#ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED | |
#define BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED | |
// MS compatible compilers support #pragma once | |
#if defined(_MSC_VER) && (_MSC_VER >= 1020) | |
# pragma once | |
#endif | |
// | |
// detail/sp_counted_base_gcc_mips.hpp - g++ on MIPS | |
// | |
// Copyright (c) 2009, Spirent Communications, Inc. | |
// | |
// 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 <boost/detail/sp_typeinfo.hpp> | |
namespace boost | |
{ | |
namespace detail | |
{ | |
inline void atomic_increment( int * pw ) | |
{ | |
// ++*pw; | |
int tmp; | |
__asm__ __volatile__ | |
( | |
"0:\n\t" | |
"ll %0, %1\n\t" | |
"addiu %0, 1\n\t" | |
"sc %0, %1\n\t" | |
"beqz %0, 0b": | |
"=&r"( tmp ), "=m"( *pw ): | |
"m"( *pw ) | |
); | |
} | |
inline int atomic_decrement( int * pw ) | |
{ | |
// return --*pw; | |
int rv, tmp; | |
__asm__ __volatile__ | |
( | |
"0:\n\t" | |
"ll %1, %2\n\t" | |
"addiu %0, %1, -1\n\t" | |
"sc %0, %2\n\t" | |
"beqz %0, 0b\n\t" | |
"addiu %0, %1, -1": | |
"=&r"( rv ), "=&r"( tmp ), "=m"( *pw ): | |
"m"( *pw ): | |
"memory" | |
); | |
return rv; | |
} | |
inline int atomic_conditional_increment( int * pw ) | |
{ | |
// if( *pw != 0 ) ++*pw; | |
// return *pw; | |
int rv, tmp; | |
__asm__ __volatile__ | |
( | |
"0:\n\t" | |
"ll %0, %2\n\t" | |
"beqz %0, 1f\n\t" | |
"addiu %1, %0, 1\n\t" | |
"sc %1, %2\n\t" | |
"beqz %1, 0b\n\t" | |
"addiu %0, %0, 1\n\t" | |
"1:": | |
"=&r"( rv ), "=&r"( tmp ), "=m"( *pw ): | |
"m"( *pw ): | |
"memory" | |
); | |
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<int const volatile &>( use_count_ ); | |
} | |
}; | |
} // namespace detail | |
} // namespace boost | |
#endif // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_MIPS_HPP_INCLUDED |