From b51965dddbed68f23c5e8c169c23c794313ce5f6 Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Tue, 28 Jun 2011 17:17:23 +0200 Subject: Add boost subset as an implementation detail --- .../smart_ptr/detail/sp_counted_base_gcc_ia64.hpp | 157 +++++++++++++++++++++ 1 file changed, 157 insertions(+) create mode 100644 cutl/details/boost/smart_ptr/detail/sp_counted_base_gcc_ia64.hpp (limited to 'cutl/details/boost/smart_ptr/detail/sp_counted_base_gcc_ia64.hpp') diff --git a/cutl/details/boost/smart_ptr/detail/sp_counted_base_gcc_ia64.hpp b/cutl/details/boost/smart_ptr/detail/sp_counted_base_gcc_ia64.hpp new file mode 100644 index 0000000..4ada0a2 --- /dev/null +++ b/cutl/details/boost/smart_ptr/detail/sp_counted_base_gcc_ia64.hpp @@ -0,0 +1,157 @@ +#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED +#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED + +// +// detail/sp_counted_base_gcc_ia64.hpp - g++ on IA64 +// +// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. +// Copyright 2004-2006 Peter Dimov +// Copyright 2005 Ben Hutchings +// +// 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 +// + +#include + +namespace cutl_details_boost +{ + +namespace detail +{ + +inline void atomic_increment( int * pw ) +{ + // ++*pw; + + int tmp; + + // No barrier is required here but fetchadd always has an acquire or + // release barrier associated with it. We choose release as it should be + // cheaper. + __asm__ ("fetchadd4.rel %0=%1,1" : + "=r"(tmp), "=m"(*pw) : + "m"( *pw )); +} + +inline int atomic_decrement( int * pw ) +{ + // return --*pw; + + int rv; + + __asm__ (" fetchadd4.rel %0=%1,-1 ;; \n" + " cmp.eq p7,p0=1,%0 ;; \n" + "(p7) ld4.acq %0=%1 " : + "=&r"(rv), "=m"(*pw) : + "m"( *pw ) : + "p7"); + + return rv; +} + +inline int atomic_conditional_increment( int * pw ) +{ + // if( *pw != 0 ) ++*pw; + // return *pw; + + int rv, tmp, tmp2; + + __asm__ ("0: ld4 %0=%3 ;; \n" + " cmp.eq p7,p0=0,%0 ;; \n" + "(p7) br.cond.spnt 1f \n" + " mov ar.ccv=%0 \n" + " add %1=1,%0 ;; \n" + " cmpxchg4.acq %2=%3,%1,ar.ccv ;; \n" + " cmp.ne p7,p0=%0,%2 ;; \n" + "(p7) br.cond.spnt 0b \n" + " mov %0=%1 ;; \n" + "1:" : + "=&r"(rv), "=&r"(tmp), "=&r"(tmp2), "=m"(*pw) : + "m"( *pw ) : + "ar.ccv", "p7"); + + return rv; +} + +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) + +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; + + 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 static_cast( use_count_ ); // TODO use ld.acq here + } +}; + +} // namespace detail + +} // namespace cutl_details_boost + +#endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED -- cgit v1.1