1 // Copyright 2005 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_GLOBAL_INDEX_MAP_HPP 10 #define BOOST_PARALLEL_GLOBAL_INDEX_MAP_HPP 11 12 #include <boost/property_map/property_map.hpp> 13 #include <vector> 14 #include <boost/shared_ptr.hpp> 15 16 namespace boost { namespace parallel { 17 18 template<typename IndexMap, typename GlobalMap> 19 class global_index_map 20 { 21 public: 22 typedef typename property_traits<IndexMap>::key_type key_type; 23 typedef typename property_traits<IndexMap>::value_type value_type; 24 typedef value_type reference; 25 typedef readable_property_map_tag category; 26 27 template<typename ProcessGroup> global_index_map(ProcessGroup pg,value_type num_local_indices,IndexMap index_map,GlobalMap global)28 global_index_map(ProcessGroup pg, value_type num_local_indices, 29 IndexMap index_map, GlobalMap global) 30 : index_map(index_map), global(global) 31 { 32 typedef typename ProcessGroup::process_id_type process_id_type; 33 starting_index.reset(new std::vector<value_type>(num_processes(pg) + 1)); 34 send(pg, 0, 0, num_local_indices); 35 synchronize(pg); 36 37 // Populate starting_index in all processes 38 if (process_id(pg) == 0) { 39 (*starting_index)[0] = 0; 40 for (process_id_type src = 0; src < num_processes(pg); ++src) { 41 value_type n; 42 receive(pg, src, 0, n); 43 (*starting_index)[src + 1] = (*starting_index)[src] + n; 44 } 45 for (process_id_type dest = 1; dest < num_processes(pg); ++dest) 46 send(pg, dest, 1, &starting_index->front(), num_processes(pg)); 47 synchronize(pg); 48 } else { 49 synchronize(pg); 50 receive(pg, 0, 1, &starting_index->front(), num_processes(pg)); 51 } 52 } 53 54 friend inline value_type get(const global_index_map & gim,const key_type & x)55 get(const global_index_map& gim, const key_type& x) 56 { 57 using boost::get; 58 return (*gim.starting_index)[get(gim.global, x).first] 59 + get(gim.index_map, x); 60 } 61 62 private: 63 shared_ptr<std::vector<value_type> > starting_index; 64 IndexMap index_map; 65 GlobalMap global; 66 }; 67 68 } } // end namespace boost::parallel 69 70 #endif // BOOST_PARALLEL_GLOBAL_INDEX_MAP_HPP 71