ping-pong.c for Latency

Working Code - Umbreen
Signed-off-by: Gaurav Kukreja <mailme.gaurav@gmail.com>

mpi-assign3/ping-pong.c

 #include "mpi.h"
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdlib.h>
 #include "result.h"
 
 #define FNAME_CMDARG 1
-extern char *filename;
 
 struct data_latency data_l;
+char *filename;
 
 int main (int argc, char **argv)
 {
-
-	int my_proc,other_proc,i,j, nprocs;
+	int PING_PONG_LIMIT=5;
+	int my_rank,partner_rank,i,j, nprocs;
 	int tag=10;
 	char a, b;
 	double tstart, tend;
@@ -21,40 +22,50 @@ int main (int argc, char **argv)
 
 	MPI_Init(&argc, &argv);
 	MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
-	MPI_Comm_rank(MPI_COMM_WORLD, &my_proc);
+	MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
 
 	for(i=1; i<nprocs; i++)
 	{
-		other_proc=i;
-		MPI_Barrier(MPI_COMM_WORLD);
+		int ping_pong_count=0;
 
+		MPI_Barrier(MPI_COMM_WORLD);
 
-		if (my_proc == 0) {
-
+		if (my_rank == 0) {
+			partner_rank=i;
 			tstart = MPI_Wtime();
-			for(j=0; j<5; j++)
-			{
-				MPI_Send(&a, 0, MPI_DOUBLE, other_proc, 10, MPI_COMM_WORLD);
-				MPI_Recv(&b, 0, MPI_DOUBLE, other_proc, 10, MPI_COMM_WORLD, &status);
+			while (ping_pong_count < PING_PONG_LIMIT) {
+				// Increment the ping pong count before you send it
+				ping_pong_count++;
+				MPI_Send(&ping_pong_count,1 , MPI_INT, partner_rank, 10, MPI_COMM_WORLD);
+				//printf("%d sent and incremented ping_pong_count %d to %d\n",my_rank, ping_pong_count, partner_rank);
+				MPI_Recv(&ping_pong_count,1, MPI_INT, partner_rank, 10, MPI_COMM_WORLD, &status);
+				//printf("%d received ping_pong_count %d from %d\n", my_rank, ping_pong_count, partner_rank);
 			}
 			tend = MPI_Wtime();
 
-		} else {
-			for(j=0; j<5; j++)
-			{
-				MPI_Recv(&b, 0, MPI_DOUBLE, 0, 10, MPI_COMM_WORLD, &status);
-
-				MPI_Send(&b, 0, MPI_DOUBLE, 0, 10, MPI_COMM_WORLD);
+		} 
+		else if(my_rank==i) {
+			while (ping_pong_count < PING_PONG_LIMIT) {
+				MPI_Recv(&ping_pong_count,1 , MPI_INT,0,10, MPI_COMM_WORLD, &status);
+				//printf("%d received ping_pong_count %d from %d\n",my_rank, ping_pong_count, 0);
+				// Increment the ping pong count before you send it
+				ping_pong_count++;
+				MPI_Send(&ping_pong_count,1, MPI_INT,0,10, MPI_COMM_WORLD);
+				//printf("%d sent and incremented ping_pong_count %d to %d\n",my_rank, ping_pong_count, 0);
 			}
 
 		}
 
 		MPI_Barrier(MPI_COMM_WORLD);
+		if(my_rank==0){
 			data_l.source_thread = 0;
-		data_l.dest_thread = other_proc;
+			data_l.dest_thread = partner_rank;
 			data_l.latency = (tend - tstart)/10;
 			submit_latency_data(data_l);
-		printf("Latency for process %d = %lf\n",other_proc, tend-tstart);
+
+			printf("Latency for process %d = %lf\n",partner_rank, (tend-tstart)/10);
+		}
 	}
 	MPI_Finalize();
+	return 0;
 }

mpi-assign3/result.c

 #include <stdio.h>
 #include "result.h"
 
-char *filename;
+extern char *filename;
 
 int submit_bandwidth_data(struct data_bandwidth data_b)
 {
 	FILE* fp;
 	fp = fopen(filename, "a");
 
-	fprintf(fp, "%d/t%d/t%d/t%lf/t%lf/n", data_b.source_thread,
+	fprintf(fp, "%d\t%d\t%d\t%lf\t%lf\n", data_b.source_thread,
 			data_b.dest_thread, data_b.log_size, 
 			data_b.time, data_b.bandwidth);
 
@@ -21,7 +21,7 @@ int submit_latency_data(struct data_latency data_l)
 	FILE* fp;
 	fp=fopen(filename, "a");
 	
-	fprintf(fp, "%d/t%d/t%lf/n", data_l.source_thread,
+	fprintf(fp, "%d\t%d\t%lf\n", data_l.source_thread,
 			data_l.dest_thread, data_l.latency);
 
 	fclose(fp);

mpi-assign3/result.h

@@ -15,8 +15,10 @@ struct data_bandwidth {
 	double bandwidth;
 };
 
-int submit_latency_data(struct data_latency);
+int submit_latency_data(struct data_latency data_l);
 
-int submit_bandwidth_data(struct data_bandwidth);
+int submit_bandwidth_data(struct data_bandwidth data_b);
+
+int write_hello();
 
 #endif