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#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;
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 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
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