#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED | |
#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED | |
// | |
// detail/sp_counted_base_acc_ia64.hpp - aC++ on HP-UX IA64 | |
// | |
// Copyright 2007 Baruch Zilber | |
// Copyright 2007 Boris Gubenko | |
// | |
// 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> | |
#include <machine/sys/inline.h> | |
namespace boost | |
{ | |
namespace detail | |
{ | |
inline void atomic_increment( int * pw ) | |
{ | |
// ++*pw; | |
_Asm_fetchadd(_FASZ_W, _SEM_REL, pw, +1, _LDHINT_NONE); | |
} | |
inline int atomic_decrement( int * pw ) | |
{ | |
// return --*pw; | |
int r = static_cast<int>(_Asm_fetchadd(_FASZ_W, _SEM_REL, pw, -1, _LDHINT_NONE)); | |
if (1 == r) | |
{ | |
_Asm_mf(); | |
} | |
return r - 1; | |
} | |
inline int atomic_conditional_increment( int * pw ) | |
{ | |
// if( *pw != 0 ) ++*pw; | |
// return *pw; | |
int v = *pw; | |
for (;;) | |
{ | |
if (0 == v) | |
{ | |
return 0; | |
} | |
_Asm_mov_to_ar(_AREG_CCV, | |
v, | |
(_UP_CALL_FENCE | _UP_SYS_FENCE | _DOWN_CALL_FENCE | _DOWN_SYS_FENCE)); | |
int r = static_cast<int>(_Asm_cmpxchg(_SZ_W, _SEM_ACQ, pw, v + 1, _LDHINT_NONE)); | |
if (r == v) | |
{ | |
return r + 1; | |
} | |
v = r; | |
} | |
} | |
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_ ); // TODO use ld.acq here | |
} | |
}; | |
} // namespace detail | |
} // namespace boost | |
#endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_ACC_IA64_HPP_INCLUDED |