1 #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
2 #define BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
5 // detail/sp_counted_base_gcc_ia64.hpp - g++ on IA64
7 // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
8 // Copyright 2004-2006 Peter Dimov
9 // Copyright 2005 Ben Hutchings
11 // Distributed under the Boost Software License, Version 1.0. (See
12 // accompanying file LICENSE_1_0.txt or copy at
13 // http://www.boost.org/LICENSE_1_0.txt)
16 // Lock-free algorithm by Alexander Terekhov
19 #include <boost/detail/sp_typeinfo.hpp>
27 inline void atomic_increment( int * pw )
33 // No barrier is required here but fetchadd always has an acquire or
34 // release barrier associated with it. We choose release as it should be
36 __asm__ ("fetchadd4.rel %0=%1,1" :
37 "=r"(tmp), "=m"(*pw) :
41 inline int atomic_decrement( int * pw )
47 __asm__ (" fetchadd4.rel %0=%1,-1 ;; \n"
48 " cmp.eq p7,p0=1,%0 ;; \n"
49 "(p7) ld4.acq %0=%1 " :
50 "=&r"(rv), "=m"(*pw) :
57 inline int atomic_conditional_increment( int * pw )
59 // if( *pw != 0 ) ++*pw;
64 __asm__ ("0: ld4 %0=%3 ;; \n"
65 " cmp.eq p7,p0=0,%0 ;; \n"
66 "(p7) br.cond.spnt 1f \n"
69 " cmpxchg4.acq %2=%3,%1,ar.ccv ;; \n"
70 " cmp.ne p7,p0=%0,%2 ;; \n"
71 "(p7) br.cond.spnt 0b \n"
74 "=&r"(rv), "=&r"(tmp), "=&r"(tmp2), "=m"(*pw) :
85 sp_counted_base( sp_counted_base const & );
86 sp_counted_base & operator= ( sp_counted_base const & );
88 int use_count_; // #shared
89 int weak_count_; // #weak + (#shared != 0)
93 sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
97 virtual ~sp_counted_base() // nothrow
101 // dispose() is called when use_count_ drops to zero, to release
102 // the resources managed by *this.
104 virtual void dispose() = 0; // nothrow
106 // destroy() is called when weak_count_ drops to zero.
108 virtual void destroy() // nothrow
113 virtual void * get_deleter( sp_typeinfo const & ti ) = 0;
117 atomic_increment( &use_count_ );
120 bool add_ref_lock() // true on success
122 return atomic_conditional_increment( &use_count_ ) != 0;
125 void release() // nothrow
127 if( atomic_decrement( &use_count_ ) == 0 )
134 void weak_add_ref() // nothrow
136 atomic_increment( &weak_count_ );
139 void weak_release() // nothrow
141 if( atomic_decrement( &weak_count_ ) == 0 )
147 long use_count() const // nothrow
149 return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here
153 } // namespace detail
157 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED