projects / ceph.git / blame
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|---|---|---|
| 7c673cae FG |
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 | ||
| 10 | #ifndef BOOST_GRAPH_PARALLEL_INPLACE_ALL_TO_ALL_HPP | |
| 11 | #define BOOST_GRAPH_PARALLEL_INPLACE_ALL_TO_ALL_HPP | |
| 12 | ||
| 13 | #ifndef BOOST_GRAPH_USE_MPI | |
| 14 | #error "Parallel BGL files should not be included unless <boost/graph/use_mpi.hpp> has been included" | |
| 15 | #endif | |
| 16 | ||
| 17 | // | |
| 18 | // Implements the inplace all-to-all communication algorithm. | |
| 19 | // | |
| 20 | #include <vector> | |
| 21 | #include <iterator> | |
| 22 | ||
| 23 | namespace boost { namespace parallel { | |
| 24 | ||
| 25 | template<typename ProcessGroup, typename T> | |
| 26 | // where {LinearProcessGroup<ProcessGroup>, MessagingProcessGroup<ProcessGroup>} | |
| 27 | void | |
| 28 | inplace_all_to_all(ProcessGroup pg, | |
| 29 | const std::vector<std::vector<T> >& outgoing, | |
| 30 | std::vector<std::vector<T> >& incoming) | |
| 31 | { | |
| 32 | typedef typename std::vector<T>::size_type size_type; | |
| 33 | ||
| 34 | typedef typename ProcessGroup::process_size_type process_size_type; | |
| 35 | typedef typename ProcessGroup::process_id_type process_id_type; | |
| 36 | ||
| 37 | process_size_type p = num_processes(pg); | |
| 38 | ||
| 39 | // Make sure there are no straggling messages | |
| 40 | synchronize(pg); | |
| 41 | ||
| 42 | // Send along the count (always) and the data (if count > 0) | |
| 43 | for (process_id_type dest = 0; dest < p; ++dest) { | |
| 44 | if (dest != process_id(pg)) { | |
| 45 | send(pg, dest, 0, outgoing[dest].size()); | |
| 46 | if (!outgoing[dest].empty()) | |
| 47 | send(pg, dest, 1, &outgoing[dest].front(), outgoing[dest].size()); | |
| 48 | } | |
| 49 | } | |
| 50 | ||
| 51 | // Make sure all of the data gets transferred | |
| 52 | synchronize(pg); | |
| 53 | ||
| 54 | // Receive the sizes and data | |
| 55 | for (process_id_type source = 0; source < p; ++source) { | |
| 56 | if (source != process_id(pg)) { | |
| 57 | size_type size; | |
| 58 | receive(pg, source, 0, size); | |
| 59 | incoming[source].resize(size); | |
| 60 | if (size > 0) | |
| 61 | receive(pg, source, 1, &incoming[source].front(), size); | |
| 62 | } else if (&incoming != &outgoing) { | |
| 63 | incoming[source] = outgoing[source]; | |
| 64 | } | |
| 65 | } | |
| 66 | } | |
| 67 | ||
| 68 | template<typename ProcessGroup, typename T> | |
| 69 | // where {LinearProcessGroup<ProcessGroup>, MessagingProcessGroup<ProcessGroup>} | |
| 70 | void | |
| 71 | inplace_all_to_all(ProcessGroup pg, std::vector<std::vector<T> >& data) | |
| 72 | { | |
| 73 | inplace_all_to_all(pg, data, data); | |
| 74 | } | |
| 75 | ||
| 76 | } } // end namespace boost::parallel | |
| 77 | ||
| 78 | #endif // BOOST_GRAPH_PARALLEL_INPLACE_ALL_TO_ALL_HPP |