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mpi - table exchange improved

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This commit is contained in:
Joachim Schoeberl 2012-08-30 19:24:20 +00:00
parent d0b8d63889
commit 7233ecdcd5
1 changed files with 41 additions and 0 deletions
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41
libsrc/general/mpi_interface.hpp
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@ -185,6 +185,7 @@ namespace netgen
send a table entry to each of the prcesses in the group ...
receive-table entries will be set
*/
/*
template <typename T>
inline void MyMPI_ExchangeTable (TABLE<T> & send_data,
TABLE<T> & recv_data, int tag,
@ -211,6 +212,46 @@ namespace netgen
MPI_Barrier (comm);
MPI_Waitall (requests.Size(), &requests[0], MPI_STATUS_IGNORE);
}
*/
template <typename T>
inline void MyMPI_ExchangeTable (TABLE<T> & send_data,
TABLE<T> & recv_data, int tag,
MPI_Comm comm = MPI_COMM_WORLD)
{
int ntasks, rank;
MPI_Comm_size(comm, &ntasks);
MPI_Comm_rank(comm, &rank);
Array<int> send_sizes(ntasks);
Array<int> recv_sizes(ntasks);
for (int i = 0; i < ntasks; i++)
send_sizes[i] = send_data[i].Size();
MPI_Alltoall (&send_sizes[0], 1, MPI_INT,
&recv_sizes[0], 1, MPI_INT, comm);
/*
// in-place is buggy !
MPI_Alltoall (MPI_IN_PLACE, 1, MPI_INT,
&recv_sizes[0], 1, MPI_INT, comm);
*/
for (int i = 0; i < ntasks; i++)
recv_data.SetEntrySize (i, recv_sizes[i], sizeof(int));
Array<MPI_Request> requests;
for (int dest = 0; dest < ntasks; dest++)
if (dest != rank && send_data[dest].Size())
requests.Append (MyMPI_ISend (send_data[dest], dest, tag, comm));
for (int dest = 0; dest < ntasks; dest++)
if (dest != rank && recv_data[dest].Size())
requests.Append (MyMPI_IRecv (recv_data[dest], dest, tag, comm));
// MPI_Barrier (comm);
MPI_Waitall (requests.Size(), &requests[0], MPI_STATUS_IGNORE);
}