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/smart_ptr/detail/sp_typeinfo_.hpp>
20 #include <boost/config.hpp>
28 inline void atomic_increment( int * pw )
34 // No barrier is required here but fetchadd always has an acquire or
35 // release barrier associated with it. We choose release as it should be
37 __asm__ ("fetchadd4.rel %0=%1,1" :
38 "=r"(tmp), "=m"(*pw) :
42 inline int atomic_decrement( int * pw )
48 __asm__ (" fetchadd4.rel %0=%1,-1 ;; \n"
49 " cmp.eq p7,p0=1,%0 ;; \n"
50 "(p7) ld4.acq %0=%1 " :
51 "=&r"(rv), "=m"(*pw) :
58 inline int atomic_conditional_increment( int * pw )
60 // if( *pw != 0 ) ++*pw;
65 __asm__ ("0: ld4 %0=%3 ;; \n"
66 " cmp.eq p7,p0=0,%0 ;; \n"
67 "(p7) br.cond.spnt 1f \n"
70 " cmpxchg4.acq %2=%3,%1,ar.ccv ;; \n"
71 " cmp.ne p7,p0=%0,%2 ;; \n"
72 "(p7) br.cond.spnt 0b \n"
75 "=&r"(rv), "=&r"(tmp), "=&r"(tmp2), "=m"(*pw) :
82 class BOOST_SYMBOL_VISIBLE sp_counted_base
86 sp_counted_base( sp_counted_base const & );
87 sp_counted_base & operator= ( sp_counted_base const & );
89 int use_count_; // #shared
90 int weak_count_; // #weak + (#shared != 0)
94 sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
98 virtual ~sp_counted_base() // nothrow
102 // dispose() is called when use_count_ drops to zero, to release
103 // the resources managed by *this.
105 virtual void dispose() = 0; // nothrow
107 // destroy() is called when weak_count_ drops to zero.
109 virtual void destroy() // nothrow
114 virtual void * get_deleter( sp_typeinfo_ const & ti ) = 0;
115 virtual void * get_local_deleter( sp_typeinfo_ const & ti ) = 0;
116 virtual void * get_untyped_deleter() = 0;
120 atomic_increment( &use_count_ );
123 bool add_ref_lock() // true on success
125 return atomic_conditional_increment( &use_count_ ) != 0;
128 void release() // nothrow
130 if( atomic_decrement( &use_count_ ) == 0 )
137 void weak_add_ref() // nothrow
139 atomic_increment( &weak_count_ );
142 void weak_release() // nothrow
144 if( atomic_decrement( &weak_count_ ) == 0 )
150 long use_count() const // nothrow
152 return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here
156 } // namespace detail
160 #endif // #ifndef BOOST_SMART_PTR_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED