // Substitute for bad_weak_ptr object in the case of -fno-exceptions. |
| inline void |
| __throw_bad_weak_ptr() |
| { _GLIBCXX_THROW_OR_ABORT(bad_weak_ptr()); } |
| |
| using __gnu_cxx::_Lock_policy; |
| using __gnu_cxx::__default_lock_policy; |
| using __gnu_cxx::_S_single; |
| using __gnu_cxx::_S_mutex; |
| using __gnu_cxx::_S_atomic; |
| |
| // Empty helper class except when the template argument is _S_mutex. |
| template<_Lock_policy _Lp> |
| class _Mutex_base |
| { |
| protected: |
| // The atomic policy uses fully-fenced builtins, single doesn't care. |
| enum { _S_need_barriers = 0 }; |
| }; |
| |
| template<> |
| class _Mutex_base<_S_mutex> |
| : public __gnu_cxx::__mutex |
| { |
| protected: |
| // This policy is used when atomic builtins are not available. |
| // The replacement atomic operations might not have the necessary |
| // memory barriers. |
| enum { _S_need_barriers = 1 }; |
| }; |
| |
| template<_Lock_policy _Lp = __default_lock_policy> |
| class _Sp_counted_base |
| : public _Mutex_base<_Lp> |
| { |
| public: |
| _Sp_counted_base() noexcept |
| : _M_use_count(1), _M_weak_count(1) { } |
| |
| virtual |
| ~_Sp_counted_base() noexcept |
| { } |
| |
| // Called when _M_use_count drops to zero, to release the resources |
| // managed by *this. |
| virtual void |
| _M_dispose() noexcept = 0; |
| |
| // Called when _M_weak_count drops to zero. |
| virtual void |
| _M_destroy() noexcept |
| { delete this; } |
| |
| virtual void* |
| _M_get_deleter(const std::type_info&) = 0; |
| |
| void |
| _M_add_ref_copy() |
| { __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); } |
| |
| void |
| _M_add_ref_lock(); |
| |
| void |
| _M_release() noexcept |
| { |
| // Be race-detector-friendly. For more info see bits/c++config. |
| _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count); |
| if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1) |
| { |
| _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count); |
| _M_dispose(); |
| // There must be a memory barrier between dispose() and destroy() |
| // to ensure that the effects of dispose() are observed in the |
| // thread that runs destroy(). |
| // See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html |
| if (_Mutex_base<_Lp>::_S_need_barriers) |
| { |
| _GLIBCXX_READ_MEM_BARRIER; |
| _GLIBCXX_WRITE_MEM_BARRIER; |
| } |
| |
| // Be race-detector-friendly. For more info see bits/c++config. |
| _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count); |
| if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, |
| -1) == 1) |
| { |
| _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count); |
| _M_destroy(); |
| } |
| } |
| } |
| |
| void |
| _M_weak_add_ref() noexcept |
| { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); } |
| |
| void |
| _M_weak_release() noexcept |
| { |
| // Be race-detector-friendly. For more info see bits/c++config. |
| _GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count); |
| if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1) |
| { |
| _GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count); |
| if (_Mutex_base<_Lp>::_S_need_barriers) |
| { |
| // See _M_release(), |
| // destroy() must observe results of dispose() |
| _GLIBCXX_READ_MEM_BARRIER; |
| _GLIBCXX_WRITE_MEM_BARRIER; |
| } |
| _M_destroy(); |
| } |
| } |
| |
| long |
| _M_get_use_count() const noexcept |
| { |
| // No memory barrier is used here so there is no synchronization |
| // with other threads. |
| return __atomic_load_n(&_M_use_count, __ATOMIC_RELAXED); |
| } |
| |
| private: |
| _Sp_counted_base(_Sp_counted_base const&) = delete; |
| _Sp_counted_base& operator=(_Sp_counted_base const&) = delete; |
| |
| _Atomic_word _M_use_count; // #shared |
| _Atomic_word _M_weak_count; // #weak + (#shared != 0) |
| }; |
| |
| template<> |
| inline void |
| _Sp_counted_base<_S_single>:: |
| _M_add_ref_lock() |
| { |
| if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0) |
| { |
| _M_use_count = 0; |
| __throw_bad_weak_ptr(); |
| } |
| } |
| |
| template<> |
| inline void |
| _Sp_counted_base<_S_mutex>:: |
| _M_add_ref_lock() |
| { |
| __gnu_cxx::__scoped_lock sentry(*this); |
| if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0) |
| { |
| _M_use_count = 0; |
| __throw_bad_weak_ptr(); |
| } |
| } |
| |
| template<> |
| inline void |
| _Sp_counted_base<_S_atomic>:: |
| _M_add_ref_lock() |
| { |
| // Perform lock-free add-if-not-zero operation. |
| _Atomic_word __count = _M_get_use_count(); |
| do |
| { |
| if (__count == 0) |
| __throw_bad_weak_ptr(); |
| // Replace the current counter value with the old value + 1, as |
| // long as it's not changed meanwhile. |
| } |
| while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1, |
| true, __ATOMIC_ACQ_REL, |
| __ATOMIC_RELAXED)); |
| } |
| |
| |
| // Forward declarations. |
| template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> |
