ceph/src/boost/boost/graph/parallel/algorithm.hpp

   1 // Copyright 2004 The Trustees of Indiana University.
   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: Douglas Gregor
   8 //           Andrew Lumsdaine
   9 #ifndef BOOST_PARALLEL_ALGORITHM_HPP
  10 #define BOOST_PARALLEL_ALGORITHM_HPP
  11
  12 #ifndef BOOST_GRAPH_USE_MPI
  13 #error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included"
  14 #endif
  15
  16 #include <boost/optional.hpp>
  17 #include <boost/config.hpp> // for BOOST_STATIC_CONSTANT
  18 #include <vector>
  19
  20 namespace boost { namespace parallel {
  21   template<typename BinaryOp>
  22   struct is_commutative
  23   {
  24     BOOST_STATIC_CONSTANT(bool, value = false);
  25   };
  26
  27   template<typename T>
  28   struct minimum
  29   {
  30     typedef T first_argument_type;
  31     typedef T second_argument_type;
  32     typedef T result_type;
  33     const T& operator()(const T& x, const T& y) const { return x < y? x : y; }
  34   };
  35
  36   template<typename T>
  37   struct maximum
  38   {
  39     typedef T first_argument_type;
  40     typedef T second_argument_type;
  41     typedef T result_type;
  42     const T& operator()(const T& x, const T& y) const { return x < y? y : x; }
  43   };
  44
  45   template<typename T>
  46   struct sum
  47   {
  48     typedef T first_argument_type;
  49     typedef T second_argument_type;
  50     typedef T result_type;
  51     const T operator()(const T& x, const T& y) const { return x + y; }
  52   };
  53
  54   template<typename ProcessGroup, typename InputIterator,
  55            typename OutputIterator, typename BinaryOperation>
  56   OutputIterator
  57   reduce(ProcessGroup pg, typename ProcessGroup::process_id_type root,
  58          InputIterator first, InputIterator last, OutputIterator out,
  59          BinaryOperation bin_op);
  60
  61   template<typename ProcessGroup, typename T, typename BinaryOperation>
  62   inline T
  63   all_reduce(ProcessGroup pg, const T& value, BinaryOperation bin_op)
  64   {
  65     T result;
  66     all_reduce(pg,
  67                const_cast<T*>(&value), const_cast<T*>(&value+1),
  68                &result, bin_op);
  69     return result;
  70   }
  71
  72   template<typename ProcessGroup, typename T, typename BinaryOperation>
  73   inline T
  74   scan(ProcessGroup pg, const T& value, BinaryOperation bin_op)
  75   {
  76     T result;
  77     scan(pg,
  78          const_cast<T*>(&value), const_cast<T*>(&value+1),
  79          &result, bin_op);
  80     return result;
  81   }
  82
  83
  84   template<typename ProcessGroup, typename InputIterator, typename T>
  85   void
  86   all_gather(ProcessGroup pg, InputIterator first, InputIterator last,
  87              std::vector<T>& out);
  88 } } // end namespace boost::parallel
  89
  90 #include <boost/graph/parallel/detail/inplace_all_to_all.hpp>
  91
  92 #endif // BOOST_PARALLEL_ALGORITHM_HPP