// Copyright 2005 The Trustees of Indiana University. | |
// Use, modification and distribution is subject to the Boost Software | |
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
// http://www.boost.org/LICENSE_1_0.txt) | |
// Authors: Douglas Gregor | |
// Andrew Lumsdaine | |
#ifndef BOOST_PARALLEL_GLOBAL_INDEX_MAP_HPP | |
#define BOOST_PARALLEL_GLOBAL_INDEX_MAP_HPP | |
#ifndef BOOST_GRAPH_USE_MPI | |
#error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included" | |
#endif | |
#include <boost/property_map/property_map.hpp> | |
#include <vector> | |
#include <boost/shared_ptr.hpp> | |
namespace boost { namespace parallel { | |
template<typename IndexMap, typename GlobalMap> | |
class global_index_map | |
{ | |
public: | |
typedef typename property_traits<IndexMap>::key_type key_type; | |
typedef typename property_traits<IndexMap>::value_type value_type; | |
typedef value_type reference; | |
typedef readable_property_map_tag category; | |
template<typename ProcessGroup> | |
global_index_map(ProcessGroup pg, value_type num_local_indices, | |
IndexMap index_map, GlobalMap global) | |
: index_map(index_map), global(global) | |
{ | |
typedef typename ProcessGroup::process_id_type process_id_type; | |
starting_index.reset(new std::vector<value_type>(num_processes(pg) + 1)); | |
send(pg, 0, 0, num_local_indices); | |
synchronize(pg); | |
// Populate starting_index in all processes | |
if (process_id(pg) == 0) { | |
(*starting_index)[0] = 0; | |
for (process_id_type src = 0; src < num_processes(pg); ++src) { | |
value_type n; | |
receive(pg, src, 0, n); | |
(*starting_index)[src + 1] = (*starting_index)[src] + n; | |
} | |
for (process_id_type dest = 1; dest < num_processes(pg); ++dest) | |
send(pg, dest, 1, &starting_index->front(), num_processes(pg)); | |
synchronize(pg); | |
} else { | |
synchronize(pg); | |
receive(pg, 0, 1, &starting_index->front(), num_processes(pg)); | |
} | |
} | |
friend inline value_type | |
get(const global_index_map& gim, const key_type& x) | |
{ | |
using boost::get; | |
return (*gim.starting_index)[get(gim.global, x).first] | |
+ get(gim.index_map, x); | |
} | |
private: | |
shared_ptr<std::vector<value_type> > starting_index; | |
IndexMap index_map; | |
GlobalMap global; | |
}; | |
} } // end namespace boost::parallel | |
#endif // BOOST_PARALLEL_GLOBAL_INDEX_MAP_HPP |