| class __shared_ptr; |
| |
| template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> |
| class __weak_ptr; |
| |
| template<typename _Tp, _Lock_policy _Lp = __default_lock_policy> |
| class __enable_shared_from_this; |
| |
| template<typename _Tp> |
| class shared_ptr; |
| |
| template<typename _Tp> |
| class weak_ptr; |
| |
| template<typename _Tp> |
| struct owner_less; |
| |
| template<typename _Tp> |
| class enable_shared_from_this; |
| |
| template<_Lock_policy _Lp = __default_lock_policy> |
| class __weak_count; |
| |
| template<_Lock_policy _Lp = __default_lock_policy> |
| class __shared_count; |
| |
| |
| // Counted ptr with no deleter or allocator support |
| template<typename _Ptr, _Lock_policy _Lp> |
| class _Sp_counted_ptr final : public _Sp_counted_base<_Lp> |
| { |
| public: |
| explicit |
| _Sp_counted_ptr(_Ptr __p) |
| : _M_ptr(__p) { } |
| |
| virtual void |
| _M_dispose() noexcept |
| { delete _M_ptr; } |
| |
| virtual void |
| _M_destroy() noexcept |
| { delete this; } |
| |
| virtual void* |
| _M_get_deleter(const std::type_info&) |
| { return 0; } |
| |
| _Sp_counted_ptr(const _Sp_counted_ptr&) = delete; |
| _Sp_counted_ptr& operator=(const _Sp_counted_ptr&) = delete; |
| |
| protected: |
| _Ptr _M_ptr; // copy constructor must not throw |
| }; |
| |
| template<> |
| inline void |
| _Sp_counted_ptr<nullptr_t, _S_single>::_M_dispose() noexcept { } |
| |
| template<> |
| inline void |
| _Sp_counted_ptr<nullptr_t, _S_mutex>::_M_dispose() noexcept { } |
| |
| template<> |
| inline void |
| _Sp_counted_ptr<nullptr_t, _S_atomic>::_M_dispose() noexcept { } |
| |
| // Support for custom deleter and/or allocator |
| template<typename _Ptr, typename _Deleter, typename _Alloc, _Lock_policy _Lp> |
| class _Sp_counted_deleter final : public _Sp_counted_base<_Lp> |
| { |
| // Helper class that stores the Deleter and also acts as an allocator. |
| // Used to dispose of the owned pointer and the internal refcount |
| // Requires that copies of _Alloc can free each other's memory. |
| struct _My_Deleter |
| : public _Alloc // copy constructor must not throw |
| { |
| _Deleter _M_del; // copy constructor must not throw |
| _My_Deleter(_Deleter __d, const _Alloc& __a) |
| : _Alloc(__a), _M_del(__d) { } |
| }; |
| |
| public: |
| // __d(__p) must not throw. |
| _Sp_counted_deleter(_Ptr __p, _Deleter __d) |
| : _M_ptr(__p), _M_del(__d, _Alloc()) { } |
| |
| // __d(__p) must not throw. |
| _Sp_counted_deleter(_Ptr __p, _Deleter __d, const _Alloc& __a) |
| : _M_ptr(__p), _M_del(__d, __a) { } |
| |
| ~_Sp_counted_deleter() noexcept { } |
| |
| virtual void |
| _M_dispose() noexcept |
| { _M_del._M_del(_M_ptr); } |
| |
| virtual void |
| _M_destroy() noexcept |
| { |
| typedef typename allocator_traits<_Alloc>::template |
| rebind_traits<_Sp_counted_deleter> _Alloc_traits; |
| typename _Alloc_traits::allocator_type __a(_M_del); |
| _Alloc_traits::destroy(__a, this); |
| _Alloc_traits::deallocate(__a, this, 1); |
| } |
| |
| virtual void* |
| _M_get_deleter(const std::type_info& __ti) |
| { |
| #ifdef __GXX_RTTI |
| return __ti == typeid(_Deleter) ? &_M_del._M_del : 0; |
| #else |
| return 0; |
| #endif |
| } |
| |
| protected: |
| _Ptr _M_ptr; // copy constructor must not throw |
| _My_Deleter _M_del; // copy constructor must not throw |
| }; |
| |
| // helpers for make_shared / allocate_shared |
| |
| struct _Sp_make_shared_tag { }; |
| |
| template<typename _Tp, typename _Alloc, _Lock_policy _Lp> |
| class _Sp_counted_ptr_inplace final : public _Sp_counted_base<_Lp> |
| { |
| // Helper class that stores the pointer and also acts as an allocator. |
| // Used to dispose of the owned pointer and the internal refcount |
| // Requires that copies of _Alloc can free each other's memory. |
| struct _Impl |
| : public _Alloc // copy constructor must not throw |
| { |
| _Impl(_Alloc __a) : _Alloc(__a), _M_ptr() { } |
| _Tp* _M_ptr; |
| }; |
| |
| public: |
| template<typename... _Args> |
| _Sp_counted_ptr_inplace(_Alloc __a, _Args&&... __args) |
| : _M_impl(__a) |
| { |
| _M_impl._M_ptr = static_cast<_Tp*>(static_cast<void*>(&_M_storage)); |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 2070. allocate_shared should use allocator_traits<A>::construct |
| allocator_traits<_Alloc>::construct(__a, _M_impl._M_ptr, |
| std::forward<_Args>(__args)...); // might throw |
| } |
| |
| ~_Sp_counted_ptr_inplace() noexcept { } |
| |
| virtual void |
| _M_dispose() noexcept |
| { allocator_traits<_Alloc>::destroy(_M_impl, _M_impl._M_ptr); } |
| |
| // Override because the allocator needs to know the dynamic type |
| virtual void |
| _M_destroy() noexcept |
| { |
| typedef typename allocator_traits<_Alloc>::template |
| rebind_traits<_Sp_counted_ptr_inplace> _Alloc_traits; |
| typename _Alloc_traits::allocator_type __a(_M_impl); |
| _Alloc_traits::destroy(__a, this); |
| _Alloc_traits::deallocate(__a, this, 1); |
| } |
| |
