boost/graph/distributed/strong_components.hpp
// Copyright (C) 2004-2008 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: Nick Edmonds // Douglas Gregor // Andrew Lumsdaine #ifndef BOOST_GRAPH_DISTRIBUTED_SCC_HPP #define BOOST_GRAPH_DISTRIBUTED_SCC_HPP #ifndef BOOST_GRAPH_USE_MPI #error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included" #endif // #define PBGL_SCC_DEBUG #include <boost/assert.hpp> #include <boost/property_map/property_map.hpp> #include <boost/property_map/parallel/parallel_property_maps.hpp> #include <boost/property_map/parallel/distributed_property_map.hpp> #include <boost/property_map/parallel/caching_property_map.hpp> #include <boost/graph/parallel/algorithm.hpp> #include <boost/graph/parallel/process_group.hpp> #include <boost/graph/distributed/queue.hpp> #include <boost/graph/distributed/filtered_graph.hpp> #include <boost/pending/indirect_cmp.hpp> #include <boost/graph/breadth_first_search.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/overloading.hpp> #include <boost/graph/distributed/concepts.hpp> #include <boost/graph/distributed/local_subgraph.hpp> #include <boost/graph/parallel/properties.hpp> #include <boost/graph/named_function_params.hpp> #include <boost/graph/random.hpp> #include <boost/graph/distributed/reverse_graph.hpp> #include <boost/optional.hpp> #include <boost/graph/distributed/detail/filtered_queue.hpp> #include <boost/graph/distributed/adjacency_list.hpp> #ifdef PBGL_SCC_DEBUG #include <iostream> #include <cstdlib> #include <iomanip> #include <sys/time.h> #include <boost/graph/distributed/graphviz.hpp> // for ostringstream #endif #include <vector> #include <map> #include <boost/graph/parallel/container_traits.hpp> #ifdef PBGL_SCC_DEBUG # include <boost/graph/accounting.hpp> #endif /* PBGL_SCC_DEBUG */ // If your graph is likely to have large numbers of small strongly connected // components then running the sequential SCC algorithm on the local subgraph // and filtering components with no remote edges may increase performance // #define FILTER_LOCAL_COMPONENTS namespace boost { namespace graph { namespace distributed { namespace detail { template<typename vertex_descriptor> struct v_sets{ std::vector<vertex_descriptor> pred, succ, intersect, ps_union; }; /* Serialize vertex set */ template<typename Graph> void marshal_set( std::vector<std::vector<typename graph_traits<Graph>::vertex_descriptor> > in, std::vector<typename graph_traits<Graph>::vertex_descriptor>& out ) { for( std::size_t i = 0; i < in.size(); ++i ) { out.insert( out.end(), graph_traits<Graph>::null_vertex() ); out.insert( out.end(), in[i].begin(), in[i].end() ); } } /* Un-serialize vertex set */ template<typename Graph> void unmarshal_set( std::vector<typename graph_traits<Graph>::vertex_descriptor> in, std::vector<std::vector<typename graph_traits<Graph>::vertex_descriptor> >& out ) { typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; while( !in.empty() ) { typename std::vector<vertex_descriptor>::iterator end = std::find( in.begin(), in.end(), graph_traits<Graph>::null_vertex() ); if( end == in.begin() ) in.erase( in.begin() ); else { out.push_back(std::vector<vertex_descriptor>()); out[out.size() - 1].insert( out[out.size() - 1].end(), in.begin(), end ); in.erase( in.begin(), end ); } } } /* Determine if vertex is in subset */ template <typename Set> struct in_subset { in_subset() : m_s(0) { } in_subset(const Set& s) : m_s(&s) { } template <typename Elt> bool operator()(const Elt& x) const { return ((*m_s).find(x) != (*m_s).end()); } private: const Set* m_s; }; template<typename T> struct vertex_identity_property_map : public boost::put_get_helper<T, vertex_identity_property_map<T> > { typedef T key_type; typedef T value_type; typedef T reference; typedef boost::readable_property_map_tag category; inline value_type operator[](const key_type& v) const { return v; } inline void clear() { } }; template <typename T> inline void synchronize( vertex_identity_property_map<T> & ) { } /* BFS visitor for SCC */ template<typename Graph, typename SourceMap> struct scc_discovery_visitor : bfs_visitor<> { scc_discovery_visitor(SourceMap& sourceM) : sourceM(sourceM) {} template<typename Edge> void tree_edge(Edge e, const Graph& g) { put(sourceM, target(e,g), get(sourceM, source(e,g))); } private: SourceMap& sourceM; }; } } } } /* End namespace boost::graph::distributed::detail */ namespace boost { namespace graph { namespace distributed { enum fhp_message_tags { fhp_edges_size_msg, fhp_add_edges_msg, fhp_pred_size_msg, fhp_pred_msg, fhp_succ_size_msg, fhp_succ_msg }; template<typename Graph, typename ReverseGraph, typename VertexComponentMap, typename IsoMapFR, typename IsoMapRF, typename VertexIndexMap> void fleischer_hendrickson_pinar_strong_components(const Graph& g, VertexComponentMap c, const ReverseGraph& gr, IsoMapFR fr, IsoMapRF rf, VertexIndexMap vertex_index_map) { typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator; typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; typedef typename graph_traits<ReverseGraph>::vertex_iterator rev_vertex_iterator; typedef typename graph_traits<ReverseGraph>::vertex_descriptor rev_vertex_descriptor; typedef typename boost::graph::parallel::process_group_type<Graph>::type process_group_type; typedef typename process_group_type::process_id_type process_id_type; typedef iterator_property_map<typename std::vector<vertex_descriptor>::iterator, VertexIndexMap> ParentMap; typedef iterator_property_map<typename std::vector<default_color_type>::iterator, VertexIndexMap> ColorMap; typedef iterator_property_map<typename std::vector<vertex_descriptor>::iterator, VertexIndexMap> Rev_ParentMap; typedef std::vector<std::pair<vertex_descriptor, vertex_descriptor> > VertexPairVec; typedef typename property_map<Graph, vertex_owner_t>::const_type OwnerMap; OwnerMap owner = get(vertex_owner, g); using boost::graph::parallel::process_group; process_group_type pg = process_group(g); process_id_type id = process_id(pg); int num_procs = num_processes(pg); int n = 0; int my_n = num_vertices(g); all_reduce(pg, &my_n, &my_n+1, &n, std::plus<int>()); // // Initialization // #ifdef PBGL_SCC_DEBUG accounting::time_type start = accounting::get_time(); #endif vertex_iterator vstart, vend; rev_vertex_iterator rev_vstart, rev_vend; std::vector<std::vector<vertex_descriptor> > vertex_sets, new_vertex_sets; vertex_sets.push_back(std::vector<vertex_descriptor>()); // Remove vertices that do not have at least one in edge and one out edge new_vertex_sets.push_back(std::vector<vertex_descriptor>()); for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) if( out_degree( get(fr, *vstart), gr) > 0 && out_degree(*vstart, g) > 0 ) new_vertex_sets[0].push_back( *vstart ); // Perform sequential SCC on local subgraph, filter all components with external // edges, mark remaining components and remove them from vertex_sets #ifdef FILTER_LOCAL_COMPONENTS // This doesn't actually speed up SCC in connected graphs it seems, but it does work // and may help in the case where there are lots of small strong components. { local_subgraph<const Graph> ls(g); typedef typename property_map<local_subgraph<const Graph>, vertex_index_t>::type local_index_map_type; local_index_map_type local_index = get(vertex_index, ls); std::vector<int> ls_components_vec(num_vertices(ls)); typedef iterator_property_map<std::vector<int>::iterator, local_index_map_type> ls_components_map_type; ls_components_map_type ls_component(ls_components_vec.begin(), local_index); int num_comp = boost::strong_components(ls, ls_component); // Create map of components std::map<int, std::vector<vertex_descriptor> > local_comp_map; typedef typename graph_traits<local_subgraph<const Graph> >::vertex_iterator ls_vertex_iterator; ls_vertex_iterator vstart, vend; for( boost::tie(vstart,vend) = vertices(ls); vstart != vend; vstart++ ) local_comp_map[get(ls_component, *vstart)].push_back( *vstart ); // Filter components that have no non-local edges typedef typename graph_traits<Graph>::adjacency_iterator adjacency_iterator; typedef typename graph_traits<ReverseGraph>::adjacency_iterator rev_adjacency_iterator; adjacency_iterator abegin, aend; rev_adjacency_iterator