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Diffstat (limited to '8/sources/cxx-stl/gnu-libstdc++/4.7/include/tr1/shared_ptr.h')
| -rw-r--r-- | 8/sources/cxx-stl/gnu-libstdc++/4.7/include/tr1/shared_ptr.h | 1179 |
1 files changed, 1179 insertions, 0 deletions
diff --git a/8/sources/cxx-stl/gnu-libstdc++/4.7/include/tr1/shared_ptr.h b/8/sources/cxx-stl/gnu-libstdc++/4.7/include/tr1/shared_ptr.h new file mode 100644 index 0000000..5a1eb03 --- /dev/null +++ b/8/sources/cxx-stl/gnu-libstdc++/4.7/include/tr1/shared_ptr.h @@ -0,0 +1,1179 @@ +// <tr1/shared_ptr.h> -*- C++ -*- + +// Copyright (C) 2007, 2008, 2009, 2010, 2011, 2012 +// 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) +{ +namespace tr1 +{ +_GLIBCXX_BEGIN_NAMESPACE_VERSION + + /** + * @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() + { +#if __EXCEPTIONS + throw bad_weak_ptr(); +#else + __builtin_abort(); +#endif + } + + 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) + { + _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() // 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() + _GLIBCXX_READ_MEM_BARRIER; + _GLIBCXX_WRITE_MEM_BARRIER; + } + _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) + { +#ifdef __GXX_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 !defined(__GXX_EXPERIMENTAL_CXX0X__) || _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 !defined(__GXX_EXPERIMENTAL_CXX0X__) || _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) + { +#ifdef __GXX_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 !defined(__GXX_EXPERIMENTAL_CXX0X__) || _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 !defined(__GXX_EXPERIMENTAL_CXX0X__) || _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 |