| // Sneaky trick so __shared_ptr can get the managed pointer |
| virtual void* |
| _M_get_deleter(const std::type_info& __ti) noexcept |
| { |
| #ifdef __GXX_RTTI |
| return __ti == typeid(_Sp_make_shared_tag) |
| ? static_cast<void*>(&_M_storage) |
| : 0; |
| #else |
| return 0; |
| #endif |
| } |
| |
| private: |
| _Impl _M_impl; |
| typename aligned_storage<sizeof(_Tp), alignment_of<_Tp>::value>::type |
| _M_storage; |
| }; |
| |
| template<_Lock_policy _Lp> |
| class __shared_count |
| { |
| public: |
| constexpr __shared_count() noexcept : _M_pi(0) |
| { } |
| |
| template<typename _Ptr> |
| explicit |
| __shared_count(_Ptr __p) : _M_pi(0) |
| { |
| __try |
| { |
| _M_pi = new _Sp_counted_ptr<_Ptr, _Lp>(__p); |
| } |
| __catch(...) |
| { |
| delete __p; |
| __throw_exception_again; |
| } |
| } |
| |
| template<typename _Ptr, typename _Deleter> |
| __shared_count(_Ptr __p, _Deleter __d) |
| : __shared_count(__p, std::move(__d), allocator<int>()) |
| { } |
| |
| template<typename _Ptr, typename _Deleter, typename _Alloc> |
| __shared_count(_Ptr __p, _Deleter __d, _Alloc __a) : _M_pi(0) |
| { |
| typedef _Sp_counted_deleter<_Ptr, _Deleter, _Alloc, _Lp> _Sp_cd_type; |
| typedef typename allocator_traits<_Alloc>::template |
| rebind_traits<_Sp_cd_type> _Alloc_traits; |
| typename _Alloc_traits::allocator_type __a2(__a); |
| _Sp_cd_type* __mem = 0; |
| __try |
| { |
| __mem = _Alloc_traits::allocate(__a2, 1); |
| _Alloc_traits::construct(__a2, __mem, |
| __p, std::move(__d), std::move(__a)); |
| _M_pi = __mem; |
| } |
| __catch(...) |
| { |
| __d(__p); // Call _Deleter on __p. |
| if (__mem) |
| _Alloc_traits::deallocate(__a2, __mem, 1); |
| __throw_exception_again; |
| } |
| } |
| |
| template<typename _Tp, typename _Alloc, typename... _Args> |
| __shared_count(_Sp_make_shared_tag, _Tp*, const _Alloc& __a, |
| _Args&&... __args) |
| : _M_pi(0) |
| { |
| typedef _Sp_counted_ptr_inplace<_Tp, _Alloc, _Lp> _Sp_cp_type; |
| typedef typename allocator_traits<_Alloc>::template |
| rebind_traits<_Sp_cp_type> _Alloc_traits; |
| typename _Alloc_traits::allocator_type __a2(__a); |
| _Sp_cp_type* __mem = _Alloc_traits::allocate(__a2, 1); |
| __try |
| { |
| _Alloc_traits::construct(__a2, __mem, std::move(__a), |
| std::forward<_Args>(__args)...); |
| _M_pi = __mem; |
| } |
| __catch(...) |
| { |
| _Alloc_traits::deallocate(__a2, __mem, 1); |
| __throw_exception_again; |
| } |
| } |
| |
| #if _GLIBCXX_USE_DEPRECATED |
| // Special case for auto_ptr<_Tp> to provide the strong guarantee. |
| template<typename _Tp> |
| explicit |
| __shared_count(std::auto_ptr<_Tp>&& __r); |
| #endif |
| |
| // Special case for unique_ptr<_Tp,_Del> to provide the strong guarantee. |
| template<typename _Tp, typename _Del> |
| explicit |
| __shared_count(std::unique_ptr<_Tp, _Del>&& __r) : _M_pi(0) |
| { |
| using _Ptr = typename unique_ptr<_Tp, _Del>::pointer; |
| using _Del2 = typename conditional<is_reference<_Del>::value, |
| reference_wrapper<typename remove_reference<_Del>::type>, |
| _Del>::type; |
| using _Sp_cd_type |
| = _Sp_counted_deleter<_Ptr, _Del2, allocator<void>, _Lp>; |
| using _Alloc = allocator<_Sp_cd_type>; |
| using _Alloc_traits = allocator_traits<_Alloc>; |
| _Alloc __a; |
| _Sp_cd_type* __mem = _Alloc_traits::allocate(__a, 1); |
| _Alloc_traits::construct(__a, __mem, __r.release(), |
| __r.get_deleter()); // non-throwing |
| _M_pi = __mem; |
| } |
| |
| // Throw bad_weak_ptr when __r._M_get_use_count() == 0. |
| explicit __shared_count(const __weak_count<_Lp>& __r); |
| |
| ~__shared_count() noexcept |
| { |
| if (_M_pi != nullptr) |
| _M_pi->_M_release(); |
| } |
| |
| __shared_count(const __shared_count& __r) noexcept |
| : _M_pi(__r._M_pi) |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_add_ref_copy(); |
| } |
| |
| __shared_count& |
| operator=(const __shared_count& __r) noexcept |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| if (__tmp != _M_pi) |
| { |
| if (__tmp != 0) |
| __tmp->_M_add_ref_copy(); |
| if (_M_pi != 0) |
| _M_pi->_M_release(); |
| _M_pi = __tmp; |
| } |
| return *this; |
| } |
| |
| void |
| _M_swap(__shared_count& __r) noexcept |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| __r._M_pi = _M_pi; |
| _M_pi = __tmp; |
| } |
| |
| long |
| _M_get_use_count() const noexcept |
| { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; } |
| |
| bool |
| _M_unique() const noexcept |
| { return this->_M_get_use_count() == 1; } |
| |
| void* |
| _M_get_deleter(const std::type_info& __ti) const noexcept |
| { return _M_pi ? _M_pi->_M_get_deleter(__ti) : 0; } |
| |
| bool |
| _M_less(const __shared_count& __rhs) const noexcept |
| { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } |
| |
| bool |
| _M_less(const __weak_count<_Lp>& __rhs) const noexcept |
| { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } |
| |
| // Friend function injected into enclosing namespace and found by ADL |
