epoc32/include/stdapis/boost/detail/sp_counted_base_gcc_ia64.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_gcc_ia64.hpp	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -0,0 +1,157 @@
     1.4 +#ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
     1.5 +#define BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED
     1.6 +
     1.7 +//
     1.8 +//  detail/sp_counted_base_gcc_ia64.hpp - g++ on IA64
     1.9 +//
    1.10 +//  Copyright (c) 2001, 2002, 2003 Peter Dimov and Multi Media Ltd.
    1.11 +//  Copyright 2004-2006 Peter Dimov
    1.12 +//  Copyright 2005 Ben Hutchings
    1.13 +//
    1.14 +//  Distributed under the Boost Software License, Version 1.0. (See
    1.15 +//  accompanying file LICENSE_1_0.txt or copy at
    1.16 +//  http://www.boost.org/LICENSE_1_0.txt)
    1.17 +//
    1.18 +//
    1.19 +//  Lock-free algorithm by Alexander Terekhov
    1.20 +//
    1.21 +
    1.22 +#include <typeinfo>
    1.23 +
    1.24 +namespace boost
    1.25 +{
    1.26 +
    1.27 +namespace detail
    1.28 +{
    1.29 +
    1.30 +inline void atomic_increment( int * pw )
    1.31 +{
    1.32 +    // ++*pw;
    1.33 +
    1.34 +    int tmp;
    1.35 +
    1.36 +    // No barrier is required here but fetchadd always has an acquire or
    1.37 +    // release barrier associated with it.  We choose release as it should be
    1.38 +    // cheaper.
    1.39 +    __asm__ ("fetchadd4.rel %0=%1,1" :
    1.40 +         "=r"(tmp), "=m"(*pw) :
    1.41 +         "m"( *pw ));
    1.42 +}
    1.43 +
    1.44 +inline int atomic_decrement( int * pw )
    1.45 +{
    1.46 +    // return --*pw;
    1.47 +
    1.48 +    int rv;
    1.49 +
    1.50 +    __asm__ ("     fetchadd4.rel %0=%1,-1 ;; \n"
    1.51 +             "     cmp.eq        p7,p0=1,%0 ;; \n"
    1.52 +             "(p7) ld4.acq       %0=%1    " :
    1.53 +             "=&r"(rv), "=m"(*pw) :
    1.54 +             "m"( *pw ) :
    1.55 +             "p7");
    1.56 +
    1.57 +    return rv;
    1.58 +}
    1.59 +
    1.60 +inline int atomic_conditional_increment( int * pw )
    1.61 +{
    1.62 +    // if( *pw != 0 ) ++*pw;
    1.63 +    // return *pw;
    1.64 +
    1.65 +    int rv, tmp, tmp2;
    1.66 +
    1.67 +    __asm__ ("0:   ld4          %0=%3           ;; \n"
    1.68 +         "     cmp.eq       p7,p0=0,%0        ;; \n"
    1.69 +         "(p7) br.cond.spnt 1f                \n"
    1.70 +         "     mov          ar.ccv=%0         \n"
    1.71 +         "     add          %1=1,%0           ;; \n"
    1.72 +         "     cmpxchg4.acq %2=%3,%1,ar.ccv ;; \n"
    1.73 +         "     cmp.ne       p7,p0=%0,%2       ;; \n"
    1.74 +         "(p7) br.cond.spnt 0b                \n"
    1.75 +         "     mov          %0=%1             ;; \n"
    1.76 +         "1:" : 
    1.77 +         "=&r"(rv), "=&r"(tmp), "=&r"(tmp2), "=m"(*pw) :
    1.78 +         "m"( *pw ) :
    1.79 +         "ar.ccv", "p7");
    1.80 +
    1.81 +    return rv;
    1.82 +}
    1.83 +
    1.84 +class sp_counted_base
    1.85 +{
    1.86 +private:
    1.87 +
    1.88 +    sp_counted_base( sp_counted_base const & );
    1.89 +    sp_counted_base & operator= ( sp_counted_base const & );
    1.90 +
    1.91 +    int use_count_;        // #shared
    1.92 +    int weak_count_;       // #weak + (#shared != 0)
    1.93 +
    1.94 +public:
    1.95 +
    1.96 +    sp_counted_base(): use_count_( 1 ), weak_count_( 1 )
    1.97 +    {
    1.98 +    }
    1.99 +
   1.100 +    virtual ~sp_counted_base() // nothrow
   1.101 +    {
   1.102 +    }
   1.103 +
   1.104 +    // dispose() is called when use_count_ drops to zero, to release
   1.105 +    // the resources managed by *this.
   1.106 +
   1.107 +    virtual void dispose() = 0; // nothrow
   1.108 +
   1.109 +    // destroy() is called when weak_count_ drops to zero.
   1.110 +
   1.111 +    virtual void destroy() // nothrow
   1.112 +    {
   1.113 +        delete this;
   1.114 +    }
   1.115 +
   1.116 +    virtual void * get_deleter( std::type_info const & ti ) = 0;
   1.117 +
   1.118 +    void add_ref_copy()
   1.119 +    {
   1.120 +        atomic_increment( &use_count_ );
   1.121 +    }
   1.122 +
   1.123 +    bool add_ref_lock() // true on success
   1.124 +    {
   1.125 +        return atomic_conditional_increment( &use_count_ ) != 0;
   1.126 +    }
   1.127 +
   1.128 +    void release() // nothrow
   1.129 +    {
   1.130 +        if( atomic_decrement( &use_count_ ) == 0 )
   1.131 +        {
   1.132 +            dispose();
   1.133 +            weak_release();
   1.134 +        }
   1.135 +    }
   1.136 +
   1.137 +    void weak_add_ref() // nothrow
   1.138 +    {
   1.139 +        atomic_increment( &weak_count_ );
   1.140 +    }
   1.141 +
   1.142 +    void weak_release() // nothrow
   1.143 +    {
   1.144 +        if( atomic_decrement( &weak_count_ ) == 0 )
   1.145 +        {
   1.146 +            destroy();
   1.147 +        }
   1.148 +    }
   1.149 +
   1.150 +    long use_count() const // nothrow
   1.151 +    {
   1.152 +        return static_cast<int const volatile &>( use_count_ ); // TODO use ld.acq here
   1.153 +    }
   1.154 +};
   1.155 +
   1.156 +} // namespace detail
   1.157 +
   1.158 +} // namespace boost
   1.159 +
   1.160 +#endif  // #ifndef BOOST_DETAIL_SP_COUNTED_BASE_GCC_IA64_HPP_INCLUDED