From 3a75bdfe83b71ef1dbc2fbf52f2d18b8174e22e5 Mon Sep 17 00:00:00 2001 From: Michele Calgaro Date: Tue, 15 Dec 2020 11:30:44 +0900 Subject: Renaming of files in preparation for code style tools. Signed-off-by: Michele Calgaro --- indexlib/boost-compat/weak_ptr.h | 192 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 192 insertions(+) create mode 100644 indexlib/boost-compat/weak_ptr.h (limited to 'indexlib/boost-compat/weak_ptr.h') diff --git a/indexlib/boost-compat/weak_ptr.h b/indexlib/boost-compat/weak_ptr.h new file mode 100644 index 000000000..338e52213 --- /dev/null +++ b/indexlib/boost-compat/weak_ptr.h @@ -0,0 +1,192 @@ +#ifndef BOOST_WEAK_PTR_H_INCLUDED +#define BOOST_WEAK_PTR_H_INCLUDED + +// +// weak_ptr.h +// +// Copyright (c) 2001, 2002, 2003 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) +// +// See http://www.boost.org/libs/smart_ptr/weak_ptr.htm for documentation. +// + +#include + +#ifdef BOOST_MSVC // moved here to work around VC++ compiler crash +# pragma warning(push) +# pragma warning(disable:4284) // odd return type for operator-> +#endif + +namespace boost +{ + +template class weak_ptr +{ +private: + + // Borland 5.5.1 specific workarounds + typedef weak_ptr this_type; + +public: + + typedef T element_type; + + weak_ptr(): px(0), pn() // never throws in 1.30+ + { + } + +// generated copy constructor, assignment, destructor are fine + + +// +// The "obvious" converting constructor implementation: +// +// template +// weak_ptr(weak_ptr const & r): px(r.px), pn(r.pn) // never throws +// { +// } +// +// has a serious problem. +// +// r.px may already have been invalidated. The px(r.px) +// conversion may require access to *r.px (virtual inheritance). +// +// It is not possible to avoid spurious access violations since +// in multithreaded programs r.px may be invalidated at any point. +// + + template + weak_ptr(weak_ptr const & r): pn(r.pn) // never throws + { + px = r.lock().get(); + } + + template + weak_ptr(shared_ptr const & r): px(r.px), pn(r.pn) // never throws + { + } + +#if !defined(BOOST_MSVC) || (BOOST_MSVC > 1200) + + template + weak_ptr & operator=(weak_ptr const & r) // never throws + { + px = r.lock().get(); + pn = r.pn; + return *this; + } + + template + weak_ptr & operator=(shared_ptr const & r) // never throws + { + px = r.px; + pn = r.pn; + return *this; + } + +#endif + + shared_ptr lock() const // never throws + { +#if defined(BOOST_HAS_THREADS) + + // optimization: avoid throw overhead + if(expired()) + { + return shared_ptr(); + } + + try + { + return shared_ptr(*this); + } + catch(bad_weak_ptr const &) + { + // Q: how can we get here? + // A: another thread may have invalidated r after the use_count test above. + return shared_ptr(); + } + +#else + + // optimization: avoid try/catch overhead when single threaded + return expired()? shared_ptr(): shared_ptr(*this); + +#endif + } + + long use_count() const // never throws + { + return pn.use_count(); + } + + bool expired() const // never throws + { + return pn.use_count() == 0; + } + + void reset() // never throws in 1.30+ + { + this_type().swap(*this); + } + + void swap(this_type & other) // never throws + { + std::swap(px, other.px); + pn.swap(other.pn); + } + + void _internal_assign(T * px2, detail::shared_count const & pn2) + { + px = px2; + pn = pn2; + } + + template bool _internal_less(weak_ptr const & rhs) const + { + return pn < rhs.pn; + } + +// Tasteless as this may seem, making all members public allows member templates +// to work in the absence of member template friends. (Matthew Langston) + +#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS + +private: + + template friend class weak_ptr; + template friend class shared_ptr; + +#endif + + T * px; // contained pointer + detail::weak_count pn; // reference counter + +}; // weak_ptr + +template inline bool operator<(weak_ptr const & a, weak_ptr const & b) +{ + return a._internal_less(b); +} + +template void swap(weak_ptr & a, weak_ptr & b) +{ + a.swap(b); +} + +// deprecated, provided for backward compatibility +template shared_ptr make_shared(weak_ptr const & r) +{ + return r.lock(); +} + +} // namespace boost + +#ifdef BOOST_MSVC +# pragma warning(pop) +#endif + +#endif // #ifndef BOOST_WEAK_PTR_H_INCLUDED -- cgit v1.2.1