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author | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2014-07-23 15:25:44 +0200 |
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committer | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2014-07-23 15:25:44 +0200 |
commit | 8286ac511144e4f17d34eac9affb97e50646344a (patch) | |
tree | f1af7320d7b6be6be059216d0ad08ac7b4f73fd0 /libcutl/cutl/details/boost/smart_ptr/detail/sp_counted_base_vacpp_ppc.hpp | |
parent | a15cf65c44d5c224169c32ef5495b68c758134b7 (diff) |
Imported Upstream version 4.0.0upstream/4.0.0
Diffstat (limited to 'libcutl/cutl/details/boost/smart_ptr/detail/sp_counted_base_vacpp_ppc.hpp')
-rw-r--r-- | libcutl/cutl/details/boost/smart_ptr/detail/sp_counted_base_vacpp_ppc.hpp | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/libcutl/cutl/details/boost/smart_ptr/detail/sp_counted_base_vacpp_ppc.hpp b/libcutl/cutl/details/boost/smart_ptr/detail/sp_counted_base_vacpp_ppc.hpp new file mode 100644 index 0000000..3973606 --- /dev/null +++ b/libcutl/cutl/details/boost/smart_ptr/detail/sp_counted_base_vacpp_ppc.hpp @@ -0,0 +1,151 @@ +#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_VACPP_PPC_HPP_INCLUDED +#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_VACPP_PPC_HPP_INCLUDED + +// +// detail/sp_counted_base_vacpp_ppc.hpp - xlC(vacpp) on POWER +// based on: detail/sp_counted_base_w32.hpp +// +// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. +// Copyright 2004-2005 Peter Dimov +// Copyright 2006 Michael van der Westhuizen +// Copyright 2012 IBM Corp. +// +// 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) +// +// +// Lock-free algorithm by Alexander Terekhov +// +// Thanks to Ben Hitchings for the #weak + (#shared != 0) +// formulation +// + +#include <cutl/details/boost/detail/sp_typeinfo.hpp> + +extern "builtin" void __lwsync(void); +extern "builtin" void __isync(void); +extern "builtin" int __fetch_and_add(volatile int* addr, int val); +extern "builtin" int __compare_and_swap(volatile int*, int*, int); + +namespace cutl_details_boost +{ + +namespace detail +{ + +inline void atomic_increment( int *pw ) +{ + // ++*pw; + __lwsync(); + __fetch_and_add(pw, 1); + __isync(); +} + +inline int atomic_decrement( int *pw ) +{ + // return --*pw; + __lwsync(); + int originalValue = __fetch_and_add(pw, -1); + __isync(); + + return (originalValue - 1); +} + +inline int atomic_conditional_increment( int *pw ) +{ + // if( *pw != 0 ) ++*pw; + // return *pw; + + __lwsync(); + int v = *const_cast<volatile int*>(pw); + for (;;) + // loop until state is known + { + if (v == 0) return 0; + if (__compare_and_swap(pw, &v, v + 1)) + { + __isync(); return (v + 1); + } + } +} + +class sp_counted_base +{ +private: + + sp_counted_base( sp_counted_base const & ); + sp_counted_base & operator= ( sp_counted_base const & ); + + int use_count_; // #shared + int weak_count_; // #weak + (#shared != 0) + char pad[64] __attribute__((__aligned__(64))); + // pad to prevent false sharing +public: + + sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) + { + } + + virtual ~sp_counted_base() // nothrow + { + } + + // dispose() is called when use_count_ drops to zero, to release + // the resources managed by *this. + + virtual void dispose() = 0; // nothrow + + // destroy() is called when weak_count_ drops to zero. + + virtual void destroy() // nothrow + { + delete this; + } + + virtual void * get_deleter( sp_typeinfo const & ti ) = 0; + virtual void * get_untyped_deleter() = 0; + + void add_ref_copy() + { + atomic_increment( &use_count_ ); + } + + bool add_ref_lock() // true on success + { + return atomic_conditional_increment( &use_count_ ) != 0; + } + + void release() // nothrow + { + if( atomic_decrement( &use_count_ ) == 0 ) + { + dispose(); + weak_release(); + } + } + + void weak_add_ref() // nothrow + { + atomic_increment( &weak_count_ ); + } + + void weak_release() // nothrow + { + if( atomic_decrement( &weak_count_ ) == 0 ) + { + destroy(); + } + } + + long use_count() const // nothrow + { + return *const_cast<volatile int*>(&use_count_); + } +}; + +} // namespace detail + +} // namespace cutl_details_boost + +#endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_VACPP_PPC_HPP_INCLUDED |