epoc32/include/stdapis/boost/detail/sp_counted_base_cw_ppc.hpp
branchSymbian2
changeset 2 2fe1408b6811
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/epoc32/include/stdapis/boost/detail/sp_counted_base_cw_ppc.hpp	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -0,0 +1,170 @@
     1.4 +#ifndef BOOST_DETAIL_SP_COUNTED_BASE_CW_PPC_HPP_INCLUDED
     1.5 +#define BOOST_DETAIL_SP_COUNTED_BASE_CW_PPC_HPP_INCLUDED
     1.6 +
     1.7 +// MS compatible compilers support #pragma once
     1.8 +
     1.9 +#if defined(_MSC_VER) && (_MSC_VER >= 1020)
    1.10 +# pragma once
    1.11 +#endif
    1.12 +
    1.13 +//
    1.14 +//  detail/sp_counted_base_cw_ppc.hpp - CodeWarrior on PowerPC
    1.15 +//
    1.16 +//  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
    1.17 +//  Copyright 2004-2005 Peter Dimov
    1.18 +//
    1.19 +//  Distributed under the Boost Software License, Version 1.0. (See
    1.20 +//  accompanying file LICENSE_1_0.txt or copy at
    1.21 +//  http://www.boost.org/LICENSE_1_0.txt)
    1.22 +//
    1.23 +//
    1.24 +//  Lock-free algorithm by Alexander Terekhov
    1.25 +//
    1.26 +//  Thanks to Ben Hitchings for the #weak + (#shared != 0)
    1.27 +//  formulation
    1.28 +//
    1.29 +
    1.30 +#include <typeinfo>
    1.31 +
    1.32 +namespace boost
    1.33 +{
    1.34 +
    1.35 +namespace detail
    1.36 +{
    1.37 +
    1.38 +inline void atomic_increment( register long * pw )
    1.39 +{
    1.40 +    register int a;
    1.41 +
    1.42 +    asm
    1.43 +    {
    1.44 +loop:
    1.45 +
    1.46 +    lwarx   a, 0, pw
    1.47 +    addi    a, a, 1
    1.48 +    stwcx.  a, 0, pw
    1.49 +    bne-    loop
    1.50 +    }
    1.51 +}
    1.52 +
    1.53 +inline long atomic_decrement( register long * pw )
    1.54 +{
    1.55 +    register int a;
    1.56 +
    1.57 +    asm
    1.58 +    {
    1.59 +    sync
    1.60 +
    1.61 +loop:
    1.62 +
    1.63 +    lwarx   a, 0, pw
    1.64 +    addi    a, a, -1
    1.65 +    stwcx.  a, 0, pw
    1.66 +    bne-    loop
    1.67 +
    1.68 +    isync
    1.69 +    }
    1.70 +
    1.71 +    return a;
    1.72 +}
    1.73 +
    1.74 +inline long atomic_conditional_increment( register long * pw )
    1.75 +{
    1.76 +    register int a;
    1.77 +
    1.78 +    asm
    1.79 +    {
    1.80 +loop:
    1.81 +
    1.82 +    lwarx   a, 0, pw
    1.83 +    cmpwi   a, 0
    1.84 +    beq     store
    1.85 +
    1.86 +    addi    a, a, 1
    1.87 +
    1.88 +store:
    1.89 +
    1.90 +    stwcx.  a, 0, pw
    1.91 +    bne-    loop
    1.92 +    }
    1.93 +
    1.94 +    return a;
    1.95 +}
    1.96 +
    1.97 +class sp_counted_base
    1.98 +{
    1.99 +private:
   1.100 +
   1.101 +    sp_counted_base( sp_counted_base const & );
   1.102 +    sp_counted_base & operator= ( sp_counted_base const & );
   1.103 +
   1.104 +    long use_count_;        // #shared
   1.105 +    long weak_count_;       // #weak + (#shared != 0)
   1.106 +
   1.107 +public:
   1.108 +
   1.109 +    sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
   1.110 +    {
   1.111 +    }
   1.112 +
   1.113 +    virtual ~sp_counted_base() // nothrow
   1.114 +    {
   1.115 +    }
   1.116 +
   1.117 +    // dispose() is called when use_count_ drops to zero, to release
   1.118 +    // the resources managed by *this.
   1.119 +
   1.120 +    virtual void dispose() = 0; // nothrow
   1.121 +
   1.122 +    // destroy() is called when weak_count_ drops to zero.
   1.123 +
   1.124 +    virtual void destroy() // nothrow
   1.125 +    {
   1.126 +        delete this;
   1.127 +    }
   1.128 +
   1.129 +    virtual void * get_deleter( std::type_info const & ti ) = 0;
   1.130 +
   1.131 +    void add_ref_copy()
   1.132 +    {
   1.133 +        atomic_increment( &use_count_ );
   1.134 +    }
   1.135 +
   1.136 +    bool add_ref_lock() // true on success
   1.137 +    {
   1.138 +        return atomic_conditional_increment( &use_count_ ) != 0;
   1.139 +    }
   1.140 +
   1.141 +    void release() // nothrow
   1.142 +    {
   1.143 +        if( atomic_decrement( &use_count_ ) == 0 )
   1.144 +        {
   1.145 +            dispose();
   1.146 +            weak_release();
   1.147 +        }
   1.148 +    }
   1.149 +
   1.150 +    void weak_add_ref() // nothrow
   1.151 +    {
   1.152 +        atomic_increment( &weak_count_ );
   1.153 +    }
   1.154 +
   1.155 +    void weak_release() // nothrow
   1.156 +    {
   1.157 +        if( atomic_decrement( &weak_count_ ) == 0 )
   1.158 +        {
   1.159 +            destroy();
   1.160 +        }
   1.161 +    }
   1.162 +
   1.163 +    long use_count() const // nothrow
   1.164 +    {
   1.165 +        return static_cast<long const volatile &>( use_count_ );
   1.166 +    }
   1.167 +};
   1.168 +
   1.169 +} // namespace detail
   1.170 +
   1.171 +} // namespace boost
   1.172 +
   1.173 +#endif  // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_CW_PPC_HPP_INCLUDED