[857] | 1 | #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
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| 2 | #define BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
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| 3 |
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| 4 | //
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| 5 | // detail/sp_counted_base_gcc_ia64.hpp - g++ on IA64
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| 6 | //
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| 7 | // Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
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| 8 | // Copyright 2004-2005 Peter Dimov
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| 9 | // Copyright 2005 Ben Hutchings
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| 10 | //
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| 11 | // Distributed under the Boost Software License, Version 1.0. (See
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| 12 | // accompanying file LICENSE_1_0.txt or copy at
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| 13 | // http://www.boost.org/LICENSE_1_0.txt)
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| 14 | //
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| 15 | //
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| 16 | // Lock-free algorithm by Alexander Terekhov
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| 17 | //
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| 18 |
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| 19 | #include <typeinfo>
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| 20 |
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| 21 | namespace boost
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| 22 | {
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| 23 |
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| 24 | namespace detail
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| 25 | {
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| 26 |
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| 27 | inline void atomic_increment( long * pw )
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| 28 | {
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| 29 | // ++*pw;
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| 30 |
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| 31 | long tmp;
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| 32 |
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| 33 | // No barrier is required here but fetchadd always has an acquire or
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| 34 | // release barrier associated with it. We choose release as it should be
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| 35 | // cheaper.
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| 36 | __asm__ ("fetchadd8.rel %0=[%2],1" :
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| 37 | "=r"(tmp), "=m"(*pw) :
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| 38 | "r"(pw));
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| 39 | }
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| 40 |
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| 41 | inline long atomic_decrement( long * pw )
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| 42 | {
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| 43 | // return --*pw;
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| 44 |
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| 45 | long rv;
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| 46 |
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| 47 | __asm__ (" fetchadd8.rel %0=[%2],-1 ;; \n"
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| 48 | " cmp.eq p7,p0=1,%0 ;; \n"
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| 49 | "(p7) ld8.acq %0=[%2] " :
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| 50 | "=&r"(rv), "=m"(*pw) :
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| 51 | "r"(pw) :
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| 52 | "p7");
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| 53 |
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| 54 | return rv;
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| 55 | }
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| 56 |
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| 57 | inline long atomic_conditional_increment( long * pw )
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| 58 | {
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| 59 | // if( *pw != 0 ) ++*pw;
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| 60 | // return *pw;
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| 61 |
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| 62 | long rv, tmp, tmp2;
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| 63 |
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| 64 | __asm__ ("0: ld8 %0=[%4] ;; \n"
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| 65 | " cmp.eq p7,p0=0,%0 ;; \n"
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| 66 | "(p7) br.cond.spnt 1f \n"
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| 67 | " mov ar.ccv=%0 \n"
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| 68 | " add %1=1,%0 ;; \n"
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| 69 | " cmpxchg8.acq %2=[%4],%1,ar.ccv ;; \n"
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| 70 | " cmp.ne p7,p0=%0,%2 ;; \n"
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| 71 | "(p7) br.cond.spnt 0b \n"
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| 72 | " mov %0=%1 ;; \n"
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| 73 | "1:" :
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| 74 | "=&r"(rv), "=&r"(tmp), "=&r"(tmp2), "=m"(*pw) :
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| 75 | "r"(pw) :
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| 76 | "ar.ccv", "p7");
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| 77 |
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| 78 | return rv;
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| 79 | }
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| 80 |
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| 81 | class sp_counted_base
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| 82 | {
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| 83 | private:
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| 84 |
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| 85 | sp_counted_base( sp_counted_base const & );
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| 86 | sp_counted_base & operator= ( sp_counted_base const & );
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| 87 |
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| 88 | long use_count_; // #shared
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| 89 | long weak_count_; // #weak + (#shared != 0)
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| 90 |
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| 91 | public:
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| 92 |
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| 93 | sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
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| 94 | {
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| 95 | }
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| 96 |
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| 97 | virtual ~sp_counted_base() // nothrow
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| 98 | {
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| 99 | }
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| 100 |
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| 101 | // dispose() is called when use_count_ drops to zero, to release
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| 102 | // the resources managed by *this.
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| 103 |
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| 104 | virtual void dispose() = 0; // nothrow
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| 105 |
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| 106 | // destroy() is called when weak_count_ drops to zero.
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| 107 |
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| 108 | virtual void destroy() // nothrow
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| 109 | {
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| 110 | delete this;
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| 111 | }
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| 112 |
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| 113 | virtual void * get_deleter( std::type_info const & ti ) = 0;
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| 114 |
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| 115 | void add_ref_copy()
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| 116 | {
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| 117 | atomic_increment( &use_count_ );
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| 118 | }
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| 119 |
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| 120 | bool add_ref_lock() // true on success
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| 121 | {
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| 122 | return atomic_conditional_increment( &use_count_ ) != 0;
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| 123 | }
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| 124 |
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| 125 | void release() // nothrow
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| 126 | {
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| 127 | if( atomic_decrement( &use_count_ ) == 0 )
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| 128 | {
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| 129 | dispose();
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| 130 | weak_release();
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| 131 | }
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| 132 | }
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| 133 |
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| 134 | void weak_add_ref() // nothrow
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| 135 | {
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| 136 | atomic_increment( &weak_count_ );
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| 137 | }
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| 138 |
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| 139 | void weak_release() // nothrow
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| 140 | {
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| 141 | if( atomic_decrement( &weak_count_ ) == 0 )
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| 142 | {
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| 143 | destroy();
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| 144 | }
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| 145 | }
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| 146 |
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| 147 | long use_count() const // nothrow
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| 148 | {
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| 149 | return static_cast<long const volatile &>( use_count_ );
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| 150 | }
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| 151 | };
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| 152 |
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| 153 | } // namespace detail
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| 154 |
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| 155 | } // namespace boost
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| 156 |
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| 157 | #endif // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
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