io3.c

The example for Boor USING MPI2

/* example of parallel MPI write into a single file */
#include "mpi.h"
#include <stdio.h>
#define BUFSIZE 100

int main(int argc, char *argv[])
{
    int i, myrank, buf[BUFSIZE];
    MPI_File thefile;

    MPI_Init(&argc, &argv);
    MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
    for (i=0; i<BUFSIZE; i++)
        buf[i] = myrank * BUFSIZE + i;
    MPI_File_open(MPI_COMM_WORLD, "testfile",
		  MPI_MODE_CREATE | MPI_MODE_WRONLY,
		  MPI_INFO_NULL, &thefile);
    MPI_File_set_view(thefile, myrank * BUFSIZE * sizeof(int),
		      MPI_INT, MPI_INT, "native", MPI_INFO_NULL);
    MPI_File_write(thefile, buf, BUFSIZE, MPI_INT,
		   MPI_STATUS_IGNORE);
    MPI_File_close(&thefile);
    MPI_Finalize();
    return 0;
}