1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/epoc32/include/stdapis/boost/detail/sp_counted_base_gcc_x86.hpp	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -0,0 +1,173 @@
     1.4 +#ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_X86_HPP_INCLUDED
     1.5 +#define BOOST_DETAIL_SP_COUNTED_BASE_GCC_X86_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_gcc_x86.hpp - g++ on 486+ or AMD64
    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 int atomic_exchange_and_add( int * pw, int dv )
    1.39 +{
    1.40 +    // int r = *pw;
    1.41 +    // *pw += dv;
    1.42 +    // return r;
    1.43 +
    1.44 +    int r;
    1.45 +
    1.46 +    __asm__ __volatile__
    1.47 +    (
    1.48 +        "lock\n\t"
    1.49 +        "xadd %1, %0":
    1.50 +        "=m"( *pw ), "=r"( r ): // outputs (%0, %1)
    1.51 +        "m"( *pw ), "1"( dv ): // inputs (%2, %3 == %1)
    1.52 +        "memory", "cc" // clobbers
    1.53 +    );
    1.54 +
    1.55 +    return r;
    1.56 +}
    1.57 +
    1.58 +inline void atomic_increment( int * pw )
    1.59 +{
    1.60 +    //atomic_exchange_and_add( pw, 1 );
    1.61 +
    1.62 +    __asm__
    1.63 +    (
    1.64 +        "lock\n\t"
    1.65 +        "incl %0":
    1.66 +        "=m"( *pw ): // output (%0)
    1.67 +        "m"( *pw ): // input (%1)
    1.68 +        "cc" // clobbers
    1.69 +    );
    1.70 +}
    1.71 +
    1.72 +inline int atomic_conditional_increment( int * pw )
    1.73 +{
    1.74 +    // int rv = *pw;
    1.75 +    // if( rv != 0 ) ++*pw;
    1.76 +    // return rv;
    1.77 +
    1.78 +    int rv, tmp;
    1.79 +
    1.80 +    __asm__
    1.81 +    (
    1.82 +        "movl %0, %%eax\n\t"
    1.83 +        "0:\n\t"
    1.84 +        "test %%eax, %%eax\n\t"
    1.85 +        "je 1f\n\t"
    1.86 +        "movl %%eax, %2\n\t"
    1.87 +        "incl %2\n\t"
    1.88 +        "lock\n\t"
    1.89 +        "cmpxchgl %2, %0\n\t"
    1.90 +        "jne 0b\n\t"
    1.91 +        "1:":
    1.92 +        "=m"( *pw ), "=&a"( rv ), "=&r"( tmp ): // outputs (%0, %1, %2)
    1.93 +        "m"( *pw ): // input (%3)
    1.94 +        "cc" // clobbers
    1.95 +    );
    1.96 +
    1.97 +    return rv;
    1.98 +}
    1.99 +
   1.100 +class sp_counted_base
   1.101 +{
   1.102 +private:
   1.103 +
   1.104 +    sp_counted_base( sp_counted_base const & );
   1.105 +    sp_counted_base & operator= ( sp_counted_base const & );
   1.106 +
   1.107 +    int use_count_;        // #shared
   1.108 +    int weak_count_;       // #weak + (#shared != 0)
   1.109 +
   1.110 +public:
   1.111 +
   1.112 +    sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
   1.113 +    {
   1.114 +    }
   1.115 +
   1.116 +    virtual ~sp_counted_base() // nothrow
   1.117 +    {
   1.118 +    }
   1.119 +
   1.120 +    // dispose() is called when use_count_ drops to zero, to release
   1.121 +    // the resources managed by *this.
   1.122 +
   1.123 +    virtual void dispose() = 0; // nothrow
   1.124 +
   1.125 +    // destroy() is called when weak_count_ drops to zero.
   1.126 +
   1.127 +    virtual void destroy() // nothrow
   1.128 +    {
   1.129 +        delete this;
   1.130 +    }
   1.131 +
   1.132 +    virtual void * get_deleter( std::type_info const & ti ) = 0;
   1.133 +
   1.134 +    void add_ref_copy()
   1.135 +    {
   1.136 +        atomic_increment( &use_count_ );
   1.137 +    }
   1.138 +
   1.139 +    bool add_ref_lock() // true on success
   1.140 +    {
   1.141 +        return atomic_conditional_increment( &use_count_ ) != 0;
   1.142 +    }
   1.143 +
   1.144 +    void release() // nothrow
   1.145 +    {
   1.146 +        if( atomic_exchange_and_add( &use_count_, -1 ) == 1 )
   1.147 +        {
   1.148 +            dispose();
   1.149 +            weak_release();
   1.150 +        }
   1.151 +    }
   1.152 +
   1.153 +    void weak_add_ref() // nothrow
   1.154 +    {
   1.155 +        atomic_increment( &weak_count_ );
   1.156 +    }
   1.157 +
   1.158 +    void weak_release() // nothrow
   1.159 +    {
   1.160 +        if( atomic_exchange_and_add( &weak_count_, -1 ) == 1 )
   1.161 +        {
   1.162 +            destroy();
   1.163 +        }
   1.164 +    }
   1.165 +
   1.166 +    long use_count() const // nothrow
   1.167 +    {
   1.168 +        return static_cast<int const volatile &>( use_count_ );
   1.169 +    }
   1.170 +};
   1.171 +
   1.172 +} // namespace detail
   1.173 +
   1.174 +} // namespace boost
   1.175 +
   1.176 +#endif  // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_X86_HPP_INCLUDED