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Diffstat (limited to 'libs/mpi/src/point_to_point.cpp')
-rw-r--r-- | libs/mpi/src/point_to_point.cpp | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/libs/mpi/src/point_to_point.cpp b/libs/mpi/src/point_to_point.cpp new file mode 100644 index 000000000..dd0d9bcf0 --- /dev/null +++ b/libs/mpi/src/point_to_point.cpp @@ -0,0 +1,98 @@ +// Copyright 2005 Douglas Gregor. + +// 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) + +// Message Passing Interface 1.1 -- Section 3. MPI Point-to-point + +/* There is the potential for optimization here. We could keep around + a "small message" buffer of size N that we just receive into by + default. If the message is N - sizeof(int) bytes or smaller, it can + just be sent with that buffer. If it's larger, we send the first N + - sizeof(int) bytes in the first packet followed by another + packet. The size of the second packet will be stored in an integer + at the end of the first packet. + + We will introduce this optimization later, when we have more + performance test cases and have met our functionality goals. */ + +#include <boost/mpi/detail/point_to_point.hpp> +#include <boost/mpi/datatype.hpp> +#include <boost/mpi/exception.hpp> +#include <cassert> + +namespace boost { namespace mpi { namespace detail { + +void +packed_archive_send(MPI_Comm comm, int dest, int tag, + const packed_oarchive& ar) +{ + const void* size = &ar.size(); + BOOST_MPI_CHECK_RESULT(MPI_Send, + (const_cast<void*>(size), 1, + get_mpi_datatype<std::size_t>(ar.size()), + dest, tag, comm)); + BOOST_MPI_CHECK_RESULT(MPI_Send, + (const_cast<void*>(ar.address()), ar.size(), + MPI_PACKED, + dest, tag, comm)); +} + +int +packed_archive_isend(MPI_Comm comm, int dest, int tag, + const packed_oarchive& ar, + MPI_Request* out_requests, int num_out_requests) +{ + assert(num_out_requests >= 2); + const void* size = &ar.size(); + BOOST_MPI_CHECK_RESULT(MPI_Isend, + (const_cast<void*>(size), 1, + get_mpi_datatype<std::size_t>(ar.size()), + dest, tag, comm, out_requests)); + BOOST_MPI_CHECK_RESULT(MPI_Isend, + (const_cast<void*>(ar.address()), ar.size(), + MPI_PACKED, + dest, tag, comm, out_requests + 1)); + + return 2; +} + +int +packed_archive_isend(MPI_Comm comm, int dest, int tag, + const packed_iarchive& ar, + MPI_Request* out_requests, int num_out_requests) +{ + assert(num_out_requests >= 2); + + const void* size = &ar.size(); + BOOST_MPI_CHECK_RESULT(MPI_Isend, + (const_cast<void*>(size), 1, + get_mpi_datatype<std::size_t>(ar.size()), + dest, tag, comm, out_requests)); + BOOST_MPI_CHECK_RESULT(MPI_Isend, + (const_cast<void*>(ar.address()), ar.size(), + MPI_PACKED, + dest, tag, comm, out_requests + 1)); + + return 2; +} + +void +packed_archive_recv(MPI_Comm comm, int source, int tag, packed_iarchive& ar, + MPI_Status& status) +{ + std::size_t count; + BOOST_MPI_CHECK_RESULT(MPI_Recv, + (&count, 1, get_mpi_datatype<std::size_t>(count), + source, tag, comm, &status)); + + // Prepare input buffer and receive the message + ar.resize(count); + BOOST_MPI_CHECK_RESULT(MPI_Recv, + (ar.address(), ar.size(), MPI_PACKED, + status.MPI_SOURCE, status.MPI_TAG, + comm, &status)); +} + +} } } // end namespace boost::mpi::detail |