ceph/src/boost/libs/mpi/include/boost/mpi/detail/mpi_datatype_cache.hpp

   1 // (C) Copyright 2005 Matthias Troyer
   2
   3 // Use, modification and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //  Authors: Matthias Troyer
   8
   9 #ifndef BOOST_MPI_DETAIL_TYPE_MPI_DATATYPE_CACHE_HPP
  10 #define BOOST_MPI_DETAIL_TYPE_MPI_DATATYPE_CACHE_HPP
  11
  12 #include <boost/mpi/datatype_fwd.hpp>
  13 #include <boost/mpi/detail/mpi_datatype_oarchive.hpp>
  14 #include <boost/mpi/exception.hpp>
  15 #include <boost/utility/enable_if.hpp>
  16 #include <boost/mpl/assert.hpp>
  17 #include <boost/noncopyable.hpp>
  18 #include <typeinfo>
  19
  20 // The std::type_info::before function in Visual C++ 8.0 (and probably earlier)
  21 // incorrectly returns an "int" instead of a "bool". Then the compiler has the
  22 // audacity to complain when that "int" is converted to a "bool". Silence
  23 // this warning.
  24 #ifdef BOOST_MSVC
  25 #  pragma warning(push)
  26 #  pragma warning(disable : 4800)
  27 #endif
  28
  29 namespace boost { namespace mpi { namespace detail {
  30
  31 /// @brief comparison function object for two std::type_info pointers
  32 ///
  33 /// is implemented using the before() member function of the std::type_info
  34 /// class
  35
  36 struct type_info_compare
  37 {
  38   bool operator()(std::type_info const* lhs, std::type_info const* rhs) const
  39   {
  40     return lhs->before(*rhs);
  41   }
  42 };
  43
  44
  45 /// @brief a map of MPI data types, indexed by their type_info
  46 ///
  47 ///
  48 class BOOST_MPI_DECL mpi_datatype_map
  49  : public boost::noncopyable
  50 {
  51   struct implementation;
  52
  53   implementation *impl;
  54
  55 public:
  56   mpi_datatype_map();
  57   ~mpi_datatype_map();
  58
  59   template <class T>
  60   MPI_Datatype datatype(const T& x = T(), typename boost::enable_if<is_mpi_builtin_datatype<T> >::type* =0)
  61   {
  62     return get_mpi_datatype<T>(x);
  63   }
  64
  65   template <class T>
  66   MPI_Datatype datatype(const T& x =T(), typename boost::disable_if<is_mpi_builtin_datatype<T> >::type* =0 )
  67   {
  68     BOOST_MPL_ASSERT((is_mpi_datatype<T>));
  69
  70     // check whether the type already exists
  71     std::type_info const* t = &typeid(T);
  72     MPI_Datatype datatype = get(t);
  73     if (datatype == MPI_DATATYPE_NULL) {
  74       // need to create a type
  75       mpi_datatype_oarchive ar(x);
  76       datatype = ar.get_mpi_datatype();
  77       set(t, datatype);
  78     }
  79
  80     return datatype;
  81   }
  82
  83   void clear();
  84
  85 private:
  86   MPI_Datatype get(const std::type_info* t);
  87   void set(const std::type_info* t, MPI_Datatype datatype);
  88 };
  89
  90 /// Retrieve the MPI datatype cache
  91 BOOST_MPI_DECL mpi_datatype_map& mpi_datatype_cache();
  92
  93 } } } // end namespace boost::mpi::detail
  94
  95 #ifdef BOOST_MSVC
  96 #  pragma warning(pop)
  97 #endif
  98
  99 #endif // BOOST_MPI_DETAIL_TYPE_MPI_DATATYPE_CACHE_HPP