| // shared_ptr and weak_ptr implementation -*- C++ -*- |
| |
| // Copyright (C) 2007-2015 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.h |
| * This is an internal header file, included by other library headers. |
| * Do not attempt to use it directly. @headername{memory} |
| */ |
| |
| #ifndef _SHARED_PTR_H |
| #define _SHARED_PTR_H 1 |
| |
| #include <bits/shared_ptr_base.h> |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| /** |
| * @addtogroup pointer_abstractions |
| * @{ |
| */ |
| |
| /// 20.7.2.2.11 shared_ptr I/O |
| template<typename _Ch, typename _Tr, typename _Tp, _Lock_policy _Lp> |
| inline std::basic_ostream<_Ch, _Tr>& |
| operator<<(std::basic_ostream<_Ch, _Tr>& __os, |
| const __shared_ptr<_Tp, _Lp>& __p) |
| { |
| __os << __p.get(); |
| return __os; |
| } |
| |
| /// 20.7.2.2.10 shared_ptr get_deleter |
| template<typename _Del, typename _Tp, _Lock_policy _Lp> |
| inline _Del* |
| get_deleter(const __shared_ptr<_Tp, _Lp>& __p) noexcept |
| { |
| #if __cpp_rtti |
| return static_cast<_Del*>(__p._M_get_deleter(typeid(_Del))); |
| #else |
| return 0; |
| #endif |
| } |
| |
| |
| /** |
| * @brief A smart pointer with reference-counted copy semantics. |
| * |
| * The object pointed to is deleted when the last shared_ptr pointing to |
| * it is destroyed or reset. |
| */ |
| template<typename _Tp> |
| class shared_ptr : public __shared_ptr<_Tp> |
| { |
| template<typename _Ptr> |
| using _Convertible |
| = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type; |
| |
| public: |
| /** |
| * @brief Construct an empty %shared_ptr. |
| * @post use_count()==0 && get()==0 |
| */ |
| constexpr shared_ptr() noexcept |
| : __shared_ptr<_Tp>() { } |
| |
| shared_ptr(const shared_ptr&) noexcept = default; |
| |
| /** |
| * @brief Construct a %shared_ptr that owns the pointer @a __p. |
| * @param __p A pointer that is convertible to element_type*. |
| * @post use_count() == 1 && get() == __p |
| * @throw std::bad_alloc, in which case @c delete @a __p is called. |
| */ |
| template<typename _Tp1> |
| explicit shared_ptr(_Tp1* __p) |
| : __shared_ptr<_Tp>(__p) { } |
| |
| /** |
| * @brief Construct a %shared_ptr that owns the pointer @a __p |
| * and the deleter @a __d. |
| * @param __p A pointer. |
| * @param __d A deleter. |
| * @post use_count() == 1 && get() == __p |
| * @throw std::bad_alloc, in which case @a __d(__p) is called. |
| * |
| * Requirements: _Deleter's copy constructor and destructor must |
| * not throw |
| * |
| * __shared_ptr will release __p by calling __d(__p) |
| */ |
| template<typename _Tp1, typename _Deleter> |
| shared_ptr(_Tp1* __p, _Deleter __d) |
| : __shared_ptr<_Tp>(__p, __d) { } |
| |
| /** |
| * @brief Construct a %shared_ptr that owns a null pointer |
| * and the deleter @a __d. |
| * @param __p A null pointer constant. |
| * @param __d A deleter. |
| * @post use_count() == 1 && get() == __p |
| * @throw std::bad_alloc, in which case @a __d(__p) is called. |
| * |
| * Requirements: _Deleter's copy constructor and destructor must |
| * not throw |
| * |
| * The last owner will call __d(__p) |
| */ |
| template<typename _Deleter> |
| shared_ptr(nullptr_t __p, _Deleter __d) |
| : __shared_ptr<_Tp>(__p, __d) { } |
| |
| /** |
| * @brief Construct a %shared_ptr that owns the pointer @a __p |
| * and the deleter @a __d. |
| * @param __p A pointer. |
| * @param __d A deleter. |
| * @param __a An allocator. |
| * @post use_count() == 1 && get() == __p |
| * @throw std::bad_alloc, in which case @a __d(__p) is called. |
| * |