rev_abegin, rev_aend; for( std::size_t i = 0; i < num_comp; ++i ) { bool local = true; for( std::size_t j = 0; j < local_comp_map[i].size(); j++ ) { for( boost::tie(abegin,aend) = adjacent_vertices(local_comp_map[i][j], g); abegin != aend; abegin++ ) if( get(owner, *abegin) != id ) { local = false; break; } if( local ) for( boost::tie(rev_abegin,rev_aend) = adjacent_vertices(get(fr, local_comp_map[i][j]), gr); rev_abegin != rev_aend; rev_abegin++ ) if( get(owner, *rev_abegin) != id ) { local = false; break; } if( !local ) break; } if( local ) // Mark and remove from new_vertex_sets for( std::size_t j = 0; j < local_comp_map[i].size(); j++ ) { put( c, local_comp_map[i][j], local_comp_map[i][0] ); typename std::vector<vertex_descriptor>::iterator pos = std::find(new_vertex_sets[0].begin(), new_vertex_sets[0].end(), local_comp_map[i][j]); if( pos != new_vertex_sets[0].end() ) new_vertex_sets[0].erase(pos); } } } #endif // FILTER_LOCAL_COMPONENTS all_gather( pg, new_vertex_sets[0].begin(), new_vertex_sets[0].end(), vertex_sets[0] ); new_vertex_sets.clear(); #ifdef PBGL_SCC_DEBUG accounting::time_type end = accounting::get_time(); if(id == 0) std::cerr << "Trim local SCCs time = " << accounting::print_time(end - start) << " seconds.\n"; #endif if( vertex_sets[0].empty() ) return; // // Recursively determine SCCs // #ifdef PBGL_SCC_DEBUG int iterations = 0; #endif // Only need to be able to map starting vertices for BFS from now on fr.clear(); do { #ifdef PBGL_SCC_DEBUG if(id == 0) { printf("\n\nIteration %d:\n\n", iterations++); if( iterations > 1 ) { end = accounting::get_time(); std::cerr << "Running main loop destructors time = " << accounting::print_time(end - start) << " seconds.\n"; } start = accounting::get_time(); } #endif // Get forward->reverse mappings for BFS start vertices for (std::size_t i = 0; i < vertex_sets.size(); ++i) get(fr, vertex_sets[i][0]); synchronize(fr); // Determine local vertices to start BFS from std::vector<vertex_descriptor> local_start; for( std::size_t i = id; i < vertex_sets.size(); i += num_procs ) local_start.push_back(vertex_sets[i][0]); if( local_start.empty() ) local_start.push_back(vertex_sets[0][0]); // Make filtered graphs typedef std::set<vertex_descriptor> VertexSet; typedef std::set<rev_vertex_descriptor> Rev_VertexSet; VertexSet filter_set_g; Rev_VertexSet filter_set_gr; typename VertexSet::iterator fs; int active_vertices = 0; for (std::size_t i = 0; i < vertex_sets.size(); i++) active_vertices += vertex_sets[i].size(); // This is a completely random bound if ( active_vertices < 0.05*n ) { // TODO: This set insertion is ridiculously inefficient, make it an in-place-merge? for (std::size_t i = 0; i < vertex_sets.size(); i++) filter_set_g.insert(vertex_sets[i].begin(), vertex_sets[i].end()); for (fs = filter_set_g.begin(); fs != filter_set_g.end(); ++fs ) filter_set_gr.insert(get(fr, *fs)); } filtered_graph<const Graph, keep_all, detail::in_subset<VertexSet> > fg(g, keep_all(), detail::in_subset<VertexSet>(filter_set_g)); filtered_graph<const ReverseGraph, keep_all, detail::in_subset<VertexSet> > fgr(gr, keep_all(), detail::in_subset<VertexSet>(filter_set_gr)); // Add additional starting vertices to BFS queue typedef filtered_queue<queue<vertex_descriptor>, boost::detail::has_not_been_seen<VertexIndexMap> > local_queue_type; typedef boost::graph::distributed::distributed_queue<process_group_type, OwnerMap, local_queue_type> queue_t; typedef typename property_map<ReverseGraph, vertex_owner_t>::const_type RevOwnerMap; typedef filtered_queue<queue<rev_vertex_descriptor>, boost::detail::has_not_been_seen<VertexIndexMap> > rev_local_queue_type; typedef boost::graph::distributed::distributed_queue<process_group_type, RevOwnerMap, rev_local_queue_type> rev_queue_t; queue_t Q(process_group(g), owner, make_filtered_queue(queue<vertex_descriptor>(), boost::detail::has_not_been_seen<VertexIndexMap> (num_vertices(g), vertex_index_map)), false); rev_queue_t Qr(process_group(gr), get(vertex_owner, gr), make_filtered_queue(queue<rev_vertex_descriptor>(), boost::detail::has_not_been_seen<VertexIndexMap> (num_vertices(gr), vertex_index_map)), false); for( std::size_t i = 1; i < local_start.size(); ++i ) { Q.push(local_start[i]); Qr.push(get(fr, local_start[i])); } #ifdef PBGL_SCC_DEBUG end = accounting::get_time(); if(id == 0) std::cerr << " Initialize BFS time = " << accounting::print_time(end - start) << " seconds.