a554497024
From-SVN: r267494
1171 lines
32 KiB
C++
1171 lines
32 KiB
C++
// <tr1/shared_ptr.h> -*- C++ -*-
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// Copyright (C) 2007-2019 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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// shared_count.hpp
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// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
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// shared_ptr.hpp
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// Copyright (C) 1998, 1999 Greg Colvin and Beman Dawes.
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// Copyright (C) 2001, 2002, 2003 Peter Dimov
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// weak_ptr.hpp
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// Copyright (C) 2001, 2002, 2003 Peter Dimov
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// enable_shared_from_this.hpp
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// Copyright (C) 2002 Peter Dimov
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// GCC Note: based on version 1.32.0 of the Boost library.
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/** @file tr1/shared_ptr.h
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* This is an internal header file, included by other library headers.
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* Do not attempt to use it directly. @headername{tr1/memory}
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*/
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#ifndef _TR1_SHARED_PTR_H
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#define _TR1_SHARED_PTR_H 1
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namespace std _GLIBCXX_VISIBILITY(default)
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{
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_GLIBCXX_BEGIN_NAMESPACE_VERSION
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namespace tr1
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{
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/**
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* @brief Exception possibly thrown by @c shared_ptr.
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* @ingroup exceptions
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*/
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class bad_weak_ptr : public std::exception
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{
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public:
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virtual char const*
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what() const throw()
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{ return "tr1::bad_weak_ptr"; }
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};
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// Substitute for bad_weak_ptr object in the case of -fno-exceptions.
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inline void
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__throw_bad_weak_ptr()
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{ _GLIBCXX_THROW_OR_ABORT(bad_weak_ptr()); }
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using __gnu_cxx::_Lock_policy;
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using __gnu_cxx::__default_lock_policy;
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using __gnu_cxx::_S_single;
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using __gnu_cxx::_S_mutex;
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using __gnu_cxx::_S_atomic;
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// Empty helper class except when the template argument is _S_mutex.
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template<_Lock_policy _Lp>
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class _Mutex_base
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{
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protected:
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// The atomic policy uses fully-fenced builtins, single doesn't care.
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enum { _S_need_barriers = 0 };
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};
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template<>
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class _Mutex_base<_S_mutex>
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: public __gnu_cxx::__mutex
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{
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protected:
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// This policy is used when atomic builtins are not available.
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// The replacement atomic operations might not have the necessary
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// memory barriers.
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enum { _S_need_barriers = 1 };
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};
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template<_Lock_policy _Lp = __default_lock_policy>
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class _Sp_counted_base
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: public _Mutex_base<_Lp>
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{
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public:
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_Sp_counted_base()
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: _M_use_count(1), _M_weak_count(1) { }
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virtual
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~_Sp_counted_base() // nothrow
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{ }
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// Called when _M_use_count drops to zero, to release the resources
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// managed by *this.
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virtual void
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_M_dispose() = 0; // nothrow
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// Called when _M_weak_count drops to zero.
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virtual void
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_M_destroy() // nothrow
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{ delete this; }
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virtual void*
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_M_get_deleter(const std::type_info&) = 0;
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void
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_M_add_ref_copy()
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{ __gnu_cxx::__atomic_add_dispatch(&_M_use_count, 1); }
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void
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_M_add_ref_lock();
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void
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_M_release() // nothrow
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{
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// Be race-detector-friendly. For more info see bits/c++config.
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_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_use_count);
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if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, -1) == 1)
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{
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_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_use_count);
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_M_dispose();
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// There must be a memory barrier between dispose() and destroy()
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// to ensure that the effects of dispose() are observed in the
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// thread that runs destroy().
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// See http://gcc.gnu.org/ml/libstdc++/2005-11/msg00136.html
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if (_Mutex_base<_Lp>::_S_need_barriers)
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{
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__atomic_thread_fence (__ATOMIC_ACQ_REL);
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}
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// Be race-detector-friendly. For more info see bits/c++config.