| friend inline bool |
| operator==(const __shared_count& __a, const __shared_count& __b) noexcept |
| { return __a._M_pi == __b._M_pi; } |
| |
| private: |
| friend class __weak_count<_Lp>; |
| |
| _Sp_counted_base<_Lp>* _M_pi; |
| }; |
| |
| |
| template<_Lock_policy _Lp> |
| class __weak_count |
| { |
| public: |
| constexpr __weak_count() noexcept : _M_pi(0) |
| { } |
| |
| __weak_count(const __shared_count<_Lp>& __r) noexcept |
| : _M_pi(__r._M_pi) |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_weak_add_ref(); |
| } |
| |
| __weak_count(const __weak_count<_Lp>& __r) noexcept |
| : _M_pi(__r._M_pi) |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_weak_add_ref(); |
| } |
| |
| ~__weak_count() noexcept |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_weak_release(); |
| } |
| |
| __weak_count<_Lp>& |
| operator=(const __shared_count<_Lp>& __r) noexcept |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| if (__tmp != 0) |
| __tmp->_M_weak_add_ref(); |
| if (_M_pi != 0) |
| _M_pi->_M_weak_release(); |
| _M_pi = __tmp; |
| return *this; |
| } |
| |
| __weak_count<_Lp>& |
| operator=(const __weak_count<_Lp>& __r) noexcept |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| if (__tmp != 0) |
| __tmp->_M_weak_add_ref(); |
| if (_M_pi != 0) |
| _M_pi->_M_weak_release(); |
| _M_pi = __tmp; |
| return *this; |
| } |
| |
| void |
| _M_swap(__weak_count<_Lp>& __r) noexcept |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| __r._M_pi = _M_pi; |
| _M_pi = __tmp; |
| } |
| |
| long |
| _M_get_use_count() const noexcept |
| { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; } |
| |
| bool |
| _M_less(const __weak_count& __rhs) const noexcept |
| { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } |
| |
| bool |
| _M_less(const __shared_count<_Lp>& __rhs) const noexcept |
| { return std::less<_Sp_counted_base<_Lp>*>()(this->_M_pi, __rhs._M_pi); } |
| |
| // Friend function injected into enclosing namespace and found by ADL |
| friend inline bool |
| operator==(const __weak_count& __a, const __weak_count& __b) noexcept |
| { return __a._M_pi == __b._M_pi; } |
| |
| private: |
| friend class __shared_count<_Lp>; |
| |
| _Sp_counted_base<_Lp>* _M_pi; |
| }; |
| |
| // Now that __weak_count is defined we can define this constructor: |
| template<_Lock_policy _Lp> |
| inline __shared_count<_Lp>:: __shared_count(const __weak_count<_Lp>& __r) |
| : _M_pi(__r._M_pi) |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_add_ref_lock(); |
| else |
| __throw_bad_weak_ptr(); |
| } |
| |
| |
| // Support for enable_shared_from_this. |
| |
| // Friend of __enable_shared_from_this. |
| template<_Lock_policy _Lp, typename _Tp1, typename _Tp2> |
| void |
| __enable_shared_from_this_helper(const __shared_count<_Lp>&, |
| const __enable_shared_from_this<_Tp1, |
| _Lp>*, const _Tp2*) noexcept; |
| |
| // Friend of enable_shared_from_this. |
| template<typename _Tp1, typename _Tp2> |
| void |
| __enable_shared_from_this_helper(const __shared_count<>&, |
| const enable_shared_from_this<_Tp1>*, |
| const _Tp2*) noexcept; |
| |
| template<_Lock_policy _Lp> |
| inline void |
| __enable_shared_from_this_helper(const __shared_count<_Lp>&, ...) noexcept |
| { } |
| |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| class __shared_ptr |
| { |
| public: |
| typedef _Tp element_type; |
| |
| constexpr __shared_ptr() noexcept |
| : _M_ptr(0), _M_refcount() |
| { } |
| |
| template<typename _Tp1> |
| explicit __shared_ptr(_Tp1* __p) |
| : _M_ptr(__p), _M_refcount(__p) |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| static_assert( sizeof(_Tp1) > 0, "incomplete type" ); |
| __enable_shared_from_this_helper(_M_refcount, __p, __p); |
| } |
| |
| template<typename _Tp1, typename _Deleter> |
| __shared_ptr(_Tp1* __p, _Deleter __d) |
| : _M_ptr(__p), _M_refcount(__p, __d) |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| // TODO requires _Deleter CopyConstructible and __d(__p) well-formed |
| __enable_shared_from_this_helper(_M_refcount, __p, __p); |
| } |
| |
| template<typename _Tp1, typename _Deleter, typename _Alloc> |
| __shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a) |
| : _M_ptr(__p), _M_refcount(__p, __d, std::move(__a)) |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| // TODO requires _Deleter CopyConstructible and __d(__p) well-formed |
| __enable_shared_from_this_helper(_M_refcount, __p, __p); |
| } |
| |
| template<typename _Deleter> |
| __shared_ptr(nullptr_t __p, _Deleter __d) |
| : _M_ptr(0), _M_refcount(__p, __d) |
| { } |
| |
| template<typename _Deleter, typename _Alloc> |
| __shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a) |
| : _M_ptr(0), _M_refcount(__p, __d, std::move(__a)) |
| { } |
| |
| template<typename _Tp1> |
| __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, _Tp* __p) noexcept |
| : _M_ptr(__p), _M_refcount(__r._M_refcount) // never throws |