\n"; start = accounting::get_time(); #endif #ifdef PBGL_SCC_DEBUG accounting::time_type start2 = accounting::get_time(); #endif // Forward BFS std::vector<default_color_type> color_map_s(num_vertices(g)); ColorMap color_map(color_map_s.begin(), vertex_index_map); std::vector<vertex_descriptor> succ_map_s(num_vertices(g), graph_traits<Graph>::null_vertex()); ParentMap succ_map(succ_map_s.begin(), vertex_index_map); for( std::size_t i = 0; i < vertex_sets.size(); ++i ) put(succ_map, vertex_sets[i][0], vertex_sets[i][0]); #ifdef PBGL_SCC_DEBUG accounting::time_type end2 = accounting::get_time(); if(id == 0) std::cerr << " Initialize forward BFS time = " << accounting::print_time(end2 - start2) << " seconds.\n"; #endif if (active_vertices < 0.05*n) breadth_first_search(fg, local_start[0], Q, detail::scc_discovery_visitor<filtered_graph<const Graph, keep_all, detail::in_subset<VertexSet> >, ParentMap> (succ_map), color_map); else breadth_first_search(g, local_start[0], Q, detail::scc_discovery_visitor<const Graph, ParentMap>(succ_map), color_map); #ifdef PBGL_SCC_DEBUG start2 = accounting::get_time(); #endif // Reverse BFS color_map.clear(); // reuse color map since g and gr have same vertex index std::vector<vertex_descriptor> pred_map_s(num_vertices(gr), graph_traits<Graph>::null_vertex()); Rev_ParentMap pred_map(pred_map_s.begin(), vertex_index_map); for( std::size_t i = 0; i < vertex_sets.size(); ++i ) put(pred_map, get(fr, vertex_sets[i][0]), vertex_sets[i][0]); #ifdef PBGL_SCC_DEBUG end2 = accounting::get_time(); if(id == 0) std::cerr << " Initialize reverse BFS time = " << accounting::print_time(end2 - start2) << " seconds.\n"; #endif if (active_vertices < 0.05*n) breadth_first_search(fgr, get(fr, local_start[0]), Qr, detail::scc_discovery_visitor<filtered_graph<const ReverseGraph, keep_all, detail::in_subset<Rev_VertexSet> >, Rev_ParentMap> (pred_map), color_map); else breadth_first_search(gr, get(fr, local_start[0]), Qr, detail::scc_discovery_visitor<const ReverseGraph, Rev_ParentMap>(pred_map), color_map); #ifdef PBGL_SCC_DEBUG end = accounting::get_time(); if(id == 0) std::cerr << " Perform forward and reverse BFS time = " << accounting::print_time(end - start) << " seconds.\n"; start = accounting::get_time(); #endif // Send predecessors and successors discovered by this proc to the proc responsible for // this BFS tree typedef struct detail::v_sets<vertex_descriptor> Vsets; std::map<vertex_descriptor, Vsets> set_map; std::map<vertex_descriptor, int> dest_map; std::vector<VertexPairVec> successors(num_procs); std::vector<VertexPairVec> predecessors(num_procs); // Calculate destinations for messages for (std::size_t i = 0; i < vertex_sets.size(); ++i) dest_map[vertex_sets[i][0]] = i % num_procs; for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) { vertex_descriptor v = get(succ_map, *vstart); if( v != graph_traits<Graph>::null_vertex() ) { if (dest_map[v] == id) set_map[v].succ.push_back(*vstart); else successors[dest_map[v]].push_back( std::make_pair(v, *vstart) ); } } for( boost::tie(rev_vstart, rev_vend) = vertices(gr); rev_vstart != rev_vend; rev_vstart++ ) { vertex_descriptor v = get(pred_map, *rev_vstart); if( v != graph_traits<Graph>::null_vertex() ) { if (dest_map[v] == id) set_map[v].pred.push_back(get(rf, *rev_vstart)); else predecessors[dest_map[v]].push_back( std::make_pair(v, get(rf, *rev_vstart)) ); } } // Send predecessor and successor messages for (process_id_type i = 0; i < num_procs; ++i) { if (!successors[i].empty()) { send(pg, i, fhp_succ_size_msg, successors[i].size()); send(pg, i, fhp_succ_msg, &successors[i][0], successors[i].size()); } if (!predecessors[i].empty()) { send(pg, i, fhp_pred_size_msg, predecessors[i].size()); send(pg, i, fhp_pred_msg, &predecessors[i][0], predecessors[i].size()); } } synchronize(pg); // Receive