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/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
#include "mpi.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define LARGE_SIZE 100*1024
#define RNDV_SIZE 256*1024
char big_buffer[RNDV_SIZE] = "big garbage";
int main(int argc, char *argv[])
{
int size, rank;
char buffer[100] = "garbage";
MPI_Status status;
int tag = 1;
int reps = 1;
int i;
printf("Simple Send/Recv test.\n");
fflush(stdout);
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &size);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
if (size < 2) {
printf("Two processes needed.\n");
MPI_Finalize();
return 0;
}
if (argc > 1) {
reps = atoi(argv[1]);
if (reps < 1)
reps = 1;
}
if (rank == 0) {
printf("Rank 0: sending 100 bytes messages to process 1.\n");
fflush(stdout);
strcpy(buffer, "Hello process one.");
for (i = 0; i < reps; i++) {
MPI_Send(buffer, 100, MPI_BYTE, 1, tag, MPI_COMM_WORLD);
MPI_Recv(buffer, 100, MPI_BYTE, 1, tag, MPI_COMM_WORLD, &status);
}
strcpy(big_buffer, "Hello again process one.");
printf("Rank 0: sending %dk bytes messages to process 1.\n", LARGE_SIZE / 1024);
fflush(stdout);
for (i = 0; i < reps; i++) {
MPI_Send(big_buffer, LARGE_SIZE, MPI_BYTE, 1, tag, MPI_COMM_WORLD);
MPI_Recv(big_buffer, LARGE_SIZE, MPI_BYTE, 1, tag, MPI_COMM_WORLD, &status);
}
strcpy(big_buffer, "Hello yet again process one.");
printf("Rank 0: sending %dk bytes messages to process 1.\n", RNDV_SIZE / 1024);
fflush(stdout);
for (i = 0; i < reps; i++) {
MPI_Send(big_buffer, RNDV_SIZE, MPI_BYTE, 1, tag, MPI_COMM_WORLD);
MPI_Recv(big_buffer, RNDV_SIZE, MPI_BYTE, 1, tag, MPI_COMM_WORLD, &status);
}
} else if (rank == 1) {
printf("Rank 1: receiving messages from process 0.\n");
fflush(stdout);
for (i = 0; i < reps; i++) {
MPI_Recv(buffer, 100, MPI_BYTE, 0, tag, MPI_COMM_WORLD, &status);
MPI_Send(buffer, 100, MPI_BYTE, 0, tag, MPI_COMM_WORLD);
}
printf("Rank 1: received message '%s'\n", buffer);
fflush(stdout);
for (i = 0; i < reps; i++) {
MPI_Recv(big_buffer, LARGE_SIZE, MPI_BYTE, 0, tag, MPI_COMM_WORLD, &status);
MPI_Send(big_buffer, LARGE_SIZE, MPI_BYTE, 0, tag, MPI_COMM_WORLD);
}
printf("Rank 1: received message '%s'\n", big_buffer);
fflush(stdout);
for (i = 0; i < reps; i++) {
MPI_Recv(big_buffer, RNDV_SIZE, MPI_BYTE, 0, tag, MPI_COMM_WORLD, &status);
MPI_Send(big_buffer, RNDV_SIZE, MPI_BYTE, 0, tag, MPI_COMM_WORLD);
}
printf("Rank 1: received message '%s'\n", big_buffer);
fflush(stdout);
} else {
printf("Rank %d, I am not participating.\n", rank);
fflush(stdout);
}
MPI_Finalize();
return 0;
}
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