62 строки
1.4 KiB
C
62 строки
1.4 KiB
C
/*
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* Copyright (c) 2004-2007 High Performance Computing Center Stuttgart,
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* University of Stuttgart. All rights reserved.
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* $COPYRIGHT$
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*
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* Additional copyrights may follow
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*
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* $HEADER$
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*/
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#include <stdio.h>
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#include "mpi.h"
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int main( int argc, char *argv[] )
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{
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int rank, size;
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int send_value,recv_value;
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MPI_Status status;
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MPI_Request send_request;
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MPI_Request recv_request;
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MPI_Init( &argc, &argv );
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MPI_Comm_rank( MPI_COMM_WORLD, &rank );
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MPI_Comm_size( MPI_COMM_WORLD, &size );
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send_value = 10;
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recv_value = 0;
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if (size != 2) {
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fprintf (stderr, "Error: Need 2 processes\n");
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MPI_Finalize ();
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}
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MPI_Isend (&send_value, 1, MPI_INT,
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(rank + 1) % size, 4711, MPI_COMM_WORLD, &send_request);
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MPI_Irecv (&recv_value, 1, MPI_INT,
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(rank + size - 1) % size, 4711, MPI_COMM_WORLD, &recv_request);
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/*
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* Reading or writing of the send buffer before
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* non blocking send is finished will cause an error.
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*/
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printf("\nsent: %d\n",send_value);
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send_value = 12;
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MPI_Wait (&send_request, &status);
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MPI_Wait (&recv_request, &status);
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/*
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* Using of send buffer after non blocking send
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* is finished will be ok.
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*/
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printf("\nsent: %d\n",send_value);
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send_value = 16;
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MPI_Finalize ();
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return 0;
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}
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