predecessor and successor messages and handle them while (optional<std::pair<process_id_type, int> > m = probe(pg)) { BOOST_ASSERT(m->second == fhp_succ_size_msg || m->second == fhp_pred_size_msg); std::size_t num_requests; receive(pg, m->first, m->second, num_requests); VertexPairVec requests(num_requests); if (m->second == fhp_succ_size_msg) { receive(pg, m->first, fhp_succ_msg, &requests[0], num_requests); std::map<vertex_descriptor, int> added; for (std::size_t i = 0; i < requests.size(); ++i) { set_map[requests[i].first].succ.push_back(requests[i].second); added[requests[i].first]++; } // If order of vertex traversal in vertices() is std::less<vertex_descriptor>, // then the successor sets will be in order for (std::size_t i = 0; i < local_start.size(); ++i) if (added[local_start[i]] > 0) std::inplace_merge(set_map[local_start[i]].succ.begin(), set_map[local_start[i]].succ.end() - added[local_start[i]], set_map[local_start[i]].succ.end(), std::less<vertex_descriptor>()); } else { receive(pg, m->first, fhp_pred_msg, &requests[0], num_requests); std::map<vertex_descriptor, int> added; for (std::size_t i = 0; i < requests.size(); ++i) { set_map[requests[i].first].pred.push_back(requests[i].second); added[requests[i].first]++; } if (boost::is_same<detail::vertex_identity_property_map<vertex_descriptor>, IsoMapRF>::value) for (std::size_t i = 0; i < local_start.size(); ++i) if (added[local_start[i]] > 0) std::inplace_merge(set_map[local_start[i]].pred.begin(), set_map[local_start[i]].pred.end() - added[local_start[i]], set_map[local_start[i]].pred.end(), std::less<vertex_descriptor>()); } } #ifdef PBGL_SCC_DEBUG end = accounting::get_time(); if(id == 0) std::cerr << " All gather successors and predecessors time = " << accounting::print_time(end - start) << " seconds.\n"; start = accounting::get_time(); #endif // // Filter predecessor and successor sets and perform set arithmetic // new_vertex_sets.clear(); if( std::size_t(id) < vertex_sets.size() ) { //If this proc has one or more unique starting points for( std::size_t i = 0; i < local_start.size(); ++i ) { vertex_descriptor v = local_start[i]; // Replace this sort with an in-place merges during receive step if possible if (!boost::is_same<detail::vertex_identity_property_map<vertex_descriptor>, IsoMapRF>::value) std::sort(set_map[v].pred.begin(), set_map[v].pred.end(), std::less<vertex_descriptor>()); // Limit predecessor and successor sets to members of the original set std::vector<vertex_descriptor> temp; std::set_intersection( vertex_sets[id + i*num_procs].begin(), vertex_sets[id + i*num_procs].end(), set_map[v].pred.begin(), set_map[v].pred.end(), back_inserter(temp), std::less<vertex_descriptor>()); set_map[v].pred.clear(); std::swap(set_map[v].pred, temp); std::set_intersection( vertex_sets[id + i*num_procs].begin(), vertex_sets[id + i*num_procs].end(), set_map[v].succ.begin(), set_map[v].succ.end(), back_inserter(temp), std::less<vertex_descriptor>()); set_map[v].succ.clear(); std::swap(set_map[v].succ, temp); // Intersection(pred, succ) std::set_intersection(set_map[v].pred.begin(), set_map[v].pred.end(), set_map[v].succ.begin(), set_map[v].succ.end(), back_inserter(set_map[v].intersect), std::less<vertex_descriptor>()); // Union(pred, succ) std::set_union(set_map[v].pred.begin(), set_map[v].pred.end(), set_map[v].succ.begin(), set_map[v].succ.end(), back_inserter(set_map[v].ps_union), std::less<vertex_descriptor>()); new_vertex_sets.push_back(std::vector<vertex_descriptor>()); // Original set - Union(pred, succ) std::set_difference(vertex_sets[id + i*num_procs].begin(), vertex_sets[id + i*num_procs].end(), set_map[v].ps_union.begin(), set_map[v].ps_union.end(), back_inserter(new_vertex_sets[new_vertex_sets.size() - 1]), std::less<vertex_descriptor>()); set_map[v].ps_union.clear(); new_vertex_sets.push_back(std::vector<vertex_descriptor>()); // Pred - Intersect(pred, succ) std::set_difference(set_map[v].pred.begin(), set_map[v].pred.end(), set_map[v].intersect.begin(), set_map[v].intersect.end(), back_inserter(new_vertex_sets[new_vertex_sets.size() - 