| * Requirements: _Deleter's copy constructor and destructor must |
| * not throw _Alloc's copy constructor and destructor must not |
| * throw. |
| * |
| * __shared_ptr will release __p by calling __d(__p) |
| */ |
| template<typename _Tp1, typename _Deleter, typename _Alloc> |
| shared_ptr(_Tp1* __p, _Deleter __d, _Alloc __a) |
| : __shared_ptr<_Tp>(__p, __d, std::move(__a)) { } |
| |
| /** |
| * @brief Construct a %shared_ptr that owns a null pointer |
| * and the deleter @a __d. |
| * @param __p A null pointer constant. |
| * @param __d A deleter. |
| * @param __a An allocator. |
| * @post use_count() == 1 && get() == __p |
| * @throw std::bad_alloc, in which case @a __d(__p) is called. |
| * |
| * Requirements: _Deleter's copy constructor and destructor must |
| * not throw _Alloc's copy constructor and destructor must not |
| * throw. |
| * |
| * The last owner will call __d(__p) |
| */ |
| template<typename _Deleter, typename _Alloc> |
| shared_ptr(nullptr_t __p, _Deleter __d, _Alloc __a) |
| : __shared_ptr<_Tp>(__p, __d, std::move(__a)) { } |
| |
| // Aliasing constructor |
| |
| /** |
| * @brief Constructs a %shared_ptr instance that stores @a __p |
| * and shares ownership with @a __r. |
| * @param __r A %shared_ptr. |
| * @param __p A pointer that will remain valid while @a *__r is valid. |
| * @post get() == __p && use_count() == __r.use_count() |
| * |
| * This can be used to construct a @c shared_ptr to a sub-object |
| * of an object managed by an existing @c shared_ptr. |
| * |
| * @code |
| * shared_ptr< pair<int,int> > pii(new pair<int,int>()); |
| * shared_ptr<int> pi(pii, &pii->first); |
| * assert(pii.use_count() == 2); |
| * @endcode |
| */ |
| template<typename _Tp1> |
| shared_ptr(const shared_ptr<_Tp1>& __r, _Tp* __p) noexcept |
| : __shared_ptr<_Tp>(__r, __p) { } |
| |
| /** |
| * @brief If @a __r is empty, constructs an empty %shared_ptr; |
| * otherwise construct a %shared_ptr that shares ownership |
| * with @a __r. |
| * @param __r A %shared_ptr. |
| * @post get() == __r.get() && use_count() == __r.use_count() |
| */ |
| template<typename _Tp1, typename = _Convertible<_Tp1*>> |
| shared_ptr(const shared_ptr<_Tp1>& __r) noexcept |
| : __shared_ptr<_Tp>(__r) { } |
| |
| /** |
| * @brief Move-constructs a %shared_ptr instance from @a __r. |
| * @param __r A %shared_ptr rvalue. |
| * @post *this contains the old value of @a __r, @a __r is empty. |
| */ |
| shared_ptr(shared_ptr&& __r) noexcept |
| : __shared_ptr<_Tp>(std::move(__r)) { } |
| |
| /** |
| * @brief Move-constructs a %shared_ptr instance from @a __r. |
| * @param __r A %shared_ptr rvalue. |
| * @post *this contains the old value of @a __r, @a __r is empty. |
| */ |
| template<typename _Tp1, typename = _Convertible<_Tp1*>> |
| shared_ptr(shared_ptr<_Tp1>&& __r) noexcept |
| : __shared_ptr<_Tp>(std::move(__r)) { } |
| |
| /** |
| * @brief Constructs a %shared_ptr that shares ownership with @a __r |
| * and stores a copy of the pointer stored in @a __r. |
| * @param __r A weak_ptr. |
| * @post use_count() == __r.use_count() |
| * @throw bad_weak_ptr when __r.expired(), |
| * in which case the constructor has no effect. |
| */ |
| template<typename _Tp1> |
| explicit shared_ptr(const weak_ptr<_Tp1>& __r) |
| : __shared_ptr<_Tp>(__r) { } |
| |
| #if _GLIBCXX_USE_DEPRECATED |
| template<typename _Tp1> |
| shared_ptr(std::auto_ptr<_Tp1>&& __r); |
| #endif |
| |
| // _GLIBCXX_RESOLVE_LIB_DEFECTS |
| // 2399. shared_ptr's constructor from unique_ptr should be constrained |
| template<typename _Tp1, typename _Del, typename |
