| // <tr1/shared_ptr.h> -*- C++ -*- |
| |
| // Copyright (C) 2007-2020 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/>. |
| |
| // 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) |
| |
| // GCC Note: based on version 1.32.0 of the Boost library. |
| |
| /** @file tr1/shared_ptr.h |
| * This is an internal header file, included by other library headers. |
| * Do not attempt to use it directly. @headername{tr1/memory} |
| */ |
| |
| #ifndef _TR1_SHARED_PTR_H |
| #define _TR1_SHARED_PTR_H 1 |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| namespace tr1 |
| { |
| /** |
| * @brief Exception possibly thrown by @c shared_ptr. |
| * @ingroup exceptions |
| */ |
| class bad_weak_ptr : public std::exception |
| { |
| public: |
| virtual char const* |
| what() const throw() |
| { return "tr1::bad_weak_ptr"; } |
| }; |
| |
| // 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() |
| : _M_use_count(1), _M_weak_count(1) { } |
| |
| virtual |
| ~_Sp_counted_base() // nothrow |
| { } |
| |
| // Called when _M_use_count drops to zero, to release the resources |
| // managed by *this. |
| virtual void |
| _M_dispose() = 0; // nothrow |
| |
| // Called when _M_weak_count drops to zero. |
| virtual void |
| _M_destroy() // nothrow |
| { 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() // nothrow |
| { |
| // 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) |
| { |
| __atomic_thread_fence (__ATOMIC_ACQ_REL); |
| } |
| |
| // 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() // nothrow |
| { __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); } |
| |
| void |
| _M_weak_release() // nothrow |
| { |
| // 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() |
| __atomic_thread_fence (__ATOMIC_ACQ_REL); |
| } |
| _M_destroy(); |
| } |
| } |
| |
| long |
| _M_get_use_count() const // nothrow |
| { |
| // No memory barrier is used here so there is no synchronization |
| // with other threads. |
| return const_cast<const volatile _Atomic_word&>(_M_use_count); |
| } |
| |
| private: |
| _Sp_counted_base(_Sp_counted_base const&); |
| _Sp_counted_base& operator=(_Sp_counted_base const&); |
| |
| _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_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)); |
| } |
| |
| template<typename _Ptr, typename _Deleter, _Lock_policy _Lp> |
| class _Sp_counted_base_impl |
| : public _Sp_counted_base<_Lp> |
| { |
| public: |
| // Precondition: __d(__p) must not throw. |
| _Sp_counted_base_impl(_Ptr __p, _Deleter __d) |
| : _M_ptr(__p), _M_del(__d) { } |
| |
| virtual void |
| _M_dispose() // nothrow |
| { _M_del(_M_ptr); } |
| |
| virtual void* |
| _M_get_deleter(const std::type_info& __ti) |
| { |
| #if __cpp_rtti |
| return __ti == typeid(_Deleter) ? &_M_del : 0; |
| #else |
| return 0; |
| #endif |
| } |
| |
| private: |
| _Sp_counted_base_impl(const _Sp_counted_base_impl&); |
| _Sp_counted_base_impl& operator=(const _Sp_counted_base_impl&); |
| |
| _Ptr _M_ptr; // copy constructor must not throw |
| _Deleter _M_del; // copy constructor must not throw |
| }; |
| |
| template<_Lock_policy _Lp = __default_lock_policy> |
| class __weak_count; |
| |
| template<typename _Tp> |
| struct _Sp_deleter |
| { |
| typedef void result_type; |
| typedef _Tp* argument_type; |
| void operator()(_Tp* __p) const { delete __p; } |
| }; |
| |
| template<_Lock_policy _Lp = __default_lock_policy> |
| class __shared_count |
| { |
| public: |
| __shared_count() |
| : _M_pi(0) // nothrow |
| { } |
| |
| template<typename _Ptr> |
| __shared_count(_Ptr __p) : _M_pi(0) |
| { |
| __try |
| { |
| typedef typename std::tr1::remove_pointer<_Ptr>::type _Tp; |