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_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
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if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count,
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-1) == 1)
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{
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_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
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_M_destroy();
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}
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}
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}
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void
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_M_weak_add_ref() // nothrow
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{ __gnu_cxx::__atomic_add_dispatch(&_M_weak_count, 1); }
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void
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_M_weak_release() // nothrow
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{
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// Be race-detector-friendly. For more info see bits/c++config.
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_GLIBCXX_SYNCHRONIZATION_HAPPENS_BEFORE(&_M_weak_count);
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if (__gnu_cxx::__exchange_and_add_dispatch(&_M_weak_count, -1) == 1)
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{
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_GLIBCXX_SYNCHRONIZATION_HAPPENS_AFTER(&_M_weak_count);
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if (_Mutex_base<_Lp>::_S_need_barriers)
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{
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// See _M_release(),
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// destroy() must observe results of dispose()
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__atomic_thread_fence (__ATOMIC_ACQ_REL);
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}
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_M_destroy();
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}
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}
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long
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_M_get_use_count() const // nothrow
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{
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// No memory barrier is used here so there is no synchronization
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// with other threads.
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return const_cast<const volatile _Atomic_word&>(_M_use_count);
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}
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private:
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_Sp_counted_base(_Sp_counted_base const&);
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_Sp_counted_base& operator=(_Sp_counted_base const&);
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_Atomic_word _M_use_count; // #shared
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_Atomic_word _M_weak_count; // #weak + (#shared != 0)
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};
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template<>
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inline void
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_Sp_counted_base<_S_single>::
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_M_add_ref_lock()
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{
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if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
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{
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_M_use_count = 0;
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__throw_bad_weak_ptr();
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}
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}
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template<>
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inline void
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_Sp_counted_base<_S_mutex>::
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_M_add_ref_lock()
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{
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__gnu_cxx::__scoped_lock sentry(*this);
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if (__gnu_cxx::__exchange_and_add_dispatch(&_M_use_count, 1) == 0)
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{
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_M_use_count = 0;
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__throw_bad_weak_ptr();
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}
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}
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template<>
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inline void
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_Sp_counted_base<_S_atomic>::
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_M_add_ref_lock()
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{
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// Perform lock-free add-if-not-zero operation.
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_Atomic_word __count = _M_use_count;
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do
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{
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if (__count == 0)
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__throw_bad_weak_ptr();
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// Replace the current counter value with the old value + 1, as
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// long as it's not changed meanwhile.
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}
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while (!__atomic_compare_exchange_n(&_M_use_count, &__count, __count + 1,
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true, __ATOMIC_ACQ_REL,
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__ATOMIC_RELAXED));
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}
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template<typename _Ptr, typename _Deleter, _Lock_policy _Lp>
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class _Sp_counted_base_impl
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: public _Sp_counted_base<_Lp>
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{
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public:
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// Precondition: __d(__p) must not throw.
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_Sp_counted_base_impl(_Ptr __p, _Deleter __d)
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: _M_ptr(__p), _M_del(__d) { }
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virtual void
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_M_dispose() // nothrow
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{ _M_del(_M_ptr); }
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virtual void*
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_M_get_deleter(const std::type_info& __ti)
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{
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#if __cpp_rtti
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return __ti == typeid(_Deleter) ? &_M_del : 0;
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#else
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return 0;
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#endif
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}
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private:
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_Sp_counted_base_impl(const _Sp_counted_base_impl&);
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_Sp_counted_base_impl& operator=(const _Sp_counted_base_impl&);
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_Ptr _M_ptr; // copy constructor must not throw
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_Deleter _M_del; // copy constructor must not throw
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};
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template<_Lock_policy _Lp = __default_lock_policy>
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class __weak_count;
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template<typename _Tp>
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struct _Sp_deleter
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{
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typedef void result_type;
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typedef _Tp* argument_type;
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void operator()(_Tp* __p) const { delete __p; }
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};
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template<_Lock_policy _Lp = __default_lock_policy>
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class __shared_count
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{
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public:
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__shared_count()
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: _M_pi(0) // nothrow
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{ }
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template<typename _Ptr>
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__shared_count(_Ptr __p) : _M_pi(0)
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{
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__try
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{
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typedef typename std::tr1::remove_pointer<_Ptr>::type _Tp;
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_M_pi = new _Sp_counted_base_impl<_Ptr, _Sp_deleter<_Tp>, _Lp>(
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__p, _Sp_deleter<_Tp>());
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}
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__catch(...)