1]), std::less<vertex_descriptor>()); set_map[v].pred.clear(); new_vertex_sets.push_back(std::vector<vertex_descriptor>()); // Succ - Intersect(pred, succ) std::set_difference(set_map[v].succ.begin(), set_map[v].succ.end(), set_map[v].intersect.begin(), set_map[v].intersect.end(), back_inserter(new_vertex_sets[new_vertex_sets.size() - 1]), std::less<vertex_descriptor>()); set_map[v].succ.clear(); // Label SCC just identified with the 'first' vertex in that SCC for( std::size_t j = 0; j < set_map[v].intersect.size(); j++ ) put(c, set_map[v].intersect[j], set_map[v].intersect[0]); set_map[v].intersect.clear(); } } #ifdef PBGL_SCC_DEBUG end = accounting::get_time(); if(id == 0) std::cerr << " Perform set arithemetic time = " << accounting::print_time(end - start) << " seconds.\n"; start = accounting::get_time(); #endif // Remove sets of size 1 from new_vertex_sets typename std::vector<std::vector<vertex_descriptor> >::iterator vviter; for( vviter = new_vertex_sets.begin(); vviter != new_vertex_sets.end(); /*in loop*/ ) if( (*vviter).size() < 2 ) vviter = new_vertex_sets.erase( vviter ); else vviter++; // All gather new sets and recur (gotta marshal and unmarshal sets first) vertex_sets.clear(); std::vector<vertex_descriptor> serial_sets, all_serial_sets; detail::marshal_set<Graph>( new_vertex_sets, serial_sets ); all_gather( pg, serial_sets.begin(), serial_sets.end(), all_serial_sets ); detail::unmarshal_set<Graph>( all_serial_sets, vertex_sets ); #ifdef PBGL_SCC_DEBUG end = accounting::get_time(); if(id == 0) { std::cerr << " Serialize and gather new vertex sets time = " << accounting::print_time(end - start) << " seconds.\n\n\n"; printf("Vertex sets: %d\n", (int)vertex_sets.size() ); for( std::size_t i = 0; i < vertex_sets.size(); ++i ) printf(" %d: %d\n", i, (int)vertex_sets[i].size() ); } start = accounting::get_time(); #endif // HACK!?! -- This would be more properly implemented as a topological sort // Remove vertices without an edge to another vertex in the set and an edge from another // vertex in the set typedef typename graph_traits<Graph>::out_edge_iterator out_edge_iterator; out_edge_iterator estart, eend; typedef typename graph_traits<ReverseGraph>::out_edge_iterator r_out_edge_iterator; r_out_edge_iterator restart, reend; for (std::size_t i = 0; i < vertex_sets.size(); ++i) { std::vector<vertex_descriptor> new_set; for (std::size_t j = 0; j < vertex_sets[i].size(); ++j) { vertex_descriptor v = vertex_sets[i][j]; if (get(owner, v) == id) { boost::tie(estart, eend) = out_edges(v, g); while (estart != eend && find(vertex_sets[i].begin(), vertex_sets[i].end(), target(*estart,g)) == vertex_sets[i].end()) estart++; if (estart != eend) { boost::tie(restart, reend) = out_edges(get(fr, v), gr); while (restart != reend && find(vertex_sets[i].begin(), vertex_sets[i].end(), get(rf, target(*restart,gr))) == vertex_sets[i].end()) restart++; if (restart != reend) new_set.push_back(v); } } } vertex_sets[i].clear(); all_gather(pg, new_set.begin(), new_set.end(), vertex_sets[i]); std::sort(vertex_sets[i].begin(), vertex_sets[i].end(), std::less<vertex_descriptor>()); } #ifdef PBGL_SCC_DEBUG end = accounting::get_time(); if(id == 0) std::cerr << " Trim vertex sets time = " << accounting::print_time(end - start) << " seconds.\n\n\n"; start = accounting::get_time(); #endif } while ( !vertex_sets.empty() ); // Label vertices not in a SCC as their own SCC for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) if( get(c, *vstart) == graph_traits<Graph>::null_vertex() ) put(c, *vstart, *vstart); synchronize(c); } template<typename Graph, typename ReverseGraph, typename IsoMap> void build_reverse_graph( const Graph& g, ReverseGraph& gr, IsoMap& fr, IsoMap& rf ) { typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator; typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; typedef typename graph_traits<Graph>::out_edge_iterator out_edge_iterator; typedef typename boost::graph::parallel::process_group_type<Graph>::type process_group_type; typedef typename process_group_type::process_id_type