| = _Convertible<typename unique_ptr<_Tp1, _Del>::pointer>> |
| shared_ptr(std::unique_ptr<_Tp1, _Del>&& __r) |
| : __shared_ptr<_Tp>(std::move(__r)) { } |
| |
| /** |
| * @brief Construct an empty %shared_ptr. |
| * @post use_count() == 0 && get() == nullptr |
| */ |
| constexpr shared_ptr(nullptr_t) noexcept : shared_ptr() { } |
| |
| shared_ptr& operator=(const shared_ptr&) noexcept = default; |
| |
| template<typename _Tp1> |
| shared_ptr& |
| operator=(const shared_ptr<_Tp1>& __r) noexcept |
| { |
| this->__shared_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| |
| #if _GLIBCXX_USE_DEPRECATED |
| template<typename _Tp1> |
| shared_ptr& |
| operator=(std::auto_ptr<_Tp1>&& __r) |
| { |
| this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
| return *this; |
| } |
| #endif |
| |
| shared_ptr& |
| operator=(shared_ptr&& __r) noexcept |
| { |
| this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
| return *this; |
| } |
| |
| template<class _Tp1> |
| shared_ptr& |
| operator=(shared_ptr<_Tp1>&& __r) noexcept |
| { |
| this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
| return *this; |
| } |
| |
| template<typename _Tp1, typename _Del> |
| shared_ptr& |
| operator=(std::unique_ptr<_Tp1, _Del>&& __r) |
| { |
| this->__shared_ptr<_Tp>::operator=(std::move(__r)); |
| return *this; |
| } |
| |
| private: |
| // 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) |
| : __shared_ptr<_Tp>(__tag, __a, std::forward<_Args>(__args)...) |
| { } |
| |
| template<typename _Tp1, typename _Alloc, typename... _Args> |
| friend shared_ptr<_Tp1> |
| allocate_shared(const _Alloc& __a, _Args&&... __args); |
| |
| // This constructor is non-standard, it is used by weak_ptr::lock(). |
| shared_ptr(const weak_ptr<_Tp>& __r, std::nothrow_t) |
| : __shared_ptr<_Tp>(__r, std::nothrow) { } |
| |
| friend class weak_ptr<_Tp>; |
| }; |
| |
| // 20.7.2.2.7 shared_ptr comparisons |
| template<typename _Tp1, typename _Tp2> |
| inline bool |
| operator==(const shared_ptr<_Tp1>& __a, |
| const shared_ptr<_Tp2>& __b) noexcept |
| { return __a.get() == __b.get(); } |
| |
| template<typename _Tp> |
| inline bool |
| operator==(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
| { return !__a; } |
| |
| template<typename _Tp> |
| inline bool |
| operator==(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
| { return !__a; } |
| |
| template<typename _Tp1, typename _Tp2> |
| inline bool |
| operator!=(const shared_ptr<_Tp1>& __a, |
| const shared_ptr<_Tp2>& __b) noexcept |
| { return __a.get() != __b.get(); } |
| |
| template<typename _Tp> |
| inline bool |
| operator!=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
| { return (bool)__a; } |
| |
| template<typename _Tp> |
| inline bool |
| operator!=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
| { return (bool)__a; } |
| |
| template<typename _Tp1, typename _Tp2> |
| inline bool |
| operator<(const shared_ptr<_Tp1>& __a, |
| const shared_ptr<_Tp2>& __b) noexcept |
| { |
| typedef typename std::common_type<_Tp1*, _Tp2*>::type _CT; |
| return std::less<_CT>()(__a.get(), __b.get()); |
| } |
| |
| template<typename _Tp> |
| inline bool |
| operator<(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
| { return std::less<_Tp*>()(__a.get(), nullptr); } |
| |
| template<typename _Tp> |
| inline bool |
| operator<(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
| { return std::less<_Tp*>()(nullptr, __a.get()); } |
| |
| template<typename _Tp1, typename _Tp2> |
| inline bool |
| operator<=(const shared_ptr<_Tp1>& __a, |