| { } |
| |
| __shared_ptr(const __shared_ptr&) noexcept = default; |
| __shared_ptr& operator=(const __shared_ptr&) noexcept = default; |
| ~__shared_ptr() = default; |
| |
| template<typename _Tp1, typename = typename |
| std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
| __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) |
| { } |
| |
| __shared_ptr(__shared_ptr&& __r) noexcept |
| : _M_ptr(__r._M_ptr), _M_refcount() |
| { |
| _M_refcount._M_swap(__r._M_refcount); |
| __r._M_ptr = 0; |
| } |
| |
| template<typename _Tp1, typename = typename |
| std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
| __shared_ptr(__shared_ptr<_Tp1, _Lp>&& __r) noexcept |
| : _M_ptr(__r._M_ptr), _M_refcount() |
| { |
| _M_refcount._M_swap(__r._M_refcount); |
| __r._M_ptr = 0; |
| } |
| |
| template<typename _Tp1> |
| explicit __shared_ptr(const __weak_ptr<_Tp1, _Lp>& __r) |
| : _M_refcount(__r._M_refcount) // may throw |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| |
| // It is now safe to copy __r._M_ptr, as |
| // _M_refcount(__r._M_refcount) did not throw. |
| _M_ptr = __r._M_ptr; |
| } |
| |
| // If an exception is thrown this constructor has no effect. |
| template<typename _Tp1, typename _Del> |
| __shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r) |
| : _M_ptr(__r.get()), _M_refcount() |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| auto __tmp = __r.get(); |
| _M_refcount = __shared_count<_Lp>(std::move(__r)); |
| __enable_shared_from_this_helper(_M_refcount, __tmp, __tmp); |
| } |
| |
| #if _GLIBCXX_USE_DEPRECATED |
| // Postcondition: use_count() == 1 and __r.get() == 0 |
| template<typename _Tp1> |
| __shared_ptr(std::auto_ptr<_Tp1>&& __r); |
| #endif |
| |
| /* TODO: use delegating constructor */ |
| constexpr __shared_ptr(nullptr_t) noexcept |
| : _M_ptr(0), _M_refcount() |
| { } |
| |
| template<typename _Tp1> |
| __shared_ptr& |
| operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| { |
| _M_ptr = __r._M_ptr; |
| _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw |
| return *this; |
| } |
| |
| #if _GLIBCXX_USE_DEPRECATED |
| template<typename _Tp1> |
| __shared_ptr& |
| operator=(std::auto_ptr<_Tp1>&& __r) |
| { |
| __shared_ptr(std::move(__r)).swap(*this); |
| return *this; |
| } |
| #endif |
| |
| __shared_ptr& |
| operator=(__shared_ptr&& __r) noexcept |
| { |
| __shared_ptr(std::move(__r)).swap(*this); |
| return *this; |
| } |
| |
| template<class _Tp1> |
| __shared_ptr& |
| operator=(__shared_ptr<_Tp1, _Lp>&& __r) noexcept |
| { |
| __shared_ptr(std::move(__r)).swap(*this); |
| return *this; |
| } |
| |
| template<typename _Tp1, typename _Del> |
| __shared_ptr& |
| operator=(std::unique_ptr<_Tp1, _Del>&& __r) |
| { |
| __shared_ptr(std::move(__r)).swap(*this); |
| return *this; |
| } |
| |
| void |
| reset() noexcept |
| { __shared_ptr().swap(*this); } |
| |
| template<typename _Tp1> |
| void |
| reset(_Tp1* __p) // _Tp1 must be complete. |
| { |
| // Catch self-reset errors. |
| _GLIBCXX_DEBUG_ASSERT(__p == 0 || __p != _M_ptr); |
| __shared_ptr(__p).swap(*this); |
| } |
| |
| template<typename _Tp1, typename _Deleter> |
| void |
| reset(_Tp1* __p, _Deleter __d) |
| { __shared_ptr(__p, __d).swap(*this); } |
| |
| template<typename _Tp1, typename _Deleter, typename _Alloc> |
| void |
| reset(_Tp1* __p, _Deleter __d, _Alloc __a) |
| { __shared_ptr(__p, __d, std::move(__a)).swap(*this); } |
| |
| // Allow class instantiation when _Tp is [cv-qual] void. |
| typename std::add_lvalue_reference<_Tp>::type |
| operator*() const noexcept |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0); |
| return *_M_ptr; |
| } |
| |
| _Tp* |
| operator->() const noexcept |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0); |
| return _M_ptr; |
| } |
| |
| _Tp* |
| get() const noexcept |
| { return _M_ptr; } |
| |
| explicit operator bool() const // never throws |
| { return _M_ptr == 0 ? false : true; } |
| |
| bool |
| unique() const noexcept |
| { return _M_refcount._M_unique(); } |
| |
| long |
| use_count() const noexcept |
| { return _M_refcount._M_get_use_count(); } |
| |
| void |
| swap(__shared_ptr<_Tp, _Lp>& __other) noexcept |
| { |
| std::swap(_M_ptr, __other._M_ptr); |
| _M_refcount._M_swap(__other._M_refcount); |
| } |
| |
| template<typename _Tp1> |
| bool |
| owner_before(__shared_ptr<_Tp1, _Lp> const& __rhs) const |
| { return _M_refcount._M_less(__rhs._M_refcount); } |
| |
| template<typename _Tp1> |
| bool |
| owner_before(__weak_ptr<_Tp1, _Lp> const& __rhs) const |
| { return _M_refcount._M_less(__rhs._M_refcount); } |
| |
| #ifdef __GXX_RTTI |
| protected: |
| // This constructor is non-standard, it is used by allocate_shared. |
| template<typename _Alloc, typename... _Args> |
| __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a, |
| _Args&&... __args) |
| : _M_ptr(), _M_refcount(__tag, (_Tp*)0, __a, |