process_id_type; typedef std::vector<std::pair<vertex_descriptor, vertex_descriptor> > VertexPairVec; typename property_map<Graph, vertex_owner_t>::const_type owner = get(vertex_owner, g); process_group_type pg = process_group(g); process_id_type id = process_id(pg); int n; vertex_iterator vstart, vend; int num_procs = num_processes(pg); vertex_descriptor v; out_edge_iterator oestart, oeend; for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) { v = add_vertex(gr); put(fr, *vstart, v); put(rf, v, *vstart); } gr.distribution() = g.distribution(); int my_n = num_vertices(g); all_reduce(pg, &my_n, &my_n+1, &n, std::plus<int>()); for (int i = 0; i < n; ++i) get(fr, vertex(i,g)); synchronize(fr); // Add edges to gr std::vector<std::pair<vertex_descriptor, vertex_descriptor> > new_edges; for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) for( boost::tie(oestart, oeend) = out_edges(*vstart, g); oestart != oeend; oestart++ ) new_edges.push_back( std::make_pair(get(fr, target(*oestart,g)), get(fr, source(*oestart, g))) ); std::vector<VertexPairVec> edge_requests(num_procs); typename std::vector<std::pair<vertex_descriptor, vertex_descriptor> >::iterator iter; for( iter = new_edges.begin(); iter != new_edges.end(); iter++ ) { std::pair<vertex_descriptor, vertex_descriptor> p1 = *iter; if( get(owner, p1.first ) == id ) add_edge( p1.first, p1.second, gr ); else edge_requests[get(owner, p1.first)].push_back(p1); } new_edges.clear(); // Send edge addition requests for (process_id_type p = 0; p < num_procs; ++p) { if (!edge_requests[p].empty()) { VertexPairVec reqs(edge_requests[p].begin(), edge_requests[p].end()); send(pg, p, fhp_edges_size_msg, reqs.size()); send(pg, p, fhp_add_edges_msg, &reqs[0], reqs.size()); } } synchronize(pg); // Receive edge addition requests and handle them while (optional<std::pair<process_id_type, int> > m = probe(pg)) { BOOST_ASSERT(m->second == fhp_edges_size_msg); std::size_t num_requests; receive(pg, m->first, m->second, num_requests); VertexPairVec requests(num_requests); receive(pg, m->first, fhp_add_edges_msg, &requests[0], num_requests); for( std::size_t i = 0; i < requests.size(); ++i ) add_edge( requests[i].first, requests[i].second, gr ); } synchronize(gr); } template<typename Graph, typename VertexComponentMap, typename ComponentMap> typename property_traits<ComponentMap>::value_type number_components(const Graph& g, VertexComponentMap r, ComponentMap c) { typedef typename boost::graph::parallel::process_group_type<Graph>::type process_group_type; typedef typename graph_traits<Graph>::vertex_iterator vertex_iterator; typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; typedef typename property_traits<ComponentMap>::value_type ComponentMapType; std::vector<vertex_descriptor> my_roots, all_roots; vertex_iterator vstart, vend; for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) if( find( my_roots.begin(), my_roots.end(), get(r, *vstart) ) == my_roots.end() ) my_roots.push_back( get(r, *vstart) ); all_gather( process_group(g), my_roots.begin(), my_roots.end(), all_roots ); /* Number components */ std::map<vertex_descriptor, ComponentMapType> comp_numbers; ComponentMapType c_num = 0; // Compute component numbers for (std::size_t i = 0; i < all_roots.size(); ++i ) if ( comp_numbers.count(all_roots[i]) == 0 ) comp_numbers[all_roots[i]] = c_num++; // Broadcast component numbers for( boost::tie(vstart, vend) = vertices(g); vstart != vend; vstart++ ) put( c, *vstart, comp_numbers[get(r,*vstart)] ); // Broadcast number of components if (process_id(process_group(g)) == 0) { typedef typename process_group_type::process_size_type process_size_type; for (process_size_type dest = 1, n = num_processes(process_group(g)); dest != n; ++dest) send(process_group(g), dest, 0, c_num); } synchronize(process_group(g)); if (process_id(process_group(g)) != 0) receive(process_group(g), 0, 0, c_num); synchronize(c); return c_num; } template<typename Graph, typename ComponentMap, typename VertexComponentMap, typename VertexIndexMap> typename property_traits<ComponentMap>::value_type