A performance test doesn't work with nanomsg (bus) - c

Question

I'd like to use nanomsg as bus-system. So I tried to code a performance test and testing it by using two PCs.
At first I wrote an server, which connects to the other server:
#include <nanomsg/nn.h>
#include <nanomsg/bus.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
int main(int argc, char *argv[]) {
if (argc == 2) {
int socket = nn_socket (AF_SP_RAW, NN_BUS);
assert(nn_bind (socket, "tcp://*:27384") != -1);
assert(nn_connect (socket, argv[1]) != -1);
assert(nn_device(socket, -1) != -1);
nn_close(socket);
}
}
In my case I run these commands as:
On the first PC:./server tcp://192.168.1.11:27384
On the second PC:./server tcp://192.168.1.241:27384
They are connected, to prove it, I used nanocat and connected it locally to the server:
On the first PC:
nanocat --bus --connect tcp://127.0.0.1:27384 --data foo --interval 1 --ascii
On the second PC:
nanocat --bus --connect tcp://127.0.0.1:27384 --data bar --interval 1 --ascii
On the first PC, I received a 'bar' every second, on the second PC a 'foo', also every second.
So I wrote now the receiver.
#include <nanomsg/nn.h>
#include <nanomsg/bus.h>
#include <string.h>
#include <stdio.h>
#include <assert.h>
int main(int argc, char *argv[]) {
int socket = nn_socket (AF_SP, NN_BUS);
assert(nn_connect (socket, "tcp://127.0.0.1:27384") != -1);
sleep(1);
unsigned char buffer[4096];
while(1) {
int n = nn_recv(socket, buffer, 4096, 0);
if (n > 0) {
nn_send(socket, buffer, strlen(buffer), 0);
}
}
nn_close(socket);
}
It receives a message and sends it back.
Then I wrote the sender:
#include <nanomsg/nn.h>
#include <nanomsg/bus.h>
#include <stdio.h>
#include <unistd.h>
#include <time.h>
#include <string.h>
#define NANO_PER_SEC 1000000000.0
int main(int argc, char *argv[]) {
int socket = nn_socket (AF_SP, NN_BUS);
nn_connect (socket, "tcp://127.0.0.1:27384");
sleep(1);
unsigned char buffer[4096];
int i = 0;
for (i = 0; i < 1024; i++) {
buffer[i] = 'a';
}
buffer[i] = '\0';
struct timespec start, end;
double start_sec, end_sec, elapsed_sec;
double average;
double m[4096];
for (i = 0; i < 4096; i++) {
clock_gettime(CLOCK_REALTIME, &start);
int ns = nn_send(socket, buffer, strlen(buffer), 0);
int nr = nn_recv(socket, buffer, 4096, 0);
clock_gettime(CLOCK_REALTIME, &end);
start_sec = start.tv_sec + start.tv_nsec/NANO_PER_SEC;
end_sec = end.tv_sec + end.tv_nsec/NANO_PER_SEC;
m[i] = end_sec - start_sec;
}
elapsed_sec = 0.0;
for (i = 0; i < 4096; i++) {
elapsed_sec = elapsed_sec + m[i];
}
average = (elapsed_sec / 4096.0) * 1000000.0;
printf("Average: %.3f micros\nWhole: %.12f seconds\n", average, elapsed_sec);
nn_close(socket);
}
The sender transmits 4096 times 1kbyte to the receiver and measures the time,
so I get the whole time and the average time.
At first I test it at only one PC locally, in three opened bash-terminals.
First terminal:./server tcp://192.168.1.11:27384
Second terminal:./receiver
Third terminal:./sender
So, I got from the "sender" programme this output:
Average: 60.386 micros
Whole: 0.247341632843 seconds
Then I tried to run this:
On first PC:
./server tcp://192.168.1.11:27384
./receiver
On second PC:
./server tcp://192.168.1.241:27384
./sender
But it stucks, the first PC running the "receiver" doesn't receive any message from the second PC, which runs the "sender". I don't get it whats wrong, because with nanocat it works fine.
Can somebody please help me?