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{
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delete __p;
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__throw_exception_again;
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}
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}
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template<typename _Ptr, typename _Deleter>
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__shared_count(_Ptr __p, _Deleter __d) : _M_pi(0)
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{
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__try
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{
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_M_pi = new _Sp_counted_base_impl<_Ptr, _Deleter, _Lp>(__p, __d);
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}
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__catch(...)
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{
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__d(__p); // Call _Deleter on __p.
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__throw_exception_again;
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}
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}
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// Special case for auto_ptr<_Tp> to provide the strong guarantee.
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template<typename _Tp>
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explicit
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__shared_count(std::auto_ptr<_Tp>& __r)
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: _M_pi(new _Sp_counted_base_impl<_Tp*,
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_Sp_deleter<_Tp>, _Lp >(__r.get(), _Sp_deleter<_Tp>()))
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{ __r.release(); }
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// Throw bad_weak_ptr when __r._M_get_use_count() == 0.
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explicit
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__shared_count(const __weak_count<_Lp>& __r);
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~__shared_count() // nothrow
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{
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if (_M_pi != 0)
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_M_pi->_M_release();
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}
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__shared_count(const __shared_count& __r)
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: _M_pi(__r._M_pi) // nothrow
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{
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if (_M_pi != 0)
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_M_pi->_M_add_ref_copy();
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}
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__shared_count&
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operator=(const __shared_count& __r) // nothrow
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{
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_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
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if (__tmp != _M_pi)
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{
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if (__tmp != 0)
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__tmp->_M_add_ref_copy();
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if (_M_pi != 0)
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_M_pi->_M_release();
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_M_pi = __tmp;
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}
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return *this;
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}
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void
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_M_swap(__shared_count& __r) // nothrow
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{
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_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
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__r._M_pi = _M_pi;
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_M_pi = __tmp;
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}
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long
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_M_get_use_count() const // nothrow
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{ return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }
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bool
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_M_unique() const // nothrow
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{ return this->_M_get_use_count() == 1; }
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friend inline bool
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operator==(const __shared_count& __a, const __shared_count& __b)
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{ return __a._M_pi == __b._M_pi; }
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friend inline bool
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operator<(const __shared_count& __a, const __shared_count& __b)
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{ return std::less<_Sp_counted_base<_Lp>*>()(__a._M_pi, __b._M_pi); }
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void*
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_M_get_deleter(const std::type_info& __ti) const
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{ return _M_pi ? _M_pi->_M_get_deleter(__ti) : 0; }
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private:
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friend class __weak_count<_Lp>;
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_Sp_counted_base<_Lp>* _M_pi;
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};
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template<_Lock_policy _Lp>
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class __weak_count
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{
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public:
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__weak_count()
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: _M_pi(0) // nothrow
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{ }
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__weak_count(const __shared_count<_Lp>& __r)
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: _M_pi(__r._M_pi) // nothrow
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{
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if (_M_pi != 0)
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_M_pi->_M_weak_add_ref();
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}
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__weak_count(const __weak_count<_Lp>& __r)
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: _M_pi(__r._M_pi) // nothrow
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{
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if (_M_pi != 0)
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_M_pi->_M_weak_add_ref();
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}
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~__weak_count() // nothrow
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{
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if (_M_pi != 0)
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_M_pi->_M_weak_release();
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}
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__weak_count<_Lp>&