| const shared_ptr<_Tp2>& __b) noexcept |
| { return !(__b < __a); } |
| |
| template<typename _Tp> |
| inline bool |
| operator<=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
| { return !(nullptr < __a); } |
| |
| template<typename _Tp> |
| inline bool |
| operator<=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
| { return !(__a < nullptr); } |
| |
| template<typename _Tp1, typename _Tp2> |
| inline bool |
| operator>(const shared_ptr<_Tp1>& __a, |
| const shared_ptr<_Tp2>& __b) noexcept |
| { return (__b < __a); } |
| |
| template<typename _Tp> |
| inline bool |
| operator>(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
| { return std::less<_Tp*>()(nullptr, __a.get()); } |
| |
| template<typename _Tp> |
| inline bool |
| operator>(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
| { return std::less<_Tp*>()(__a.get(), nullptr); } |
| |
| template<typename _Tp1, typename _Tp2> |
| inline bool |
| operator>=(const shared_ptr<_Tp1>& __a, |
| const shared_ptr<_Tp2>& __b) noexcept |
| { return !(__a < __b); } |
| |
| template<typename _Tp> |
| inline bool |
| operator>=(const shared_ptr<_Tp>& __a, nullptr_t) noexcept |
| { return !(__a < nullptr); } |
| |
| template<typename _Tp> |
| inline bool |
| operator>=(nullptr_t, const shared_ptr<_Tp>& __a) noexcept |
| { return !(nullptr < __a); } |
| |
| template<typename _Tp> |
| struct less<shared_ptr<_Tp>> : public _Sp_less<shared_ptr<_Tp>> |
| { }; |
| |
| // 20.7.2.2.8 shared_ptr specialized algorithms. |
| template<typename _Tp> |
| inline void |
| swap(shared_ptr<_Tp>& __a, shared_ptr<_Tp>& __b) noexcept |
| { __a.swap(__b); } |
| |
| // 20.7.2.2.9 shared_ptr casts. |
| template<typename _Tp, typename _Tp1> |
| inline shared_ptr<_Tp> |
| static_pointer_cast(const shared_ptr<_Tp1>& __r) noexcept |
| { return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get())); } |
| |
| template<typename _Tp, typename _Tp1> |
| inline shared_ptr<_Tp> |
| const_pointer_cast(const shared_ptr<_Tp1>& __r) noexcept |
| { return shared_ptr<_Tp>(__r, const_cast<_Tp*>(__r.get())); } |
| |
| template<typename _Tp, typename _Tp1> |
| inline shared_ptr<_Tp> |
| dynamic_pointer_cast(const shared_ptr<_Tp1>& __r) noexcept |
| { |
| if (_Tp* __p = dynamic_cast<_Tp*>(__r.get())) |
| return shared_ptr<_Tp>(__r, __p); |
| return shared_ptr<_Tp>(); |
| } |
| |
| |
| /** |
| * @brief A smart pointer with weak semantics. |
| * |
| * With forwarding constructors and assignment operators. |
| */ |
| template<typename _Tp> |
| class weak_ptr : public __weak_ptr<_Tp> |
| { |
| template<typename _Ptr> |
| using _Convertible |
| = typename enable_if<is_convertible<_Ptr, _Tp*>::value>::type; |
| |
| public: |
| constexpr weak_ptr() noexcept = default; |
| |
| template<typename _Tp1, typename = _Convertible<_Tp1*>> |
| weak_ptr(const shared_ptr<_Tp1>& __r) noexcept |
| : __weak_ptr<_Tp>(__r) { } |
| |
| weak_ptr(const weak_ptr&) noexcept = default; |
| |
| template<typename _Tp1, typename = _Convertible<_Tp1*>> |
| weak_ptr(const weak_ptr<_Tp1>& __r) noexcept |
| : __weak_ptr<_Tp>(__r) { } |
| |
| weak_ptr(weak_ptr&&) noexcept = default; |
| |
| template<typename _Tp1, typename = _Convertible<_Tp1*>> |
| weak_ptr(weak_ptr<_Tp1>&& __r) noexcept |
| : __weak_ptr<_Tp>(std::move(__r)) { } |
| |
| weak_ptr& |
| operator=(const weak_ptr& __r) noexcept = default; |
| |
| template<typename _Tp1> |
| weak_ptr& |
| operator=(const weak_ptr<_Tp1>& __r) noexcept |
| { |
| this->__weak_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| |
| template<typename _Tp1> |
| weak_ptr& |
