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/* -*- c-file-style: "GNU" -*- */
/*
* Copyright (C) CNRS, INRIA, Université Bordeaux 1, Télécom SudParis
* See COPYING in top-level directory.
*/
#include "mpi.h"
#include <stdio.h>
int main(int argc, char *argv[]) {
int rank, size;
int i, index;
int buffer[400];
MPI_Request request[4];
MPI_Status status[4];
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
if (size != 4) {
printf("Please run with 4 processes.\n");
fflush(stdout);
MPI_Finalize();
return 1;
}
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
if (rank == 0) {
for (i = 0; i < size * 100; i++)
buffer[i] = i / 100;
for(int round = 0; round < 2; round++) {
for (i = 0; i < size - 1; i++) {
if(round == 0) {
MPI_Isend(&buffer[i * 100], 100, MPI_INT, i + 1, 123, MPI_COMM_WORLD,
&request[i]);
} else
MPI_Irecv(&buffer[i * 100], 100, MPI_INT, i + 1, 123, MPI_COMM_WORLD,
&request[i]);
}
while (1) {
/* just for testing if eztrace works when some of the requests are already successful when calling mpi_waitall */
int flag;
MPI_Status status;
MPI_Test(&request[0], &flag, &status);
if (flag) {
break;
}
}
MPI_Waitall(size - 1, request, status);
MPI_Waitall(size - 1, request, status);
}
} else {
MPI_Recv(buffer, 100, MPI_INT, 0, 123, MPI_COMM_WORLD, &status[0]);
printf("%d: buffer[0] = %d\n", rank, buffer[0]);
MPI_Send(buffer, 100, MPI_INT, 0, 123, MPI_COMM_WORLD);
fflush(stdout);
}
MPI_Finalize();
return 0;
}
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