1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/epoc32/include/stdapis/boost/detail/atomic_count.hpp	Tue Mar 16 16:12:26 2010 +0000
     1.3 @@ -0,0 +1,108 @@
     1.4 +#ifndef BOOST_DETAIL_ATOMIC_COUNT_HPP_INCLUDED
     1.5 +#define BOOST_DETAIL_ATOMIC_COUNT_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 +//  boost/detail/atomic_count.hpp - thread/SMP safe reference counter
    1.15 +//
    1.16 +//  Copyright (c) 2001, 2002 Peter Dimov and Multi Media Ltd.
    1.17 +//
    1.18 +// Distributed under the Boost Software License, Version 1.0. (See
    1.19 +// accompanying file LICENSE_1_0.txt or copy at
    1.20 +// http://www.boost.org/LICENSE_1_0.txt)
    1.21 +//
    1.22 +//  typedef <implementation-defined> boost::detail::atomic_count;
    1.23 +//
    1.24 +//  atomic_count a(n);
    1.25 +//
    1.26 +//    (n is convertible to long)
    1.27 +//
    1.28 +//    Effects: Constructs an atomic_count with an initial value of n
    1.29 +//
    1.30 +//  a;
    1.31 +//
    1.32 +//    Returns: (long) the current value of a
    1.33 +//
    1.34 +//  ++a;
    1.35 +//
    1.36 +//    Effects: Atomically increments the value of a
    1.37 +//    Returns: nothing
    1.38 +//
    1.39 +//  --a;
    1.40 +//
    1.41 +//    Effects: Atomically decrements the value of a
    1.42 +//    Returns: (long) zero if the new value of a is zero,
    1.43 +//      unspecified non-zero value otherwise (usually the new value)
    1.44 +//
    1.45 +//    Important note: when --a returns zero, it must act as a
    1.46 +//      read memory barrier (RMB); i.e. the calling thread must
    1.47 +//      have a synchronized view of the memory
    1.48 +//
    1.49 +//    On Intel IA-32 (x86) memory is always synchronized, so this
    1.50 +//      is not a problem.
    1.51 +//
    1.52 +//    On many architectures the atomic instructions already act as
    1.53 +//      a memory barrier.
    1.54 +//
    1.55 +//    This property is necessary for proper reference counting, since
    1.56 +//      a thread can update the contents of a shared object, then
    1.57 +//      release its reference, and another thread may immediately
    1.58 +//      release the last reference causing object destruction.
    1.59 +//
    1.60 +//    The destructor needs to have a synchronized view of the
    1.61 +//      object to perform proper cleanup.
    1.62 +//
    1.63 +//    Original example by Alexander Terekhov:
    1.64 +//
    1.65 +//    Given:
    1.66 +//
    1.67 +//    - a mutable shared object OBJ;
    1.68 +//    - two threads THREAD1 and THREAD2 each holding 
    1.69 +//      a private smart_ptr object pointing to that OBJ.
    1.70 +//
    1.71 +//    t1: THREAD1 updates OBJ (thread-safe via some synchronization)
    1.72 +//      and a few cycles later (after "unlock") destroys smart_ptr;
    1.73 +//
    1.74 +//    t2: THREAD2 destroys smart_ptr WITHOUT doing any synchronization 
    1.75 +//      with respect to shared mutable object OBJ; OBJ destructors
    1.76 +//      are called driven by smart_ptr interface...
    1.77 +//
    1.78 +
    1.79 +#include <boost/config.hpp>
    1.80 +
    1.81 +#ifndef BOOST_HAS_THREADS
    1.82 +
    1.83 +namespace boost
    1.84 +{
    1.85 +
    1.86 +namespace detail
    1.87 +{
    1.88 +
    1.89 +typedef long atomic_count;
    1.90 +
    1.91 +}
    1.92 +
    1.93 +}
    1.94 +
    1.95 +#elif defined(BOOST_AC_USE_PTHREADS)
    1.96 +#  include <boost/detail/atomic_count_pthreads.hpp>
    1.97 +#elif defined(WIN32) || defined(_WIN32) || defined(__WIN32__)
    1.98 +#  include <boost/detail/atomic_count_win32.hpp>
    1.99 +#elif defined(__GLIBCPP__) || defined(__GLIBCXX__)
   1.100 +#  include <boost/detail/atomic_count_gcc.hpp>
   1.101 +#elif defined(BOOST_HAS_PTHREADS)
   1.102 +#  define BOOST_AC_USE_PTHREADS
   1.103 +#  include <boost/detail/atomic_count_pthreads.hpp>
   1.104 +#else
   1.105 +
   1.106 +// Use #define BOOST_DISABLE_THREADS to avoid the error
   1.107 +#error Unrecognized threading platform
   1.108 +
   1.109 +#endif
   1.110 +
   1.111 +#endif // #ifndef BOOST_DETAIL_ATOMIC_COUNT_HPP_INCLUDED