| operator=(const shared_ptr<_Tp1>& __r) noexcept |
| { |
| this->__weak_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| |
| weak_ptr& |
| operator=(weak_ptr&& __r) noexcept = default; |
| |
| template<typename _Tp1> |
| weak_ptr& |
| operator=(weak_ptr<_Tp1>&& __r) noexcept |
| { |
| this->__weak_ptr<_Tp>::operator=(std::move(__r)); |
| return *this; |
| } |
| |
| shared_ptr<_Tp> |
| lock() const noexcept |
| { return shared_ptr<_Tp>(*this, std::nothrow); } |
| }; |
| |
| // 20.7.2.3.6 weak_ptr specialized algorithms. |
| template<typename _Tp> |
| inline void |
| swap(weak_ptr<_Tp>& __a, weak_ptr<_Tp>& __b) noexcept |
| { __a.swap(__b); } |
| |
| |
| /// Primary template owner_less |
| template<typename _Tp> |
| struct owner_less; |
| |
| /// Partial specialization of owner_less for shared_ptr. |
| template<typename _Tp> |
| struct owner_less<shared_ptr<_Tp>> |
| : public _Sp_owner_less<shared_ptr<_Tp>, weak_ptr<_Tp>> |
| { }; |
| |
| /// Partial specialization of owner_less for weak_ptr. |
| template<typename _Tp> |
| struct owner_less<weak_ptr<_Tp>> |
| : public _Sp_owner_less<weak_ptr<_Tp>, shared_ptr<_Tp>> |
| { }; |
| |
| /** |
| * @brief Base class allowing use of member function shared_from_this. |
| */ |
| template<typename _Tp> |
| 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> |
| shared_from_this() |
| { return shared_ptr<_Tp>(this->_M_weak_this); } |
| |
| shared_ptr<const _Tp> |
| shared_from_this() const |
| { return shared_ptr<const _Tp>(this->_M_weak_this); } |
| |
| private: |
| template<typename _Tp1> |
| void |
| _M_weak_assign(_Tp1* __p, const __shared_count<>& __n) const noexcept |
| { _M_weak_this._M_assign(__p, __n); } |
| |
| template<typename _Tp1> |
| friend void |
| __enable_shared_from_this_helper(const __shared_count<>& __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> _M_weak_this; |
| }; |
| |
| /** |
| * @brief Create an object that is owned by a shared_ptr. |
| * @param __a An allocator. |
| * @param __args Arguments for the @a _Tp object's constructor. |
| * @return A shared_ptr that owns the newly created object. |
| * @throw An exception thrown from @a _Alloc::allocate or from the |
| * constructor of @a _Tp. |
| * |
| * A copy of @a __a will be used to allocate memory for the shared_ptr |
| * and the new object. |
| */ |
| template<typename _Tp, typename _Alloc, typename... _Args> |
| inline shared_ptr<_Tp> |
| allocate_shared(const _Alloc& __a, _Args&&... __args) |
| { |
| return shared_ptr<_Tp>(_Sp_make_shared_tag(), __a, |
| std::forward<_Args>(__args)...); |
| } |
| |
| /** |
| * @brief Create an object that is owned by a shared_ptr. |
| * @param __args Arguments for the @a _Tp object's constructor. |
| * @return A shared_ptr that owns the newly created object. |
| * @throw std::bad_alloc, or an exception thrown from the |
| * constructor of @a _Tp. |
| */ |
| template<typename _Tp, typename... _Args> |
| inline shared_ptr<_Tp> |
| make_shared(_Args&&... __args) |
| { |
| typedef typename std::remove_const<_Tp>::type _Tp_nc; |
| return std::allocate_shared<_Tp>(std::allocator<_Tp_nc>(), |
| std::forward<_Args>(__args)...); |
| } |
| |
| /// std::hash specialization for shared_ptr. |
| template<typename _Tp> |
| struct hash<shared_ptr<_Tp>> |
| : public __hash_base<size_t, shared_ptr<_Tp>> |
| { |
| size_t |
| operator()(const shared_ptr<_Tp>& __s) const noexcept |
| { return std::hash<_Tp*>()(__s.get()); } |
| }; |
| |
| // @} group pointer_abstractions |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #endif // _SHARED_PTR_H |