| // 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_GRAPH_PARALLEL_INPLACE_ALL_TO_ALL_HPP |
| #define BOOST_GRAPH_PARALLEL_INPLACE_ALL_TO_ALL_HPP |
| |
| #ifndef BOOST_GRAPH_USE_MPI |
| #error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included" |
| #endif |
| |
| // |
| // Implements the inplace all-to-all communication algorithm. |
| // |
| #include <vector> |
| #include <iterator> |
| |
| namespace boost { namespace parallel { |
| |
| template<typename ProcessGroup, typename T> |
| // where {LinearProcessGroup<ProcessGroup>, MessagingProcessGroup<ProcessGroup>} |
| void |
| inplace_all_to_all(ProcessGroup pg, |
| const std::vector<std::vector<T> >& outgoing, |
| std::vector<std::vector<T> >& incoming) |
| { |
| typedef typename std::vector<T>::size_type size_type; |
| |
| typedef typename ProcessGroup::process_size_type process_size_type; |
| typedef typename ProcessGroup::process_id_type process_id_type; |
| |
| process_size_type p = num_processes(pg); |
| |
| // Make sure there are no straggling messages |
| synchronize(pg); |
| |
| // Send along the count (always) and the data (if count > 0) |
| for (process_id_type dest = 0; dest < p; ++dest) { |
| if (dest != process_id(pg)) { |
| send(pg, dest, 0, outgoing[dest].size()); |
| if (!outgoing[dest].empty()) |
| send(pg, dest, 1, &outgoing[dest].front(), outgoing[dest].size()); |
| } |
| } |
| |
| // Make sure all of the data gets transferred |
| synchronize(pg); |
| |
| // Receive the sizes and data |
| for (process_id_type source = 0; source < p; ++source) { |
| if (source != process_id(pg)) { |
| size_type size; |
| receive(pg, source, 0, size); |
| incoming[source].resize(size); |
| if (size > 0) |
| receive(pg, source, 1, &incoming[source].front(), size); |
| } else if (&incoming != &outgoing) { |
| incoming[source] = outgoing[source]; |
| } |
| } |
| } |
| |
| template<typename ProcessGroup, typename T> |
| // where {LinearProcessGroup<ProcessGroup>, MessagingProcessGroup<ProcessGroup>} |
| void |
| inplace_all_to_all(ProcessGroup pg, std::vector<std::vector<T> >& data) |
| { |
| inplace_all_to_all(pg, data, data); |
| } |
| |
| } } // end namespace boost::parallel |
| |
| #endif // BOOST_GRAPH_PARALLEL_INPLACE_ALL_TO_ALL_HPP |