| _M_pi = new _Sp_counted_base_impl<_Ptr, _Sp_deleter<_Tp>, _Lp>( |
| __p, _Sp_deleter<_Tp>()); |
| } |
| __catch(...) |
| { |
| delete __p; |
| __throw_exception_again; |
| } |
| } |
| |
| template<typename _Ptr, typename _Deleter> |
| __shared_count(_Ptr __p, _Deleter __d) : _M_pi(0) |
| { |
| __try |
| { |
| _M_pi = new _Sp_counted_base_impl<_Ptr, _Deleter, _Lp>(__p, __d); |
| } |
| __catch(...) |
| { |
| __d(__p); // Call _Deleter on __p. |
| __throw_exception_again; |
| } |
| } |
| |
| // Special case for auto_ptr<_Tp> to provide the strong guarantee. |
| template<typename _Tp> |
| explicit |
| __shared_count(std::auto_ptr<_Tp>& __r) |
| : _M_pi(new _Sp_counted_base_impl<_Tp*, |
| _Sp_deleter<_Tp>, _Lp >(__r.get(), _Sp_deleter<_Tp>())) |
| { __r.release(); } |
| |
| // Throw bad_weak_ptr when __r._M_get_use_count() == 0. |
| explicit |
| __shared_count(const __weak_count<_Lp>& __r); |
| |
| ~__shared_count() // nothrow |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_release(); |
| } |
| |
| __shared_count(const __shared_count& __r) |
| : _M_pi(__r._M_pi) // nothrow |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_add_ref_copy(); |
| } |
| |
| __shared_count& |
| operator=(const __shared_count& __r) // nothrow |
| { |
| _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) // nothrow |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| __r._M_pi = _M_pi; |
| _M_pi = __tmp; |
| } |
| |
| long |
| _M_get_use_count() const // nothrow |
| { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; } |
| |
| bool |
| _M_unique() const // nothrow |
| { return this->_M_get_use_count() == 1; } |
| |
| friend inline bool |
| operator==(const __shared_count& __a, const __shared_count& __b) |
| { return __a._M_pi == __b._M_pi; } |
| |
| friend inline bool |
| operator<(const __shared_count& __a, const __shared_count& __b) |
| { return std::less<_Sp_counted_base<_Lp>*>()(__a._M_pi, __b._M_pi); } |
| |
| void* |
| _M_get_deleter(const std::type_info& __ti) const |
| { return _M_pi ? _M_pi->_M_get_deleter(__ti) : 0; } |
| |
| private: |
| friend class __weak_count<_Lp>; |
| |
| _Sp_counted_base<_Lp>* _M_pi; |
| }; |
| |
| |
| template<_Lock_policy _Lp> |
| class __weak_count |
| { |
| public: |
| __weak_count() |
| : _M_pi(0) // nothrow |
| { } |
| |
| __weak_count(const __shared_count<_Lp>& __r) |
| : _M_pi(__r._M_pi) // nothrow |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_weak_add_ref(); |
| } |
| |
| __weak_count(const __weak_count<_Lp>& __r) |
| : _M_pi(__r._M_pi) // nothrow |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_weak_add_ref(); |
| } |
| |
| ~__weak_count() // nothrow |
| { |
| if (_M_pi != 0) |
| _M_pi->_M_weak_release(); |
| } |
| |
| __weak_count<_Lp>& |
| operator=(const __shared_count<_Lp>& __r) // nothrow |
| { |
| _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) // nothrow |
| { |
| _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) // nothrow |
| { |
| _Sp_counted_base<_Lp>* __tmp = __r._M_pi; |
| __r._M_pi = _M_pi; |
| _M_pi = __tmp; |
| } |
| |
| long |
| _M_get_use_count() const // nothrow |
| { return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; } |
| |
| friend inline bool |
| operator==(const __weak_count<_Lp>& __a, const __weak_count<_Lp>& __b) |
| { return __a._M_pi == __b._M_pi; } |
| |
| friend inline bool |
| operator<(const __weak_count<_Lp>& __a, const __weak_count<_Lp>& __b) |
| { return std::less<_Sp_counted_base<_Lp>*>()(__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(); |
| } |
| |
| // 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> |
