mirror of
https://github.com/yuzu-emu/ext-boost.git
synced 2024-12-23 11:45:27 +00:00
154 lines
3.4 KiB
C++
154 lines
3.4 KiB
C++
|
#ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_VACPP_PPC_HPP_INCLUDED
|
||
|
#define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_VACPP_PPC_HPP_INCLUDED
|
||
|
|
||
|
//
|
||
|
// detail/sp_counted_base_vacpp_ppc.hpp - xlC(vacpp) on POWER
|
||
|
// based on: detail/sp_counted_base_w32.hpp
|
||
|
//
|
||
|
// Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
|
||
|
// Copyright 2004-2005 Peter Dimov
|
||
|
// Copyright 2006 Michael van der Westhuizen
|
||
|
// Copyright 2012 IBM Corp.
|
||
|
//
|
||
|
// 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
|
||
|
//
|
||
|
// Thanks to Ben Hitchings for the #weak + (#shared != 0)
|
||
|
// formulation
|
||
|
//
|
||
|
|
||
|
#include <boost/smart_ptr/detail/sp_typeinfo_.hpp>
|
||
|
#include <boost/config.hpp>
|
||
|
|
||
|
extern "builtin" void __lwsync(void);
|
||
|
extern "builtin" void __isync(void);
|
||
|
extern "builtin" int __fetch_and_add(volatile int* addr, int val);
|
||
|
extern "builtin" int __compare_and_swap(volatile int*, int*, int);
|
||
|
|
||
|
namespace boost
|
||
|
{
|
||
|
|
||
|
namespace detail
|
||
|
{
|
||
|
|
||
|
inline void atomic_increment( int *pw )
|
||
|
{
|
||
|
// ++*pw;
|
||
|
__lwsync();
|
||
|
__fetch_and_add(pw, 1);
|
||
|
__isync();
|
||
|
}
|
||
|
|
||
|
inline int atomic_decrement( int *pw )
|
||
|
{
|
||
|
// return --*pw;
|
||
|
__lwsync();
|
||
|
int originalValue = __fetch_and_add(pw, -1);
|
||
|
__isync();
|
||
|
|
||
|
return (originalValue - 1);
|
||
|
}
|
||
|
|
||
|
inline int atomic_conditional_increment( int *pw )
|
||
|
{
|
||
|
// if( *pw != 0 ) ++*pw;
|
||
|
// return *pw;
|
||
|
|
||
|
__lwsync();
|
||
|
int v = *const_cast<volatile int*>(pw);
|
||
|
for (;;)
|
||
|
// loop until state is known
|
||
|
{
|
||
|
if (v == 0) return 0;
|
||
|
if (__compare_and_swap(pw, &v, v + 1))
|
||
|
{
|
||
|
__isync(); return (v + 1);
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
class BOOST_SYMBOL_VISIBLE 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)
|
||
|
char pad[64] __attribute__((__aligned__(64)));
|
||
|
// pad to prevent false sharing
|
||
|
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_local_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 *const_cast<volatile int*>(&use_count_);
|
||
|
}
|
||
|
};
|
||
|
|
||
|
} // namespace detail
|
||
|
|
||
|
} // namespace boost
|
||
|
|
||
|
#endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_VACPP_PPC_HPP_INCLUDED
|