| std::forward<_Args>(__args)...) |
| { |
| // _M_ptr needs to point to the newly constructed object. |
| // This relies on _Sp_counted_ptr_inplace::_M_get_deleter. |
| void* __p = _M_refcount._M_get_deleter(typeid(__tag)); |
| _M_ptr = static_cast<_Tp*>(__p); |
| __enable_shared_from_this_helper(_M_refcount, _M_ptr, _M_ptr); |
| } |
| #else |
| template<typename _Alloc> |
| struct _Deleter |
| { |
| void operator()(_Tp* __ptr) |
| { |
| typedef allocator_traits<_Alloc> _Alloc_traits; |
| _Alloc_traits::destroy(_M_alloc, __ptr); |
| _Alloc_traits::deallocate(_M_alloc, __ptr, 1); |
| } |
| _Alloc _M_alloc; |
| }; |
| |
| template<typename _Alloc, typename... _Args> |
| __shared_ptr(_Sp_make_shared_tag __tag, const _Alloc& __a, |
| _Args&&... __args) |
| : _M_ptr(), _M_refcount() |
| { |
| typedef typename _Alloc::template rebind<_Tp>::other _Alloc2; |
| _Deleter<_Alloc2> __del = { _Alloc2(__a) }; |
| typedef allocator_traits<_Alloc2> __traits; |
| _M_ptr = __traits::allocate(__del._M_alloc, 1); |
| __try |
| { |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 2070. allocate_shared should use allocator_traits<A>::construct |
| __traits::construct(__del._M_alloc, _M_ptr, |
| std::forward<_Args>(__args)...); |
| } |
| __catch(...) |
| { |
| __traits::deallocate(__del._M_alloc, _M_ptr, 1); |
| __throw_exception_again; |
| } |
| __shared_count<_Lp> __count(_M_ptr, __del, __del._M_alloc); |
| _M_refcount._M_swap(__count); |
| __enable_shared_from_this_helper(_M_refcount, _M_ptr, _M_ptr); |
| } |
| #endif |
| |
| template<typename _Tp1, _Lock_policy _Lp1, typename _Alloc, |
| typename... _Args> |
| friend __shared_ptr<_Tp1, _Lp1> |
| __allocate_shared(const _Alloc& __a, _Args&&... __args); |
| |
| private: |
| void* |
| _M_get_deleter(const std::type_info& __ti) const noexcept |
| { return _M_refcount._M_get_deleter(__ti); } |
| |
| template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr; |
| template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr; |
| |
| template<typename _Del, typename _Tp1, _Lock_policy _Lp1> |
| friend _Del* get_deleter(const __shared_ptr<_Tp1, _Lp1>&) noexcept; |
| |
| _Tp* _M_ptr; // Contained pointer. |
| __shared_count<_Lp> _M_refcount; // Reference counter. |
| }; |
| |
| |
| // 20.7.2.2.7 shared_ptr comparisons |
| template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> |
| inline bool |
| operator==(const __shared_ptr<_Tp1, _Lp>& __a, |
| const __shared_ptr<_Tp2, _Lp>& __b) noexcept |
| { return __a.get() == __b.get(); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator==(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept |
| { return !__a; } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator==(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept |
| { return !__a; } |
| |
| template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> |
| inline bool |
| operator!=(const __shared_ptr<_Tp1, _Lp>& __a, |
| const __shared_ptr<_Tp2, _Lp>& __b) noexcept |
| { return __a.get() != __b.get(); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator!=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept |
| { return (bool)__a; } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator!=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept |
| { return (bool)__a; } |
| |
| template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> |
| inline bool |
| operator<(const __shared_ptr<_Tp1, _Lp>& __a, |
| const __shared_ptr<_Tp2, _Lp>& __b) noexcept |
| { |
| typedef typename std::common_type<_Tp1*, _Tp2*>::type _CT; |
| return std::less<_CT>()(__a.get(), __b.get()); |
| } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator<(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept |
| { return std::less<_Tp*>()(__a.get(), nullptr); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator<(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept |
| { return std::less<_Tp*>()(nullptr, __a.get()); } |
| |
| template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> |
| inline bool |
| operator<=(const __shared_ptr<_Tp1, _Lp>& __a, |
| const __shared_ptr<_Tp2, _Lp>& __b) noexcept |
| { return !(__b < __a); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator<=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept |
| { return !(nullptr < __a); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator<=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept |
| { return !(__a < nullptr); } |
| |
| template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> |
| inline bool |
| operator>(const __shared_ptr<_Tp1, _Lp>& __a, |
| const __shared_ptr<_Tp2, _Lp>& __b) noexcept |
| { return (__b < __a); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator>(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept |
| { return std::less<_Tp*>()(nullptr, __a.get()); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator>(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept |
| { return std::less<_Tp*>()(__a.get(), nullptr); } |
| |
| template<typename _Tp1, typename _Tp2, _Lock_policy _Lp> |
| inline bool |
| operator>=(const __shared_ptr<_Tp1, _Lp>& __a, |
| const __shared_ptr<_Tp2, _Lp>& __b) noexcept |
| { return !(__a < __b); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator>=(const __shared_ptr<_Tp, _Lp>& __a, nullptr_t) noexcept |
| { return !(__a < nullptr); } |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| inline bool |
| operator>=(nullptr_t, const __shared_ptr<_Tp, _Lp>& __a) noexcept |
| { return !(nullptr < __a); } |
| |
| template<typename _Sp> |
| struct _Sp_less : public binary_function<_Sp, _Sp, bool> |
| { |
| bool |
| operator()(const _Sp& __lhs, const _Sp& __rhs) const noexcept |
| { |
| typedef typename _Sp::element_type element_type; |
| return std::less<element_type*>()(__lhs.get(), __rhs.get()); |
| } |
| }; |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| struct less<__shared_ptr<_Tp, _Lp>> |
| : public _Sp_less<__shared_ptr<_Tp, _Lp>> |
| { }; |
| |
| // 2.2.3.8 shared_ptr specialized algorithms. |
| template<typename _Tp, _Lock_policy _Lp> |
| inline void |
| swap(__shared_ptr<_Tp, _Lp>& __a, __shared_ptr<_Tp, _Lp>& __b) noexcept |
| { __a.swap(__b); } |
| |
| // 2.2.3.9 shared_ptr casts |
| |
| // The seemingly equivalent code: |
| // shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get())) |
| // will eventually result in undefined behaviour, attempting to |
| // delete the same object twice. |
| /// static_pointer_cast |
| template<typename _Tp, typename _Tp1, _Lock_policy _Lp> |
| inline __shared_ptr<_Tp, _Lp> |
| static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| { return __shared_ptr<_Tp, _Lp>(__r, static_cast<_Tp*>(__r.get())); } |
| |
| // The seemingly equivalent code: |
| // shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get())) |
| // will eventually result in undefined behaviour, attempting to |
| // delete the same object twice. |
| /// const_pointer_cast |
| template<typename _Tp, typename _Tp1, _Lock_policy _Lp> |
| inline __shared_ptr<_Tp, _Lp> |
| const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| { return __shared_ptr<_Tp, _Lp>(__r, const_cast<_Tp*>(__r.get())); } |
| |
| // The seemingly equivalent code: |
| // shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get())) |
| // will eventually result in undefined behaviour, attempting to |
| // delete the same object twice. |
| /// dynamic_pointer_cast |
| template<typename _Tp, typename _Tp1, _Lock_policy _Lp> |
| inline __shared_ptr<_Tp, _Lp> |
| dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| { |
| if (_Tp* __p = dynamic_cast<_Tp*>(__r.get())) |
| return __shared_ptr<_Tp, _Lp>(__r, __p); |
| return __shared_ptr<_Tp, _Lp>(); |
| } |
| |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| class __weak_ptr |
| { |
| public: |
| typedef _Tp element_type; |
| |
| constexpr __weak_ptr() noexcept |
| : _M_ptr(0), _M_refcount() |
| { } |
| |
| __weak_ptr(const __weak_ptr&) noexcept = default; |
| __weak_ptr& operator=(const __weak_ptr&) noexcept = default; |
| ~__weak_ptr() = default; |
| |
| // The "obvious" converting constructor implementation: |
| // |
| // template<typename _Tp1> |
| // __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) |
| // : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws |
| // { } |
| // |
| // has a serious problem. |
| // |
| // __r._M_ptr may already have been invalidated. The _M_ptr(__r._M_ptr) |
| // conversion may require access to *__r._M_ptr (virtual inheritance). |
| // |
| // It is not possible to avoid spurious access violations since |
| // in multithreaded programs __r._M_ptr may be invalidated at any point. |
| template<typename _Tp1, typename = typename |
| std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
| __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) noexcept |
| : _M_refcount(__r._M_refcount) |
| { _M_ptr = __r.lock().get(); } |
| |
| template<typename _Tp1, typename = typename |
| std::enable_if<std::is_convertible<_Tp1*, _Tp*>::value>::type> |
| __weak_ptr(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) |
| { } |
| |
| template<typename _Tp1> |
| __weak_ptr& |
| operator=(const __weak_ptr<_Tp1, _Lp>& __r) noexcept |
| { |
| _M_ptr = __r.lock().get(); |
| _M_refcount = __r._M_refcount; |
| return *this; |
| } |
| |
| template<typename _Tp1> |
| __weak_ptr& |
| operator=(const __shared_ptr<_Tp1, _Lp>& __r) noexcept |
| { |
| _M_ptr = __r._M_ptr; |
| _M_refcount = __r._M_refcount; |
| return *this; |
| } |
| |
| __shared_ptr<_Tp, _Lp> |
| lock() const noexcept |
| { |
| #ifdef __GTHREADS |
| // Optimization: avoid throw overhead. |
| if (expired()) |
| return __shared_ptr<element_type, _Lp>(); |
| |
| __try |
| { |
| return __shared_ptr<element_type, _Lp>(*this); |
| } |
| __catch(const bad_weak_ptr&) |