| class enable_shared_from_this; |
| |
| // 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*); |
| |
| // 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*); |
| |
| template<_Lock_policy _Lp> |
| inline void |
| __enable_shared_from_this_helper(const __shared_count<_Lp>&, ...) |
| { } |
| |
| |
| struct __static_cast_tag { }; |
| struct __const_cast_tag { }; |
| struct __dynamic_cast_tag { }; |
| |
| // 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, _Lock_policy _Lp> |
| class __shared_ptr |
| { |
| public: |
| typedef _Tp element_type; |
| |
| __shared_ptr() |
| : _M_ptr(0), _M_refcount() // never throws |
| { } |
| |
| template<typename _Tp1> |
| explicit |
| __shared_ptr(_Tp1* __p) |
| : _M_ptr(__p), _M_refcount(__p) |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| typedef int _IsComplete[sizeof(_Tp1)]; |
| __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); |
| } |
| |
| // generated copy constructor, assignment, destructor are fine. |
| |
| template<typename _Tp1> |
| __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r) |
| : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws |
| { __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) } |
| |
| 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 (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED |
| // Postcondition: use_count() == 1 and __r.get() == 0 |
| template<typename _Tp1> |
| explicit |
| __shared_ptr(std::auto_ptr<_Tp1>& __r) |
| : _M_ptr(__r.get()), _M_refcount() |
| { // TODO requries delete __r.release() well-formed |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| typedef int _IsComplete[sizeof(_Tp1)]; |
| _Tp1* __tmp = __r.get(); |
| _M_refcount = __shared_count<_Lp>(__r); |
| __enable_shared_from_this_helper(_M_refcount, __tmp, __tmp); |
| } |
| |
| #endif |
| |
| template<typename _Tp1> |
| __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, __static_cast_tag) |
| : _M_ptr(static_cast<element_type*>(__r._M_ptr)), |
| _M_refcount(__r._M_refcount) |
| { } |
| |
| template<typename _Tp1> |
| __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, __const_cast_tag) |
| : _M_ptr(const_cast<element_type*>(__r._M_ptr)), |
| _M_refcount(__r._M_refcount) |
| { } |
| |
| template<typename _Tp1> |
| __shared_ptr(const __shared_ptr<_Tp1, _Lp>& __r, __dynamic_cast_tag) |
| : _M_ptr(dynamic_cast<element_type*>(__r._M_ptr)), |
| _M_refcount(__r._M_refcount) |
| { |
| if (_M_ptr == 0) // need to allocate new counter -- the cast failed |
| _M_refcount = __shared_count<_Lp>(); |
| } |
| |
| template<typename _Tp1> |
| __shared_ptr& |
| operator=(const __shared_ptr<_Tp1, _Lp>& __r) // never throws |
| { |
| _M_ptr = __r._M_ptr; |
| _M_refcount = __r._M_refcount; // __shared_count::op= doesn't throw |
| return *this; |
| } |
| |
| #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED |
| template<typename _Tp1> |
| __shared_ptr& |
| operator=(std::auto_ptr<_Tp1>& __r) |
| { |
| __shared_ptr(__r).swap(*this); |
| return *this; |
| } |
| #endif |
| |
| void |
| reset() // never throws |
| { __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); } |
| |
| // Allow class instantiation when _Tp is [cv-qual] void. |
| typename std::tr1::add_reference<_Tp>::type |
| operator*() const // never throws |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0); |
| return *_M_ptr; |
| } |
| |
| _Tp* |
| operator->() const // never throws |
| { |
| _GLIBCXX_DEBUG_ASSERT(_M_ptr != 0); |
| return _M_ptr; |
| } |
| |
| _Tp* |
| get() const // never throws |
| { return _M_ptr; } |
| |
| // Implicit conversion to "bool" |
| private: |
