--- /dev/null
+#include <stdio.h>
+#include <stdlib.h>
+#include <mpi.h>
+
+#define GETTIMEOFDAY_ERROR 1
+
+#define N_START 1
+#define N_STOP 1024*1024
+#define N_NEXT (N*2)
+#define ITER 100
+#define ONE_MILLION 1000000.0
+#define RAND_SEED 842270
+
+int main(int argc, char* argv[]) {
+
+ int size, rank;
+ int N, I;
+ struct timeval *start_time, *stop_time;
+ double seconds;
+ int i, j, k;
+ char *buffer;
+ int check;
+
+ srandom(RAND_SEED);
+
+ MPI_Init(&argc, &argv);
+
+ MPI_Comm_rank(MPI_COMM_WORLD, &rank);
+ MPI_Comm_size(MPI_COMM_WORLD, &size);
+
+ if (0 == rank) {
+ start_time = (struct timeval *)malloc(sizeof(struct timeval));
+ stop_time = (struct timeval *)malloc(sizeof(struct timeval));
+ }
+
+ for (N = N_START ; N <= N_STOP ; N = N_NEXT) {
+
+ buffer = malloc(sizeof(char) * N);
+
+ if (0 == rank) {
+ for (j = 0; j < N; j++) {
+ buffer[j] = (char)(random() % 256);
+ }
+ if (-1 == gettimeofday(start_time, NULL)) {
+ printf("couldn't set start_time on node 0!\n");
+ MPI_Abort(MPI_COMM_WORLD, GETTIMEOFDAY_ERROR);
+ exit(EXIT_FAILURE);
+ }
+ }
+
+ for (i = 0; i < ITER; i++) {
+ MPI_Bcast(buffer, N, MPI_BYTE, 0, MPI_COMM_WORLD);
+ if (0 == rank) {
+ for (j = 1; j < size; j++) {
+ MPI_Recv(&check, 1, MPI_INT, MPI_ANY_SOURCE, 1, MPI_COMM_WORLD, MPI_STATUS_IGNORE);
+ }
+ } else {
+ MPI_Send(&rank, 1, MPI_INT, 0, 1, MPI_COMM_WORLD);
+ }
+ }
+
+ if (0 == rank) {
+ if (-1 == gettimeofday(stop_time, NULL)) {
+ printf("couldn't set start_time on node 0!\n");
+ MPI_Abort(MPI_COMM_WORLD, GETTIMEOFDAY_ERROR);
+ exit(EXIT_FAILURE);
+ }
+ seconds = (double)(stop_time->tv_sec - start_time->tv_sec) + (double)(stop_time->tv_usec - start_time->tv_usec) / ONE_MILLION;
+ }
+
+ free(buffer);
+
+ if (0 == rank) {
+ printf("N: %10d, iter: %d, time: %10f s, avg rate: %12f Mbps\n", N, ITER, seconds, ((double)N * ITER * 8) / (1024.0 * 1024.0 * seconds));
+ }
+
+ }
+
+ if (0 == rank) {
+ free(start_time);
+ free(stop_time);
+ }
+
+ MPI_Finalize();
+
+ return 0;
+}