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operator=(const __shared_count<_Lp>& __r) // nothrow
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{
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_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
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if (__tmp != 0)
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__tmp->_M_weak_add_ref();
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if (_M_pi != 0)
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_M_pi->_M_weak_release();
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_M_pi = __tmp;
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return *this;
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}
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__weak_count<_Lp>&
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operator=(const __weak_count<_Lp>& __r) // nothrow
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{
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_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
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if (__tmp != 0)
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__tmp->_M_weak_add_ref();
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if (_M_pi != 0)
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_M_pi->_M_weak_release();
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_M_pi = __tmp;
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return *this;
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}
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void
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_M_swap(__weak_count<_Lp>& __r) // nothrow
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{
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_Sp_counted_base<_Lp>* __tmp = __r._M_pi;
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__r._M_pi = _M_pi;
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_M_pi = __tmp;
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}
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long
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_M_get_use_count() const // nothrow
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{ return _M_pi != 0 ? _M_pi->_M_get_use_count() : 0; }
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friend inline bool
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operator==(const __weak_count<_Lp>& __a, const __weak_count<_Lp>& __b)
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{ return __a._M_pi == __b._M_pi; }
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friend inline bool
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operator<(const __weak_count<_Lp>& __a, const __weak_count<_Lp>& __b)
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{ return std::less<_Sp_counted_base<_Lp>*>()(__a._M_pi, __b._M_pi); }
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private:
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friend class __shared_count<_Lp>;
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_Sp_counted_base<_Lp>* _M_pi;
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};
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// now that __weak_count is defined we can define this constructor:
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template<_Lock_policy _Lp>
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inline
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__shared_count<_Lp>::
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__shared_count(const __weak_count<_Lp>& __r)
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: _M_pi(__r._M_pi)
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{
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if (_M_pi != 0)
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_M_pi->_M_add_ref_lock();
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else
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__throw_bad_weak_ptr();
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}
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// Forward declarations.
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template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
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class __shared_ptr;
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template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
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class __weak_ptr;
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template<typename _Tp, _Lock_policy _Lp = __default_lock_policy>
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class __enable_shared_from_this;
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template<typename _Tp>
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class shared_ptr;
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template<typename _Tp>
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class weak_ptr;
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template<typename _Tp>
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class enable_shared_from_this;
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// Support for enable_shared_from_this.
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// Friend of __enable_shared_from_this.
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template<_Lock_policy _Lp, typename _Tp1, typename _Tp2>
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void
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__enable_shared_from_this_helper(const __shared_count<_Lp>&,
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const __enable_shared_from_this<_Tp1,
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_Lp>*, const _Tp2*);
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|
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// Friend of enable_shared_from_this.
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template<typename _Tp1, typename _Tp2>
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|
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>
|
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shared_ptr(const shared_ptr<_Tp1>& __r, __static_cast_tag)
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: __shared_ptr<_Tp>(__r, __static_cast_tag()) { }
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|
|
|
template<typename _Tp1>
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|
shared_ptr(const shared_ptr<_Tp1>& __r, __const_cast_tag)
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|
: __shared_ptr<_Tp>(__r, __const_cast_tag()) { }
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|
|
|
template<typename _Tp1>
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|
shared_ptr(const shared_ptr<_Tp1>& __r, __dynamic_cast_tag)
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|
: __shared_ptr<_Tp>(__r, __dynamic_cast_tag()) { }
|
|
|
|
template<typename _Tp1>
|
|
shared_ptr&
|
|
operator=(const shared_ptr<_Tp1>& __r) // never throws
|
|
{
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|
this->__shared_ptr<_Tp>::operator=(__r);
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|
return *this;
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|
}
|
|
|
|
#if (__cplusplus < 201103L) || _GLIBCXX_USE_DEPRECATED
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template<typename _Tp1>
|
|
shared_ptr&
|
|
operator=(std::auto_ptr<_Tp1>& __r)
|
|
{
|
|
this->__shared_ptr<_Tp>::operator=(__r);
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|
return *this;
|
|
}
|
|
#endif
|
|
};
|
|
|
|
// 2.2.3.8 shared_ptr specialized algorithms.
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|
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
|