| typedef _Tp* __shared_ptr::*__unspecified_bool_type; |
| |
| public: |
| operator __unspecified_bool_type() const // never throws |
| { return _M_ptr == 0 ? 0 : &__shared_ptr::_M_ptr; } |
| |
| bool |
| unique() const // never throws |
| { return _M_refcount._M_unique(); } |
| |
| long |
| use_count() const // never throws |
| { return _M_refcount._M_get_use_count(); } |
| |
| void |
| swap(__shared_ptr<_Tp, _Lp>& __other) // never throws |
| { |
| std::swap(_M_ptr, __other._M_ptr); |
| _M_refcount._M_swap(__other._M_refcount); |
| } |
| |
| private: |
| void* |
| _M_get_deleter(const std::type_info& __ti) const |
| { return _M_refcount._M_get_deleter(__ti); } |
| |
| template<typename _Tp1, _Lock_policy _Lp1> |
| bool |
| _M_less(const __shared_ptr<_Tp1, _Lp1>& __rhs) const |
| { return _M_refcount < __rhs._M_refcount; } |
| |
| 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>&); |
| |
| // Friends injected into enclosing namespace and found by ADL: |
| template<typename _Tp1> |
| friend inline bool |
| operator==(const __shared_ptr& __a, const __shared_ptr<_Tp1, _Lp>& __b) |
| { return __a.get() == __b.get(); } |
| |
| template<typename _Tp1> |
| friend inline bool |
| operator!=(const __shared_ptr& __a, const __shared_ptr<_Tp1, _Lp>& __b) |
| { return __a.get() != __b.get(); } |
| |
| template<typename _Tp1> |
| friend inline bool |
| operator<(const __shared_ptr& __a, const __shared_ptr<_Tp1, _Lp>& __b) |
| { return __a._M_less(__b); } |
| |
| _Tp* _M_ptr; // Contained pointer. |
| __shared_count<_Lp> _M_refcount; // Reference counter. |
| }; |
| |
| // 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) |
| { __a.swap(__b); } |
| |
| // 2.2.3.9 shared_ptr casts |
| /* The seemingly equivalent |
| * shared_ptr<_Tp, _Lp>(static_cast<_Tp*>(__r.get())) |
| * will eventually result in undefined behaviour, |
| * attempting to delete the same object twice. |
| */ |
| template<typename _Tp, typename _Tp1, _Lock_policy _Lp> |
| inline __shared_ptr<_Tp, _Lp> |
| static_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) |
| { return __shared_ptr<_Tp, _Lp>(__r, __static_cast_tag()); } |
| |
| /* The seemingly equivalent |
| * shared_ptr<_Tp, _Lp>(const_cast<_Tp*>(__r.get())) |
| * will eventually result in undefined behaviour, |
| * attempting to delete the same object twice. |
| */ |
| template<typename _Tp, typename _Tp1, _Lock_policy _Lp> |
| inline __shared_ptr<_Tp, _Lp> |
| const_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) |
| { return __shared_ptr<_Tp, _Lp>(__r, __const_cast_tag()); } |
| |
| /* The seemingly equivalent |
| * shared_ptr<_Tp, _Lp>(dynamic_cast<_Tp*>(__r.get())) |
| * will eventually result in undefined behaviour, |
| * attempting to delete the same object twice. |
| */ |
| template<typename _Tp, typename _Tp1, _Lock_policy _Lp> |
| inline __shared_ptr<_Tp, _Lp> |
| dynamic_pointer_cast(const __shared_ptr<_Tp1, _Lp>& __r) |
| { return __shared_ptr<_Tp, _Lp>(__r, __dynamic_cast_tag()); } |
| |
| // 2.2.3.7 shared_ptr I/O |
| template<typename _Ch, typename _Tr, typename _Tp, _Lock_policy _Lp> |
| std::basic_ostream<_Ch, _Tr>& |
| operator<<(std::basic_ostream<_Ch, _Tr>& __os, |
| const __shared_ptr<_Tp, _Lp>& __p) |
| { |
| __os << __p.get(); |
| return __os; |
| } |
| |
| // 2.2.3.10 shared_ptr get_deleter (experimental) |
| template<typename _Del, typename _Tp, _Lock_policy _Lp> |
| inline _Del* |
| get_deleter(const __shared_ptr<_Tp, _Lp>& __p) |
| { |
| #if __cpp_rtti |
| return static_cast<_Del*>(__p._M_get_deleter(typeid(_Del))); |
| #else |
| return 0; |
| #endif |
| } |
| |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| class __weak_ptr |
