williamr@2: #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_PPC_HPP_INCLUDED williamr@2: #define BOOST_DETAIL_SP_COUNTED_BASE_GCC_PPC_HPP_INCLUDED williamr@2: williamr@2: // MS compatible compilers support #pragma once williamr@2: williamr@2: #if defined(_MSC_VER) && (_MSC_VER >= 1020) williamr@2: # pragma once williamr@2: #endif williamr@2: williamr@2: // williamr@2: // detail/sp_counted_base_gcc_ppc.hpp - g++ on PowerPC williamr@2: // williamr@2: // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd. williamr@2: // Copyright 2004-2005 Peter Dimov williamr@2: // williamr@2: // Distributed under the Boost Software License, Version 1.0. (See williamr@2: // accompanying file LICENSE_1_0.txt or copy at williamr@2: // http://www.boost.org/LICENSE_1_0.txt) williamr@2: // williamr@2: // williamr@2: // Lock-free algorithm by Alexander Terekhov williamr@2: // williamr@2: // Thanks to Ben Hitchings for the #weak + (#shared != 0) williamr@2: // formulation williamr@2: // williamr@2: williamr@2: #include williamr@2: williamr@2: namespace boost williamr@2: { williamr@2: williamr@2: namespace detail williamr@2: { williamr@2: williamr@2: inline void atomic_increment( int * pw ) williamr@2: { williamr@2: // ++*pw; williamr@2: williamr@2: int tmp; williamr@2: williamr@2: __asm__ williamr@2: ( williamr@2: "0:\n\t" williamr@2: "lwarx %1, 0, %2\n\t" williamr@2: "addi %1, %1, 1\n\t" williamr@2: "stwcx. %1, 0, %2\n\t" williamr@2: "bne- 0b": williamr@2: williamr@2: "=m"( *pw ), "=&b"( tmp ): williamr@2: "r"( pw ), "m"( *pw ): williamr@2: "cc" williamr@2: ); williamr@2: } williamr@2: williamr@2: inline int atomic_decrement( int * pw ) williamr@2: { williamr@2: // return --*pw; williamr@2: williamr@2: int rv; williamr@2: williamr@2: __asm__ __volatile__ williamr@2: ( williamr@2: "sync\n\t" williamr@2: "0:\n\t" williamr@2: "lwarx %1, 0, %2\n\t" williamr@2: "addi %1, %1, -1\n\t" williamr@2: "stwcx. %1, 0, %2\n\t" williamr@2: "bne- 0b\n\t" williamr@2: "isync": williamr@2: williamr@2: "=m"( *pw ), "=&b"( rv ): williamr@2: "r"( pw ), "m"( *pw ): williamr@2: "memory", "cc" williamr@2: ); williamr@2: williamr@2: return rv; williamr@2: } williamr@2: williamr@2: inline int atomic_conditional_increment( int * pw ) williamr@2: { williamr@2: // if( *pw != 0 ) ++*pw; williamr@2: // return *pw; williamr@2: williamr@2: int rv; williamr@2: williamr@2: __asm__ williamr@2: ( williamr@2: "0:\n\t" williamr@2: "lwarx %1, 0, %2\n\t" williamr@2: "cmpwi %1, 0\n\t" williamr@2: "beq 1f\n\t" williamr@2: "addi %1, %1, 1\n\t" williamr@2: "1:\n\t" williamr@2: "stwcx. %1, 0, %2\n\t" williamr@2: "bne- 0b": williamr@2: williamr@2: "=m"( *pw ), "=&b"( rv ): williamr@2: "r"( pw ), "m"( *pw ): williamr@2: "cc" williamr@2: ); williamr@2: williamr@2: return rv; williamr@2: } williamr@2: williamr@2: class sp_counted_base williamr@2: { williamr@2: private: williamr@2: williamr@2: sp_counted_base( sp_counted_base const & ); williamr@2: sp_counted_base & operator= ( sp_counted_base const & ); williamr@2: williamr@2: int use_count_; // #shared williamr@2: int weak_count_; // #weak + (#shared != 0) williamr@2: williamr@2: public: williamr@2: williamr@2: sp_counted_base(): use_count_( 1 ), weak_count_( 1 ) williamr@2: { williamr@2: } williamr@2: williamr@2: virtual ~sp_counted_base() // nothrow williamr@2: { williamr@2: } williamr@2: williamr@2: // dispose() is called when use_count_ drops to zero, to release williamr@2: // the resources managed by *this. williamr@2: williamr@2: virtual void dispose() = 0; // nothrow williamr@2: williamr@2: // destroy() is called when weak_count_ drops to zero. williamr@2: williamr@2: virtual void destroy() // nothrow williamr@2: { williamr@2: delete this; williamr@2: } williamr@2: williamr@2: virtual void * get_deleter( std::type_info const & ti ) = 0; williamr@2: williamr@2: void add_ref_copy() williamr@2: { williamr@2: atomic_increment( &use_count_ ); williamr@2: } williamr@2: williamr@2: bool add_ref_lock() // true on success williamr@2: { williamr@2: return atomic_conditional_increment( &use_count_ ) != 0; williamr@2: } williamr@2: williamr@2: void release() // nothrow williamr@2: { williamr@2: if( atomic_decrement( &use_count_ ) == 0 ) williamr@2: { williamr@2: dispose(); williamr@2: weak_release(); williamr@2: } williamr@2: } williamr@2: williamr@2: void weak_add_ref() // nothrow williamr@2: { williamr@2: atomic_increment( &weak_count_ ); williamr@2: } williamr@2: williamr@2: void weak_release() // nothrow williamr@2: { williamr@2: if( atomic_decrement( &weak_count_ ) == 0 ) williamr@2: { williamr@2: destroy(); williamr@2: } williamr@2: } williamr@2: williamr@2: long use_count() const // nothrow williamr@2: { williamr@2: return static_cast( use_count_ ); williamr@2: } williamr@2: }; williamr@2: williamr@2: } // namespace detail williamr@2: williamr@2: } // namespace boost williamr@2: williamr@2: #endif // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_PPC_HPP_INCLUDED