| { |
| // Q: How can we get here? |
| // A: Another thread may have invalidated r after the |
| // use_count test above. |
| return __shared_ptr<element_type, _Lp>(); |
| } |
| |
| #else |
| // Optimization: avoid try/catch overhead when single threaded. |
| return expired() ? __shared_ptr<element_type, _Lp>() |
| : __shared_ptr<element_type, _Lp>(*this); |
| |
| #endif |
| } // XXX MT |
| |
| long |
| use_count() const noexcept |
| { return _M_refcount._M_get_use_count(); } |
| |
| bool |
| expired() const noexcept |
| { return _M_refcount._M_get_use_count() == 0; } |
| |
| template<typename _Tp1> |
| bool |
| owner_before(const __shared_ptr<_Tp1, _Lp>& __rhs) const |
| { return _M_refcount._M_less(__rhs._M_refcount); } |
| |
| template<typename _Tp1> |
| bool |
| owner_before(const __weak_ptr<_Tp1, _Lp>& __rhs) const |
| { return _M_refcount._M_less(__rhs._M_refcount); } |
| |
| void |
| reset() noexcept |
| { __weak_ptr().swap(*this); } |
| |
| void |
| swap(__weak_ptr& __s) noexcept |
| { |
| std::swap(_M_ptr, __s._M_ptr); |
| _M_refcount._M_swap(__s._M_refcount); |
| } |
| |
| private: |
| // Used by __enable_shared_from_this. |
| void |
| _M_assign(_Tp* __ptr, const __shared_count<_Lp>& __refcount) noexcept |
| { |
| _M_ptr = __ptr; |
| _M_refcount = __refcount; |
| } |
| |
| template<typename _Tp1, _Lock_policy _Lp1> friend class __shared_ptr; |
| template<typename _Tp1, _Lock_policy _Lp1> friend class __weak_ptr; |
| friend class __enable_shared_from_this<_Tp, _Lp>; |
| friend class enable_shared_from_this<_Tp>; |
| |
| _Tp* _M_ptr; // Contained pointer. |
| __weak_count<_Lp> _M_refcount; // Reference counter. |
| }; |
| |
| // 20.7.2.3.6 weak_ptr specialized algorithms. |
| template<typename _Tp, _Lock_policy _Lp> |
| inline void |
| swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b) noexcept |
| { __a.swap(__b); } |
| |
| template<typename _Tp, typename _Tp1> |
| struct _Sp_owner_less : public binary_function<_Tp, _Tp, bool> |
| { |
| bool |
| operator()(const _Tp& __lhs, const _Tp& __rhs) const |
| { return __lhs.owner_before(__rhs); } |
| |
| bool |
| operator()(const _Tp& __lhs, const _Tp1& __rhs) const |
| { return __lhs.owner_before(__rhs); } |
| |
| bool |
| operator()(const _Tp1& __lhs, const _Tp& __rhs) const |
| { return __lhs.owner_before(__rhs); } |
| }; |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| struct owner_less<__shared_ptr<_Tp, _Lp>> |
| : public _Sp_owner_less<__shared_ptr<_Tp, _Lp>, __weak_ptr<_Tp, _Lp>> |
| { }; |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| struct owner_less<__weak_ptr<_Tp, _Lp>> |
| : public _Sp_owner_less<__weak_ptr<_Tp, _Lp>, __shared_ptr<_Tp, _Lp>> |
| { }; |
| |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| class __enable_shared_from_this |
| { |
| protected: |
| constexpr __enable_shared_from_this() noexcept { } |
| |
| __enable_shared_from_this(const __enable_shared_from_this&) noexcept { } |
| |
| __enable_shared_from_this& |
| operator=(const __enable_shared_from_this&) noexcept |
| { return *this; } |
| |
| ~__enable_shared_from_this() { } |
| |
| public: |
| __shared_ptr<_Tp, _Lp> |
| shared_from_this() |
| { return __shared_ptr<_Tp, _Lp>(this->_M_weak_this); } |
| |
| __shared_ptr<const _Tp, _Lp> |
| shared_from_this() const |
| { return __shared_ptr<const _Tp, _Lp>(this->_M_weak_this); } |
| |
| private: |
| template<typename _Tp1> |
| void |
| _M_weak_assign(_Tp1* __p, const __shared_count<_Lp>& __n) const noexcept |
| { _M_weak_this._M_assign(__p, __n); } |
| |
| template<typename _Tp1> |
| friend void |
| __enable_shared_from_this_helper(const __shared_count<_Lp>& __pn, |
| const __enable_shared_from_this* __pe, |
| const _Tp1* __px) noexcept |
| { |
| if (__pe != 0) |
| __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn); |
| } |
| |
| mutable __weak_ptr<_Tp, _Lp> _M_weak_this; |
| }; |
| |
| |
| template<typename _Tp, _Lock_policy _Lp, typename _Alloc, typename... _Args> |
| inline __shared_ptr<_Tp, _Lp> |
| __allocate_shared(const _Alloc& __a, _Args&&... __args) |
| { |
| return __shared_ptr<_Tp, _Lp>(_Sp_make_shared_tag(), __a, |
| std::forward<_Args>(__args)...); |
| } |
| |
| template<typename _Tp, _Lock_policy _Lp, typename... _Args> |
| inline __shared_ptr<_Tp, _Lp> |
| __make_shared(_Args&&... __args) |
| { |
| typedef typename std::remove_const<_Tp>::type _Tp_nc; |
| return std::__allocate_shared<_Tp, _Lp>(std::allocator<_Tp_nc>(), |
| std::forward<_Args>(__args)...); |
| } |
| |
| /// std::hash specialization for __shared_ptr. |
| template<typename _Tp, _Lock_policy _Lp> |
| struct hash<__shared_ptr<_Tp, _Lp>> |
| : public __hash_base<size_t, __shared_ptr<_Tp, _Lp>> |
| { |
| size_t |
| operator()(const __shared_ptr<_Tp, _Lp>& __s) const noexcept |
| { return std::hash<_Tp*>()(__s.get()); } |
| }; |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #endif // _SHARED_PTR_BASE_H |