| { |
| public: |
| typedef _Tp element_type; |
| |
| __weak_ptr() |
| : _M_ptr(0), _M_refcount() // never throws |
| { } |
| |
| // Generated copy constructor, assignment, destructor are fine. |
| |
| // 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> |
| __weak_ptr(const __weak_ptr<_Tp1, _Lp>& __r) |
| : _M_refcount(__r._M_refcount) // never throws |
| { |
| __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) |
| _M_ptr = __r.lock().get(); |
| } |
| |
| template<typename _Tp1> |
| __weak_ptr(const __shared_ptr<_Tp1, _Lp>& __r) |
| : _M_ptr(__r._M_ptr), _M_refcount(__r._M_refcount) // never throws |
| { __glibcxx_function_requires(_ConvertibleConcept<_Tp1*, _Tp*>) } |
| |
| template<typename _Tp1> |
| __weak_ptr& |
| operator=(const __weak_ptr<_Tp1, _Lp>& __r) // never throws |
| { |
| _M_ptr = __r.lock().get(); |
| _M_refcount = __r._M_refcount; |
| return *this; |
| } |
| |
| template<typename _Tp1> |
| __weak_ptr& |
| operator=(const __shared_ptr<_Tp1, _Lp>& __r) // never throws |
| { |
| _M_ptr = __r._M_ptr; |
| _M_refcount = __r._M_refcount; |
| return *this; |
| } |
| |
| __shared_ptr<_Tp, _Lp> |
| lock() const // never throws |
| { |
| #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 // never throws |
| { return _M_refcount._M_get_use_count(); } |
| |
| bool |
| expired() const // never throws |
| { return _M_refcount._M_get_use_count() == 0; } |
| |
| void |
| reset() // never throws |
| { __weak_ptr().swap(*this); } |
| |
| void |
| swap(__weak_ptr& __s) // never throws |
| { |
| 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) |
| { |
| _M_ptr = __ptr; |
| _M_refcount = __refcount; |
| } |
| |
| template<typename _Tp1> |
| bool |
| _M_less(const __weak_ptr<_Tp1, _Lp>& __rhs) const |
| { return _M_refcount < __rhs._M_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>; |
| |
| // Friend injected into namespace and found by ADL. |
| template<typename _Tp1> |
| friend inline bool |
| operator<(const __weak_ptr& __lhs, const __weak_ptr<_Tp1, _Lp>& __rhs) |
| { return __lhs._M_less(__rhs); } |
| |
| _Tp* _M_ptr; // Contained pointer. |
| __weak_count<_Lp> _M_refcount; // Reference counter. |
| }; |
| |
| // 2.2.4.7 weak_ptr specialized algorithms. |
| template<typename _Tp, _Lock_policy _Lp> |
| inline void |
| swap(__weak_ptr<_Tp, _Lp>& __a, __weak_ptr<_Tp, _Lp>& __b) |
| { __a.swap(__b); } |
| |
| |
| template<typename _Tp, _Lock_policy _Lp> |
| class __enable_shared_from_this |
| { |
| protected: |
| __enable_shared_from_this() { } |
| |
| __enable_shared_from_this(const __enable_shared_from_this&) { } |
| |
| __enable_shared_from_this& |
| operator=(const __enable_shared_from_this&) |
| { 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 |
| { _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) |
| { |
| if (__pe != 0) |
| __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn); |
| } |
| |
| mutable __weak_ptr<_Tp, _Lp> _M_weak_this; |
| }; |
| |
| |
| // The actual shared_ptr, with forwarding constructors and |
| // assignment operators. |
| template<typename _Tp> |
| class shared_ptr |
| : public __shared_ptr<_Tp> |
| { |
| public: |
| shared_ptr() |
| : __shared_ptr<_Tp>() { } |
| |
| template<typename _Tp1> |
| explicit |
| shared_ptr(_Tp1* __p) |
| : __shared_ptr<_Tp>(__p) { } |
| |
| template<typename _Tp1, typename _Deleter> |
| shared_ptr(_Tp1* __p, _Deleter __d) |
| : __shared_ptr<_Tp>(__p, __d) { } |
| |
| template<typename _Tp1> |
| shared_ptr(const shared_ptr<_Tp1>& __r) |
| : __shared_ptr<_Tp>(__r) { } |
| |
| template<typename _Tp1> |
| explicit |
| shared_ptr(const weak_ptr<_Tp1>& __r) |