fleischer_hendrickson_pinar_strong_components_impl (const Graph& g, ComponentMap c, VertexComponentMap r, VertexIndexMap vertex_index_map, incidence_graph_tag) { typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; typedef iterator_property_map<typename std::vector<vertex_descriptor>::iterator, VertexIndexMap> IsoMap; typename boost::graph::parallel::process_group_type<Graph>::type pg = process_group(g); #ifdef PBGL_SCC_DEBUG accounting::time_type start = accounting::get_time(); #endif typedef adjacency_list<listS, distributedS<typename boost::graph::parallel::process_group_type<Graph>::type, vecS>, directedS > ReverseGraph; ReverseGraph gr(0, pg); std::vector<vertex_descriptor> fr_s(num_vertices(g)); std::vector<vertex_descriptor> rf_s(num_vertices(g)); IsoMap fr(fr_s.begin(), vertex_index_map); // fr = forward->reverse IsoMap rf(rf_s.begin(), vertex_index_map); // rf = reverse->forward build_reverse_graph(g, gr, fr, rf); #ifdef PBGL_SCC_DEBUG accounting::time_type end = accounting::get_time(); if(process_id(process_group(g)) == 0) std::cerr << "Reverse graph initialization time = " << accounting::print_time(end - start) << " seconds.\n"; #endif fleischer_hendrickson_pinar_strong_components(g, r, gr, fr, rf, vertex_index_map); typename property_traits<ComponentMap>::value_type c_num = number_components(g, r, c); return c_num; } template<typename Graph, typename ComponentMap, typename VertexComponentMap, typename VertexIndexMap> typename property_traits<ComponentMap>::value_type fleischer_hendrickson_pinar_strong_components_impl (const Graph& g, ComponentMap c, VertexComponentMap r, VertexIndexMap vertex_index_map, bidirectional_graph_tag) { typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; reverse_graph<Graph> gr(g); detail::vertex_identity_property_map<vertex_descriptor> fr, rf; fleischer_hendrickson_pinar_strong_components(g, r, gr, fr, rf, vertex_index_map); typename property_traits<ComponentMap>::value_type c_num = number_components(g, r, c); return c_num; } template<typename Graph, typename ComponentMap, typename VertexIndexMap> inline typename property_traits<ComponentMap>::value_type fleischer_hendrickson_pinar_strong_components (const Graph& g, ComponentMap c, VertexIndexMap vertex_index_map) { typedef typename graph_traits<Graph>::vertex_descriptor vertex_descriptor; typedef iterator_property_map<typename std::vector<vertex_descriptor>::iterator, VertexIndexMap> VertexComponentMap; typename boost::graph::parallel::process_group_type<Graph>::type pg = process_group(g); if (num_processes(pg) == 1) { local_subgraph<const Graph> ls(g); return boost::strong_components(ls, c); } // Create a VertexComponentMap for intermediate labeling of SCCs std::vector<vertex_descriptor> r_s(num_vertices(g), graph_traits<Graph>::null_vertex()); VertexComponentMap r(r_s.begin(), vertex_index_map); return fleischer_hendrickson_pinar_strong_components_impl (g, c, r, vertex_index_map, typename graph_traits<Graph>::traversal_category()); } template<typename Graph, typename ComponentMap> inline typename property_traits<ComponentMap>::value_type fleischer_hendrickson_pinar_strong_components(const Graph& g, ComponentMap c) { return fleischer_hendrickson_pinar_strong_components(g, c, get(vertex_index, g)); } } // end namespace distributed using distributed::fleischer_hendrickson_pinar_strong_components; } // end namespace graph template<class Graph, class ComponentMap, class P, class T, class R> inline typename property_traits<ComponentMap>::value_type strong_components (const Graph& g, ComponentMap comp, const bgl_named_params<P, T, R>& BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, distributed_graph_tag)) { return graph::fleischer_hendrickson_pinar_strong_components(g, comp); } template<class Graph, class ComponentMap> inline typename property_traits<ComponentMap>::value_type strong_components (const Graph& g, ComponentMap comp BOOST_GRAPH_ENABLE_IF_MODELS_PARM(Graph, distributed_graph_tag)) { return graph::fleischer_hendrickson_pinar_strong_components(g, comp); } } /* end namespace boost */ #endif // BOOST_GRAPH_DISTRIBUTED_SCC_HPP