| : __shared_ptr<_Tp>(__r) { } |
| |
| #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED |
| template<typename _Tp1> |
| explicit |
| shared_ptr(std::auto_ptr<_Tp1>& __r) |
| : __shared_ptr<_Tp>(__r) { } |
| #endif |
| |
| template<typename _Tp1> |
| shared_ptr(const shared_ptr<_Tp1>& __r, __static_cast_tag) |
| : __shared_ptr<_Tp>(__r, __static_cast_tag()) { } |
| |
| template<typename _Tp1> |
| shared_ptr(const shared_ptr<_Tp1>& __r, __const_cast_tag) |
| : __shared_ptr<_Tp>(__r, __const_cast_tag()) { } |
| |
| template<typename _Tp1> |
| shared_ptr(const shared_ptr<_Tp1>& __r, __dynamic_cast_tag) |
| : __shared_ptr<_Tp>(__r, __dynamic_cast_tag()) { } |
| |
| template<typename _Tp1> |
| shared_ptr& |
| operator=(const shared_ptr<_Tp1>& __r) // never throws |
| { |
| this->__shared_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| |
| #if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED |
| template<typename _Tp1> |
| shared_ptr& |
| operator=(std::auto_ptr<_Tp1>& __r) |
| { |
| this->__shared_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| #endif |
| }; |
| |
| // 2.2.3.8 shared_ptr specialized algorithms. |
| template<typename _Tp> |
| inline void |
| swap(__shared_ptr<_Tp>& __a, __shared_ptr<_Tp>& __b) |
| { __a.swap(__b); } |
| |
| template<typename _Tp, typename _Tp1> |
| inline shared_ptr<_Tp> |
| static_pointer_cast(const shared_ptr<_Tp1>& __r) |
| { return shared_ptr<_Tp>(__r, __static_cast_tag()); } |
| |
| template<typename _Tp, typename _Tp1> |
| inline shared_ptr<_Tp> |
| const_pointer_cast(const shared_ptr<_Tp1>& __r) |
| { return shared_ptr<_Tp>(__r, __const_cast_tag()); } |
| |
| template<typename _Tp, typename _Tp1> |
| inline shared_ptr<_Tp> |
| dynamic_pointer_cast(const shared_ptr<_Tp1>& __r) |
| { return shared_ptr<_Tp>(__r, __dynamic_cast_tag()); } |
| |
| |
| // The actual weak_ptr, with forwarding constructors and |
| // assignment operators. |
| template<typename _Tp> |
| class weak_ptr |
| : public __weak_ptr<_Tp> |
| { |
| public: |
| weak_ptr() |
| : __weak_ptr<_Tp>() { } |
| |
| template<typename _Tp1> |
| weak_ptr(const weak_ptr<_Tp1>& __r) |
| : __weak_ptr<_Tp>(__r) { } |
| |
| template<typename _Tp1> |
| weak_ptr(const shared_ptr<_Tp1>& __r) |
| : __weak_ptr<_Tp>(__r) { } |
| |
| template<typename _Tp1> |
| weak_ptr& |
| operator=(const weak_ptr<_Tp1>& __r) // never throws |
| { |
| this->__weak_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| |
| template<typename _Tp1> |
| weak_ptr& |
| operator=(const shared_ptr<_Tp1>& __r) // never throws |
| { |
| this->__weak_ptr<_Tp>::operator=(__r); |
| return *this; |
| } |
| |
| shared_ptr<_Tp> |
| lock() const // never throws |
| { |
| #ifdef __GTHREADS |
| if (this->expired()) |
| return shared_ptr<_Tp>(); |
| |
| __try |
| { |
| return shared_ptr<_Tp>(*this); |
| } |
| __catch(const bad_weak_ptr&) |
| { |
| return shared_ptr<_Tp>(); |
| } |
| #else |
| return this->expired() ? shared_ptr<_Tp>() |
| : shared_ptr<_Tp>(*this); |
| #endif |
| } |
| }; |
| |
| template<typename _Tp> |
| class enable_shared_from_this |
| { |
| protected: |
| enable_shared_from_this() { } |
| |
| enable_shared_from_this(const enable_shared_from_this&) { } |
| |
| enable_shared_from_this& |
| operator=(const enable_shared_from_this&) |
| { 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 |
| { _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) |
| { |
| if (__pe != 0) |
| __pe->_M_weak_assign(const_cast<_Tp1*>(__px), __pn); |
| } |
| |
| mutable weak_ptr<_Tp> _M_weak_this; |
| }; |
| } |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } |
| |
| #endif // _TR1_SHARED_PTR_H |
